Chemical vapor deposition apparatus with gas distribution plate adjustment structure

Abstract

The utility model discloses a kind of chemical vapor deposition equipment with uniform gas disc adjusting structure, including reaction cavity, heating disc being set in reaction cavity, the uniform gas disc being set in the reaction cavity and being located above the heating disc, the electrically conductive cover that is covered on the uniform gas disc to form buffer gas cavity inside, the cover has gas inlet, still including radio frequency generating device electrically connected with the gas inlet, the side portion of the reaction cavity has reaction cavity door, the top of the reaction cavity is equipped with the step hole of circumferential equidistance around the gas inlet, the step hole is equipped with the insulating adjusting bolt, the lower portion of the cover is provided with threaded through hole corresponding the step hole, the screw rod end of the adjusting bolt is connected on the threaded through hole, the step hole is also provided with sealing nut that seals and covers the step hole. The utility model has the advantages of convenient adjustment uniform gas disc height and levelness and avoid or reduce gas pipe blockage.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor manufacturing equipment technology, and relates to a chemical vapor deposition equipment with a gas equalization disk adjustment structure. Background Technology

[0002] Currently, plasma-enhanced chemical vapor deposition (PECVD) is a commonly used process in semiconductor manufacturing to deposit film structures on wafer surfaces. Existing PECVD equipment structures include a reaction chamber containing a heating plate for placing the wafer, an RF source, etc. Process gas is introduced into the reaction chamber through a gas pipe, and a thin film structure is formed on the wafer surface under the action of the RF source.

[0003] For plasma to deposit on the wafer surface, the vapor leveling disk needs to be positioned above the wafer at a certain distance, meaning the vapor leveling disk must be at a certain height relative to the heating disk. In existing technologies, the height of the vapor leveling disk relative to the heating disk is fixed and cannot be adjusted. However, different wafer products require different manufacturing processes, and the fixed height of the vapor leveling disk relative to the heating disk leads to a mismatch with the corresponding process, resulting in suboptimal vapor deposition quality for some wafer products. Furthermore, if the vapor leveling disk is not level relative to the heating disk, it can cause uneven film thickness on the wafer, resulting in poor quality or even defective products. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a chemical vapor deposition device with a gas equalization plate adjustment structure, so as to facilitate the adjustment of the height and level of the gas equalization plate relative to the heating plate, thereby overcoming the shortcomings of the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A chemical vapor deposition apparatus with a gas equalization plate adjustment structure includes a reaction chamber, a heating plate disposed within the reaction chamber, a gas equalization plate disposed within the reaction chamber above the heating plate, a conductive cover covering the gas equalization plate to form a buffer gas chamber inside, the cover having an air inlet, and a radio frequency generator electrically connected to the air inlet. The side of the reaction chamber has a reaction chamber door. The apparatus is characterized in that: the top of the reaction chamber has stepped holes evenly spaced around the air inlet, and an insulated adjusting bolt is disposed within each stepped hole; a threaded through hole is disposed on the cover corresponding to the lower part of each stepped hole; the screw end of the adjusting bolt is threadedly connected to the threaded through hole; and a sealing nut is also provided to seal and cover the stepped hole.

[0007] Using the above technical solution, the gas distribution plate and the cover are suspended in the reaction chamber. By turning the adjusting bolts in each stepped hole, the height and level of the gas distribution plate relative to the heating plate can be easily adjusted. This ensures that the plasma is effectively deposited on the wafer and that the plasma deposition is uniform, thus helping to ensure the quality of wafer deposition.

[0008] In a specific embodiment of this utility model, the adjusting bolt is a ceramic bolt.

[0009] In a specific embodiment of this utility model, the top of the reaction chamber has a mounting port, the mounting port is sealed with a mounting plate, the mounting plate has a central hole, and an insulating flange is sealed and mounted on the central hole.

[0010] In a specific embodiment of this utility model, a mixing chamber is further provided above the reaction chamber. The mixing chamber has an inlet and an outlet. A first gas supply pipe is connected to the inlet of the mixing chamber, and a second gas supply pipe is connected to the first gas supply pipe near the inlet. In this way, the two gases to be pre-reacted are respectively transported to the mixing chamber through the first and second gas supply pipes, and finally mixed within the mixing chamber. This avoids the problem of clogging the gas supply pipes before mixing. Although there is a short section of mixed gas near the inlet in the first gas supply pipe, the distance is very short, and the mixing time before entering the mixing chamber is extremely short, leaving no time for reaction to form accumulations, thus preventing clogging.

[0011] In a specific embodiment of this utility model, the air inlet is connected upward to a conductive lower pipe extending through the flange, and the air outlet is connected downward to an insulated upper pipe connected to the lower pipe. The radio frequency generator is connected to the lower pipe via a wire. The insulation of the upper pipe ensures that the radio frequency generator can only apply the radio frequency electric field to the conductive cover and the gas equalization plate to form plasma, but the radio frequency electric field will not be conducted to the mixing chamber, the first gas delivery pipe, or the second gas delivery pipe.

[0012] In a specific embodiment of this utility model, a pin is provided on the heating plate that can extend upward from inside the heating plate.

[0013] In a specific embodiment of this utility model, a shielding cover is also included to cover the reaction chamber and the mixing chamber, and the first gas supply pipe and the second gas supply pipe extend out from the shielding cover.

[0014] In a specific embodiment of this utility model, the material of the upper pipe is PFA.

[0015] In summary, this utility model has the advantages of conveniently adjusting the height and level of the gas distribution plate and avoiding or reducing gas pipe blockage. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a partial three-dimensional structural diagram of the present invention after the shielding cover has been removed;

[0018] Figure 3 This is a schematic diagram of the external structure of the reaction chamber;

[0019] Figure 4 This is a schematic diagram showing the inside of the reaction chamber after it has been cut open.

[0020] Figure 5 This is a schematic diagram of the gas distribution disk. Detailed Implementation

[0021] like Figure 1 and Figure 2 As shown, the chemical vapor deposition apparatus of this invention with a gas equalization plate adjustment structure includes a reaction chamber 100 and a mixing chamber 200. The reaction chamber 100 is fixed to the top of the cabinet 400, and the mixing chamber 200 is located above the reaction chamber 100.

[0022] Among them, such as Figure 3 and Figure 4 As shown, the reaction chamber 100 is equipped with a heating plate 110, a gas distribution plate 120, and a cover 130. The gas distribution plate 120 is positioned above the heating plate 110, with gaps between them. Figure 5 As shown, the gas equalization disk 120 has numerous uniformly distributed gas equalization nozzles 121. A cover 130 covers the gas equalization disk 120 to form a buffer gas chamber 140 inside. The reaction chamber 100, the gas equalization disk 120, and the cover 130 are all made of aluminum. An air inlet 131 is located in the center of the cover 130. A circular baffle 141 is fixed below the air inlet 131 inside the buffer gas chamber 140. This baffle 141 diffuses the incoming process gas to the surrounding area of ​​the chamber. The air inlet 131 extends upwards out of the reaction chamber 100 through a conductive lower pipe 132. A programmable reaction chamber door 101 is also provided on the side of the reaction chamber 100. In this embodiment, the reaction chamber door 101 is a pneumatic door, but it could also be an electric door.

[0023] The bottom of the reaction chamber 100 has a first vacuum port 150, which is connected to a vacuum pump (not shown) via a first extraction pipe 151 located inside the cabinet 400. A first control valve is installed on the first extraction pipe 151. A first vacuum gauge is installed inside the reaction chamber 100 to monitor the vacuum level within the chamber in real time.

[0024] Furthermore, the heating plate 110 is equipped with multiple programmable ejector pins 111 that can extend upwards from inside the heating plate 110. In this embodiment, the ejector pins 111 are pneumatic ejector pins, but they can also be driven in other ways, such as electric ejector pins. Specifically, the cylinder of the pneumatic ejector pin is fixed below the reaction chamber 100, and the piston rod of the pneumatic ejector pin passes through the bottom plate of the reaction chamber in a sealed manner and is connected to each ejector pin 111 through the bracket 111a.

[0025] For example Figure 2 and combined Figure 4 As shown, the mixing chamber 200 is made of aluminum and is located above the reaction chamber 100. The mixing chamber 200 has an inlet at the top and an outlet at the bottom. A first gas supply pipe 211 is connected to the inlet, and an upper supply pipe 213, connected to the lower supply pipe 132, is installed downwards from the outlet. A second gas supply pipe 212 is connected to the first gas supply pipe 211 near the inlet. With this structure, the two gases to be pre-reacted are respectively transported to the mixing chamber 200 through the first gas supply pipe 211 and the second gas supply pipe 212. Finally, they are mixed within the mixing chamber 200 to form the process gas. This avoids clogging the gas supply pipes before mixing. Although there is a short section of mixed gas near the inlet on the first gas supply pipe 211, the distance is very short, and the mixing time before entering the mixing chamber is extremely short, insufficient to react and form accumulations, thus preventing clogging. For example, the first gas supply pipe 211 can deliver oxygen alone or a mixture containing oxygen (other gases in the mixture will not react with oxygen), and the second gas supply pipe can deliver SiH4 alone or a mixture containing SiH4 (other gases in the mixture will not react with SiH4).

[0026] In this embodiment, the first gas supply pipe 211, the second gas supply pipe 212, and the lower pipe 132 are all made of 316L stainless steel. The upper pipe 213 is an insulating pipe. In this embodiment, the upper pipe 213 is made of PFA, which, in addition to its insulating properties, also has corrosion resistance.

[0027] In this embodiment, the top of the reaction chamber 100 is provided with a mounting port, which is sealed with a mounting plate 160. The mounting plate 160 is also made of aluminum. The mounting plate 160 has a central hole, on which an insulating flange 161 is sealed and mounted. In this embodiment, the flange 161 is a ceramic disc, which has the characteristics of high temperature resistance and insulation, and prevents electrical conduction to the reaction chamber 100. Three stepped holes 170 are evenly distributed around the central hole along a circular axis on the mounting plate 160. Each of the three stepped holes 170 is provided with an adjusting bolt 171. The head of the adjusting bolt 171 is located above the step, and the screw passes downward through the mounting plate 160. The end face of the head is provided with a hexagonal countersunk hole or a slotted groove for easy insertion of a special tool for turning. The cover 130 is provided with threaded through holes 131 below the positions corresponding to the three stepped holes 170. The screw end of the adjusting bolt 171 is threadedly connected to the threaded through hole 131. In this embodiment, the adjusting bolt 171 is made of ceramic, providing high-temperature insulation and preventing electrical conduction to the reaction chamber 100. A sealing nut 172 is also provided in the stepped hole 170. The sealing nut 172 seals the stepped hole 170, preventing gas leakage from the gap between the adjusting bolt 171 and the stepped hole 170. The sealing nut 172 is also made of aluminum. As is well known, the sealing between the above-mentioned parts can be achieved using high-temperature resistant sealing rings.

[0028] With this structure, the height and level of the gas distribution plate 120 relative to the heating plate 110 can be easily adjusted by turning the adjusting bolts in each stepped hole 170. This ensures that the plasma is effectively deposited on the wafer and that the plasma deposition is uniform, thus helping to ensure the quality of wafer deposition.

[0029] A radio frequency generator 220 is also provided next to the mixing chamber 200. The output of the radio frequency generator 200 is electrically connected to the lower pipe 132.

[0030] In addition, a shielding cover 230 is fixed to the top of the mixing chamber 200, covering the mixing chamber 200 and the radio frequency generator 220. The first gas supply pipe 211 and the second gas supply pipe 212 extend out from the shielding cover. The shielding cover 230 can shield the electromagnetic radiation generated when the equipment is working, avoiding pollution to the environment.

[0031] The above describes the structure of the chemical vapor deposition equipment of this utility model, and its working principle is as follows:

[0032] The reaction chamber 100 is in a vacuum state during operation. The gases delivered by the first gas supply pipe 211 and the second gas supply pipe 212 are mixed in the mixing chamber 200 to form the process gas, which is then introduced into the buffer chamber 140. The radio frequency generator 220 provides a set power radio frequency power to the gas equalization plate 120 and the cover 130, causing the process gas in the buffer chamber 140 to form plasma. The plasma is sprayed onto the wafer heated by the heating plate 100 below through the gas equalization nozzles 121 on the gas equalization plate 120, thereby depositing a thin film on the wafer surface. The vacuum state in the reaction chamber 100 is formed and closed by computer-controlled opening and closing of the first control valve.

[0033] In this invention, when placing or removing a wafer from the heating plate 110 using the electric fork 310, the ejector pin 111 needs to be controlled to lift it. Specifically, when placing a wafer onto the heating plate 110, the electric fork 310 is first controlled to move the wafer above the heating plate 110. Then, the ejector pin 111 lifts the wafer from below until it is lifted off the electric fork 310. Next, the electric fork 310 retracts out of the reaction chamber. After the fork 313 of the electric fork 310 leaves the heating plate 110, the ejector pin 111 is controlled to fall until the wafer completely rests on the surface of the heating plate 110. When it is necessary to remove the wafer from the heating plate, firstly, control the ejector pin 111 to lift the wafer away from the surface of the heating plate 110. Then, control the electric fork 310 to enter the reaction chamber and position the fork 310 below the wafer. Next, control the ejector pin 111 to fall so that the wafer falls onto the fork 310. Finally, control the electric fork 310 to retract and exit the reaction chamber with the wafer, transferring the wafer into the transfer chamber 300.

[0034] Therefore, this invention has the advantages of conveniently adjusting the height and level of the gas distribution plate and avoiding or reducing gas pipe blockage.

Claims

1. A chemical vapor deposition apparatus with a gas equalization disk adjustment structure, comprising a reaction chamber, a heating disk disposed within the reaction chamber, a gas equalization disk disposed within the reaction chamber above the heating disk, a conductive cover covering the gas equalization disk to form a buffer gas chamber inside, the cover having an air inlet, and further comprising a radio frequency generator electrically connected to the air inlet, the reaction chamber having a reaction chamber door on its side, characterized in that: The top of the reaction chamber is provided with stepped holes at equal intervals around the air inlet. An insulated adjusting bolt is provided in the stepped hole. A threaded through hole is provided on the cover below the stepped hole. The screw end of the adjusting bolt is threaded to the threaded through hole. A sealing nut is also provided to seal and cover the stepped hole.

2. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 1, characterized in that, The adjusting bolt is a ceramic bolt.

3. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 1, characterized in that, The top of the reaction chamber has a mounting port, and a mounting plate is sealed on the mounting port. The mounting plate has a central hole, and an insulating flange is sealed on the central hole.

4. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 3, characterized in that, A mixing chamber is also provided above the reaction chamber. The mixing chamber has an air inlet and an air outlet. A first gas supply pipe is connected to the air inlet of the mixing chamber, and a second gas supply pipe is connected to the first gas supply pipe near the air inlet.

5. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 4, characterized in that, The air inlet is connected upward to a conductive lower pipe that extends out of the flange, and the air outlet is connected downward to an upper pipe that is connected to and insulated from the lower pipe. The radio frequency generator is connected to the lower pipe via a wire.

6. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 1, characterized in that, The heating plate is equipped with a pin that can extend upward from inside the heating plate.

7. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 5, characterized in that, It also includes a shielding cover that covers the reaction chamber and the mixing chamber, with the first gas supply pipe and the second gas supply pipe extending out from inside the shielding cover.

8. The chemical vapor deposition apparatus with a gas equalization disk adjustment structure according to claim 5, characterized in that, The material of the upper pipe is PFA.

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