Microwave plasma chemical vapor deposition equipment

Abstract

The utility model provides microwave plasma chemical vapor deposition equipment, and belongs to the technical field of microwaves. The deposition equipment comprises a rack, a cavity, a sample table and a lifting driving device, wherein the rack comprises a discharge cavity bottom plate; and the bottom of the cavity is connected with the upper part of the discharge cavity bottom plate to define a discharge cavity. The sample table is arranged in the discharge cavity, a lifting rod is arranged at the bottom of the sample table, a mounting hole is formed in a bottom plate of the discharge cavity, and the lifting rod slidably penetrates through the mounting hole. The lifting driving device is connected with the bottom of the lifting rod and used for driving the lifting rod to drive the sample table to move up and down. By moving the sample table up and down for a certain distance, the distribution condition of an electromagnetic field can be improved, so that the plasma balls are flatter, the coating thickness is more uniform, and the coating quality is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of microwave technology, specifically, relate to a microwave plasma chemical vapor deposition equipment. BACKGROUND

[0002] The microwave plasma chemical vapor deposition technology is that the microwave generated by the microwave generator is entered into the cavity of the reactor through the waveguide pipe and the isolator, and the mixed gas of methane and hydrogen is passed into the cavity, under the excitation of the microwave, the discharge is carried out in the cavity chamber, the molecules of the reaction gas are ionized, and the plasma is generated. The sample table is arranged in the cavity, and the substrate is arranged on the sample table. After the reaction gas molecules are ionized, the carbon element will deposit on the substrate to form a diamond coating. The uniformity of the thickness of the diamond coating is one of the important indexes of the coating quality, and the current deposition equipment is not uniform in coating thickness, which leads to poor coating quality. UTILITY MODEL CONTENTS

[0003] The utility model aims at providing a microwave plasma chemical vapor deposition equipment which can significantly improve the coating quality.

[0004] The utility model is realized as follows:

[0005] A microwave plasma chemical vapor deposition equipment comprises:

[0006] A rack comprises a discharge cavity bottom plate;

[0007] A cavity is connected with the upper part of the discharge cavity bottom plate at the bottom and forms a discharge cavity;

[0008] A sample table is arranged in the discharge cavity, the bottom of the sample table is provided with a lifting rod, the discharge cavity bottom plate is provided with a mounting hole, and the lifting rod can slidably pass through the mounting hole;

[0009] A lifting driving device is connected with the bottom of the lifting rod and is used for driving the lifting rod to move the sample table up and down.

[0010] Further, the lifting driving device comprises a motor and a transmission assembly, the motor is connected with the lifting rod through the transmission assembly and is used for driving the lifting rod to move up and down.

[0011] Further, the transmission assembly comprises a lifting plate and a plurality of lead screws, and the lifting plate is fixedly connected with the lifting rod.

[0012] The plurality of lead screws are vertically arranged and rotatably connected with the rack, axial movement of the plurality of lead screws is limited; each of the lead screws is sleeved with a nut, and the plurality of nuts are fixedly connected with the lifting plate; the motor is drivingly connected with the plurality of lead screws and can drive the plurality of lead screws to synchronously rotate.

[0013] Further, the lower ends of the plurality of lead screws are respectively provided with pulleys, and the transmission assembly further comprises a belt, the pulleys of the plurality of lead screws being connected through the belt.

[0014] Further, a connecting plate is further included, the connecting plate being arranged between the discharge cavity bottom plate and the lifting plate, and the upper ends of the plurality of lead screws being rotatably connected with the connecting plate.

[0015] Further, a sleeve is arranged between the connecting plate and the discharge cavity bottom plate, the sleeve being sleeved on the lifting rod, the upper end of the sleeve being fixedly connected with the discharge cavity bottom plate, and the lower end of the sleeve being fixedly connected with the connecting plate; the lifting rod movably penetrates through the connecting plate, and a sealing element is arranged between the lifting rod and the connecting plate; the sleeve is provided with a gas extraction hole.

[0016] Further, the lifting rod is swingably connected with the rack, so that the inclination angle of the sample table can be adjusted.

[0017] Further, the lower part of the lifting rod is fixedly connected with a moving block, and the moving block is arranged on the lifting plate.

[0018] A pushing block is arranged around the moving block, the pushing block being fixedly connected with the lifting plate, and a pushing screw is arranged on each of the pushing blocks; rotating the pushing screw in a first direction can make the pushing screw abut against the moving block and push the moving block to move, and rotating the pushing screw in a direction opposite to the first direction can make the pushing screw separate from the moving block.

[0019] Further, an inner cavity plate is further arranged in the discharge cavity, and the inner cavity plate is in sliding fit with the inner wall of the cavity.

[0020] An inner bellows and an outer bellows are arranged between the inner cavity plate and the discharge cavity bottom plate, the inner bellows being sleeved on the lifting rod, and the outer bellows being sleeved on the inner bellows; the upper ends of the inner bellows and the outer bellows are in sealing connection with the inner cavity plate, the lower ends of the inner bellows and the outer bellows are in sealing connection with the discharge cavity bottom plate, and a containing space is formed between the inner bellows and the outer bellows.

[0021] The discharge cavity bottom plate is provided with a gas extraction hole, the gas extraction hole being in communication with the containing space and being used for connecting a gas extraction pipe.

[0022] Further, the inner side and the outer side of the inner bellows and the outer bellows are provided with a shaped telescopic tube, so as to reduce the radial deformation of the inner bellows and the outer bellows.

[0023] The utility model discloses beneficial effect is:

[0024] The microwave plasma chemical vapor deposition equipment obtained by the above design, when the temperature measuring instrument measures that the temperature of the sample table center is higher than the average temperature of the edge, then it shows that the sample table center temperature is too high, the inventor finds through research that the sample table center temperature is too high, shows that the plasma ball is not enough flat, namely the center electromagnetic field is too strong, and the edge is relatively weak, and the electromagnetic field distribution is one of important factors that influence the uniformity of the film thickness, when, the sample table is moved a certain distance upwards, namely the electromagnetic field distribution situation can be improved, makes the plasma ball more flat, and then can make the film thickness more uniform, improves the film quality. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be briefly introduced to the drawing needed to be used in the embodiment, it should be understood that the following drawings only shows some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for ordinary skilled person in the art, under the premise of not paying the creative labor, can also obtain other related drawings according to these drawings.

[0026] Figure 1 It is the sectional view of the deposition equipment provided by the embodiment of the utility model;

[0027] Figure 2 It is the perspective view of the deposition equipment provided by the embodiment of the utility model;

[0028] Figure 3 It is the top view of the sample table provided by the embodiment of the utility model;

[0029] Figure 4 It is the curve graph of the temperature of the sample table edge position with the distance between the sample table edge position and the plasma ball when the deposition equipment works.

[0030] Icon: 1-deposition equipment;11-cavity;121-discharge cavity bottom plate;1211-pumping hole;122-connection plate;13-sample table;14-lifting rod;15-lifting drive device;151-motor;152-lifting plate;153-screw;154-nut;155-belt;16-sleeve;17-moving block;18-thrust block;181-thrust screw;191-cavity inner plate;192-inner bellows;193-outer bellows;194-shaped telescopic tube;2-plasma ball. DETAILED DESCRIPTION EMBODIMENT

[0031] Please refer to Figures 1-3 The embodiment provides a microwave plasma chemical vapor deposition device 1, which comprises a rack, a cavity 11 and a sample table 13, wherein the cavity 11 is fixedly installed on a discharge cavity bottom plate 121 of the rack, and the sample table 13 is arranged in the cavity 11. When discharging, an electromagnetic field is mainly distributed in an upper part of the sample table 13, and the shape of the electromagnetic field is ellipsoidal, which is commonly called a plasma ball. It is found by the inventors that the flatter the plasma ball is, the higher the uniformity of film coating on a substrate on the sample table 13 is. It is further found by the inventors that the distance between the sample table 13 and the plasma ball 2 can affect the flatness of the plasma ball 2, that is, by adjusting the height of the sample table 13, the flatness of the plasma ball 2 can be adjusted.

[0032] In order to adjust the height of the sample table 13, the deposition device 1 is further provided with a lifting driving device 15; the bottom of the sample table 13 is connected with the lifting driving device 15 through a lifting rod 14. The lifting driving device 15 is used for driving the sample table 13 to move up and down, so as to adjust the distribution of the electromagnetic field in the cavity 11, and make the plasma ball 2 more flattened.

[0033] In addition, the deposition device provided by the embodiment can also adjust the inclination angle of the sample table 13 and the discharge cavity bottom plate 121. By adjusting the inclination angle of the sample table 13, the distances between each position (position 1, position 2, position 3, position 4 and position 5) on the sample table 13 and the plasma ball 2 can be changed, so that the temperature distribution of each position on the sample table 13 is more uniform, and the film coating quality is further improved.

[0034] Specifically, the cavity 11 is in a cylindrical structure, and the bottom thereof is fixedly connected with the discharge cavity bottom plate 121 of the rack; the cavity 11, the discharge cavity bottom plate 121 and a cover plate (not shown in the figure) of the discharge cavity form the discharge cavity by being enclosed. The middle part of the discharge cavity bottom plate 121 is provided with a mounting hole, and the outer diameter of the lifting rod 14 at the bottom of the sample table 13 is smaller than the inner diameter of the mounting hole, so that the lifting rod 14 can freely move in the mounting hole.

[0035] The lifting driving device 15 comprises a motor 151 and a transmission assembly. The motor 151 is connected with the bottom of the lifting rod 14 through the transmission assembly, so as to drive the lifting rod 14 to move up and down together with the sample table 13. The transmission assembly can have various structural forms. For example, in other embodiments, a rack can be arranged on the lifting rod 14, and the motor 151 drives the rack to move up and down through a gear. Alternatively, the rotation of the lifting rod 14 around its own axis is limited, a nut 154 is arranged on the lifting rod 14, and the axial movement of the nut 154 is limited. The motor 151 drives the nut 154 to rotate, so that the lifting rod 14 can also move up and down. Alternatively, in other embodiments, the lifting driving device can also be an electric push rod connected with the lifting rod of the sample table.

[0036] Since the deposition device 1 provided in the embodiment needs to not only move up and down, but also adjust the included angle between the sample table 13 and the bottom plate 121 of the discharge cavity (i.e. the inclination angle of the sample table 13), the transmission assembly provided in the embodiment is different from the conventional structure.

[0037] In the embodiment, the transmission assembly comprises a lifting plate 152 and four lead screws 153. The lifting plate 152 is arranged at the bottom of the bottom plate 12 of the discharge cavity. The middle part of the lifting plate 152 is provided with a through hole, the lifting rod 14 passes through the through hole in the middle part of the lifting plate 152 and is fixedly connected with the lifting plate 152, so that the lifting rod 14 and the lifting plate 152 can move up and down synchronously. The four lead screws 153 are vertically arranged and respectively arranged around the lifting plate 152. The lead screws 153 are rotatably connected with the rack, and the bottom parts of the four lead screws 153 are respectively provided with pulleys. The four pulleys are connected through a belt 155. The upper part of one of the lead screws 153 is drivingly connected with the motor 151. The motor 151 drives the lead screw 153 to rotate and drives the remaining lead screws 153 to rotate synchronously through the belt 155. The middle part of the lead screw 153 is sleeved with the nut 154, and the nut 154 is fixedly connected with the lifting plate 152. The axial movement of the lead screw 153 is limited. Therefore, when the lead screw 153 rotates under the driving of the motor 151, the nut 154 moves axially along the lead screw 153, thereby driving the lifting plate 152 to move up and down.

[0038] Further, the rack further comprises a connecting plate 122, which is arranged between the discharge cavity bottom plate 121 and the lifting plate 152, and the upper end of the lead screw 153 is rotatably connected with the connecting plate 122. A sleeve 16 is further arranged between the connecting plate 122 and the discharge cavity bottom plate 121, and the upper and lower ends of the sleeve 16 are fixedly connected with the discharge cavity bottom plate 121 and the connecting plate 122 respectively. The middle part of the connecting plate 122 is provided with a through hole, and the lifting plate 152 movably passes through the through hole in the middle part of the connecting plate 122; and the connecting plate 122 and the lifting plate 152 are sealingly connected through an extensible bellows. The sidewall of the sleeve 16 is provided with an air extraction hole, so as to facilitate the extraction of air in the discharge cavity and form a vacuum discharge environment.

[0039] The upper part of the lifting rod 14 is swingably connected (directly or indirectly) with the rack, so that the included angle between the axis of the lifting rod 14 and the discharge cavity bottom plate 121 can be adjusted; and when the lifting rod 14 swings, it can drive the sample table 13 to swing, and thus the inclination angle of the sample table 13 is changed.

[0040] In order to facilitate the adjustment of the included angle between the sample table 13 and the discharge cavity bottom plate 121, the bottom of the lifting rod 14 is provided with a pushing assembly, which moves the bottom plate of the lifting rod 14 in different directions, and thus the inclination angle of the sample table 13 is adjusted. Specifically, the lifting plate 152 is provided with a moving block 17, and the middle part of the moving block 17 is provided with a through hole, and the lifting rod 14 passes through the through hole and is fixedly connected with the moving block 17. The periphery of the moving block 17 is provided with a top pushing block 18, and the top pushing block 18 is an L-shaped structure and is fixedly connected with the moving plate. The top pushing block 18 is provided with a top pushing screw 181, and one of the top pushing screws 181 is rotated in a first direction, at this time, the top pushing screw 181 moves towards the moving block 17, and thus can abut against the moving block 17, and the top pushing screw 181 can push the moving block 17 to move by continuing to rotate. The top pushing screw 181 is rotated in a direction opposite to the first direction, and the top pushing screw 181 moves away from the moving block 17.

[0041] In addition, the moving block 17 and the lifting plate 152 are further detachably connected through a bolt. Specifically, the lifting plate 152 is provided with a strip-shaped hole extending along the radial direction of the lifting shaft, and the moving block 17 is provided with a bolt through hole, and the bolt passes through the bolt through hole and the strip-shaped hole; when it is necessary to adjust the inclination angle of the lifting rod 14 and the sample table 13, the bolt is loosened, the moving block 17 is pushed to a predetermined position, and then the bolt is tightened.

[0042] Further, the discharge cavity is provided with a cavity-plate 191, which is a circular plate provided with a through hole in the middle and is in sliding fit with the inner wall of the cavity 11 at the outer edge; the cavity-plate 191 is located below the sample table 13, and the through hole of the cavity-plate 191 is provided with a swing bearing, and the lifting rod 14 passes through the inner ring of the bearing, so as to realize the swing of the lifting rod 14. In other embodiments, the lifting rod 14 can also be connected with the discharge cavity bottom plate 121 or the connecting plate 122 through the swing bearing.

[0043] In order to adjust the distance between the cavity-plate 191 and the sample table 13, and further adjust the distribution of the electromagnetic field, the inner bellows 192 and the outer bellows 193 are arranged between the cavity-plate 191 and the discharge cavity bottom plate 121, the inner bellows 192 is sleeved on the lifting rod 14, and the outer bellows 193 is sleeved on the inner bellows 192. The upper ends of the inner bellows 192 and the outer bellows 193 are in sealed connection with the cavity-plate 191, the lower ends of the inner bellows 192 and the outer bellows 193 are in sealed connection with the discharge cavity bottom plate 121, and a containing space is formed between the inner bellows 192 and the outer bellows 193. The discharge cavity bottom plate 121 is provided with a gas extraction hole 1211, which is in communication with the containing space and is used for connecting a gas extraction pipe. By inflating or deflating the containing space, the height of the cavity-plate 191 can be adjusted.

[0044] In order to accurately control the lifting height of the cavity-plate 191, the radial deformation amount of the inner bellows 192 and the outer bellows 193 should be reduced as much as possible; therefore, the inner side and the outer side of the inner bellows 192 and the outer bellows 193 are provided with a shaped telescopic tube 194.

[0045] The method for using the microwave plasma chemical vapor deposition device 1 comprises the following steps:

[0046] The temperature of the center point and the edge of the sample table 13 in four directions is detected in real time, and the temperature of the 1, 2, 3, 4 and 5 positions is correspondingly attached. Figure 3

[0047] When the temperature of the center point of the sample table 13 is higher than the average temperature of the edge of the sample table 13, the sample table 13 is lifted by a preset distance, at this time, the sample table 13 is appropriately lifted by a preset distance, so that the sample table 13 is closer to the electromagnetic field, which can make the ellipsoidal plasma ball more flat;

[0048] After continuing to monitor for a preset time, when the temperature of the center point of the sample table 13 is still higher than the average temperature of the edge of the sample table 13, the height of the cavity-plate 191 is lowered. The height of the cavity-plate 191 is appropriately lowered, so that the distance between the cavity-plate 191 and the sample table 13 is larger, which can also make the ellipsoidal electromagnetic field more flat.

[0049] Please refer to Figure 4 ​, the edge temperature of the sample table, which presents regular changes with the distance between the edge position of the sample table and the plasma ball, starts to increase with the increase of the distance, at this time, the corresponding Figure 4 half of the temperature curve; then, the edge temperature decreases with the decrease of the distance, at this time, the corresponding Figure 4 half of the temperature curve. When the microwave plasma chemical vapor deposition equipment is normally working, the distance between the edge position of the sample table and the plasma ball corresponds to the Figure 4 half of the temperature curve.

[0050] When the temperature difference between the two temperature measuring points opposite to the edge of the sample table 13 is greater than a preset difference (for example, 50℃), the inclination angle of the sample table 13 is adjusted, so that the lower temperature side of the sample table 13 moves a preset distance away from the plasma ball. By adjusting the inclination angle of the sample table 13, the ellipsoidal plasma ball can be made more flat.

[0051] By adjusting the height and the inclination angle of the sample table 13 in real time, the electromagnetic field distribution is improved, so that the film thickness is more uniform, and the film quality is improved.

[0052] The above only describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A microwave plasma chemical vapor deposition apparatus, characterized by comprising: The utility model relates to a microwave plasma chemical vapor deposition equipment, including: A rack, the rack includes the discharge cavity bottom plate; The bottom of the cavity is connected with the upper part of the discharge cavity bottom plate, and the discharge cavity is formed; A sample stage is arranged in the discharge cavity, the bottom of the sample stage is provided with a lifting rod, the discharge cavity bottom plate is provided with a mounting hole, and the lifting rod can slide through the mounting hole; A lifting driving device is connected with the bottom of the lifting rod for driving the lifting rod to move up and down with the sample stage.

2. The microwave plasma chemical vapor deposition equipment according to claim 1, wherein: The lifting driving device includes a motor and a transmission assembly, the motor is connected with the lifting rod through the transmission assembly, and is used to drive the lifting rod to move up and down.

3. The microwave plasma chemical vapor deposition equipment according to claim 2, wherein: The transmission assembly includes a lifting plate and a plurality of lead screws, the lifting plate is fixedly connected with the lifting rod; The plurality of lead screws are vertically arranged and rotatably connected with the rack, the axial movement of the plurality of lead screws is limited, a nut is sleeved on each lead screw, and the plurality of nuts are fixedly connected with the lifting plate; the motor is in transmission connection with the plurality of lead screws, and can drive the plurality of lead screws to synchronously rotate.

4. The microwave plasma chemical vapor deposition equipment according to claim 3, wherein: The lower ends of the plurality of lead screws are respectively provided with pulleys, and the transmission assembly further includes a belt, and the pulleys of the plurality of lead screws are connected through the belt.

5. The microwave plasma chemical vapor deposition equipment according to claim 4, wherein: The rack further includes a connecting plate, the connecting plate is arranged between the discharge cavity bottom plate and the lifting plate, and the upper ends of the plurality of lead screws are rotatably connected with the connecting plate.

6. The microwave plasma chemical vapor deposition equipment according to claim 5, wherein: A sleeve is arranged between the connecting plate and the discharge cavity bottom plate, the sleeve is sleeved on the lifting rod, the upper end of the sleeve is fixedly connected with the discharge cavity bottom plate, and the lower end is fixedly connected with the connecting plate; the lifting rod movably penetrates through the connecting plate, a sealing element is arranged between the lifting rod and the connecting plate, and a gas extraction hole is arranged on the sleeve.

7. The microwave plasma chemical vapor deposition equipment according to claim 4, wherein: The lifting rod is swingably connected with the rack, so that the inclination angle of the sample stage can be adjusted.

8. The microwave plasma chemical vapor deposition equipment according to claim 7, wherein: The lower part of the lifting rod is fixedly connected with a moving block, and the moving block is arranged on the lifting plate. The moving block is provided with a pushing block around, the pushing block is fixedly connected with the lifting plate, a pushing screw is arranged on each pushing block; rotating the pushing screw in a first direction can make the pushing screw abut against the moving block and push the moving block to move, and rotating the pushing screw in a direction opposite to the first direction can make the pushing screw separate from the moving block.

9. The microwave plasma chemical vapor deposition device according to any one of claims 1-8, characterized in that: The discharge cavity is further provided with an inner cavity plate, and the inner cavity plate is in sliding fit with the inner wall of the cavity; The inner cavity plate and the discharge cavity bottom plate are provided with an inner bellows and an outer bellows, the inner bellows is sleeved on the lifting rod, and the outer bellows is sleeved on the inner bellows; the upper ends of the inner bellows and the outer bellows are in sealed connection with the inner cavity plate, the lower ends of the inner bellows and the outer bellows are in sealed connection with the discharge cavity bottom plate, and a containing space is formed between the inner bellows and the outer bellows; The discharge cavity bottom plate is provided with a gas extraction hole, the gas extraction hole is in communication with the containing space, and the gas extraction hole is used for connecting a gas extraction pipe.

10. The microwave plasma chemical vapor deposition device according to claim 9, characterized in that: The inner side and the outer side of the inner bellows and the outer bellows are provided with a shaped telescopic pipe, so as to reduce the radial deformation amount of the inner bellows and the outer bellows.

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