Vapor deposition equipment and execution method of vapor deposition process

Abstract

The invention provides vapor deposition equipment and an execution method of a vapor deposition process, belongs to the technical field of vapor deposition, and aims to solve the problem of non-uniform film formation during deposition of two gases in the vapor deposition process. The vapor deposition equipment mainly comprises a reaction cavity; a plurality of gas outlets facing the inner side of the reaction cavity are formed in the lower side of the gas spraying head, and the upper side of the gas spraying head is connected with a first gas source; the upper surface of the base is used for bearing a substrate, and a diffusion space is formed between the base and the gas spraying head; and the gas transmission ring is arranged around the diffusion space, the interior of the gas transmission ring is divided into two opposite gas flow channels, the inner side face of each gas flow channel is provided with a gas outlet communicating with the diffusion space, and the gas transmission ring is mainly used for executing the vapor deposition process.

Description

Technical Field

[0001] The present invention relates to the field of vapor deposition processes, and more particularly to the field of vapor deposition equipment and methods for performing vapor deposition processes. Background Art

[0002] Vapor deposition processes mainly utilize various process gases to react under certain conditions to form an epitaxial layer on the surface of a substrate, mainly including physical vapor deposition (PVD) and chemical vapor deposition (CVD).

[0003] Process gases generally enter the reaction chamber through a gas showerhead. However, as the structure of the substrate surface becomes more complex, the requirement for the uniformity of the formed epitaxial layer is also getting higher. In order to achieve more uniform process growth in an epitaxial layer with a thinner thickness, it is required that various process gases enter the reaction chamber alternately to implement the atomic layer deposition (ALD) technology of monolayer molecular film formation.

[0004] However, when using the existing technology gas showerhead to alternately transport multiple gases, in order to prevent the gases from reacting before reaching the substrate and causing the generation of particle contamination, different gases need to be transported along mutually isolated gas channels, such as a dual-channel showerhead design. However, the processing and design of the showerhead are often more complex, and it is difficult to ensure that both gases are uniformly distributed on the substrate surface, thus affecting the film formation uniformity. Summary of the Invention

[0005] In order to solve the technical problems of particle contamination caused by the reaction of two reaction gases in the showerhead and the non-uniform film formation caused by the gas showerhead transporting different types of gases, the present invention provides a vapor deposition device, including:

[0006] A reaction chamber;

[0007] A gas showerhead, which has a plurality of air outlet holes on its lower side facing the inner side of the reaction chamber, and is connected to a first gas source on its upper side;

[0008] A base, whose upper surface is used to carry a substrate, and a diffusion space is formed between the base and the gas showerhead;

[0009] A gas delivery ring, which is arranged around the diffusion space, and the gas delivery ring includes two relatively arranged gas flow channels, and an air outlet communicating with the diffusion space is provided on the inner side surface of each gas flow channel.

[0010] Optionally, the gas flow channel is connected to a second gas source through an air inlet, and the reaction gases in the first gas source and the second gas source are alternately introduced into the diffusion space.

[0011] Optionally, the gas flow channel is also connected to a suction pump through a suction port.

[0012] Optionally, the air inlet and the air extraction port are oppositely arranged at both ends of the air flow channel.

[0013] Optionally, the air inlets of the two air flow channels are respectively located at the two ends of the two air flow channels that are far apart from each other.

[0014] Optionally, the air flow channel is further connected to a purging gas source.

[0015] Optionally, the air flow channel is connected to a purging gas source through the air inlet.

[0016] Optionally, the air inlet is connected to a manifold. The main pipeline of the manifold is connected to the air inlet. The two branch pipelines of the manifold are respectively connected to a second gas source and a purging origin, and a switching valve is arranged on each branch pipeline.

[0017] Optionally, an air extraction pump is connected to the bottom of the reaction chamber.

[0018] Optionally, the first gas source includes one or more of HfCl4, MoF6, MoCl5, Mo(CO)6, TiCl4, WF6, ZrCl4, and the second gas source includes one or more of H20, O3, H2, B2H6, Si2H6.

[0019] Optionally, a wafer transfer port is arranged on the side wall of the reaction chamber, and the susceptor can be lifted between above and below the plane where the wafer transfer port is located.

[0020] Optionally, it further includes a controller, which is used to open one air flow channel to transport reaction gas to the diffusion space, and then open another air flow channel to transport reaction gas to the diffusion space.

[0021] Optionally, a plurality of auxiliary air channels are further separated in the gas delivery ring for adjusting gas distribution.

[0022] Optionally, the interval of the air outlet gradually decreases from the air inlet to the distal end of the air flow channel; and / or, the caliber size of the air outlet gradually increases from the air inlet to the distal end of the air flow channel.

[0023] Furthermore, the present invention further provides a method for implementing a chemical vapor deposition process, which uses the chemical vapor deposition equipment according to any one of the above, and includes the following steps:

[0024] Input the first reaction gas into the reaction chamber through the gas shower head for a continuous time of T1.

[0025] Input the purging gas into the reaction chamber through the gas shower head for a continuous time of T2.

[0026] Continuously input a second reaction gas into the reaction chamber through a section of the gas flow channel for a time period T3;

[0027] Continuously input a second reaction gas into the reaction chamber through another section of the gas flow channel for a time period T3;

[0028] Continuously input a purge gas into the gas channel for a time period T4.

[0029] Optionally, when continuously inputting a purge gas into the gas channel, the gas channel is simultaneously evacuated.

[0030] Optionally, when continuously inputting a purge gas into the reaction chamber through the gas spray head and continuously inputting a purge gas into the gas channel, the diffusion space is simultaneously evacuated.

[0031] Optionally, the second reaction gas is different from the first reaction gas.

[0032] At least one of the above technical solutions has the following advantages or beneficial effects: By separately feeding two gases into the reaction chamber through a gas spray head and a gas delivery ring, the complex design when using a gas spray head to deliver two gases is avoided, and the gas delivery ring can switch the input of the same gas from both sides to make up for the film formation deviation caused by gas delivery from one side. At the same time, each gas flow channel of the gas delivery ring has air extraction holes, and the air extraction holes and the air inlet are located at both ends of the gas flow channel, which can use the cleaning gas to purge the dead corners of the channel before the next gas delivery to ensure no residue and prevent unwanted mixing during the next gas delivery. In addition, the initial rate of the air outlet of the gas flow channel gradually increases along the circumferential direction, which can further improve the uniform distribution of the gas on the substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 Structural schematic diagram of a chemical vapor deposition device according to an embodiment of the present invention;

[0035] Figure 2 Structural schematic diagram of a chemical vapor deposition device according to another embodiment of the present invention;

[0036] Figures 3A - 3C Structural schematic diagram of a gas delivery ring for different embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] In a vapor deposition apparatus, especially an atomic layer deposition apparatus, in order to achieve thickness control of the deposited layer at the atomic level and obtain excellent vertical uniformity or planar consistency, it is necessary to alternately introduce gases into the reaction chamber. Each time of alternation, only one layer of deposition film is grown on the substrate. During the process of alternate introduction, it is required that the gases diffuse uniformly above the substrate. However, when alternately transporting different gases in the same gas inlet structure, due to reasons such as component processing errors, it is very difficult to ensure that the two gases do not contact. Even if a purge process is added, it is also very difficult to remove gas residues. If the two gases react in advance before reaching the substrate, it will cause blockage of the pores of the gas showerhead or particles formed will fall onto the surface of the substrate, resulting in contamination.

[0039] Figure 1 A schematic structural diagram of a vapor deposition apparatus according to the present invention is shown, which specifically includes a reaction chamber 110 for accommodating various components required for the process reaction and providing the required conditions for the process reaction; a gas showerhead 120 located above the interior of the reaction chamber 110, with a plurality of air outlet holes on its lower side facing the inner side of the reaction chamber, and its upper side is connected to a first gas source 121. In some embodiments, a gas distribution chamber can be provided inside the gas showerhead 120. The gas provided by the first gas source 121 is uniformly diffused through the gas distribution chamber and then discharged from a plurality of air outlet holes uniformly distributed on the lower surface of the gas showerhead 120 to reach above the substrate W for the first-step process reaction; a susceptor 130 located below the interior of the reaction chamber 110, whose upper surface is used to carry the substrate W. The susceptor 130 is disposed opposite to the gas showerhead 120 and a diffusion space is formed therebetween. After the reaction gas is uniformly dispersed in the diffusion space, it can uniformly contact the upper surface of the substrate W to generate the first layer of reactants. In some embodiments, when a wafer transfer port is provided on the side wall of the reaction chamber to transfer the substrate, the susceptor 130 can be lowered below the plane where the wafer transfer port is located, and during the process reaction, the susceptor 130 can be raised above the plane where the wafer transfer port is located.

[0040] An air delivery ring 140 located at a height between the gas showerhead 120 and the susceptor 130, which is arranged around the diffusion space. The interior of the air delivery ring 140 is separated into two relatively arranged air flow channels 141 and 142 by a partition 143. Figure 3AAs shown, an air outlet 145 communicating with the diffusion space is provided on the inner side surface of each section of the air flow channel. The air flow channels 141 and 142 of the air delivery ring 140 can independently input reaction gases into the diffusion space respectively, avoiding contact with the gases in the gas spray head 120. At the same time, in order to avoid the air flow collision caused by inputting gases from the side, the air flow channels 141 and 142 can introduce gases from two directions successively, and finally a uniform deposition layer is formed on the surface of the substrate W. In some embodiments, the air flow channel is connected with a second gas source 143 through an air inlet, and the reaction gases in the first gas source 121 and the second gas source 143 are alternately introduced into the diffusion space. Specifically, after the gas spray head 120 conveys the reaction gas, the controller can selectively choose the air flow channel. For example, the air flow channel 142 allows the reaction gas 1431 of the second gas source to be blown into the diffusion space from the left side to react with the first layer of reactants generated by the first gas source 121 on the surface of the substrate W to generate the required deposition film. However, at this time, it will inevitably cause the deposition film to be thick in the area of the substrate W close to the air flow channel 142 and thin in the area of the substrate W far from the air flow channel 142. Therefore, in the next step, the reaction gas 1431 is blown into the diffusion space from the right side through the air flow channel 141, and thus a uniform deposition layer is obtained on the surface of the substrate W by comprehensive consideration of both sides.

[0041] Among them, the first gas source 121 and the second gas source 143 can be different types of single gases or mixed gases with different component ratios. If the target deposition layer is hafnium oxide HfO2, one of the first gas source and the second gas source can be hafnium tetrachloride HfCl4, and the other can be water vapor H2O or ozone O3; when the deposition layer is Mo, one of the first gas source and the second gas source can be molybdenum hexafluoride MoF6, molybdenum pentachloride MoCl5 or molybdenum hexacarbonyl Mo(CO)6, and the other can be hydrogen H2; when the deposition layer is titanium oxide TiO2, one of the first gas source and the second gas source can be titanium tetrachloride TiCl4, and the other can be H2O; when the deposition layer is tungsten W, one of the first gas source and the second gas source can be tungsten hexafluoride WF6, and the other can be diborane B2H6 or disilane Si2H6; when the deposition layer is zirconium oxide ZrO2, one of the first gas source and the second gas source can be zirconium tetrachloride ZrCl4, and the other can be H2O.

[0042] Such as Figure 2The gas deposition equipment shown is another embodiment of the present invention. The difference between this embodiment and the above embodiment is that an air extraction pump 111 is connected to the air flow channels 141 and 142 through an air extraction port to extract the gas in the air flow channels, further avoiding the residue of the second source gas in the pipeline. At the same time, the first source gas can be extracted by the air extraction pump connected to the reaction chamber. In some embodiments, the two air extraction pumps can be the same one. In order to remove the reaction gas in the air flow channels more thoroughly, the air flow channels can also be connected to a purge gas source 144, and purge gas is introduced during the air extraction process to accelerate the flow of the purge gas in the air flow channels and purge the reaction gas that may exist in the dead corners of the gas transmission ring 140 structure. Among them, the purge gas source 144 can share a main gas transmission line with the second gas source 143 through a manifold and enter the air flow channels through the gas transmission ports of the air flow channels 141 and 142. In addition, a plurality of on-off valves 1421, 1422, 1423, 1411, 1412 and 1413 are provided on the branch of the manifold and the pipeline connected to the air extraction pump 111 to control the timing of introducing different gases and air extraction. The purge gas can be an inert gas, such as helium. In some embodiments, by adjusting the intensity of the air extraction pump 111, the reaction gas introduced into the air flow channels 141 and 142 can flow faster in the air flow channels to promote the uniform distribution of the reaction gas.

[0043] As Figures 3A - 3C shown is a top view of the gas transmission ring 140 of different embodiments of the cross-section along the Figure 1 A-A line of Figure 3A In it, the reaction gas 1431 enters from the intake port at the upper end of the arc-shaped air flow channel and enters the diffusion space above the substrate from the air outlet 145 on the inner side. At the same time, the purge gas can also enter from the same intake port, while the air extraction port 146 is located at the far end opposite to the intake port. In this way, during air extraction, the purge gas will not be extracted in advance but will traverse the inside of the air flow channel. In this embodiment, the interval of the air outlet 145 along the direction of the reaction gas 1431 gradually decreases, or the diameter of the air outlet gradually increases along the direction of the reaction gas 1431, that is, as Figure 3A shown, the degree of blocking of the reaction gas is changed from the intake port to the far end of the air flow channel to offset the non-uniformity caused by the time difference of the reaction gas flowing through the air outlet 145 along the circumference. In other embodiments, the intake port can also be located in the middle of the air flow channel, or the air extraction port 146 is located at the corresponding two ends.

[0044] As Figure 3B shown, the difference from the above embodiment is that the gas transmission ring can be composed of two separated segments, making the air flow channels 141 and 142 not connected. As Figure 3CAs shown, the difference from the above embodiment is that the air inlets of the two sections of the gas flow channels are located at opposite ends. Correspondingly, the air extraction ports 146 are also located at opposite ends, thereby compensating for the flow rate difference of the air outlets at different positions on the reaction gas flow path in one section of the gas flow channel. In the above embodiment, in addition to the gas flow channels that mainly play a ventilation role in the gas delivery ring, multiple auxiliary air channels can also be included to flexibly adjust the gas distribution above the substrate.

[0045] Furthermore, the present invention also provides an execution method for a chemical vapor deposition process, in combination with Figure 2 using the above chemical vapor deposition equipment, specifically including the following steps:

[0046] S1. Continuously input the first reaction gas into the reaction chamber through the gas spray head 120 for a time T1, so that the first layer of reactants is adsorbed on the surface of the substrate W. During this process, the switching valves 1411, 1412, 1413, 1421, 1422, and 1423 are all in the closed state. During the process, parameters such as the heating temperature and air pressure can also be adjusted according to needs;

[0047] S2. Continuously input the purge gas into the reaction chamber through the gas spray head 120 for a time T2. At the same time, the air extraction pump below the reaction chamber can also be kept open to cooperate with the purge gas to purge the first reaction gas in the gas spray head 120 and the diffusion space, preventing the second reaction gas from undergoing a chemical reaction before contacting the substrate. During this process, the switching valves 1411, 1412, 1413, 1421, 1422, and 1423 are also in the closed state;

[0048] S3-1. Open the switching valve 1411 and continuously input the second reaction gas into the reaction chamber through the gas flow channel 141 for a time T3, so that the first layer of reactants can react with the second reaction gas to form the first deposition layer;

[0049] S3-2. Close the switching valve 1411, open the switching valve 1421, and continuously input the second reaction gas into the reaction chamber through the gas flow channel 142 for a time T3. The time for introducing the second reaction gas in the two steps is basically the same, only the direction of the gas flow is opposite, to compensate for the first layer of reactants that were not completely reacted in the previous step from the other side, and a relatively uniform and consistent deposition layer is obtained on the surface of the substrate;

[0050] S4. Close the switching valves 1411 and 1421, open the switching valves 1413 and 1423, and continuously input the purge gas into the two gas channels for a time T4 to purge the remaining second reaction gas and prepare for the next introduction of the first reaction gas. At the same time, the switching valves 1412 and 1422 can also be opened to evacuate the gas channels. The air extraction pump at the bottom of the reaction chamber can also continue to be kept open so that the purge gas can also purge the diffusion space through the air outlet of the gas delivery ring 140.

[0051] S1 - S4 constitute a process cycle. The specific implementation process may include multiple process cycles to achieve the deposition of a thin film with a certain thickness.

[0052] Although the content of the present invention has been introduced in detail through the above - mentioned preferred embodiments, it should be recognized that the above description should not be regarded as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A vapor deposition device, characterized in that, Comprising: A reaction chamber; A gas showerhead, having a plurality of air outlets on its lower side facing the inner side of the reaction chamber, and connected to a first gas source on its upper side; A pedestal, whose upper surface is used to carry a substrate, and a diffusion space is formed between the pedestal and the gas showerhead; A gas delivery ring, which is arranged around the diffusion space, the gas delivery ring includes two oppositely arranged air flow channels, and the inner side surface of each air flow channel is provided with an air outlet communicating with the diffusion space.

2. The vapor deposition device according to claim 1, wherein The air flow channel is connected to a second gas source through an air inlet, and the reaction gases in the first gas source and the second gas source are alternately introduced into the diffusion space.

3. The vapor deposition apparatus according to claim 2, wherein The air flow channel is also connected to a suction pump through a suction port.

4. The vapor deposition apparatus according to claim 3, characterized in that, The air inlet and the suction port are oppositely arranged at both ends of the air flow channel.

5. The vapor deposition device according to claim 2, characterized in that, The air inlets of the two air flow channels are respectively located at the two ends of the two air flow channels that are far apart from each other.

6. The vapor deposition apparatus according to claim 2, wherein, The air flow channel is also connected to a purging gas source.

7. The vapor deposition apparatus according to claim 3, characterized in that, The air flow channel is connected to a purging gas source through the air inlet.

8. The vapor deposition apparatus according to claim 7, wherein, The air inlet is connected to a manifold, the main path of the manifold is connected to the air inlet, the two branches of the manifold are respectively connected to the second gas source and the purging gas source, and a switching valve is arranged on each branch.

9. The vapor deposition apparatus according to claim 1, characterized in that, A suction pump is connected to the bottom of the reaction chamber.

10. The vapor deposition apparatus according to claim 2, characterized in that, The first gas source includes one or more of HfCl4, MoF6, MoCl5, Mo(CO)6, TiCl4, WF6, ZrCl4, and the second gas source includes one or more of H20, O3, H2, B2H6, Si2H6.

11. The vapor deposition apparatus according to claim 1, characterized in that, A wafer transfer port is arranged on the side wall of the reaction chamber, and the pedestal can be lifted between above and below the plane where the wafer transfer port is located.

12. The vapor deposition apparatus according to claim 1, characterized in that, It further includes a controller, which is used to open one air flow channel to transport the reaction gas to the diffusion space, and then open the other air flow channel to transport the reaction gas to the diffusion space.

13. The vapor deposition apparatus according to claim 1, wherein A plurality of auxiliary air channels are further partitioned inside the gas delivery ring for adjusting the gas distribution.

14. The vapor deposition device according to claim 2, wherein The interval of the air outlets gradually decreases from the air inlet to the distal end of the air flow channel; and / or, the diameter of the air outlets gradually increases from the air inlet to the distal end of the air flow channel.

15. A method for implementing a chemical vapor deposition process, applying the chemical vapor deposition device according to any one of claims 1-14, characterized in that, Including the following steps: Continuously input a first reaction gas into the reaction chamber through the gas showerhead for a time T1; Continuously input a purging gas into the reaction chamber through the gas showerhead for a time T2; Continuously input a second reaction gas into the reaction chamber through one air flow channel for a time T3; Continuously input a second reaction gas into the reaction chamber through the other air flow channel for a time T3; Continuously input a purging gas into the gas channel for a time T4.

16. The execution method according to claim 15, characterized in that, When continuously inputting a purging gas into the gas channel, the gas channel is simultaneously evacuated.

17. The execution method according to claim 16, characterized in that, When continuously inputting a purging gas into the reaction chamber through the gas showerhead and continuously inputting a purging gas into the gas channel, the diffusion space is simultaneously evacuated.

18. The execution method according to claim 17, wherein The second reaction gas is different from the first reaction gas.

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