Ceramic ring in a pecvd apparatus structure

Abstract

The application discloses a ceramic ring in a PECVD equipment structure and relates to the technical field of PECVD films, which comprises a gas cabinet, a top plate is arranged on the lower side of the gas cabinet, a gas distribution plate is arranged on the lower side of the top plate, a pump ring is arranged on the lower side of the gas distribution plate, a sliding block is arranged on the pump ring, a ceramic ring is arranged on the lower side of the pump ring, a heating plate is arranged on the lower side of the ceramic ring, and an inner cavity and an outer cavity are arranged in the heating plate. The gas cabinet cooperates with the gas distribution plate to control the gas dispersibility and deviation, improves the film uniformity, makes the vertical gas speed reaching the wafer surface tend to be uniform, and the ceramic ring and the exhaust ring are both provided with exhaust holes, the exhaust holes play the role of exhaust, and can prevent excessive gas escape. The position of the exhaust hole of the ceramic ring and the distribution of the sealing of the hole are adjusted, the phenomenon of uneven gas flow rate, overall deviation of the speed center and different film coating rates and uneven thickness is solved.

Description

TECHNICAL FIELD

[0001] The application relates to the PECVD film technology field, in particular to a ceramic ring in a PECVD equipment structure. BACKGROUND

[0002] The gas flow rate perpendicular to the wafer surface in the PECVD process cavity is subjected to finite element analysis. Real parameters such as temperature in the real reaction cavity are input to simulate the cavity flow field, temperature field and wafer surface speed uniformity. The ceramic ring is a gas outflow channel after reaction, the holes on the traditional ceramic ring are uniformly distributed channels, and the reacted gas is discharged from one side of the exhaust port after passing through each channel. Because the exhaust hole only exists on one side of the system, the center of the combined speed of the reaction gas reaching the wafer surface is not always in the center, which greatly affects the overall film thickness uniformity. Therefore, the technical personnel in the field provide a ceramic ring in a PECVD equipment structure to solve the problems in the background technology. SUMMARY

[0003] The purpose of the present application is to provide a ceramic ring in a PECVD equipment structure to solve the problems in the background technology.

[0004] To achieve the above purpose, the present application provides the following technical scheme:

[0005] A ceramic ring in a PECVD equipment structure, comprising a gas cabinet, the lower side of the gas cabinet is provided with a top plate, the lower side of the top plate is provided with a uniform gas disc, the lower side of the uniform gas disc is provided with a pump ring, the pump ring is provided with a sliding block, the lower side of the pump ring is provided with a ceramic ring, the lower side of the ceramic ring is provided with a heating disc, and the inside of the heating disc is provided with an inner cavity and an outer cavity.

[0006] As a further scheme of the present application: wherein the pump ring is provided with two groups of sliding channels, the sliding channels are slidably connected with sliding blocks, and the sliding blocks are provided with limiting rods.

[0007] As a further scheme of the present application: wherein the outer side of the ceramic ring is provided with an exhaust ring, and a plurality of exhaust holes are formed in the exhaust ring.

[0008] As a further scheme of the present application: wherein a wafer is arranged at the connection between the heating disc and the ceramic ring.

[0009] As a further scheme of the present application: wherein the outer side of the ceramic ring is coated with a Y2O3 coating.

[0010] As a further scheme of the present application: wherein the number of the exhaust holes is 40-50, the angle of the exhaust holes is 7-12 degrees, and the diameter of the exhaust holes is 5-10 mm.

[0011] Compared with the prior art, the present application has the beneficial effects of:

[0012] The gas cabinet cooperates with the gas distribution plate to control the gas dispersibility and deviation, plays a role in improving the film uniformity, makes the vertical gas velocity reaching the wafer surface tend to be uniform, and the exhaust holes are arranged on the ceramic ring and the exhaust ring, the exhaust holes play a role in exhausting, and can prevent excessive escape of the gas, the above structure solves the problems of non-uniform gas flow rate, overall deviation of the speed center, and further causes different film coating rates and uneven thickness by adjusting the position and hole sealing distribution of the ceramic ring exhaust holes. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a schematic diagram of the gas cabinet structure in the present application;

[0014] Figure 2 It is a schematic diagram of the overall structure in the present application;

[0015] Figure 3 It is a schematic diagram of the overall structure in the present application;

[0016] Figure 4 It is a schematic diagram of the gas velocity distribution of the inner cavity and the outer cavity when the center line position of the exhaust hole is located on the upper side of the wafer in the present application;

[0017] Figure 5 It is a schematic diagram of the gas velocity distribution of the inner cavity and the outer cavity when the center line position of the exhaust hole is located on the lower side of the wafer in the present application;

[0018] Figure 6 It is a schematic diagram of the theoretical curve in the present application;

[0019] Figure 7 It is a schematic diagram before adjusting the exhaust hole density in the present application;

[0020] Figure 8 It is a schematic diagram after adjusting the exhaust hole density in the present application;

[0021] The corresponding relationship between the annotations of the various drawings in the figure and the component names is as follows:

[0022] 1, gas cabinet; 2, top plate; 3, gas distribution plate; 4, pump ring; 5, ceramic ring; 6, heating plate; 7, inner cavity; 8, outer cavity; 9, wafer; 10, exhaust ring; 11, sliding block. DETAILED DESCRIPTION

[0023] Please refer to Figures 1-8The application discloses a ceramic ring in a PECVD equipment structure, which comprises a gas cabinet 1, a top plate 2 arranged on the lower side of the gas cabinet 1, a gas distribution plate 3 arranged on the lower side of the top plate 2, a pump ring 4 arranged on the lower side of the gas distribution plate 3, a sliding block 11 arranged on the pump ring 4, two groups of sliding grooves formed in the pump ring 4, the sliding block 11 slidably connected in the sliding grooves, a limiting rod arranged on the sliding block 11, a ceramic ring 5 arranged on the lower side of the pump ring 4, a Y2O3 coating layer coated on the outer side of the ceramic ring 5, a heating plate 6 arranged on the lower side of the ceramic ring 5, and a wafer 9 arranged at the connecting position of the heating plate 6 and the ceramic ring 5, wherein an inner cavity 7 and an outer cavity 8 are arranged in the heating plate 6.

[0024] As shown in Figure 1 and 2 , the outer side of the ceramic ring 5 is provided with an exhaust ring 10, a plurality of exhaust holes are formed in the exhaust ring 10, the number of the exhaust holes is 40-50, the angle of the exhaust holes is 7-12 degrees, and the diameter of the exhaust holes is 5-10 mm, wherein the sliding block 11 can be used in cooperation with the exhaust holes in the exhaust ring 10, and the exhaust holes in the exhaust ring 10 can be steplessly adjusted.

[0025] Exhaust hole design embodiment

[0026] Boundary condition setting of finite element analysis:

[0027] Condition Entrance Outlet heater

[0028] condition1 Mass = 7.14 * 4703 / 4 T = 80 P = 2.7 torr T = 80 T = 400 DEG C

[0029] After finite element analysis, when the exhaust holes are adjusted to be tangent to the plane on the heating plate 6, the same boundary conditions and parameters are set, and through the cloud picture, it is found that when the position of the exhaust holes is lowered by several mm, the central velocity position is offset to the outlet side a little, and the tangential velocity gradient becomes more uniform, and the position continues to move until the theoretical best position is found through calculation and simulation.

[0030] As shown in Figure 4 , 5 and 6, through the cloud picture, it is found that only adjusting the position of the exhaust holes, whether below the heating plate 6 or above the heating plate 6, the velocity center is offset from the model center, and the problem of the velocity center of the gas flowing vertically to the wafer 9 cannot be solved by only adjusting the exhaust position, through finite element simulation analysis, by adjusting the arrangement density of the exhaust holes, it is finally confirmed that the unilateral density arrangement should be between 15-18 exhaust holes, therefore, the model optimization needs to be carried out in this interval, and the corresponding function relationship or curve relationship between the density value in the range of 180 degrees and the velocity center offset is tried to be established, so as to carry out theoretical calculation.

[0031] Wherein:

[0032] Y = a * x^3 - b * x^2 + c * x - d

[0033] Y: velocity center offset relative distance

[0034] X: single-sided hole density

[0035] Through the above formula, the theoretical optimal single-sided hole density arrangement when Y = 0 and the velocity center has no offset can be obtained.

[0036] Working principle: The gas cabinet 1 cooperates with the air distribution plate 3 to control the gas dispersion and offset, plays a role in improving the uniformity of the film, makes the vertical gas velocity reaching the wafer 9 surface tend to be uniform, and the ceramic ring 5 and the exhaust ring 10 are provided with exhaust holes, the exhaust holes play a role in exhaust, and can prevent excessive gas escape, the above structure solves the phenomenon of uneven gas flow rate, overall offset of the velocity center, and further causes different film coating rates and uneven thickness by adjusting the position and hole sealing distribution of the exhaust holes of the ceramic ring 5.

[0037] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A PECVD apparatus structure comprising a gas cabinet (1), characterized in that, The lower side of the gas cabinet (1) is provided with a top plate (2), the lower side of the top plate (2) is provided with a uniform gas disc (3), the lower side of the uniform gas disc (3) is provided with a pump ring (4), two groups of slides are formed in the pump ring (4), the slides are slidably connected with sliding blocks (11), the sliding blocks (11) are provided with limiting rods, the lower side of the pump ring (4) is provided with a ceramic ring (5), the lower side of the ceramic ring (5) is provided with a heating disc (6), the heating disc (6) is provided with an inner cavity (7) and an outer cavity (8), the outer side of the ceramic ring (5) is provided with an exhaust ring (10), and a plurality of exhaust holes are formed in the exhaust ring (10).

2. The PECVD apparatus structure of claim 1, wherein, The connection between the heating disc (6) and the ceramic ring (5) is provided with a wafer (9).

3. The PECVD apparatus structure of claim 1, wherein, The outer side of the ceramic ring (5) is coated with a Y2O3 coating.

4. The PECVD apparatus structure of claim 3, wherein, The number of the exhaust holes is 40-50, the angle of the exhaust holes is 7°-12°, and the diameter of the exhaust holes is 5mm-10mm.

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