CN101867080B - Bulk silicon micro mechanic resonator and manufacturing method thereof - Google Patents

Abstract

Translated fromChinese

本发明涉及一种体硅微机械谐振器及制作方法，其特征在于所述的谐振器是由衬底硅片、结构硅片及盖板硅片三层键合在一起形成的，衬底硅片的正面与结构硅片的背面，结构硅片的正面与盖板硅片的背面分别通过键合黏合在一起；制作时先将悬浮结构——谐振振子正下方的空腔制作好，再将器件结构层通过键合的方法制作在空腔上方，然后通过干法刻蚀在制作谐振器器件结构的同时，也将谐振器器件结构进行释放，最后利用真空圆片对准键合把盖板硅片固定在结构硅片上方。由于谐振器下方的空腔在器件结构制作之前用湿法腐蚀制成，并且采用圆片级封装对器件进行真空密封。

The invention relates to a bulk silicon micromechanical resonator and a manufacturing method, which is characterized in that the resonator is formed by bonding three layers of a substrate silicon wafer, a structural silicon wafer and a cover silicon wafer. The front side of the chip and the back side of the structural silicon chip, and the front side of the structural silicon chip and the back side of the cover silicon chip are respectively bonded together; when making the suspension structure, the cavity directly under the resonant oscillator is made first, and then the The device structure layer is made above the cavity by bonding, and then the resonator device structure is also released by dry etching while the resonator device structure is made, and finally the cover plate is aligned and bonded by vacuum wafers. The silicon wafer is fixed on top of the structural silicon wafer. Because the cavity under the resonator is formed by wet etching before the device structure is fabricated, and the device is vacuum-sealed by wafer-level packaging.

Description

Translated fromChinese

一种体硅微机械谐振器及制作方法Bulk silicon micromechanical resonator and manufacturing method thereof

技术领域technical field

本发明提供了一种体硅微机械谐振器及制作方法，更确切地说涉及一种利用MEMS等工艺制作的体硅谐振器，属于体硅微机械谐振器加工及微细加工技术领域。The invention provides a bulk silicon micromechanical resonator and a manufacturing method thereof, more precisely relates to a bulk silicon resonator manufactured by MEMS and the like, and belongs to the technical field of bulk silicon micromechanical resonator processing and microfabrication.

背景技术Background technique

时钟芯片作为电路系统中的时间基准源，在电路系统中有着重要的作用。传统的时钟芯片一般采用石英晶振作为谐振器产生信号波形。但石英晶振一般是采用切割工艺制作，使得其体积很难减小，从而阻碍了电路系统的微型化，此外石英晶振也无法和电路系统集成制作，提高了制作成本。近年来，由于微加工技术的发展，MEMS微机械谐振器得到很大的发展。MEMS谐振器具有尺寸小、功耗小、成本低、与CMOS IC(Complementary Metal OxideSemiconductor Integrated Circuit，互补金属氧化物半导体集成电路)工艺相兼容等优点，在无线通讯等领域的需求与日俱增，将成为晶体谐振器的替代物。而在微机械谐振器中，体硅纵声学波谐振器具有很高的Q值，并可以提供更高的谐振频率。As the time reference source in the circuit system, the clock chip plays an important role in the circuit system. Traditional clock chips generally use quartz crystal oscillators as resonators to generate signal waveforms. However, the quartz crystal oscillator is generally produced by cutting process, which makes it difficult to reduce its volume, which hinders the miniaturization of the circuit system. In addition, the quartz crystal oscillator cannot be integrated with the circuit system, which increases the production cost. In recent years, due to the development of micromachining technology, MEMS micromechanical resonators have been greatly developed. MEMS resonators have the advantages of small size, low power consumption, low cost, and CMOS IC (Complementary Metal Oxide Semiconductor Integrated Circuit, Complementary Metal Oxide Semiconductor Integrated Circuit, Complementary Metal Oxide Semiconductor Integrated Circuit) process and other advantages. The demand in wireless communication and other fields is increasing day by day, and will become a crystal Alternatives to resonators. Among micromechanical resonators, bulk silicon longitudinal acoustic wave resonators have a high Q value and can provide higher resonance frequencies.

体硅纵声学波微机械谐振器是利用体硅谐振振子结构的纵波谐振模态特性实现器件的谐振。谐振器振子工作的三种基本模态是：弯曲模态、扭曲模态和体模态。体模态谐振器振子可以是方形板、圆环板或者圆形板结构。图1-1(a)是谐振器工作的三种基本模态示意图，图1-1(b)是体模态谐振器谐振振子分别为方形板、圆环板及圆形板时不同谐振模式示意图(Chandorkar，S.A.，M.Agarwal，et al.(2008).″Limits of quality factor in bulk-modemicromechanical resonators.″Mems 2008：21st Ieee International Conference onMicro Electro Mechanical Systems，Technical Digest：74-77)。图1-2是方形板体硅微机械谐振器的工作原理图。其振子是一个方形的薄板，振子四周分别为驱动电极和检测电极，这样在驱动电极和振子之间加不同相位的交变电压时，由电压产生的静电力将会激励振子进入指定的谐振模式。然后通过检测输出电极端输出电流的变化，就可以将谐振器信号输出。The bulk silicon longitudinal acoustic wave micromechanical resonator uses the longitudinal wave resonance mode characteristics of the bulk silicon resonator structure to realize the resonance of the device. The three basic modes in which a resonator element operates are: bending mode, torsional mode, and bulk mode. The bulk mode resonator element can be a square plate, a ring plate or a circular plate structure. Figure 1-1(a) is a schematic diagram of the three basic modes of the resonator, and Figure 1-1(b) is the different resonance modes when the resonator of the bulk mode resonator is a square plate, a ring plate and a circular plate. Schematic (Chandorkar, SA, M. Agarwal, et al. (2008). "Limits of quality factor in bulk-mode micromechanical resonators."Mems 2008: 21st IEEE International Conference onMicro Electro Mechanical Systems, Technical Digest : 74-77). Figure 1-2 is a schematic diagram of the working principle of a square plate silicon micromechanical resonator. The vibrator is a square thin plate, and the vibrator is surrounded by driving electrodes and detection electrodes. In this way, when alternating voltages of different phases are applied between the driving electrodes and the vibrator, the electrostatic force generated by the voltage will excite the vibrator to enter the specified resonance mode. . Then, by detecting the change of the output current at the output electrode terminal, the resonator signal can be output.

传统的体硅微机械谐振器是用SOI(Silicon-On-Insulator，绝缘衬底上的硅)硅片制作的，谐振器是由结构层、埋层氧化硅和衬底硅组成。结构层包含有谐振器振子、电极、斜拉梁、金属焊盘四部分。谐振器振子正下方的衬底硅片部分可以完全去除掉(Khine，L.and M.Palaniapan(2009).″High-Qbulk-mode SOI square resonators with straight-beam anchors.″Journal ofMicromechanics and Microengineering)，也可以不去除掉(Mattila，T.，J.Kiihamaki，et al.(2002).″A 12 MHz micromechanical bulk acoustic modeoscillator.″Sensors and Actuators a-Physical 101(1-2)：1-9)。Traditional bulk silicon micromechanical resonators are made of SOI (Silicon-On-Insulator, silicon on insulating substrate) silicon wafers, and the resonators are composed of structural layers, buried silicon oxide and substrate silicon. The structural layer includes four parts: resonator vibrator, electrodes, cable-stayed beams, and metal pads. The part of the substrate silicon directly below the resonator can be completely removed (Khine, L. and M. Palaniapan (2009). "High-Qbulk-mode SOI square resonators with straight-beam anchors. "Journal ofMicromechanics and Microengineering ) , and may not be removed (Mattila, T., J. Kiihamaki, et al. (2002). "A 12 MHz micromechanical bulk acoustic modeoscillator."Sensors and Actuators a-Physical 101(1-2): 1-9) .

传统体硅微机械谐振器的制作方法主要有以下两种：Traditional bulk silicon micromechanical resonators are manufactured in two main ways:

方法1)：首先在SOI硅片上制作好金属焊盘。然后使用DRIE(Deep-Reactive-Ion-Etch，深反应离子刻蚀)工艺刻蚀出谐振器的器件结构。再通过旋涂PI(Polyimide，聚酰亚胺)做保护层，对谐振器结构进行保护，并从SOI硅片衬底背面通过硅腐蚀工艺将谐振器结构层下方的硅去除。最后将SOI衬底的氧化硅埋层去除，从而将谐振器结构释放(Lee，J.E.Y.，J.Yan，etal.(2009).″Low loss HF band SOI wine glass bulk mode capacitive square-plateresonator.″Journal of Micromechanics and Microengineering 19(7))。Method 1): First, make a metal pad on the SOI silicon wafer. Then use DRIE (Deep-Reactive-Ion-Etch, deep reactive ion etching) process to etch out the device structure of the resonator. Then spin-coat PI (Polyimide, polyimide) as a protective layer to protect the resonator structure, and remove the silicon below the resonator structure layer from the back of the SOI silicon wafer substrate through a silicon etching process. Finally, the silicon oxide buried layer of the SOI substrate is removed, thereby releasing the resonator structure (Lee, JEY, J.Yan, et al. (2009). "Low loss HF band SOI wine glass bulk mode capacitive square-plateresonator."Journal of Micromechanics and Microengineering 19(7)).

方法2)：首先在SOI硅片上做金属焊盘。然后使用DRIE工艺加工出谐振器的器件结构。最后利用湿法腐蚀将SOI硅片的氧化硅埋层去除，从而将谐振器结构释放(Shao，L.and M.Palaniapan(2008).″Effect of etch holes onquality factor of bulk-mode micromechanical resonators.″Electronics Letters44(15)：938-940)。Method 2): first make metal pads on the SOI silicon wafer. Then use the DRIE process to process the device structure of the resonator. Finally, wet etching is used to remove the silicon oxide buried layer of the SOI silicon wafer, thereby releasing the resonator structure (Shao, L. and M. Palaniapan (2008). "Effect of etch holes on quality factor of bulk-mode micromechanical resonators."Electronics Letters 44(15):938-940).

这些利用SOI MEMS工艺制作谐振器的方法存在以下问题：There are following problems in these methods of making resonators using SOI MEMS technology:

第一，以上两种传统的微机械谐振器的制作方法都是在结构层制作完成后释放结构层，工艺复杂，成本高；First, the above two traditional manufacturing methods of micromechanical resonators are to release the structural layer after the structural layer is manufactured, the process is complicated and the cost is high;

第二，方法1)要用聚酰亚胺做保护层，增加了工艺的难度和复杂度；Second, method 1) will use polyimide as the protective layer, which increases the difficulty and complexity of the process;

第三，方法1)制成的器件，由于衬底硅片被完全刻穿，因此不易进行圆片级真空封装。Third, the device manufactured by method 1) is not easy to carry out wafer-level vacuum packaging because the substrate silicon wafer is completely cut through.

第四，方法2)用湿法腐蚀SOI硅片衬底的氧化硅埋层释放结构时，存在结构层容易与衬底黏连不易完全释放的问题。Fourth, method 2) When wet etching the silicon oxide buried layer release structure of the SOI silicon wafer substrate, there is a problem that the structural layer is easily adhered to the substrate and difficult to be completely released.

发明内容Contents of the invention

针对一般体硅谐振器加工中存在的问题，特别是加工工艺难度大和复杂高等缺点，本发明提出了一种体硅微机械谐振器制作方法。Aiming at the problems existing in the processing of general bulk silicon resonators, especially the disadvantages of difficult and complicated processing technology, the invention proposes a manufacturing method of bulk silicon micromechanical resonators.

本发明提出的体硅谐振器的结构示意图如图1-3所示，整个器件的结构由七部分组成，其中：1)具有凹腔的低阻衬底硅片，凹腔处于悬空的谐振振子的正下方；2)具有体硅谐振器振子、驱动电极和检测电极结构的低阻结构硅片；3)处于衬底硅片和结构硅片之间的电隔离层；4)与盖板硅片上的焊球相接触的金属焊盘；5)用于固定悬空的谐振器振子的斜拉支撑梁，支撑梁可以是T型斜拉梁，也可以是直拉梁，见图1-4；6)含有凹腔结构的盖板硅片，它处于结构硅片正上方；7)位于盖板硅片背面的一层图形化的焊料层。The structural diagram of the bulk silicon resonator proposed by the present invention is shown in Figure 1-3, the structure of the whole device is composed of seven parts, wherein: 1) a low-resistance substrate silicon wafer with a cavity, and the cavity is in the suspended resonator 2) Low-resistance structural silicon wafer with bulk silicon resonator oscillator, driving electrode and detection electrode structure; 3) Electrical isolation layer between the substrate silicon wafer and the structural silicon wafer; 4) Cover silicon wafer 5) The cable-stayed support beam used to fix the suspended resonator vibrator. The support beam can be a T-shaped cable-stayed beam or a straight-stayed beam, as shown in Figure 1-4 ; 6) A cover silicon chip containing a cavity structure, which is directly above the structure silicon chip; 7) A layer of patterned solder layer located on the back of the cover silicon chip.

本发明提出的体硅谐振器是由衬底硅片、结构硅片及盖板硅片三层键合在一起形成的，衬底硅片的正面与结构硅片的背面，结构硅片的正面与盖板硅片的背面分别通过键合黏合在一起。结构硅片位于衬底硅片与盖板硅片之间，衬底硅片正面凹腔与盖板硅片背面凹腔组成一个真空腔室，谐振器振子位于这个真空腔室中。盖板硅片背面具有用于组成真空腔室的凹腔结构和涂覆黏合剂凹槽，凹腔处于谐振器正上方，黏合剂凹槽分布在盖板硅片凹腔的外侧一周。The bulk silicon resonator proposed by the present invention is formed by bonding three layers of substrate silicon wafer, structural silicon wafer and cover silicon wafer. The front side of the substrate silicon wafer and the back side of the structural silicon wafer, and the front and the back side of the cover silicon wafer are respectively bonded together. The structural silicon wafer is located between the substrate silicon wafer and the cover silicon wafer, the front concave cavity of the substrate silicon wafer and the back concave cavity of the cover silicon wafer form a vacuum chamber, and the resonator vibrator is located in this vacuum chamber. The back of the cover silicon wafer has a cavity structure for forming a vacuum chamber and coating adhesive grooves, the cavity is located directly above the resonator, and the adhesive grooves are distributed around the outer circumference of the cavity of the cover silicon wafer.

另外，为了增强驱动信号和检测信号的强度，提高谐振器性能，也可以将两个工作在相同模态的方形板谐振振子通过一个梁耦合连接起来，其结构示意图及工作原理图见图1-5。In addition, in order to enhance the strength of the driving signal and detection signal and improve the performance of the resonator, two square plate resonators working in the same mode can also be connected through a beam coupling. The schematic diagram of its structure and working principle are shown in Figure 1- 5.

(1)通过氧化、光刻及硅的各向异性湿法腐蚀或者干法刻蚀工艺在衬底硅片上制作出凹腔，然后通过氧化工艺，在衬底硅片上生长一层二氧化硅层；(1) Make a concave cavity on the substrate silicon wafer through oxidation, photolithography and anisotropic wet etching or dry etching process of silicon, and then grow a layer of carbon dioxide on the substrate silicon wafer through the oxidation process. silicon layer;

(2)通过键合工艺，将步骤(1)得到的衬底硅片与结构硅片键合在一起；(2) bonding the substrate silicon wafer and the structural silicon wafer obtained in step (1) together by a bonding process;

(3)利用减薄工艺，将步骤(2)得到键合硅片上的结构硅片的厚度减薄到谐振器结构所需的厚度；(3) Utilize the thinning process, step (2) obtains the thickness of the structural silicon wafer on the bonded silicon wafer to be thinned to the required thickness of the resonator structure;

(4)在步骤(3)得到的衬底硅片的背面沉积金属层；(4) depositing a metal layer on the back side of the substrate silicon wafer obtained in step (3);

(5)在步骤(4)的结构硅片的正面沉积金属层，并通过光刻、腐蚀等工艺将结构硅片正面的金属层图形化，形成与盖板硅片上的焊球相接触的金属焊盘；(5) Deposit a metal layer on the front side of the structural silicon wafer in step (4), and pattern the metal layer on the front side of the structural silicon wafer through processes such as photolithography and corrosion to form a solder ball that is in contact with the solder ball on the cover plate silicon wafer. metal pad;

(6)通过光刻和深反应离子刻蚀工艺，将步骤(5)制作的结构硅片正面加工出所需要的谐振器结构；(6) Process the required resonator structure on the front side of the structural silicon wafer made in step (5) by photolithography and deep reactive ion etching process;

(7)通过氧化、涂胶光刻、氧化硅腐蚀、硅腐蚀等方法在盖板硅片上制作出凹腔结构，对其热氧化处理后，在其上沉积用于电接触的焊盘、导线、焊球及用于真空封装的黏合剂；(7) Make a concave cavity structure on the cover silicon wafer by oxidation, gluing photolithography, silicon oxide corrosion, silicon corrosion, etc., after thermal oxidation treatment, deposit pads for electrical contact, Wires, solder balls and adhesives for vacuum packaging;

(8)将盖板硅片通过真空圆片对准键合固定在步骤(6)得到的结构硅片之上，对谐振器进行圆片级真空封装；(8) fixing the cover plate silicon chip on the structural silicon chip obtained in step (6) through vacuum wafer alignment bonding, and performing wafer-level vacuum packaging on the resonator;

(9)采用划片机对步骤(8)的所述键合圆片进行一个方向上的划片，通过划片的方法将体硅谐振器芯片盖板焊盘上的划片槽划开；(9) Using a dicing machine to perform dicing in one direction on the bonded wafer of step (8), and scribing the dicing groove on the pad of the bulk silicon resonator chip cover plate by dicing;

(10)采用划片机对步骤(9)中所述键合圆片进行横轴和纵轴方向上的划片，将圆片上的体硅谐振器单元进行分离；(10) Scribing the bonding wafer described in step (9) in the direction of the horizontal axis and the vertical axis by using a dicing machine, and separating the bulk silicon resonator unit on the wafer;

(11)将划片后得到的单个体硅谐振器芯片固定于一基板上，并通过打线的方法与基板进行电连接。(11) The single bulk silicon resonator chip obtained after slicing is fixed on a substrate, and electrically connected to the substrate by wire bonding.

本发明所提供的体硅微机械谐振器，包括衬底硅片，结构硅片，盖板硅片，衬底硅片与结构硅片之间的电绝缘层，谐振振子，焊盘，黏合剂等七部分结构，其特征在于：The bulk silicon micromechanical resonator provided by the present invention includes a substrate silicon wafer, a structural silicon wafer, a cover silicon wafer, an electrical insulating layer between the substrate silicon wafer and the structural silicon wafer, a resonator, a pad, and an adhesive Seven-part structure, characterized in that:

1)谐振器是由衬底硅片、结构硅片及盖板硅片三层键合在一起形成的，衬底硅片的正面与结构硅片的背面，结构硅片的正面与盖板硅片的背面分别通过键合黏合在一起；1) The resonator is formed by bonding three layers of substrate silicon wafer, structural silicon wafer and cover silicon wafer. The front of the substrate silicon wafer and the back of the structural silicon wafer, the front of the structural silicon wafer and the cover silicon The backs of the sheets are respectively bonded together by bonding;

2)衬底硅片具有从正面腐蚀的凹腔结构；2) The substrate silicon wafer has a concave cavity structure etched from the front;

3)谐振器振子、驱动电极和检测电极结构位于结构硅片上；3) The structure of the resonator oscillator, drive electrodes and detection electrodes is located on the structural silicon wafer;

4)衬底硅片正面凹腔与盖板硅片背面凹腔组成一个真空腔室，谐振器振子位于这个真空腔室中；4) The front concave cavity of the substrate silicon wafer and the back concave cavity of the cover silicon wafer form a vacuum chamber, and the resonator vibrator is located in this vacuum chamber;

5)结构硅片位于衬底硅片的上方，谐振振子悬空在衬底凹腔正上方；5) The structural silicon wafer is located above the substrate silicon wafer, and the resonant oscillator is suspended directly above the substrate cavity;

所述的谐振器盖板包括：The resonator cover includes:

1)盖板硅片背面具有用于组成真空腔室的凹腔结构及涂覆黏合剂凹槽，凹腔处于谐振器正上方，涂覆黏合剂凹槽分布在盖板硅片凹腔的外侧一周；1) The back of the cover silicon wafer has a concave cavity structure for forming a vacuum chamber and coating adhesive grooves. The concave cavity is directly above the resonator, and the coating adhesive grooves are distributed outside the concave cavity of the cover silicon wafer a week;

2)盖板硅片的两面都具有电绝缘介质层；2) Both sides of the silicon chip of the cover plate have an electrically insulating dielectric layer;

3)盖板的背面具有一层实现与外界电连接的图形化的金属层，金属层沉积在电绝缘层上；3) The back of the cover plate has a patterned metal layer for realizing electrical connection with the outside world, and the metal layer is deposited on the electrical insulating layer;

4)盖板硅片的金属层上有金属焊球，焊球位于结构硅片焊盘的正上方位置，当盖板硅片与结构硅片键合时，盖板上的焊球与结构硅片上的焊盘紧密接触，从而实现电接触；4) There are metal solder balls on the metal layer of the cover silicon wafer, and the solder balls are located directly above the pads of the structural silicon wafer. When the cover silicon wafer and the structural silicon wafer are bonded, the solder balls on the cover plate and the structural silicon The pads on the chip are in close contact to achieve electrical contact;

5)盖板的背面具有一圈图形化的黏合剂，黏合剂处于盖板硅片黏合剂凹槽中，其位于金属层之上，宽度要小于凹槽宽度；5) There is a circle of patterned adhesive on the back of the cover plate, and the adhesive is located in the silicon chip adhesive groove of the cover plate, which is located on the metal layer, and the width is smaller than the width of the groove;

所述的谐振器振子结构为方形板、圆形板、圆环板，也可以是悬臂梁结构，且不限于此；The structure of the resonator vibrator is a square plate, a circular plate, a ring plate, or a cantilever beam structure, and is not limited thereto;

所述的谐振器振子结构的梁为T型斜拉梁，也可以是直拉梁，且不限于此；将两个及两个以上谐振器振子通过梁连接起来，这两个或两个以上谐振器振子和梁整体作为一个谐振器振子；The beam of the resonator vibrator structure is a T-shaped cable-stayed beam, or a straight-stayed beam, and is not limited thereto; two or more resonator vibrators are connected through the beam, and the two or more The resonator oscillator and the beam as a whole act as a resonator oscillator;

本发明所述的体硅谐振器制作方法的特征在于：The bulk silicon resonator manufacturing method of the present invention is characterized in that:

①衬底硅片上的凹腔是在谐振器结构层制作完成之前就已经制作完成的；①The concave cavity on the substrate silicon wafer is fabricated before the resonator structure layer is fabricated;

②谐振器器件结构的制作和谐振器器件结构的释放是同时完成的；②The manufacture of the resonator device structure and the release of the resonator device structure are completed simultaneously;

③可以采用湿法腐蚀或者干法刻蚀的方法制作衬底凹腔和盖板凹腔结构，且不限于此；③ Wet etching or dry etching can be used to fabricate substrate cavity and cover cavity structure, but not limited thereto;

④将结构硅片减薄到谐振器结构所需的厚度，可以采用化学机械的方法，或者使用湿法腐蚀进行减薄，且不限于此；④ Thinning the structural silicon wafer to the thickness required for the resonator structure can be done by chemical mechanical methods, or by wet etching, but not limited to this;

⑤在结构硅片正面沉积金属层，通过光刻、腐蚀等工艺制作与盖板硅片上焊球相接触的金属焊盘；⑤ Deposit a metal layer on the front side of the structural silicon wafer, and make metal pads that are in contact with the solder balls on the cover silicon wafer through photolithography, corrosion and other processes;

⑥在衬底硅片背面沉积金属层，来实现器件衬底接地的电学连接；⑥Deposit a metal layer on the back of the substrate silicon wafer to realize the electrical connection of the device substrate to ground;

⑦盖板硅片可以利用金属导线实现结构硅片与外界的电连接，也可以利用重掺杂区的低阻导通特性实现结构硅片与外界的电连接，且不限于此；⑦ The silicon chip of the cover plate can use metal wires to realize the electrical connection between the structural silicon chip and the outside world, and can also use the low-resistance conduction characteristics of the heavily doped region to realize the electrical connection between the structural silicon chip and the outside world, and is not limited to this;

⑧包含谐振器结构的圆片与盖板圆片通过黏合剂进行圆片级的密闭封装，用于结构圆片与盖板圆片低温真空对准键合的黏合剂可以是玻璃浆料，也可以是聚合物或者金属，且不限于此；⑧ The wafer containing the resonator structure and the cover wafer are hermetically packaged at the wafer level through an adhesive. The adhesive used for the low-temperature vacuum alignment bonding of the structure wafer and the cover wafer can be glass paste, or Can be polymer or metal without limitation;

⑨在通过划片的方法将盖板焊盘上的划片槽划开后，再通过划片的方法将圆片上的谐振器单元进行分离，此时划片应该分别在横轴方向和纵轴方向上进行，划片厚度为键合片的厚度；⑨ After scribing the scribing groove on the pad of the cover plate, separate the resonator unit on the wafer by scribing. At this time, the scribing should be in the horizontal axis direction and the vertical axis direction, the dicing thickness is the thickness of the bonding sheet;

⑩划片后得到的单个谐振器芯片直接固定在一基板上，通过打线的方法与基板进行电连接，其中该基板可为印刷电路板、陶瓷基板或封装管壳。⑩The single resonator chip obtained after dicing is directly fixed on a substrate, and electrically connected to the substrate by wire bonding, wherein the substrate can be a printed circuit board, a ceramic substrate or a packaged shell.

由此可见，与一般的体硅微机械谐振器的结构相比：It can be seen that, compared with the structure of the general bulk silicon micromechanical resonator:

本发明提出的体硅微机械谐振器结构可以控制结构硅片与衬底硅片之间氧化层的厚度；本发明提出的体硅微机械谐振器结构可以控制衬底硅片上的凹腔的深度；电绝缘层处于衬底硅片和结构硅片之间。The bulk silicon micromechanical resonator structure proposed by the present invention can control the thickness of the oxide layer between the structural silicon wafer and the substrate silicon wafer; the bulk silicon micromechanical resonator structure proposed by the present invention can control the thickness of the concave cavity on the substrate silicon wafer Depth; the electrically insulating layer is between the substrate silicon wafer and the structural silicon wafer.

与一般的体硅微机械谐振器制作方法相比：Compared with the general method of bulk silicon micromechanical resonator fabrication:

本发明首先在衬底硅片上制作好用于结构释放的凹腔结构，在器件结构制作完成的同时就将器件结构释放了，无需后续的释放工艺，降低了工艺复杂度；In the present invention, the concave cavity structure for structure release is first fabricated on the substrate silicon wafer, and the device structure is released when the device structure is manufactured, without the need for a subsequent release process, which reduces the process complexity;

本发明采用了低阻的普通硅片和硅硅直接键合、硅的各向异性湿法腐蚀等工艺，降低器件的制作成本；The invention adopts processes such as direct bonding of low-resistance ordinary silicon wafers and silicon-silicon, anisotropic wet etching of silicon, etc., to reduce the manufacturing cost of the device;

本发明将结构层键合在事先腐蚀出凹腔的衬底硅片之上，然后利用干法刻蚀释放结构，不使用PI做保护层，因此降低了工艺的复杂度；In the present invention, the structure layer is bonded on the substrate silicon wafer with the concave cavity etched out in advance, and then the structure is released by dry etching, without using PI as the protective layer, thus reducing the complexity of the process;

本发明使用湿法腐蚀制作衬底硅片上的凹腔结构，可以控制凹腔深度，且成本低；The present invention uses wet etching to manufacture the concave cavity structure on the substrate silicon wafer, which can control the cavity depth and has low cost;

本发明将结构层悬空在衬底硅片的凹腔之上，利用干法刻蚀释放结构，不存在结构层与衬底之间黏连的问题；In the present invention, the structure layer is suspended above the concave cavity of the substrate silicon chip, and the structure is released by dry etching, so there is no problem of adhesion between the structure layer and the substrate;

本发明将盖板通过真空圆片对准键合固定在结构硅片芯片上方，衬底硅片的空腔与盖板上的空腔组成一个真空腔室，而谐振振子则正好位于此真空腔室之中，从而实现体硅微机械谐振器的圆片级真空封装，这样不仅提高了器件性能，而且适用于批量生产。In the present invention, the cover plate is fixed on the top of the structural silicon chip through the alignment and bonding of the vacuum wafer. The cavity of the substrate silicon chip and the cavity on the cover plate form a vacuum chamber, and the resonant oscillator is just located in this vacuum chamber. In the chamber, the wafer-level vacuum packaging of the bulk silicon micromechanical resonator is realized, which not only improves the performance of the device, but also is suitable for mass production.

由于本发明提出的加工方法在谐振器器件结构制作完成的同时就将器件结构释放了，无需后续释放工艺，降低了工艺复杂度；通过普通硅片的键合制作器件，降低了成本；使用湿法腐蚀制作衬底硅片上的凹腔结构，降低了成本，并且通过控制凹腔的深度，可以提高器件的性能；不使用PI做保护层，降低了加工的复杂度；采用干法刻蚀释放结构，不存在结构层与衬底黏连的问题；容易进行圆片级真空封装，提高了器件性能，适用于批量成产。Since the processing method proposed in the present invention releases the device structure when the resonator device structure is manufactured, no subsequent release process is required, which reduces the complexity of the process; the device is made by bonding ordinary silicon wafers, which reduces the cost; using wet The concave cavity structure on the substrate silicon wafer is made by corrosion method, which reduces the cost, and by controlling the depth of the concave cavity, the performance of the device can be improved; PI is not used as a protective layer, which reduces the complexity of processing; dry etching is used The release structure does not have the problem of adhesion between the structural layer and the substrate; it is easy to carry out wafer-level vacuum packaging, which improves the performance of the device and is suitable for mass production.

综上所述，本发明涉及一种体硅微机械谐振器及制作方法，其特征在于先将悬浮结构--谐振器振子正下方的空腔制作好，再通过键合的方法将器件结构层制作在空腔上方，然后通过干法刻蚀在制作谐振器器件结构的同时，将谐振器器件结构进行释放，最后利用真空圆片对准键合的方法将盖板硅片固定在结构硅片上方。由于谐振器下方的空腔在器件结构制作之前用湿法腐蚀制成，并且采用圆片级封装对器件进行真空密封，从而使制作的谐振器的成本可以大大降低。具体地说，本发明提供的体硅微机械谐振器的制作包括以下步骤：1)采用硅各向异性腐蚀在重掺杂的衬底硅片正面腐蚀出凹腔结构；2)利用硅硅直接键合工艺将衬底硅片和重掺杂的结构硅片键合在一起。3)通过减薄的方法，将结构硅片的厚度减薄到谐振器结构所需的厚度；4)在结构硅片正面和衬底硅片背面上通过金属镀膜的方法制作出金属焊盘；5)利用深刻蚀技术，从正面刻蚀结构层，释放谐振器结构；6)通过真空圆片对准键合将谐振器的结构层真空密封在盖板硅片和衬底硅片之中，实现谐振器的圆片级的真空封装。7)将划片后得到的单个体硅谐振器芯片固定在基板上，并通过打线方法与基板进行电连接。本发明可适用于批量生产，由于简化了加工工艺和采用圆片级真空封装工艺，不仅可以降低生产成本，还可以提高成品率，可实现一种低成本、高性能的体硅谐振器的制作In summary, the present invention relates to a bulk silicon micromechanical resonator and a manufacturing method, which is characterized in that the suspension structure—the cavity directly below the resonator vibrator is made first, and then the device structure layer is bonded Manufactured above the cavity, and then release the resonator device structure while making the resonator device structure by dry etching, and finally fix the cover silicon chip on the structural silicon chip by using the method of vacuum wafer alignment bonding above. Since the cavity under the resonator is formed by wet etching before the device structure is fabricated, and the device is vacuum-sealed by wafer-level packaging, the cost of the manufactured resonator can be greatly reduced. Specifically, the manufacture of the bulk silicon micromechanical resonator provided by the present invention includes the following steps: 1) using silicon anisotropic etching to etch out a cavity structure on the front side of the heavily doped substrate silicon wafer; 2) using silicon silicon to directly The bonding process bonds the substrate silicon wafer and the heavily doped structural silicon wafer together. 3) Thinning the thickness of the structural silicon wafer to the required thickness of the resonator structure by a thinning method; 4) Making a metal pad on the front of the structural silicon wafer and the back of the substrate silicon wafer by metal coating; 5) Using deep etching technology to etch the structural layer from the front to release the resonator structure; 6) Vacuum sealing the structural layer of the resonator in the cover silicon wafer and the substrate silicon wafer through vacuum wafer alignment bonding, Wafer-level vacuum packaging of resonators is realized. 7) The single bulk silicon resonator chip obtained after dicing is fixed on the substrate, and electrically connected to the substrate by wire bonding. The present invention is applicable to mass production, and because the processing technology is simplified and the wafer-level vacuum packaging technology is adopted, not only can the production cost be reduced, but also the yield rate can be increased, and the production of a low-cost, high-performance bulk silicon resonator can be realized

附图说明Description of drawings

图1-1(a)是谐振器工作的三种基本模态示意图：i)弯曲模态，ii)扭曲模态和iii)体模态；图1-1(b)是体模态谐振器谐振振子分部为方形板、圆环板及圆形板时不同谐振模式形变示意图：A)原结构图，B)Wine-Glass模态，C)Extensional模态和D)Lame模态。Figure 1-1(a) is a schematic diagram of the three basic modes of resonator operation: i) bending mode, ii) twisting mode and iii) bulk mode; Figure 1-1(b) is a bulk mode resonator Schematic diagram of the deformation of different resonance modes when the resonator is divided into square plate, ring plate and circular plate: A) original structure diagram, B) Wine-Glass mode, C) Extension mode and D) Lame mode.

图1-2是体硅微机械谐振器工作的基本原理图：图1-2(a)为Wine-Glass模态的谐振器基本工作原理示意图；图1-2(b)为Extensional模态的谐振器基本工作原理示意图。Figure 1-2 is the basic schematic diagram of the bulk silicon micromechanical resonator: Figure 1-2(a) is a schematic diagram of the basic working principle of the resonator in the Wine-Glass mode; Figure 1-2(b) is the schematic diagram of the Extensional mode Schematic diagram of the basic working principle of a resonator.

图1-3(a)是体硅微机械谐振器的剖面结构示意图；图1-3(b)是由图1-3(a)中截面A-B截面的俯视结构图。Figure 1-3(a) is a schematic cross-sectional structure diagram of a bulk silicon micromechanical resonator; Figure 1-3(b) is a top view structure diagram of the section A-B in Figure 1-3(a).

图1-4是斜拉梁分别为T型梁和直拉梁的体硅微机械谐振器的基本结构示意图(俯视图)：图1-4(a)是T型梁(T-shape anchor)结构；图1-4(b)是直拉梁(Direct anchor)结构。Figure 1-4 is a schematic diagram (top view) of the basic structure of a bulk silicon micromechanical resonator whose inclined-stayed beams are T-shaped beams and straight-stayed beams respectively: Figure 1-4(a) is a T-shaped beam (T-shape anchor) structure ; Figure 1-4(b) is a direct-tension beam (Direct anchor) structure.

图1-5是将两个体硅微机械谐振器的谐振振子通过梁耦合连接在一起的基本结构示意图。图1-5(a)两个谐振振子连接在一起的结构示意图；图1-5(b)为此种结构的器件的基本工作原理示意图。1-5 are schematic diagrams of the basic structure of connecting the resonators of two bulk silicon micromechanical resonators together through beam coupling. Figure 1-5(a) is a schematic diagram of the structure of two resonant oscillators connected together; Figure 1-5(b) is a schematic diagram of the basic working principle of the device with this structure.

图2是实施例1的具体工艺流程。Fig. 2 is the concrete process flow ofembodiment 1.

图2-1：具有凹腔结构的衬底硅片。Figure 2-1: A substrate silicon wafer with a cavity structure.

图2-2：将氧化后衬底硅片与结构硅片进行键合，并减薄结构硅片。Figure 2-2: Bonding the oxidized substrate silicon wafer with the structural silicon wafer, and thinning the structural silicon wafer.

图2-3：沉积金属后，制作金属焊盘。Figure 2-3: After depositing the metal, making the metal pad.

图2-4：释放谐振器结构。Figure 2-4: Releasing the resonator structure.

图2-5：具有组成真空腔室的凹腔和涂覆黏合剂的凹槽结构的盖板硅片。Figure 2-5: Lid silicon wafer with cavities forming the vacuum chamber and groove structures coated with adhesive.

图2-6：在氧化后的盖板硅片上沉积金属层，并制作金属焊盘与焊球。Figure 2-6: Deposit a metal layer on the oxidized cover silicon wafer, and make metal pads and solder balls.

图2-7：在盖板硅片上涂覆黏合剂。Figure 2-7: Coating adhesive on the cover silicon wafer.

图2-8：将键合圆片和盖板硅片进行对准键合。Figure 2-8: Alignment bonding of the bonded wafer and the lid silicon wafer.

图2-9：具体实施例1得到的最终器件结构。2-9: The final device structure obtained in Example 1.

图2-10：打线、固定在基板上的谐振器芯片。Figure 2-10: A resonator chip bonded to a substrate.

图3是实施例2的步骤8-14的部分工艺流程。Fig. 3 is a partial process flow of steps 8-14 of embodiment 2.

图3-1：对具有凹腔和凹槽结构的盖板硅片进行离子注入。Figure 3-1: Ion implantation of a lid silicon wafer with cavity and groove structures.

图3-2：在盖板硅片上沉积金属层后制作金属焊盘和焊球。Figure 3-2: Fabrication of metal pads and solder balls after depositing a metal layer on the lid silicon wafer.

图3-3：在盖板硅片上涂覆黏合剂。Figure 3-3: Coating adhesive on the cover silicon wafer.

图3-4：将键合圆片和盖板硅片进行对准键合。Figure 3-4: Alignment bonding of bonded wafer and lid silicon wafer.

图3-5：具体实施例2得到的最终器件结构。3-5: The final device structure obtained in Example 2.

图3-6：打线、固定在基板上的谐振器芯片。Figure 3-6: A resonator chip bonded and mounted on a substrate.

图中各数字代表的含义为：The meanings of the numbers in the figure are:

1重掺杂的衬底硅片；2衬底硅片上的凹腔；3衬底硅片上的电隔离层；4重掺杂的结构硅片；5谐振器振子；6与盖板硅片上焊球相接触的金属焊盘；7盖板硅片；8盖板硅片上的凹腔；9盖板硅片上的电隔离层；10盖板硅片上的焊盘；11黏合剂；12焊球；14涂覆黏合剂凹槽；15P型重掺杂区；16衬底硅片上的金属层；17电极；21基座或者管壳；22金属引线；23基座或者管壳上的引脚1 heavily doped substrate silicon wafer; 2 cavity on the substrate silicon wafer; 3 electrical isolation layer on the substrate silicon wafer; 4 heavily doped structural silicon wafer; 5 resonator vibrator; 6 and cover silicon The metal pads on the chip where the solder balls are in contact; 7 the cover silicon wafer; 8 the concave cavity on the cover silicon wafer; 9 the electrical isolation layer on the cover silicon wafer; 10 the pad on the cover silicon wafer; 11bonding 12 Solder balls; 14 Coating adhesive grooves; 15P-type heavily doped regions; 16 Metal layers on substrate silicon wafers; 17 Electrodes; Pins on the shell

具体实施方式Detailed ways

下面结合附图和实施例，对本发明进行详细的描述。The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

实施例1Example 1

在谐振器结构圆片和盖板圆片上都沉积了一层TiW/Au金属层，通过光刻及腐蚀的方法对结构圆片和盖板圆片上的金属层进行图形化。在盖板硅片的背面通过丝网印刷的方法涂覆上一层黏合剂(黏合剂可以是玻璃浆料，聚合物或者金属)，并将黏合剂图形化，黏合剂作为焊料层。谐振器器件通过金属层与外界电路实现电连接。衬底硅片与结构硅片的电阻率范围为0.01-0.3Ω·cm，盖板硅片的电阻率没有要求，为普通硅片。主要工艺步骤包括：A layer of TiW/Au metal layer is deposited on both the resonator structure wafer and the cover plate wafer, and the metal layer on the structure wafer and the cover plate wafer is patterned by photolithography and etching. A layer of adhesive (adhesive can be glass paste, polymer or metal) is coated on the back of the silicon wafer by screen printing, and the adhesive is patterned, and the adhesive is used as a solder layer. The resonator device is electrically connected to the external circuit through the metal layer. The resistivity range of the substrate silicon wafer and the structural silicon wafer is 0.01-0.3Ω·cm, and the resistivity of the cover silicon wafer is not required, which is an ordinary silicon wafer. The main process steps include:

(1)在抛光的重掺杂的单晶硅片上，通过氧化、光刻、硅的各向异性湿法腐蚀工艺制作用以谐振器结构释放的底部凹腔，此时衬底硅片并没有被腐穿(图2-1)；(1) On the polished heavily doped single crystal silicon wafer, the bottom cavity for the release of the resonator structure is fabricated by oxidation, photolithography, and silicon anisotropic wet etching process. At this time, the substrate silicon wafer is not Not corroded (Figure 2-1);

(2)通过热氧化在步骤(1)中的硅片上生长一层二氧化硅作电隔离层；(2) growing one layer of silicon dioxide on the silicon chip in step (1) by thermal oxidation as an electrical isolation layer;

(3)使用键合工艺，将步骤(2)的硅片与另外一片重掺杂单晶硅片直接键合在一起，并通过减薄工艺将凹腔上方的硅片减薄到谐振器结构所需的厚度(图2-2)；(3) Use the bonding process to directly bond the silicon wafer in step (2) with another heavily doped single crystal silicon wafer, and thin the silicon wafer above the cavity to the resonator structure through a thinning process Required thickness (Figure 2-2);

(4)在步骤(3)的键合圆片的背面沉积金属层；(4) depositing a metal layer on the back side of the bonded wafer in step (3);

(5)在步骤(4)的键合圆片的正面沉积金属层，并通过光刻、金属腐蚀等工艺将其图形化，在结构硅片正面制作与盖板硅片上焊球相接触的金属焊盘(图2-3)；(5) Deposit a metal layer on the front side of the bonded wafer in step (4), and pattern it by processes such as photolithography and metal corrosion, and make a solder ball on the front side of the structural silicon wafer that is in contact with the solder ball on the cover plate silicon wafer. Metal pad (Figure 2-3);

(6)通过光刻、DRIE等工艺将步骤(5)制到的键合圆片的上层硅片进行结构释放，形成谐振器的结构(图2-4)；(6) Release the structure of the upper silicon wafer of the bonded wafer prepared in step (5) through photolithography, DRIE and other processes to form the structure of the resonator (Figure 2-4);

(7)通过氧化、涂胶光刻、氧化硅腐蚀、硅腐蚀等方法在第三片低掺杂的盖板硅片上制作出组成真空腔室的凹腔结构和涂覆黏合剂的凹槽结构(图2-5)；(7) Fabricate the cavity structure forming the vacuum chamber and the grooves coated with adhesive on the third low-doped cover silicon wafer by oxidation, coating photolithography, silicon oxide etching, silicon etching, etc. Structure (Figure 2-5);

(8)对步骤(7)中的硅片进行热氧化处理后，在其背面沉积一层TiW/Au作为盖板硅片圆片上的金属层，并通过涂胶光刻及化学腐蚀的方法对TiW/Au金属层进行图形化处理。图形化好后的金属层作为盖板圆片上与外界电连接的导线及焊盘。然后通过涂胶光刻、电镀等方法在金属层上制作与结构硅片上焊盘实现电接触的焊球(图2-6)；(8) After the silicon wafer in step (7) is thermally oxidized, a layer of TiW/Au is deposited on its back as the metal layer on the silicon wafer wafer of the cover plate, and the silicon wafer is treated by gluing photolithography and chemical etching. The TiW/Au metal layer is patterned. The patterned metal layer is used as wires and pads on the cover wafer to be electrically connected to the outside. Then make solder balls on the metal layer that are in electrical contact with the pads on the structural silicon wafer by coating photolithography, electroplating, etc. (Figure 2-6);

(9)在步骤(8)中的硅片的背面通过丝网印刷的方法涂覆上一层图形化的黏合剂，作为盖板上的焊料层，然后对黏合剂进行烧结处理(图2-7)；(9) The back side of the silicon chip in step (8) is coated with a layer of patterned adhesive by screen printing as the solder layer on the cover plate, and then the adhesive is sintered (Fig. 2- 7);

(10)将步骤(6)中的包含谐振器结构单元的键合圆片与步骤(8)中的盖板硅片在真空氛围下进行低温圆片对准键合，键合温度范围为300～500℃(图2-8)；(10) Align and bond the bonding wafer containing the resonator structural unit in step (6) with the cover silicon wafer in step (8) in a vacuum atmosphere at a low temperature, and the bonding temperature range is 300 ~500°C (Figure 2-8);

(11)将步骤(10)中的键合圆片通过划片机在谐振器芯片盖板划片槽处进行划片，将盖板划片槽划开，划片厚度控制为盖板硅片的厚度；(11) Scribe the bonded wafer in step (10) by a dicing machine at the scribing groove of the resonator chip cover plate, cut the scribing groove of the cover plate, and control the thickness of the dicing to be the silicon chip of the cover plate thickness of;

(12)将步骤(11)中的键合圆片通过划片机在横轴和纵轴方向上进行划片，划片厚度控制为键合圆片的厚度。通过划片的方法将圆片上的谐振器单元进行分离，得到体硅微机械谐振器芯片(图2-9)；(12) Scribing the bonding wafer in step (11) in the direction of the horizontal axis and the vertical axis by a dicing machine, and controlling the thickness of the dicing to be the thickness of the bonding wafer. Separate the resonator units on the wafer by dicing to obtain bulk silicon micromechanical resonator chips (Figure 2-9);

(13)将谐振器芯片安装固定在一基板或管座上，并通过打线的方法将探测器与基板或管座进行电连接(图2-10)(13) Install and fix the resonator chip on a substrate or socket, and electrically connect the detector to the substrate or socket by wire bonding (Figure 2-10)

实施例2Example 2

盖板硅片采用轻掺杂的N型硅片，通过氧化、涂胶光刻、氧化硅腐蚀、离子注入等方法，在盖板硅片形成P+区。在谐振器结构圆片和盖板圆片上都沉积了一层TiW/Au金属层，通过光刻及腐蚀的方法对结构圆片和盖板圆片上的金属层进行图形化。在盖板硅片的背面通过丝网印刷的方法涂覆上一层黏合剂(黏合剂可以是玻璃浆料，聚合物或者金属)，并将黏合剂图形化，黏合剂作为焊料层。谐振器器件通过P+区与外界电路实现电连接。衬底硅片与结构硅片的电阻率范围为0.01-0.3Ω·cm，盖板硅片的电阻率范围为0.01-1Ω·cm。主要工艺步骤包括：The cover plate silicon wafer is made of lightly doped N-type silicon wafer, and the P+ region is formed on the cover plate silicon wafer through methods such as oxidation, gluing photolithography, silicon oxide corrosion, and ion implantation. A layer of TiW/Au metal layer is deposited on both the resonator structure wafer and the cover plate wafer, and the metal layer on the structure wafer and the cover plate wafer is patterned by photolithography and etching. A layer of adhesive (adhesive can be glass paste, polymer or metal) is coated on the back of the silicon wafer by screen printing, and the adhesive is patterned, and the adhesive is used as a solder layer. The resonator device is electrically connected to the external circuit through the P+ region. The resistivity range of the substrate silicon wafer and the structural silicon wafer is 0.01-0.3Ω·cm, and the resistivity range of the cover silicon wafer is 0.01-1Ω·cm. The main process steps include:

(1)在抛光的单晶硅片上，通过氧化、光刻、硅的各向异性湿法腐蚀工艺制作用以谐振器结构释放的底部凹腔，此时衬底硅片并没有被腐穿。(1) On the polished single crystal silicon wafer, the bottom cavity for the release of the resonator structure is fabricated by oxidation, photolithography, and anisotropic wet etching of silicon. At this time, the substrate silicon wafer has not been corroded. .

(2)通过热氧化在步骤(1)中的硅片上生长一层二氧化硅作为电绝缘层。(2) Growing a layer of silicon dioxide as an electrical insulating layer on the silicon wafer in step (1) by thermal oxidation.

(3)使用键合工艺，将步骤(2)的硅片与另外一片单晶硅片直接键合在一起，并通过减薄工艺将凹腔上方的硅片减薄到谐振器结构所需的厚度。(3) Use the bonding process to directly bond the silicon wafer in step (2) with another single crystal silicon wafer, and thin the silicon wafer above the cavity to the required thickness of the resonator structure through a thinning process. thickness.

(4)在步骤(3)的键合圆片的背面沉积金属层；(4) depositing a metal layer on the back side of the bonded wafer in step (3);

(5)在步骤(4)的键合圆片的正面沉积金属层，并通过光刻、金属腐蚀等工艺将其图形化，在结构硅片正面制作与盖板硅片上焊球相接触的金属焊盘。见图2-3。(5) Deposit a metal layer on the front side of the bonded wafer in step (4), and pattern it by processes such as photolithography and metal corrosion, and make a solder ball on the front side of the structural silicon wafer that is in contact with the solder ball on the cover plate silicon wafer. metal pad. See Figure 2-3.

(6)通过光刻、DRIE等工艺将步骤(5)的上层硅片进行结构释放，形成谐振器的结构。(6) Release the structure of the upper silicon wafer in step (5) by photolithography, DRIE and other processes to form a resonator structure.

(7)通过氧化、涂胶光刻、氧化硅腐蚀、硅腐蚀等方法在第三片低掺杂的硅片上制作出组成真空腔室的凹腔结构和涂覆黏合剂的凹槽结构。(7) Fabricate the cavity structure constituting the vacuum chamber and the groove structure coated with adhesive on the third low-doped silicon wafer by methods such as oxidation, coating photolithography, silicon oxide etching, and silicon etching.

(8)图形化步骤(7)得到的硅片上的氧化硅，并对其进行离子注入，在注入区域形成P+区。见图3-1。(8) patterning the silicon oxide on the silicon wafer obtained in step (7), and performing ion implantation on it to form a P+ region in the implanted region. See Figure 3-1.

(9)对步骤(8)中的硅片进行热氧化处理后，在其背面沉积一层TiW/Au作为盖板硅片圆片上的金属层，并通过涂胶光刻及化学腐蚀的方法对TiW/Au金属层进行图形化处理。图形化好后的金属层作为盖板圆片上与外界电连接的导线及焊盘。然后通过光刻、电镀等方法在金属层上制作用于与结构硅片上焊盘实现电接触的焊球。见图3-2。(9) After the silicon wafer in step (8) is thermally oxidized, a layer of TiW/Au is deposited on its back as the metal layer on the silicon wafer wafer of the cover plate, and the silicon wafer is treated by gluing photolithography and chemical etching. The TiW/Au metal layer is patterned. The patterned metal layer is used as wires and pads on the cover wafer to be electrically connected to the outside. Then, solder balls for electrical contact with pads on the structural silicon wafer are fabricated on the metal layer by methods such as photolithography and electroplating. See Figure 3-2.

(10)在步骤(9)中的硅片的背面通过丝网印刷的方法涂覆上一层图形化的黏合剂，作为盖板上的焊料层，然后对黏合剂进行烧结处理。见图3-3。(10) In the step (9), a layer of patterned adhesive is coated on the back of the silicon wafer by screen printing as a solder layer on the cover plate, and then the adhesive is sintered. See Figure 3-3.

(11)将步骤(6)中的包含谐振器结构单元的键合圆片与步骤(10)中的盖板硅片在真空氛围下进行低温圆片对准键合，键合温度范围为300～500℃。见图3-4。(11) Align and bond the bonded wafer containing the resonator structural unit in step (6) and the cover silicon wafer in step (10) in a vacuum atmosphere at a low temperature, and the bonding temperature range is 300 ~500°C. See Figure 3-4.

(12)将步骤(11)中的键合圆片通过划片机在谐振器芯片盖板划片槽处进行划片，将盖板划片槽划开，划片厚度控制为盖板硅片的厚度。(12) Scribe the bonded wafer in step (11) by a dicing machine at the scribing groove of the resonator chip cover plate, cut the scribing groove of the cover plate, and control the thickness of the dicing to be the silicon chip of the cover plate thickness of.

(13)将步骤(12)中的键合圆片通过划片机在横轴和纵轴方向上进行划片，划片厚度控制为键合圆片的厚度。通过划片的方法将圆片上的谐振器单元进行分离，得到体硅微机械谐振器芯片，得到的结构见图3-5。(13) Scribing the bonding wafer in step (12) in the direction of the horizontal axis and the vertical axis by a dicing machine, and controlling the thickness of the dicing to be the thickness of the bonding wafer. The resonator units on the wafer are separated by dicing to obtain a bulk silicon micromechanical resonator chip. The obtained structure is shown in Figure 3-5.

(14)将谐振器芯片安装固定在一基板或管座上，并通过打线的方法将探测器与基板或管座进行电连接。见图3-6。(14) Mounting and fixing the resonator chip on a substrate or a socket, and electrically connecting the detector to the substrate or socket by wire bonding. See Figure 3-6.

实施例3Example 3

体硅谐振器的衬底硅片与结构硅片采用低阻硅片，衬底硅片与结构硅片的电阻率范围为0.01-0.3Ω·cm，盖板硅片为普通硅片。为了增强驱动信号和检测信号的强度，进一步提高谐振器的性能，可将两个体硅微机械谐振器的谐振振子通过一个梁耦合连接在一起。其具体实施方案与实施例1相同。主要区别在于：(1)谐振振子不同：实施例1的谐振器的振子为一个方形板，本实施例的谐振器的振子为两个方形板通过一个梁相连接的图形，见图1-5(a)；(2)驱动电极不同：实施例1的谐振器有对称分布在谐振器振子方形板四周的四个电极，本实施例的电极有六个，见图1-5(b)。其它工艺步骤与实施例1相应步骤相同。The substrate silicon wafer and structural silicon wafer of the bulk silicon resonator adopt low-resistance silicon wafers, the resistivity range of the substrate silicon wafer and structural silicon wafer is 0.01-0.3Ω·cm, and the cover silicon wafer is an ordinary silicon wafer. In order to enhance the strength of the driving signal and the detection signal, and further improve the performance of the resonator, the resonant oscillators of the two bulk silicon micromechanical resonators can be connected together through a beam coupling. Its specific embodiment is identical withembodiment 1. The main differences are: (1) different resonator oscillators: the oscillator of the resonator inembodiment 1 is a square plate, and the oscillator of the resonator in this embodiment is a figure in which two square plates are connected by a beam, see Figure 1-5 (a); (2) Different driving electrodes: the resonator inembodiment 1 has four electrodes symmetrically distributed around the square plate of the resonator vibrator, and there are six electrodes in this embodiment, see Figure 1-5(b). Other processing steps are identical with the corresponding steps ofembodiment 1.

Claims (10)

1. bulk silicon micro mechanic resonator is characterized in that comprising silicon substrate, structure silicon chip, cover plate silicon chip, electric insulation layer, resonator oscillator, pad and binder:

Wherein, 1) described resonator is bonded together by three layers of silicon substrate, structure silicon chip and cover plate silicon chips and forms, the back side of the front of silicon substrate and structure silicon chip, and the back side of the front of structure silicon chip and cover plate silicon chip sticks together by bonding respectively;

2) silicon substrate has the curved cavity from front etch;

3) resonator oscillator, drive electrode and detector electrode structure are positioned on the structure silicon chip;

4) silicon substrate front cavity and cover plate silicon chip back side cavity form a vacuum chamber, and the resonator oscillator is arranged in this vacuum chamber;

5) the structure silicon chip is positioned at the top of silicon substrate, and the resonance oscillator is unsettled directly over the substrate cavity;

6) electric insulation layer is between silicon substrate and the structure silicon chip.

2. bulk silicon micro mechanic resonator according to claim 1 is characterized in that:

1) the cover plate silicon chip back side has for the curved cavity that forms vacuum chamber and applies the binder groove, and cavity is in directly over the resonator, applies one week of the outside that the binder groove is distributed in cover plate silicon chip cavity;

2) two sides of cover plate silicon chip all has the electric insulating medium layer;

3) back side of cover plate silicon chip has the patterned metal level that one deck is realized and the external world is electrically connected, and metal level is deposited on the electric insulation layer;

4) on the metal level of cover plate silicon chip the metal soldered ball is arranged, soldered ball be positioned at structure silicon chip pad directly over the position, when cover plate silicon chip and structure wafer bonding, the pad close contact on the soldered ball on the cover plate and the structure silicon chip, thereby realize electrically contacting;

5) back side of cover plate has the patterned binder of a circle, and binder is in the cover plate silicon chip binder groove, and it is positioned on the metal level, and width is less than recess width.

3. bulk silicon micro mechanic resonator according to claim 1 is characterized in that described resonator oscillator structure is square plate, circular slab, Circular Plate or cantilever beam structure.

4. bulk silicon micro mechanic resonator according to claim 1 is characterized in that:

1) beam of support resonator oscillator structure is T-shaped oblique pull beam or vertical pulling beam;

2) two and two above resonator oscillators are coupled together by beam, these two or more resonator oscillators and beam integral body are as a resonance oscillator.

5. bulk silicon micro mechanic resonator according to claim 1 is characterized in that described body resonistor is connected with external circuitry by metal level or is connected with external circuitry by the P+ district.

6. such as the manufacture method of each described bulk silicon micro mechanic resonator among the claim 1-5, it is characterized in that first with suspension structure---the cavity under the resonance oscillator is made, again the method for device architecture layer by bonding is produced on the cavity top, then by being dry-etched in when making the resonator structure, also the resonator structure is discharged, utilize at last vacuum disk alignment keys to close a cover plate silicon chip and be fixed on structure silicon chip top, concrete making step is:

(1) produces cavity by anisotropic wet corrosion or the dry etch process of oxidation, photoetching and silicon at silicon substrate, then by oxidation technology, at silicon substrate growth layer of silicon dioxide layer;

(2) by bonding technology, the silicon substrate that step (1) is obtained and structure wafer bonding are together;

(3) utilize reduction process, step (2) is obtained the reduced thickness of the structure silicon chip on the bonding silicon chip to the required thickness of resonator structure;

The backside deposition metal level of the silicon substrate that (4) obtains in step (3);

(5) at the front depositing metal layers of the structure silicon chip of step (4), and by photoetching, the etching process metallic layer graphic with the structure front side of silicon wafer, form with the cover plate silicon chip on the contacted metal pad of soldered ball;

(6) by photoetching and deep reaction ion etching technique, the structure front side of silicon wafer that step (5) is made processes needed resonator structure;

(7) produce curved cavity by oxidation, gluing photoetching, silica erosion, silicon caustic solution at the cover plate silicon chip, after its thermal oxidation, deposition is used for pad, wire, the soldered ball that electrically contacts and the binder that is used for Vacuum Package thereon;

(8) the cover plate silicon chip is closed by vacuum disk alignment keys be fixed on the structure silicon chip that step (6) obtains, resonator is carried out wafer-level vacuum package;

(9) adopt scribing machine that the described bonding disk of step (8) is carried out a scribing on the direction, by the method for scribing the scribe line on the body resonistor chip cover plate pad is scratched;

(10) adopt scribing machine that bonding disk described in the step (9) is carried out scribing on transverse axis and the y direction, the body resonistor unit on the disk is separated;

(11) the single body resonistor chip that obtains after the scribing is fixed on the substrate, and is electrically connected with substrate by the method for routing.

7. manufacture method as claimed in claim 6 is characterized in that the structure silicon chip is to use chemical mechanical method or wet etching method attenuate in the step 3.

8. manufacture method as claimed in claim 6 is characterized in that the release of the making resonator device architecture of resonator structure is finished simultaneously.

9. manufacture method as claimed in claim 6, the resistivity that it is characterized in that described structure silicon chip or silicon substrate is 0.01-0.3 Ω cm, the no requirement (NR) of cover plate silicon chip resistivity.

10. manufacture method as claimed in claim 6, it is characterized in that the cover plate silicon chip adopts lightly doped N-type silicon chip, behind oxidation, gluing photoetching, silica erosion and Implantation, form the P+ district at the cover plate silicon chip, the resistivity of the cover plate silicon chip that uses is 0.01-1 Ω cm.

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