Inner cavity structure with conical separator and PEALD equipment thereof

Abstract

The utility model provides an inner cavity structure with a conical separation body and PEALD equipment of the inner cavity structure, and relates to the technical field of coating equipment. Comprising an inner cavity, and a carrying table suitable for placing a wafer carrying disc is arranged in the inner cavity; a partition body is arranged above the carrying table, the partition body is suitable for forming a conical reaction space with an opening gradually increased from top to bottom above the carrying table, and the upper portion of the conical reaction space is suitable for being connected with a reaction source so that the entered reaction source can be evenly distributed on the surface of the carrying table. According to the scheme, the film thickness uniformity can be improved, the independence of a reaction region is realized, and the precursor utilization rate is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a coating equipment technical field, specifically, relate to a kind of inner cavity structure with conical partition and its PEALD equipment. BACKGROUND

[0002] Plasma enhanced atomic layer deposition (PEALD) is a kind of high-precision film preparation technology combining atomic layer deposition (PEALD) self-limiting reaction and plasma auxiliary excitation. It deposits atomic uniform thin film on the substrate surface layer by layer by periodically alternating into precursor and plasma activated reaction gas, and is widely used in semiconductor, optical coating, new energy device and other fields.

[0003] However, the traditional PEALD equipment has a large inner cavity volume, which causes a large amount of precursors to be adsorbed on the inner surface during the process, resulting in low utilization rate of precursors, and the reaction source is not uniformly distributed when it reaches the carrier, causing uneven film thickness after wafer coating. UTILITY MODEL CONTENT

[0004] The utility model proposes an improved technical solution for the problems of large coating pollution area, insufficient plasma uniformity and low utilization rate of precursors in existing PEALD equipment. The technical solution significantly improves process performance and equipment maintenance efficiency through unique inner and outer cavity design and annular exhaust hole layout.

[0005] The utility model adopts the following scheme:

[0006] An inner cavity structure with a conical partition, comprising an inner cavity, a carrier is arranged in the inner cavity for placing a wafer carrier disc; a partition is arranged above the carrier, the partition is adapted to form a conical reaction space above the carrier, the conical reaction space is adapted to connect a reaction source to make the incoming reaction source uniformly distributed on the surface of the carrier.

[0007] Further, the partition is adapted to separate the inner cavity into a reaction inner cavity and a non-reaction area, an exhaust passage is arranged between the reaction inner cavity and the non-reaction area, a first negative pressure device is connected to the non-reaction area to exhaust the gas in the reaction inner cavity through the exhaust passage.

[0008] Further, a plurality of exhaust holes are annularly arranged at the connection between the reaction inner cavity and the non-reaction area to form the exhaust passage.

[0009] Further, the carrier is detachably arranged below the inner cavity, and a lifting system is connected to the carrier to drive the carrier to move up and down, and the carrier is adapted to form the reaction inner cavity together with the inner cavity when it rises to a specified position.

[0010] Further, the periphery of the carrier is provided with an edge boss, which is connected with the shell of the inner cavity through metal surface contact.

[0011] The utility model also provides a PEALD equipment with the inner cavity structure of conical separator, the PEALD equipment includes the inner cavity structure with conical separator.

[0012] Beneficial effects:

[0013] The utility model discloses a unique conical reaction space can effectively improve the uniformity of reaction source distribution, and the layout of annular gas outlet hole realizes the laminar flow of gas, improves the uniformity of plasma and reaction gas, thereby improve the film thickness uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the inner cavity structure schematic view of the inner cavity structure with conical separator of the utility model embodiment;

[0015] Figure 2 It is the structure schematic view of another view of the inner cavity of the inner cavity structure with conical separator of the utility model embodiment;

[0016] Figure 3 It is the schematic view of a double cavity structure of the utility model embodiment;

[0017] Figure 4 It is the whole structure schematic view of the PEALD equipment of the inner cavity structure with conical separator of the utility model embodiment;

[0018] Figure 5 It is the outer cavity structure schematic view of the PEALD equipment of the inner cavity structure with conical separator of the utility model embodiment;

[0019] Figure 6 It is the structure schematic view of the carrier of the PEALD equipment of the inner cavity structure with conical separator of the utility model embodiment;

[0020] Figure 7 It is the working flow chart of the film plating process of the PEALD equipment of the inner cavity structure with conical separator of the utility model embodiment;

[0021] Reference signs: first negative pressure device 1, plasma source 2, air inlet 3, precursor inlet 4, inner cavity 5, upper cavity cover 6, gate valve 7, second negative pressure device 8, pressure controller 9, carrier disc 10, lifting system 11, carrier 12, exhaust hole 13, input port 14, mounting port 15, gas outlet channel 16, edge boss 17, gas outlet hole 18, valve 19, outer cavity 20, partition 21, reaction inner cavity 22, non-reaction area 23, inert gas input pipeline 24. DETAILED DESCRIPTION

[0022] Embodiment 1

[0023] In combination Figure 1 and Figure 2 As shown in the figure, the embodiment provides an inner cavity structure with a conical partition, which comprises an inner cavity 5 main body, wherein a carrier 12 adapted to place a wafer carrier disc is arranged in the inner cavity 5; a partition 21 is arranged above the carrier 12, and the partition 21 is adapted to form a conical reaction space with an opening gradually increasing from top to bottom above the carrier 12, and the top of the conical reaction space is adapted to be connected with a reaction source so that the entering reaction source can be uniformly distributed on the surface of the carrier 12. The partition 21 is integrally formed inside the inner cavity 5, and the partition 21 is adapted to separate the inner cavity 5 into a reaction inner cavity 22 and a non-reaction area 23, and an exhaust channel 16 is arranged between the reaction inner cavity 22 and the non-reaction area 23, and a first negative pressure device 1 is connected to the non-reaction area 23 to exhaust the gas in the reaction inner cavity 22 through the exhaust channel 16. A plurality of gas outlet holes 18 are arranged in a ring shape at the connection between the reaction inner cavity 22 and the non-reaction area 23 to form the exhaust channel 16. In this embodiment, by arranging the conical reaction space to cover above the carrier 12, the reaction source can be quickly and uniformly distributed above the carrier 12, and the reaction uniformity is improved. Further, the ring-shaped gas outlet holes are arranged to exhaust the excess reaction source, generated by-products and carrier gas, etc., which can realize the laminar flow of the gas in the reaction inner cavity 22, and further improve the reaction uniformity.

[0024] Embodiment 2

[0025] In combination Figure 3 and Figure 4 As shown in the figure, the embodiment provides a double-cavity structure, which comprises an outer cavity 20 and an inner cavity 5 with a conical partition arranged in the outer cavity 20; wherein a carrier 12 adapted to place a wafer carrier disc 10 is arranged in the inner cavity 5; and the inner cavity 5 is adapted to be connected with a reaction source to complete the film coating process in the inner cavity. By independently arranging the inner and outer cavities, the maintenance of the inner cavity can be facilitated.

[0026] Embodiment 3

[0027] In combinationFigure 4 As shown, the embodiment discloses a PEALD device with a chamber structure with a conical partition, which comprises a plasma source 2, a pumping system, and further comprises a chamber with the conical partition 5, an outer chamber 20, a lifting system 11 and a carrier 12; wherein the plasma source 2 is connected to the inner chamber 5 to supply plasma to the inner chamber 5; the inner chamber 5 is arranged inside the outer chamber 20, and an opening is formed at the bottom of the inner chamber 5 to match the carrier 12; the pumping system comprises a first negative pressure device 1 and a second negative pressure device 8, the first negative pressure device 1 is connected to the inner chamber 5 to pump away the gas in the inner chamber 5; the second negative pressure device 8 is connected to the outer chamber 20 to form a vacuum environment in the outer chamber 20; the carrier 12 is arranged in the outer chamber 20 and is adapted to fit the opening at the bottom of the inner chamber 5 to form a reaction chamber 22; the lifting system 11 is connected to the carrier 12 to control the connection and separation of the carrier 12 and the inner chamber 5.

[0028] In combination Figure 4 As shown, in the embodiment, the plasma source 2 generates plasma by radio frequency (RF) or microwave excitation, such as capacitively coupled plasma (CCP) or inductively coupled plasma (ICP), and the embodiment is described by taking ICP as an example. The plasma source 2 comprises a gas inlet 3, and process gases such as N2, O2, NH3, H2, argon, etc. are introduced from the gas inlet 3 by MFC to form N-containing plasma and active free radicals after ICP dissociation. A precursor inlet 4 is also arranged at the output port of the plasma source 2, and the precursor inlet 4 can introduce a MO source such as TMA.

[0029] In combination Figures 1 to 6 As shown, the outer chamber 20 and the inner chamber 5 form a chamber; the inner chamber 5 is arranged in the outer chamber 20, and the entire process is implemented in the inner chamber 5. Specifically, the outer chamber 20 is provided with an upper chamber cover 6, the upper chamber cover 6 is provided with an exhaust hole 13 for connecting the first negative pressure device 1, and is also provided with an output port of the plasma source 2 for connecting the plasma source 2. The side is provided with a mounting port 15 of the second negative pressure device 8 and a connecting port of the inert gas input pipeline 24. The inner chamber 5 is detachably mounted in the outer chamber 20, specifically, it can be mounted below the upper chamber cover 6 by bolts. Here, sealing ring devices are arranged at the connecting parts of the outer chamber 20 to ensure that the outer chamber 20 can be in a high vacuum state. In the embodiment, the first negative pressure device 1 adopts a dry pump, and the second negative pressure device 8 adopts a molecular pump, a valve 19 is arranged on the dry pump, and a gate valve 7 is arranged on the molecular pump for controlling opening and closing.

[0030] In combination Figures 1 to 6As shown, the inner cavity 5 is arranged to be wholly surrounded by the outer cavity 20. The inner cavity 5 is internally provided with a partition 21, the upper and lower ends of the partition 21 are respectively connected to the output port of the plasma source 2 and the carrier 12, so as to divide the inner cavity 5 into the reaction inner cavity 22 and the non-reaction area 23, the reaction inner cavity 22 and the non-reaction area 23 are provided with a gas outlet passage 16, and the first negative pressure device 1 is connected in the non-reaction area 23. Specifically, the partition 21 makes the reaction inner cavity 22 form a tapered reaction space, the tapered reaction space is gradually increased in opening along the advancing direction of the plasma, so as to make the plasma uniformly distributed on the surface of the carrier 12. The tapered reaction space can be a conical shape, or a horn shape, so that the plasma entering from the plasma source 2 can be gradually diffused to the surface of the entire carrier 12 through the tapered reaction space, so that the plasma and the process gas are uniformly distributed on the entire carrier 12, and the reaction uniformity is improved. The bottom of the partition 21 and the connection of the shell are provided with the gas outlet passage 16, and the gas outlet passage 16 is suitable for guiding the gas in the reaction inner cavity 22 to the non-reaction area 23.

[0031] In combination Figures 1 to 2 As shown, in the embodiment, the gas outlet passage 16 is annularly arranged with a plurality of gas outlet holes 18, and the plurality of gas outlet holes 18 are uniformly distributed around the circumference. It should be noted that the bottom of the partition 21 is open here, which is used to cover the carrier 12 and jointly form the reaction inner cavity 22 with the carrier 12. The annularly arranged gas outlet holes 18 are arranged, and the gas flow uniformly flows out from the bottom of the inner cavity 5, which is beneficial to realize the stable laminar flow of the gas and improve the film thickness uniformity.

[0032] In combination Figures 4 to 6As shown, the carrier 12 is adapted to match with the inner cavity 5 shell, the periphery of the carrier 12 is provided with an edge boss 17, the top surface of the edge boss 17 is connected with the shell part of the inner cavity 5 by metal surface contact, it is noted that the contact here is not sealed by a sealing ring, but only by metal surface contact, which can prevent the equipment from being damaged due to excessive gas pressure in the reaction inner cavity 22, and facilitate separation from the inner cavity 5. After forming the reaction inner cavity 22, the gas outlet channel 16 is located on the inner side of the edge boss 17, so as to facilitate the gas in the reaction inner cavity 22 to be discharged from the non-reaction area 23. The carrier 12 is internally integrated with a heating resistance wire and a thermocouple, the heating range is RT-450℃, which is used for heating the carrier disc 10 placed in the carrier 12. The carrier 12 is provided below with the lifting system 11, which can adopt an existing lifting mechanism, such as a lifting motor, etc. The lifting system 11 can control the heating carrier disc 10 to move up and down, when rising, it can cooperate with the inner cavity 5 to form the reaction inner cavity 22, so as to start the coating process; when descending, the carrier 12 is separated from the inner cavity 5, so that the carrier disc 10 in the carrier 12 can be taken out.

[0033] In combination Figure 4 As shown, the outer cavity 20 is provided with a pressure controller 9 adapted to control the inert gas entering, the pressure controller 9 is arranged on the inert gas input pipeline 24, the pressure controller 9 is configured to automatically adjust the gas flow size of the inert gas input pipeline 24 according to the preset value, so as to form a stable pressure difference between the inner and outer cavities, and the pressure of the outer cavity 20 is greater than that of the inner cavity 5, so as to prevent the process gas in the inner cavity 5 from diffusing outward to the outer cavity 20. Here, the pressure controller 9 can input inert gas to control the pressure in the outer cavity 20, so as to form a stable pressure difference between the inner and outer cavities, and the pressure of the outer cavity 20 is always greater than that of the inner cavity 5 during the whole process, for example, the pressure of the outer cavity 20 is 2torr, and the pressure of the inner cavity 5 is 0.5-0.8torr, which plays a role in preventing the process gas from diffusing outward to the outer cavity 20 to cause the outer cavity 20 to be contaminated by coating, and the gas permeating into the inner cavity 5 is only a small amount of inert gas, which has no negative impact on the reaction. The inert gas used in the embodiment can be argon.

[0034] The unique inner and outer cavity design adopted in the embodiment, the chemical reaction during the PEALD process is only carried out in the inner cavity 5, the inner cavity 5 and the outer cavity 20 work relatively independently, and since the inner cavity 5 can be separately detached, only the inner cavity 5 needs to be detached for sand blasting maintenance during maintenance, and the outer cavity 20 does not need to be maintained. Compared with the traditional open single-cavity structure, the device maintenance process is simplified, and the components that need to be maintained are reduced. At the same time, the setting reduces the surface area of the adsorbed precursor, improves the utilization rate of the precursor, and reduces the coating cost.

[0035] In combination Figure 7 As shown, in operation, the process is as follows:

[0036] S1, first open the second negative pressure device 8 to vacuum the outer cavity 20, and then the mechanical arm transmits the wafer-loaded carrier 10 from the sample cavity into the forming cavity by vacuum, and places it on the carrier 12 for heating;

[0037] S2, after heating, the lifting system 11 drives the carrier 12 to rise to contact and tightly abut the inner cavity 5, so that the reaction inner cavity 22 is formed between the inner cavity 5 and the carrier 12;

[0038] S3, close the second negative pressure device 8 and open the first negative pressure device 1, so that the state of high vacuum extracted by the second negative pressure device 8 is switched to the process gas extracted by the first negative pressure device 1;

[0039] S4, the process includes:

[0040] At the beginning of the process, after a given pressure set value, the inert gas enters the outer cavity 20 through the pressure controller 9, and the pressure controller 9 automatically adjusts the gas flow according to the set value, so that the inert gas in the outer cavity 20 is always in a steady state of flow. When the pressure of the outer cavity 20 reaches the set pressure, a stable pressure difference is formed between the inner cavity 5 and the outer cavity 20, and the pressure of the outer cavity 20 is always greater than the pressure of the inner cavity 5 during the entire process;

[0041] The process gas enters from the precursor inlet 4, and the gas source such as NH3 is introduced from the gas inlet 3 of the plasma source 2, and the ICP dissociation forms plasma and active free radicals. The entire PEALD process uses inert gas (such as argon) as a carrier gas and a purge gas for the process gas, so that the entire PEALD cycle is carried out in the reaction inner cavity 22. During the reaction process, the excess process gas, purge gas, and reaction byproducts are uniformly extracted through the gas outlet channel 16, and then extracted through the first negative pressure device 1;

[0042] S5, after the process is completed, the lifting system 11 is lowered to drive the carrier 12 to descend and remain in the lowered position, at which time the inner cavity 5 and the outer cavity 20 are in communication. Open the second negative pressure device 8 and close the first negative pressure device 1. Under the suction of the second negative pressure device 8, the outer cavity 20 is in a high vacuum state, and the carrier 10 is taken out by the mechanical arm.

[0043] Through the process scheme of the embodiment, the surface area of the adsorbed precursor can be reduced, the utilization rate of the precursor can be improved, the film coating cost can be reduced, and the film coating efficiency can be improved.

[0044] It should be understood that the above are only preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments, and any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application.

[0045] The above description of the drawings used in the embodiments only shows some embodiments of the present application, and should not be considered as limiting the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

Claims

1. An internal cavity structure with a conical partition, characterized by, The inner cavity is provided with a stage for placing a wafer carrier, a partition is arranged above the stage, the partition is adapted to form a tapered reaction space with gradually increasing opening from top to bottom above the stage, and a reaction source is connected above the tapered reaction space so that the incoming reaction source can be uniformly distributed on the surface of the stage.

2. The inner cavity structure with conical partitions according to claim 1, characterized in that, The partition is adapted to divide the inner cavity into a reaction inner cavity and a non-reaction area, an air outlet channel is arranged between the reaction inner cavity and the non-reaction area, and a first negative pressure device is connected to the non-reaction area to draw the gas in the reaction inner cavity away through the air outlet channel.

3. The inner cavity structure with conical partitions according to claim 2, characterized in that, A plurality of air outlet holes are annularly arranged at the connection between the reaction inner cavity and the non-reaction area to form the air outlet channel.

4. The inner cavity structure with conical partitions according to claim 2, wherein, The stage is detachably arranged below the inner cavity, and a lifting system is connected to the stage to drive the stage to move up and down, and the stage is adapted to form the reaction inner cavity together with the inner cavity when rising to a specified position.

5. The inner cavity structure with conical partitions according to claim 4, characterized in that, A side of the stage is provided with an edge boss, and the edge boss is connected to the shell of the inner cavity through metal surface contact.

6. A PEALD apparatus with a conical spacer body of the inner cavity structure, characterized in that, The PEALD device comprises the inner cavity structure with a tapered partition according to any one of claims 1-5.

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