CN119571450B - MOCVD reaction chamber and ceilling level adjusting method thereof - Google Patents

Abstract

The invention provides an MOCVD reaction chamber and a lifting level adjusting method thereof, which belong to the field of chemical deposition, wherein top plates are arranged right below a top cover at intervals, adjusting parts are uniformly distributed between the top plate and the top cover around the center of the surface of the top plate, each adjusting part applies acting force along the vertical direction of the surface of the top cover and adjusts the distance between the top plate and the top cover at the position of the adjusting part, a detecting part is arranged on the edge of the top plate and detects the distance between the top plate and the top cover at the position of the detecting part in real time, and a control part controls the acting force applied by the adjusting part according to detection data of the detecting part. According to the invention, whether the top plate is horizontal or not is determined by the detection part, the adjustment part is controlled to adjust the horizontal condition of the top plate according to the collected detection data, and upward or downward acting force is applied to the top plate by the adjustment parts distributed at all directions of the edge of the top plate so as to offset the horizontal unbalance of the top plate caused by the deformation of the edge of the top plate, thereby solving the negative influence of the non-horizontal surface of the top plate in the deposition process.

Description

MOCVD reaction chamber and ceilling level adjusting method thereof

Technical Field

The invention relates to the technical field of chemical deposition, in particular to an MOCVD reaction chamber and a ceilling level adjusting method thereof.

Background

MOCVD (Metal-Organic Chemical Vapor Deposition, metal organic chemical vapor deposition) reaction chambers are important devices for achieving high quality thin film deposition. The reaction chamber is the core of the MOCVD system, and is typically made of stainless steel or other highly corrosion resistant materials to withstand high temperatures and corrosive gases. The reaction chamber is designed to ensure uniformity of gas flow and uniformity of deposition. The existing MOCVD reaction chamber (also called as a reaction chamber top plate) is generally designed as an annular disc, and is fixed on the upper part of the reaction chamber, and the fixed point is a center region of the reaction chamber. The center of the lower surface of the Ceiling is provided with an air inlet component, the air inlet component throws out the reaction gas and the MO source along the periphery in a parabolic mode during operation, a region for uniformly receiving reactants is formed below the Ceiling, and a substrate is placed in the region for epitaxial growth. A more stable epitaxial growth environment can be formed under normal conditions.

However, in the existing reaction chamber design, the top plate has the problems that 1) due to the influence of self gravity of the ceilings, the sagging offset of the edges of the ceilings is more than that of the centers, 2) after the multi-furnace epitaxial growth, the deposition on the ceilings surface is increased, due to the influence of the tensile stress of the deposition, the sagging offset of the ceilings near the outside is increased, the ceilings are in the shape of a reverse pot bottom, thereby increasing the RUN number along with the epitaxial growth, the deposition on the edges of the ceilings is more than that at other positions of the ceilings, byproducts are concentrated at the edges of the ceilings, the ceilings are further aggravated, and 3) when the byproducts are concentrated and accumulated to a certain thickness at the edges of the ceilings, the ceilings are easy to fall off, and the epitaxial quality below is seriously affected.

Therefore, the lower surface of the lifting is usually cleaned after multi-furnace epitaxial growth to remove surface sediment, but the problem that the horizontal state of the lifting surface is unbalanced due to sagging deformation of the lifting edge is still difficult to solve.

Disclosure of Invention

In view of this, the invention provides an MOCVD reaction chamber and a method for adjusting the horizontal state of the ceilling surface, which are used for solving the problem that the horizontal state of the ceilling surface is unbalanced due to sagging deformation of the ceilling edge of the existing reaction chamber.

The technical scheme is that the MOCVD reaction chamber comprises a top cover, a top plate, a plurality of adjusting parts, a detecting part and a control part, wherein the top cover is arranged at the top of the MOCVD reaction chamber, the top plate is arranged right below the top cover at intervals, the adjusting parts are uniformly distributed between the top plate and the top cover around the center of the surface of the top plate, two ends of each adjusting part are respectively connected with the top cover and the edge of the top plate, each adjusting part applies acting force along the vertical direction of the surface of the top cover, the distance between the top plate and the top cover at the position of the adjusting part is adjusted, the detecting part is arranged on the edge of the top plate and detects the distance between the top plate and the top cover at the position of the detecting part in real time, and the control part controls the acting force applied by the adjusting part according to detection data of the detecting part.

On the basis of the technical scheme, the detection part preferably comprises a plurality of detection units which are uniformly distributed on the edge of the end face of the top plate, which faces the top cover, around the center of the surface of the top plate, wherein each detection unit and each adjustment part are arranged on the same radial axis of the top plate in a one-to-one correspondence manner.

Still more preferably, the device further comprises a ring body arranged on the end face of the top plate facing the top cover, wherein the center of the ring body and the center of the top plate are coaxially arranged, and a plurality of adjusting parts are uniformly distributed on the ring body and synchronously apply acting force.

Still more preferably, the control unit controls the adjusting unit to apply the force according to the detection data of the detecting unit according to a calculation formula of n=1/(a×m×g×k) +n₀, where a is the number of detecting units, m is the mass of the top plate, g is the gravitational acceleration, K is the deformation distance coefficient of the top plate, which is a coefficient corresponding to an absolute value Δh of a difference between an initial distance h₀ from the top cover when the top plate is installed and leveled and a measured distance h₁ from the top cover after the top plate is deformed, and N₀ is the compensation force for leveling when the top plate is installed.

Still more preferably, the absolute value of Δh is less than 5mm, and each 0.5mm in the absolute value of Δh is set as a value range, the absolute value of Δh comprises n value ranges, and the deformation distance coefficient corresponding to each value range of Δh is k=0.1n.

Still more preferably, the system alarms and replaces the top plate when the absolute value of Δh is > 5mm.

Still more preferably, K takes a negative value when h₀＞h₁ and takes a positive value when h₀＜h₁.

Still more preferably, the force applied by the adjusting portion is a pushing force in the direction of the top cover or a pulling force in the direction of the top plate, and the force applied by the adjusting portion is a pushing force when h₀＞h₁ and a pulling force when h₀＜h₁.

Still more preferably, the value interval of a is a positive integer from 4 to 16.

On the other hand, the invention provides a lifting level adjusting method of an MOCVD reaction chamber, which comprises the following steps of firstly detecting the initial distance h₀ between a top plate and a top cover by a detecting part in a top plate installation leveling state, secondly detecting the measured distance h₁ between the top plate and the top cover by the detecting part in a top plate deformation state, thirdly controlling the adjusting part to apply pushing force to the top plate by the control part when judging h₀＞h₁, and controlling the pulling force to be applied to the top plate by the control part when judging h₀＜h₁ by the control part.

Compared with the prior art, the MOCVD reaction chamber and the ceiling level adjusting method have the following beneficial effects:

(1) The invention determines whether the top plate is horizontal or not through the detection part, and feeds back detection information to the control part, so that the control part can control the adjustment part to adjust the horizontal condition of the top plate according to the collected detection data, and the adjustment part distributed at each direction of the edge of the top plate can apply upward or downward acting force to the top plate so as to offset the horizontal unbalance of the top plate caused by the deformation of the edge of the top plate, thereby solving the negative influence of the top plate caused by the non-horizontal surface in the deposition process and enabling the airflow field to be more balanced during the growth in the reaction chamber.

(2) This patent makes it adjusted to the horizontality through real-time adjustment roof, guarantees that the roof surface is in the horizontality in the growth process, guarantees that the environment is stable in the epitaxial growth process, reduces the concentrated gathering of accessory substance at the roof edge, and makes the accessory substance more even on the roof to reduce accessory substance and drop and improve epitaxial wafer appearance quality.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a method for adjusting the swing level of a MOCVD reaction chamber according to the present invention;

FIG. 2 is a schematic structural view of another embodiment of the MOCVD reaction chamber according to the present invention;

FIG. 3 is a schematic diagram of a control unit connection adjustment unit and a detection unit according to the present invention;

FIG. 4 is a top view of the top plate of the present invention;

fig. 5 is a top view of another embodiment of the top plate of the present invention.

In the figure, 1, a top cover 2, a top plate, 3, an adjusting part, 4, a detecting part, 41, a detecting unit, 5, a control part and 6, and a ring body.

Detailed Description

The following description of the embodiments of the present invention will clearly and fully describe the technical aspects of the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.

Referring to fig. 1, in conjunction with fig. 3, the MOCVD reactor of the present invention includes a top cover 1, a top plate 2, an adjusting part 3, a detecting part 4, and a control part 5.

Wherein, top cap 1 sets up at MOCVD reaction chamber top. The top cover 1 is generally made of an alloy material which is not easily changed in rigidity and thermal stability.

The top plate 2 is arranged right below the top cover 1 at intervals. A component is connected between the top plate 2 and the top cover 1, and the component is cylindrical. The top plate 2 is a reaction chamber, and is typically made of graphite, quartz, or the like. The center of the lower surface of the top plate 2 is provided with a conveying mechanism which bears the conveying functions of gas, MO sources and the like in the reaction chamber.

The adjusting parts 3 are uniformly distributed between the top plate 2 and the top cover 1 around the center of the surface of the top plate 2, and the adjusting parts 3 can be telescopic air rods, hydraulic cylinders or hydraulic rods. Since the deformation of the edge portion of the top plate 2 is more obvious, the two ends of the adjusting portion 3 are respectively connected with the top plate 1 and the edge of the top plate 2, the adjusting portions 3 apply force along the vertical direction of the surface of the top plate 1, and the adjusting portion 3 can basically change the applied force by stretching in the length direction, so that the distance between the top plate 2 and the top plate 1 at the position of the adjusting portion 3 is adjusted.

The detecting part 4 is arranged on the edge of the top plate 2 and detects the distance between the top plate 2 and the top cover 1 at the position of the detecting part in real time. The detection section 4 may employ a photosensor, and the distance detection is realized by a light emitting and reflecting light receiving device.

The control unit 5 controls the amount of force applied by the adjustment unit 3 based on the detection data of the detection unit 4. The control part 5 can be a singlechip or a PCB board, has the functions of data receiving and data processing and controlling the opening and closing of the regulating part 3, and is electrically connected with the detecting part 4 and the regulating part 3.

After the multi-furnace epitaxial growth, a layer of sediment with a stable structure, namely a coating layer, is formed on the lower surface of the top plate 2, has a certain tensile stress, and the influence of gravity of the top plate 2 is superposed, so that the edge of the top plate 2 is obviously deformed downwards, and the reaction gas and byproducts formed by MO aggregation are easily formed at the position, close to the edge, of the top plate 2 in the epitaxial growth process, and can refer to the shadow part positioned on the lower graph in fig. 1. After the technical scheme is adopted, after the detecting part 4 detects that the distance between the edge of the top plate 2 and the top cover 1 is changed, the control part 5 drives the adjusting part 3 to shrink to apply upward tension to the top plate 2, the edge deformation of the top plate 2 is leveled under the action of the tension to enable the lower surface of the top plate 2 to return to the state of the horizontal surface again, thereby eliminating the negative influence of the top plate 1 caused by horizontal unbalance, and enabling the airflow field to be more balanced during the growth in the reaction chamber.

In a preferred embodiment shown in fig. 4, the detecting unit 4 includes a detecting unit 41 in order to accurately detect deformation of each portion of the top plate 2.

The detection units 41 are uniformly distributed on the edge of the end face of the top plate 2, which faces the top cover 1, around the center of the surface of the top plate 2, and the detection units 41 and the adjustment parts 3 are arranged on the same radial axis of the top plate 2 in a one-to-one correspondence manner. When the edge of the top plate 2 at the position where the detecting unit 41 is located is deformed downwards, the distance between the edge of the top plate 2 at the position and the top cover 1 is changed, the distance change can be accurately detected by the detecting unit 41, different distance changes occur at different edge positions of the top plate 2, and the detecting unit 41 at the corresponding position can accurately detect.

In a preferred embodiment shown in fig. 2 and 5, the deposition of the edge portions of the top plate 2 is substantially uniform and the entire edge of the top plate 2 is deformed downward, because the reaction gas is uniformly sprayed to the periphery by the conveying mechanism on the lower surface of the top plate 2. Thus, the present embodiment also includes a ring body 6.

The top plate comprises a top plate 2, a top cover 1, a top cover 6, a plurality of adjusting parts 3, a ring body 6 and a plurality of adjusting parts 3, wherein the ring body 6 is arranged on the end face of the top plate 2 facing the top cover 1, the center of the ring body 6 is coaxially arranged with the center of the top plate 2, the maximum outer diameter of the ring body 6 is as close to the edge contour of the top plate 2 as possible, and the adjusting parts 3 are uniformly distributed on the ring body 6 and synchronously apply acting force, so that the whole edge of the top plate 2 can be pulled up more consistently, and the lower surface of the top plate 2 is better in horizontal condition.

In a preferred embodiment shown in fig. 1, the control section 5 controls the adjusting section 3 to apply the force according to the detection data of the detecting section 4 by the calculation formula,

N=1/(a×m×g×K)+N₀,

Where a is the number of detection units 41, m is the mass of the top plate 2, g is the gravitational acceleration.

K is a deformation distance coefficient of the top plate 2, which is expressed as a coefficient corresponding to an absolute value Δh of a difference between an initial distance h₀ from the top cover 1 when the top plate 2 is installed and leveled and a measured distance h₁ from the top cover 1 after the top plate 2 is deformed. The calculation formula of the distance between the top plate 2 and the top cover 1 is that,

h=t×c/2,

Where t is the time from the emission of light to the reception of reflected light by the detection unit 41 as a photosensor, and c is the speed of light.

N₀ is the compensation force of leveling when the top plate 2 is installed, and is related to the natural level degree when the top plate 2 is installed for the first time, specifically is the upward pulling force for compensating the top plate 2 against the influence of gravity after the first installation, or is the downward pushing force which needs to be applied by people because the natural upward deformation is larger when the top plate 2 is installed for the first time, so N₀ is a manual set value at the moment.

In a preferred embodiment shown in fig. 1, specifically, the absolute value of Δh is <5mm, a range of values is set for every 0.5mm in the absolute values of Δh, the absolute values of Δh include n ranges of values, and the deformation distance coefficient corresponding to each range of values of Δh is,

K=0.1n,

For example, K takes on a value of 0.2 when the absolute value of Δh is 0-0.5mm, 0.3 when the absolute value of Δh is 0.5-1mm, 0.4 when the absolute value of Δh is 1-1.5 mm. Different deformation conditions of the edges of the top plate 2 correspond to different deformation distance coefficients K of the top plate 2.

In a preferred embodiment shown in fig. 1, when the absolute value of Δh is >5mm, it represents excessive accumulation of byproducts on the top plate 2, so the control section 5 systematically alarms, alerting the operator to replace the top plate 2 or to perform maintenance on the top plate 2.

In a preferred embodiment shown in fig. 1, since the edge of the top plate 2 is deformed upward or downward according to circumstances, specifically, K takes a negative value when h₀＞h₁, and the edge of the top plate 2 is deformed upward, and K takes a positive value when h₀＜h₁, and the edge of the top plate 2 is deformed downward.

In a preferred embodiment shown in fig. 1, the force applied by the adjusting part 3 is a pushing force in the direction of the top cover 1 or a pulling force in the direction of the top plate 2, where N is a positive number, and the force applied by the adjusting part 3 is a pushing force when h₀＞h₁ and the force applied by the adjusting part 3 is a pulling force when h₀＜h₁, where N is a negative number. From practical experience, N may take a negative value, except when new or clean ceilings are installed, which is generally a positive value.

In a preferred embodiment shown in fig. 4, the value of a is related to the number of the detecting units 41, the value interval of a is a positive integer from 4 to 16, the number of detecting units 41 is too small to accurately and effectively detect the deformation condition of the whole edge of the top plate 2, and too many detecting units 41 are not beneficial to each adjusting part 3 to accurately control the reset of the edge of a certain part of the top plate 2.

Referring to fig. 1, in combination with fig. 3, a method for adjusting a swing level of an MOCVD reactor according to the present invention, which adopts an MOCVD reactor according to any of the above embodiments, includes the following steps.

In the first step, in the state where the top plate 2 is mounted and leveled, the detection unit 4 detects the initial distance h₀ of the top plate 2 from the top cover 1.

In the second step, the detecting unit 4 detects the distance h₁ between the top plate 2 and the top cover 1 in the deformed state of the top plate 2.

In the third step, when the control unit 5 determines h₀＞h₁, the control unit 5 controls the adjustment unit 3 to apply a pushing force to the top plate 2, and when the control unit 5 determines h₀＜h₁, the control unit 5 controls the adjustment unit 3 to apply a pulling force to the top plate 2.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims (8)

Translated fromChinese

1.一种MOCVD反应室，其特征在于，包括：1. A MOCVD reaction chamber, comprising:顶盖（1），设置在MOCVD反应室顶部；A top cover (1) is arranged on the top of the MOCVD reaction chamber;顶板（2），间隔设置在所述顶盖（1）正下方；A top plate (2) arranged at a distance just below the top cover (1);若干调节部（3），环绕所述顶板（2）表面中心均布在顶板（2）与顶盖（1）之间，所述调节部（3）两端分别连接顶盖（1）及顶板（2）边缘，各所述调节部（3）沿顶盖（1）表面的垂直方向施加作用力，并调整所述调节部（3）所在位置的顶板（2）与顶盖（1）的间距；A plurality of adjusting parts (3) are evenly distributed around the center of the surface of the top plate (2) and between the top plate (2) and the top cover (1), the two ends of the adjusting parts (3) are respectively connected to the edge of the top cover (1) and the top plate (2), and each of the adjusting parts (3) applies a force in a vertical direction along the surface of the top cover (1) and adjusts the distance between the top plate (2) and the top cover (1) at the position where the adjusting parts (3) are located;检测部（4），设置在所述顶板（2）边缘上并实时检测其所在位置的顶板（2）与顶盖（1）的间距；A detection unit (4) is arranged on the edge of the top plate (2) and detects in real time the distance between the top plate (2) and the top cover (1) at its location;控制部（5），根据所述检测部（4）的检测数据控制调节部（3）施加作用力的大小；A control unit (5) controls the magnitude of the force applied by the adjustment unit (3) according to the detection data of the detection unit (4);其中，所述检测部（4）包括，Wherein, the detection unit (4) comprises:若干检测单元（41），环绕所述顶板（2）表面中心均布在顶板（2）朝向顶盖（1）的端面边缘上；A plurality of detection units (41) are evenly distributed around the center of the surface of the top plate (2) and on the edge of the end surface of the top plate (2) facing the top cover (1);其中，各所述检测单元（41）与各调节部（3）一一对应设置在顶板（2）的同一径向轴线上；Wherein, each of the detection units (41) and each of the adjustment parts (3) are arranged on the same radial axis of the top plate (2) in a one-to-one correspondence;所述控制部（5）根据检测部（4）的检测数据控制调节部（3）施加作用力大小的计算公式为，The control unit (5) controls the adjustment unit (3) to apply a force according to the detection data of the detection unit (4). The calculation formula is:N=1/（a×m×g×K）＋N₀，N=1/(a×m×g×K)+N₀ ,其中，a为所述检测单元（41）的数量；m为所述顶板（2）的质量；g为重力加速度；K为所述顶板（2）的形变距离系数，其表示为所述顶板（2）安装调平时距离顶盖（1）的初始距离h₀与顶板（2）形变后距离顶盖（1）的测得距离h₁的差值的绝对值Δh所对应的系数；N₀为所述顶板（2）安装时调平的补偿力。Wherein, a is the number of the detection units (41); m is the mass of the top plate (2); g is the gravitational acceleration; K is the deformation distance coefficient of the top plate (2), which is expressed as the coefficient corresponding to the absolute value Δh of the difference between the initial distance_h0 of the top plate (2) from the top cover (1) when the top plate (2) is installed and leveled and the measured distance h1 of the top plate (₂ ) from the top cover (1) after deformation; and_N0 is the compensation force for leveling the top plate (2) when it is installed.2.根据权利要求1所述的一种MOCVD反应室，其特征在于，还包括：2. The MOCVD reaction chamber according to claim 1, further comprising:环体（6），设置在所述顶板（2）朝向顶盖（1）的端面上；A ring body (6) is arranged on the end surface of the top plate (2) facing the top cover (1);其中，所述环体（6）中心与顶板（2）中心同轴设置；若干所述调节部（3）均布在环体（6）上并同步施加作用力。The center of the ring body (6) is coaxially arranged with the center of the top plate (2); and a plurality of the adjusting parts (3) are evenly distributed on the ring body (6) and apply force synchronously.3.根据权利要求1所述的一种MOCVD反应室，其特征在于：Δh的绝对值＜5mm；设Δh绝对值中每0.5mm为一个取值范围，Δh绝对值包括n个取值范围，每个Δh绝对值的取值范围对应的形变距离系数为，3. The MOCVD reaction chamber according to claim 1, characterized in that: the absolute value of Δh is less than 5 mm; assuming that every 0.5 mm in the absolute value of Δh is a value range, the absolute value of Δh includes n value ranges, and the deformation distance coefficient corresponding to each value range of the absolute value of Δh is,K=0.1n。K=0.1n.4.根据权利要求3所述的一种MOCVD反应室，其特征在于：当Δh的绝对值＞5mm时，系统报警并更换所述顶板（2）。4. The MOCVD reaction chamber according to claim 3, characterized in that when the absolute value of Δh is greater than 5 mm, the system alarms and replaces the top plate (2).5.根据权利要求3所述的一种MOCVD反应室，其特征在于：当h₀＞h₁时，K取负值；当h₀＜h₁时，K取正值。5 . The MOCVD reaction chamber according to claim 3 , wherein when h₀ >h₁ , K takes a negative value; and when h₀ <h₁ , K takes a positive value.6.根据权利要求1所述的一种MOCVD反应室，其特征在于：所述调节部（3）施加的作用力为朝向顶盖（1）方向的推力或者朝向顶板（2）方向的拉力；当h₀＞h₁时，所述调节部（3）施加的作用力为推力，当h₀＜h₁时，所述调节部（3）施加的作用力为拉力。6. An MOCVD reaction chamber according to claim 1, characterized in that: the force applied by the adjusting portion (3) is a thrust in the direction of the top cover (1) or a pull in the direction of the top plate (2); when_h0 >_h1 , the force applied by the adjusting portion (3) is a thrust, and when_h0 <_h1 , the force applied by the adjusting portion (3) is a pull.7.根据权利要求1所述的一种MOCVD反应室，其特征在于：a取值区间为4至16的正整数。7. The MOCVD reaction chamber according to claim 1, wherein the value of a is a positive integer ranging from 4 to 16.8.一种MOCVD反应室的ceiling水平调节方法，其特征在于：采用权利要求1至7任意一项所述的一种MOCVD反应室，包括以下步骤，8. A method for adjusting the ceiling level of a MOCVD reaction chamber, characterized in that: using a MOCVD reaction chamber as claimed in any one of claims 1 to 7, comprising the following steps:步骤一，在所述顶板（2）安装调平状态下，所述检测部（4）检测出顶板（2）距离顶盖（1）的初始距离h₀；Step 1: when the top plate (2) is installed and leveled, the detection unit (4) detects an initial distance h₀ between the top plate (2) and the top cover (1);步骤二，在所述顶板（2）形变状态下，所述检测部（4）检测出顶板（2）距离顶盖（1）的测得距离h₁；Step 2: when the top plate (2) is in a deformed state, the detection unit (4) detects a measured distance h₁ between the top plate (2) and the top cover (1);步骤三，所述控制部（5）判断h₀＞h₁时，所述控制部（5）控制调节部（3）向顶板（2）施加推力；所述控制部（5）判断h₀＜h₁时，所述控制部（5）控制调节部（3）向顶板（2）施加拉力。Step three: when the control unit (5) determines that h₀ >h₁ , the control unit (5) controls the adjustment unit (3) to apply a thrust to the top plate (2); when the control unit (5) determines that h₀ <h₁ , the control unit (5) controls the adjustment unit (3) to apply a pulling force to the top plate (2).