CN1731287A - Method for Etching Wafers on Both Sides - Google Patents

Abstract

Translated fromChinese

一种双面蚀刻晶片的方法，首先，提供一晶片，该晶片包括至少一旋转轴区与至少二穿透区，且该二穿透区位于该旋转轴区的二侧。接着由该晶片的一底表面去除部分位于该旋转轴区的该晶片。随后将该晶片的底表面利用一粘着层粘贴于一负载载具上，并由该晶片的上表面去除位于该二穿透区的该晶片直至穿透该晶片。

A method for double-sided etching of a wafer, first, providing a wafer, the wafer comprising at least one rotation axis region and at least two penetration regions, and the two penetration regions are located on two sides of the rotation axis region. Then, a portion of the wafer located in the rotation axis region is removed from a bottom surface of the wafer. Subsequently, the bottom surface of the wafer is attached to a load carrier using an adhesive layer, and the wafer located in the two penetration regions is removed from the upper surface of the wafer until the wafer is penetrated.

Description

Translated fromChinese

双面蚀刻晶片的方法Method for Etching Wafers on Both Sides

技术领域technical field

本发明涉及一种双面蚀刻晶片的方法，特别是涉及一种利用双面蚀刻制造工艺制作微旋转轴的方法。The invention relates to a method for etching a wafer on both sides, in particular to a method for manufacturing a micro-rotation shaft by using a double-side etching manufacturing process.

背景技术Background technique

微机电(micro electro mechanical system，MEMS)技术为一种高度整合电子电路与机械等的新兴科技，并已广泛地被应用于制作各种具有电子与机械双重特性的元件，例如微感应器、微致动器、微马达与光开关元件等。相较于半导体元件，微机电元件由于常具有特殊的机械结构，因此于制作时若直接利用标准半导体制造工艺，所形成的结构往往精密度不佳，而无法达到微机电元件的要求。其中微旋转轴为微机电元件中常见的结构，且由于旋转轴的形状与表面状态对于旋转轴旋转的可靠性与可承受的应力影响甚巨，因此于制作微旋转轴时对于形状与表面状态的要求特别严格。Micro Electro Mechanical System (MEMS) technology is an emerging technology that highly integrates electronic circuits and machinery, and has been widely used in the production of various components with dual characteristics of electronics and machinery, such as micro sensors, micro Actuators, micro motors and optical switching elements, etc. Compared with semiconductor components, MEMS components often have special mechanical structures. Therefore, if the standard semiconductor manufacturing process is directly used during fabrication, the formed structures often have poor precision and cannot meet the requirements of MEMS components. Among them, the micro-rotating shaft is a common structure in micro-electromechanical components, and because the shape and surface state of the rotating shaft have a great influence on the reliability of the rotating shaft and the stress it can withstand, so when making the micro-rotating shaft, the shape and surface state requirements are particularly strict.

请参考图1至图3，图1为一微旋转轴10的示意图，而图2与图3为现有制作微旋转轴的方法示意图。如图1所示，微旋转轴10具有一悬吊结构，并可受电压、光线或磁场等的驱动而依图1中的箭号所示的方向旋转，因此微旋转轴10的形状必须极为精确，并具有平滑的表面以及均匀的轴体，方可确保可靠性并达到对应力承受的要求。现有制作微旋转轴10的方法如下所述。Please refer to FIG. 1 to FIG. 3 , FIG. 1 is a schematic diagram of a micro-rotating shaft 10 , and FIGS. 2 and 3 are schematic diagrams of a conventional method for manufacturing a micro-rotating shaft. As shown in Figure 1, the micro-rotating shaft 10 has a suspension structure, and can be driven by voltage, light or magnetic field to rotate in the direction shown by the arrow in Figure 1, so the shape of the micro-rotating shaft 10 must be extremely Precise, smooth surfaces and uniform shafts ensure reliability and meet stress tolerance requirements. The existing method for manufacturing the micro rotating shaft 10 is as follows.

如图2所示，首先提供一晶片20，并于分别于晶片20的底表面与上表面形成一蚀刻停止层22与一光致抗蚀剂图案24。如图3所示，接着进行一蚀刻制造工艺，利用光致抗蚀剂图案24作为一硬屏蔽，以去除未被光致抗蚀剂图案24保护的晶片20直至蚀穿晶片20，并停止于蚀刻停止层22。As shown in FIG. 2 , a wafer 20 is provided first, and an etching stop layer 22 and a photoresist pattern 24 are formed on the bottom surface and the upper surface of the wafer 20 respectively. As shown in Figure 3, carry out an etching manufacturing process then, utilize photoresist pattern 24 as a hard mask, to remove the wafer 20 that is not protected by photoresist pattern 24 until etch through wafer 20, and stop at etch stop layer 22 .

然而，现有方法于蚀穿晶片20的过程中，未考虑蚀刻均匀度与晶片20厚度的均匀度对蚀刻速率的影响，因此蚀刻制造工艺的成品率容易因为晶片20的各区域的蚀刻速率不同而无法有效控制。举例来说，当蚀刻制造工艺进行到最后阶段即将蚀穿晶片20之际，蚀刻总面积将产生剧烈变化而导致蚀刻制造工艺产生无法预期的变化。除此之外，当蚀刻至蚀刻停止层22时，极易发生侧蚀现象而产生如图3所示的底切26，进而影响微旋转轴的结构。如前所述，一旦微旋转轴的形状的精密度不佳，即会严重影响微旋转轴的可靠性。However, in the process of etching through the wafer 20 in the existing method, the influence of the uniformity of etching and the uniformity of the thickness of the wafer 20 on the etching rate is not considered, so the yield of the etching manufacturing process is easily due to the different etching rates of each area of the wafer 20. and cannot be effectively controlled. For example, when the etching process is about to etch through the wafer 20 at the final stage, the total etching area will change drastically, resulting in unpredictable changes in the etching process. In addition, when the etch-stop layer 22 is etched, the side etching phenomenon is likely to occur, resulting in an undercut 26 as shown in FIG. 3 , which further affects the structure of the micro-rotation shaft. As mentioned above, once the precision of the shape of the micro-rotation shaft is not good, the reliability of the micro-rotation shaft will be seriously affected.

有鉴于此，申请人根据此等缺点及依据多年的相关经验，悉心观察且研究之，而提出改良的本发明，以提升微旋转轴的可靠性与成品率。In view of this, based on these shortcomings and years of related experience, the applicant carefully observes and studies them, and proposes an improved invention to improve the reliability and yield of the micro-rotating shaft.

发明内容Contents of the invention

因此，本发明的主要目的在提供一种双面蚀刻晶片的方法，以改善现有技术无法克服的难题。Therefore, the main purpose of the present invention is to provide a method for etching a wafer on both sides, so as to improve the insurmountable problems in the prior art.

根据本发明的一优选实施例，提供一种制作微旋转轴的方法。首先，提供一晶片，该晶片包括至少一旋转轴区与至少二穿透区，且该二穿透区位于该旋转轴区的二侧。接着由该晶片的一底表面去除部分位于该旋转轴区的该晶片。随后将该晶片的底表面利用一粘着层粘贴于一负载载具上，并由该晶片的上表面去除位于该二穿透区的该晶片直至穿透该晶片。According to a preferred embodiment of the present invention, a method for manufacturing a micro rotating shaft is provided. Firstly, a wafer is provided, the wafer includes at least one rotation axis area and at least two penetration areas, and the two penetration areas are located at two sides of the rotation axis area. Then a part of the wafer located in the rotation axis area is removed from a bottom surface of the wafer. Then, the bottom surface of the wafer is pasted on a load carrier with an adhesive layer, and the wafer located in the two penetration regions is removed from the upper surface of the wafer until the wafer is penetrated.

由于本发明的方法利用双面蚀刻方式来制作微旋转轴结构，可有效避免于蚀刻制造工艺中蚀刻总面积变化过大造成蚀刻结果不易控制，以及蚀刻至蚀刻停止层时易发生的侧蚀问题，因此可确保微旋转轴具有良好结构，进而提升微旋转轴的可靠性与可承受的应力。Because the method of the present invention utilizes the double-sided etching method to manufacture the micro-rotating shaft structure, it can effectively avoid the difficulty in controlling the etching result caused by the excessive change of the total etching area in the etching manufacturing process, and the side etching problem that is prone to occur when etching to the etching stop layer , so it can ensure that the micro-rotation shaft has a good structure, thereby improving the reliability and the withstand stress of the micro-rotation shaft.

为了更进一步了解本发明的特征及技术内容，请参阅以下有关本发明的详细说明与附图。然而附图仅供参考与辅助说明用，并非用来对本发明加以限制者。In order to further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention. However, the drawings are only for reference and auxiliary description, and are not used to limit the present invention.

附图说明Description of drawings

图1为一微旋转轴的示意图。Fig. 1 is a schematic diagram of a micro-rotating shaft.

图2与图3为现有制作微旋转轴的方法示意图。FIG. 2 and FIG. 3 are schematic diagrams of a conventional method for manufacturing a micro-rotating shaft.

图4至图8为本发明的一优选实施例制作微旋转轴的方法示意图。简单符号说明4 to 8 are schematic diagrams of a method for manufacturing a micro-rotating shaft according to a preferred embodiment of the present invention. simple notation

10        微旋转轴              20        晶片10 Micro Rotation Axis 20 Wafer

22        蚀刻停止层            24        光致抗蚀剂图案22 Etch stop layer 24 Photoresist pattern

26        底切                  50        晶片26Undercuts 50 Wafers

52        光致抗蚀剂图案        54        旋转轴区52Photoresist pattern 54 Rotation axis area

56        粘着层                58        负载载具56Adhesive layer 58 Load carrier

60        光致抗蚀剂图案        62        穿透区60Photoresist Pattern 62 Penetration Area

具体实施方式Detailed ways

请参考图4至图8，图4至图8为本发明的一优选实施例制作微旋转轴的方法示意图。如图4所示，首先提供一晶片50，例如一硅晶片，并于晶片50的底表面形成一光致抗蚀剂图案52，以定义出一旋转轴区54的位置。如图5所示，接着进行一蚀刻制造工艺，例如一反应性离子蚀刻(reactive ionetching，RIE)，利用光致抗蚀剂图案52作为一硬屏蔽，去除位于旋转轴区54的晶片50至一预定深度。其中上述预定深度必须大于后续由晶片50的上表面进行的另一蚀刻制造工艺的变异量与晶片50厚度的变异量的总和，以避免微旋转轴的结构于后续蚀刻制造工艺中损坏。Please refer to FIG. 4 to FIG. 8 . FIG. 4 to FIG. 8 are schematic diagrams of a method for manufacturing a micro-rotating shaft according to a preferred embodiment of the present invention. As shown in FIG. 4 , awafer 50 such as a silicon wafer is firstly provided, and aphotoresist pattern 52 is formed on the bottom surface of thewafer 50 to define the position of arotation axis region 54 . As shown in FIG. 5, an etching manufacturing process, such as a reactive ion etching (RIE), is then performed, using thephotoresist pattern 52 as a hard mask to remove thewafer 50 located in therotation axis region 54 to a Scheduled depth. The predetermined depth must be greater than the sum of the variance of another etching process performed on the upper surface of thewafer 50 and the variance of the thickness of thewafer 50, so as to avoid damage to the structure of the micro-rotation axis in the subsequent etching process.

如图6所示，接着去除光致抗蚀剂图案(图未示)，并利用一粘着层56将晶片50的底表面接合于一负载载具58上。随后再于晶片50的上表面形成另一光致抗蚀剂图案60，以定义出二穿透区62的位置。其中粘着层56可选用光致抗蚀剂、金属、二氧化硅、苯环丁烯(Benzocyclobutene，BCB)、聚亚酰胺(polyimide)、二氧化硅、金属、胶带、UV胶带或腊等可利用湿蚀刻、加热或照光方式去除的材料。负载载具58则可为硅、玻璃、石英或陶瓷等相容于半导体制造工艺的材料。As shown in FIG. 6 , the photoresist pattern (not shown) is then removed, and anadhesive layer 56 is used to bond the bottom surface of thechip 50 to acarrier 58 . Then anotherphotoresist pattern 60 is formed on the upper surface of thewafer 50 to define the positions of the twopenetration regions 62 . Wherein theadhesive layer 56 can be selected from photoresist, metal, silicon dioxide, benzocyclobutene (Benzocyclobutene, BCB), polyimide (polyimide), silicon dioxide, metal, tape, UV tape or wax, etc. Material removed by wet etching, heat, or light. Theload carrier 58 can be made of silicon, glass, quartz or ceramics, which are compatible with the semiconductor manufacturing process.

如图7，接着进行另一蚀刻制造工艺，例如一反应性离子蚀刻制造工艺，利用光致抗蚀剂图案60作为一硬屏蔽，去除位于穿透区62内的晶片50。其中当蚀刻制造工艺进行至图7所示的深度时，位于旋转轴区54的晶片会呈现悬浮状态，而此时蚀刻总面积的最大变化量仅为穿透区62内的晶片面积扣除旋转轴区54内的晶片面积，因此蚀刻总面积并不会产生剧烈变化而使蚀刻制造工艺产生无法预期的变化。除此之外，由于此时尚未蚀刻至粘着层56，因此位于旋转轴区54内的晶片50亦不会产生侧蚀的现象。另外，于本实施例中第一次蚀刻制造工艺中的光致抗蚀剂图案(图未示)所定义出的旋转轴区的尺寸略大于微旋转轴的实际尺寸，藉此可增加第二次蚀刻制造工艺的定位容忍度，藉此后续形成的微旋转轴的形状与尺寸可具有优选的准确性。As shown in FIG. 7 , another etching process, such as a reactive ion etching process, is performed, using thephotoresist pattern 60 as a hard mask to remove thewafer 50 located in thepenetration region 62 . Wherein, when the etching manufacturing process proceeds to the depth shown in FIG. 7 , the wafer located in therotation axis region 54 will appear in a suspended state, and at this time, the maximum change in the total etching area is only the area of the wafer in thepenetration region 62 minus the rotation axis. The area of the wafer in thearea 54, therefore, the total etching area will not change drastically and cause unpredictable changes in the etching process. In addition, since theadhesive layer 56 has not been etched yet, thewafer 50 located in therotation axis area 54 will not be undercut. In addition, in this embodiment, the size of the rotation axis region defined by the photoresist pattern (not shown) in the first etching manufacturing process is slightly larger than the actual size of the micro rotation axis, thereby increasing the second The positioning tolerance of the sub-etch manufacturing process, whereby the shape and size of the subsequently formed micro-rotation shaft can have optimal accuracy.

如图8所示，继续进行蚀刻制造工艺直至蚀穿位于穿透区62内的晶片50为止，并将晶片50上表面的光致抗蚀剂图案60与下表面的粘着层56移除即完成微旋转轴的制作。值得注意的是粘着层56除了粘着晶片50与负载载具58的功能外，亦具有蚀刻停止层的功能，当蚀刻进行至粘着层56时，蚀刻总面积会产生较大的变化，并有可能产生侧蚀现象，然而由于位于旋转轴区54内的晶片50呈悬浮状态，且于第一次蚀刻制造工艺时于旋转轴区54所蚀刻的预定深度即将此次蚀刻制造工艺的变异量与晶片50厚度的变异量考虑在内，因此旋转轴区54内的晶片50不会受到影响。换句话说，微旋转轴的结构不会受到蚀刻制造工艺的变异量的影响，而具有如原先预期的形状，因此具有良好的可靠性。As shown in FIG. 8 , continue the etching process until thewafer 50 located in thepenetration region 62 is etched through, and thephotoresist pattern 60 on the upper surface of thewafer 50 and theadhesive layer 56 on the lower surface are removed to complete the process. Fabrication of the micro-rotating shaft. It should be noted that in addition to the function of bonding thewafer 50 and theload carrier 58, theadhesive layer 56 also has the function of an etching stop layer. When the etching is carried out to theadhesive layer 56, the total etching area will change greatly, and it is possible Undercut phenomenon occurs, but because thewafer 50 in therotation axis region 54 is in a suspended state, and the predetermined depth etched in therotation axis region 54 during the first etching manufacturing process is about the variance of this etching manufacturing process and the wafer. The variation in the thickness of thewafer 50 is taken into account so that thewafer 50 within therotational axis region 54 is not affected. In other words, the structure of the micro-rotating shaft is not affected by the variation amount of the etching manufacturing process, but has a shape as originally expected, and thus has good reliability.

相比于现有技术，本发明的方法利用双面蚀刻方式来制作微旋转轴结构，可有效避免于蚀刻制造工艺中蚀刻总面积变化过大造成蚀刻结果不易控制，以及蚀刻至蚀刻停止层时易发生的侧蚀问题，因此可确保微旋转轴具有良好结构，进而提升微旋转轴的可靠性与可承受的应力。Compared with the prior art, the method of the present invention uses a double-sided etching method to manufacture the micro-rotation shaft structure, which can effectively avoid the difficulty in controlling the etching result due to excessive changes in the total etching area in the etching manufacturing process, and when etching reaches the etching stop layer. The side erosion problem is easy to occur, so it can ensure that the micro-rotation shaft has a good structure, thereby improving the reliability and withstand stress of the micro-rotation shaft.

以上所述仅为本发明的优选实施例，凡依本发明权利要求所做的均等变化与修饰，皆应属本发明专利的涵盖范围。The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (11)

1. the method for a two-sided etched wafer, it comprises:

One wafer is provided, and this wafer comprises at least one first area and at least one second area, and the area of this first area is less than the area of this second area, and this second area partially overlaps this first area;

Carry out one first photoetching corrosion manufacturing process, remove this wafer to one predetermined depth that is positioned at this first area by a first surface of this wafer;

This first surface of this wafer is attached on the load carrier;

Carry out one second photoetching corrosion manufacturing process, by a second surface of this wafer remove be positioned at this second area but do not comprise be positioned at this first area this wafer until this wafer of eating thrown.

2. the method for claim 1, wherein this first area and this second area are in order to define a little revolute axes configuration.

3. the method for claim 1, wherein this first photoetching corrosion manufacturing process comprises:

This first surface in this wafer forms one first photoresist pattern, and this first photoresist pattern exposes this first area;

By this first surface etching not by this wafer of this first photoresist pattern covers to this predetermined depth, and this predetermined depth is greater than the summation of the amount of variability of the amount of variability of follow-up this second photoetching corrosion manufacturing process of carrying out and this wafer thickness; And

Remove this first photoresist pattern.

4. the method for claim 1, wherein this first surface of this wafer utilizes an adhesive coating to be attached on this load carrier.

5. the method for claim 1, wherein this second photoetching corrosion manufacturing process comprises:

This second surface in this wafer forms one second photoresist pattern, and this second photoresist pattern exposes this not overlapping with this first area second area;

Not by this wafer of this second photoresist pattern covers, and stop at this adhesive coating by this second surface eating thrown; And

Remove this second photoresist pattern.

6. the method for claim 1 also is included in and carries out a step that removes this adhesive coating after this second photoetching corrosion manufacturing process.

7. method of making little turning axle, it comprises:

One wafer is provided, and this wafer comprises at least one turning axle district and at least two penetrating regions, and this two penetrating region is positioned at two sides in this turning axle district;

First surface by this wafer is removed this wafer that part is positioned at this turning axle district; And

Second surface removal by this wafer is positioned at this wafer of this two penetrating region until penetrating this wafer.

8. method as claimed in claim 7, this wafer that wherein is positioned at this turning axle district utilizes etching mode to be removed.

9. method as claimed in claim 7, this wafer that wherein is positioned at this two penetrating region utilizes etching mode to be removed.

10. method as claimed in claim 7, wherein when removal was positioned at this wafer of this penetrating region, this first surface of this wafer utilized an adhesive coating to be attached on the load carrier.

11. method as claimed in claim 10 also is included in to remove and carries out a step that removes this adhesive coating behind this wafer be positioned at this penetrating region.

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