Thin film deposition apparatus
By setting multiple branch pipelines on the side of the wafer boat of the thin film deposition device and selecting branch pipelines of different inner diameters according to different height positions, the problem of uneven film thickness during film growth is solved, and more uniform film growth is achieved.
Patent Information
- Application Number
- CN202311631965.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-30
- Publication Date
- 2025-05-30
AI Technical Summary
In the prior art, when the film grows on the wafer surface, the film thickness uniformity is poor, especially at the upper part of the furnace tube, the film growth rate is faster than the central part, resulting in uneven film thickness.
A thin film deposition device is designed. By setting up multiple branch pipelines on the side of the crystal boat, the air outlets of each branch pipeline are located at different heights of the crystal boat, and branch pipelines of different inner diameters are selected to adjust the gas flow rate at each position and ensure uniform gas concentration.
By adjusting the inner diameter and gas flow of the branch pipeline, the film is grown more uniformly on the wafer surface, and the film thickness uniformity is improved.
Smart Images
Figure CN120060819A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of semiconductor technology and relates to a thin film deposition apparatus. Background Art
[0002] During the semiconductor manufacturing process, thin films with different functions need to be deposited on the surface of wafers. For example, a silicon nitride thin film can protect the wafer from external corrosive substances and mechanical damage, and is also used as a protective layer for leads and bonding pads in the integrated circuit packaging process.
[0003] In the prior art, when using a vertical furnace tube to process wafers to form a thin film on the wafer surface, one or more deposition gases are introduced into the processing chamber. The deposition gases enter from the lower part of the furnace tube and diffuse upward through the wafers to the upper part of the furnace tube. The deposition gases diffuse well among the wafers in the lower part of the furnace tube, so the film thickness uniformity of the grown thin film is good. However, when the deposition gases diffuse to the top of the furnace tube, a lot of them have been consumed by the lower wafers, resulting in uneven diffusion among the wafers at the top of the furnace tube. This causes the film growth rate at the edge part of the wafers in the upper part of the furnace tube to be faster than that at the central part, so the film thickness uniformity of the grown thin film is poor. And because the concentration of the deposition gases in the lower part of the furnace tube is higher than that in the upper part, the thickness of the thin film grown on the surface of the wafers in the upper part of the furnace tube is less than that in the lower part, and the film thickness uniformity in the furnace tube is poor.
[0004] Therefore, it is necessary to provide a new thin film deposition apparatus. Summary of the Invention
[0005] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a thin film processing apparatus for solving the problems of poor film thickness uniformity and non-uniformity of the thin film on the wafer surface in the prior art.
[0006] To achieve the above object and other related objects, a thin film deposition apparatus includes:
[0007] A processing chamber;
[0008] A susceptor located in the processing chamber for horizontally placing a plurality of wafers, and the plurality of wafers are arranged at intervals along the height direction of the susceptor;
[0009] An intake pipeline including a main pipeline and a plurality of branch pipelines connected to the main pipeline and in parallel with each other. The plurality of branch pipelines are arranged on the side of the susceptor, and the ends of the plurality of branch pipelines are respectively provided with air outlets for introducing process gases into the processing chamber, and the air outlets are respectively located at different positions in the height direction of the susceptor;
[0010] Wherein the inner diameters of the plurality of branch pipelines are different and satisfy the following relationship:
[0011]
[0012] n represents the number of branch pipelines, and the gas flow rates to be set for the multiple branch pipelines are q v1 、q v2 、…、q vn , the lengths of the multiple branch pipelines are respectively (l + ∑l e ) 1 、(l + ∑l e ) 2 、…、(l + ∑l e ) n , the inner diameters of the multiple branch pipelines are respectively d1, d2, …, dn, and the resistance coefficients of the multiple branch pipelines are respectively λ 1 、λ 2 、…、λ n .
[0013] Optionally, the multiple branch pipelines are fixedly connected to the main pipeline.
[0014] Optionally, the multiple branch pipelines are pluggably connected to the main pipeline.
[0015] Optionally, the thin film deposition device further includes a connection MFC with the main pipeline for controlling and regulating the total gas flow rate entering the processing chamber.
[0016] Optionally, the multiple branch pipelines include a first branch pipeline, a second branch pipeline and a third branch pipeline, and the outlet positions of the first branch pipeline, the second branch pipeline and the third branch pipeline increase sequentially along the height direction of the susceptor.
[0017] Optionally, the gas flow rate of the second branch pipeline is lower than the gas flow rates of the first branch pipeline and the third branch pipeline.
[0018] Optionally, the outlets of the multiple branch pipelines are fan-shaped nozzles.
[0019] Optionally, the multiple branch pipelines include a first branch pipeline and other branch pipelines whose outlet positions increase sequentially along the height direction of the susceptor, and the gas flow rate of the first branch pipeline is greater than the gas flow rates of each of the other branch pipelines.
[0020] As described above, the thin film deposition device of the present invention sets multiple branch pipelines on the side of the susceptor at different heights, and selects branch pipelines with corresponding inner diameters to enable the outlet of each branch pipeline to eject reaction gases with different flow rates, which is convenient for controlling the concentration of reaction gases at different positions of the thin film deposition device and helps to improve the uniformity of the film layer when forming a film layer on the wafer surface. Description of the Drawings
[0021] Figure 1It is a schematic structural diagram of the thin film deposition device in the embodiment of the present invention.
[0022] Figure 2 It is a schematic diagram of the intake pipeline in the embodiment of the present invention. Detailed implementation manners
[0023] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0024] When detailing the embodiments of the present invention, for the sake of convenience of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.
[0025] For the sake of convenience of description, spatial relationship terms such as "below", "beneath", "lower", "below", "under", "above", "upper", "on" etc. may be used here to describe the relationship between one element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to include other directions of the device in use or operation in addition to the directions depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can also be one or more intervening layers. As used herein, "between... and..." means including the endpoint values.
[0026] In the context of the present application, the structure in which the first feature is "above" the second feature may include an embodiment in which the first and second features are formed in direct contact, and may also include an embodiment in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.
[0027] It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.
[0028] Such as Figure 1As shown in the figure, this embodiment provides a thin film deposition apparatus, which includes a processing chamber 100, a susceptor 200 located in the processing chamber 100, an inlet gas pipeline 300 for introducing gas into the processing chamber 100, and an exhaust gas pipeline 400 for discharging gas from the processing chamber 100. A plurality of wafers W are horizontally placed at specific intervals in the height direction of the susceptor 200. The gas supplied by the inlet gas pipeline 300 to the processing chamber 100 is a reaction gas that can form a thin film on the wafers W respectively, and the gas discharged by the exhaust gas pipeline 400 is the remaining reaction gas and reaction by-products.
[0029] Reference Figure 2 As shown in the figure, the inlet gas pipeline 300 includes a main pipeline 340 and a plurality of branch pipelines communicated with the main pipeline 340. A plurality of mutually parallel branch pipelines are connected to the main pipeline 340. The main pipeline 340 is connected with an MFC (Mass Flow Controller), and the MFC controls the film thickness formed on the surface of the wafer W by adjusting the gas flow rate flowing into the main pipeline 340. In order to ensure that the wafers W on the susceptors at different heights can obtain sufficient process gas, there are at least 2 branch pipelines, and the gas concentration can be adjusted at different positions in the height direction of the susceptor 200. The plurality of branch pipelines extend to different heights in the processing chamber 100, and the plurality of branch pipelines are arranged on the side of the susceptor 200. An air outlet facing the wafer W is provided at the end of each branch pipeline. As Figure 2 As shown in the figure, in one embodiment, the branch pipelines include a first branch pipeline 310, a second branch pipeline 320, and a third branch pipeline 330 at different heights, and the air outlets of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330 are sequentially increased along the height direction of the susceptor 200; in another embodiment, the branch pipelines are only limited to the first branch pipeline 310 and the second branch pipeline 320; in other embodiments, the branch pipelines may not be limited to the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330, and may also include other branch pipelines at different heights.
[0030] The plurality of branch pipelines extend to different heights in the processing chamber 100, so that the gas flows out from different positions in the height direction of the susceptor 200, making the gas concentration at different height positions of the susceptor 200 more consistent, and solving the problem that the concentration of the deposition gas at the lower part of the furnace tube is higher than that at the upper part of the furnace tube. However, since the lower process gas will diffuse upward and the upper process gas will diffuse downward, the gas flow rate requirements for the branch pipelines at different heights are different. In order to make the gas distribution more uniform in different height directions of the susceptor 200, the gas flow rate at different height positions of the susceptor 200 can be adjusted by selecting branch pipelines with different inner diameters, so that the thickness uniformity of the thin film formed on the surfaces of the wafers at different height positions of the susceptor 200 is better.
[0031] In one embodiment, the branch pipeline can be fixedly connected to the main pipeline 340, or it can be selectively and pluggably connected to the main pipeline 340. Here, the pluggable connection method facilitates installation and subsequent maintenance. In addition, according to different film thickness requirements, the total gas flow rate into the processing chamber 100 is adjusted by the MFC, and a branch pipeline with a corresponding inner diameter is selected to be combined with the main pipeline 340 to achieve that the gas flow rate of the branch pipeline reaches a preset value. The specific selection can be obtained according to the following calculation method:
[0032] The flow rate distribution relationship of each parallel branch pipeline is as follows:
[0033]
[0034] n represents the number of branch pipelines, and the gas flow rates to be set for multiple branch pipelines are q v1 、q v2 、…、q vn , the lengths of multiple branch pipelines are respectively (l + ∑l e ) 1 、(l + ∑l e ) 2 、…、(l + ∑l e ) n , the inner diameters of multiple branch pipelines 330 are d1, d2, …, dn, and the resistance coefficients of multiple branch pipelines are respectively λ 1 、λ 2 、…、λ n .
[0035] Based on the flow rate distribution relationship of each parallel branch pipeline, combined with the flow rate of each branch pipeline and the length of each branch pipeline, the mutual relationship of the inner diameters of each branch pipeline can be obtained, and branch pipelines with different diameters are selected according to the obtained inner diameter relationship of the branch pipelines.
[0036] In one embodiment, the branch pipeline includes a first branch pipeline 310, a second branch pipeline 320, and a third branch pipeline 330. Then, the flow rate distribution relationship of each parallel branch pipeline is as follows:
[0037]
[0038] Among them, q v1 , q v2 , q v3 are respectively the gas flow rates to be set for the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330, d1, d2, d3 are respectively the inner diameters of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330, (l + ∑l e ) 1 、(l + ∑l e ) 2, (l + ∑l e ) 3 are the lengths of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330 respectively, and λ 1 , λ 2 , λ 3 are the resistance coefficients of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330 respectively.
[0039] In the above embodiment, there are three branch pipelines. The inner diameters of different branch pipelines can be selected according to the above calculation method. In other embodiments, there are other numbers of branch pipelines, which also conform to the flow distribution relationship of the parallel connection of the above branch pipelines. Only the flow rates of the corresponding number of branch pipelines need to be selected for calculation, which will not be elaborated here.
[0040] In one embodiment, the branch pipelines include a first branch pipeline 310, a second branch pipeline 320, and a third branch pipeline 330, and the outlet positions of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330 increase successively along the height direction of the susceptor 200. According to the gas diffusion characteristics, the gas in the lower region of the susceptor 200 and the gas in the upper region of the susceptor 200 will diffuse to the middle region. Therefore, the gas flow rate of the second branch pipeline 320 with the outlet position in the middle region of the susceptor 200 is set to be less than that of the first branch pipeline 310 and the third branch pipeline 330, and the gas flow rate of the first branch pipeline 310 with the outlet in the lower region of the susceptor 200 is set to be the largest. For example, the gas flow rates of the first branch pipeline 310, the second branch pipeline 320, and the third branch pipeline 330 are set to 45 sccm / min, 4 sccm / min, and 35 sccm / min respectively. Combining the flow distribution relationship of the parallel connection of each branch pipeline, the inner diameters of each branch pipeline are obtained. In other embodiments, the branch pipelines include a first branch pipeline and other branch pipelines whose outlet positions increase successively along the height direction of the susceptor 200. According to the gas diffusion characteristics, the gas in the lower region of the susceptor 200 will diffuse to the middle region. Therefore, the flow rate of the first branch pipeline is greater than that of other branch pipelines. The gas flow rates of each branch pipeline will be adjusted according to the measured parameters of the wafer W after film deposition, such as the film thickness and electrical parameters on the surface of the wafer, and the inner diameters of each branch pipeline will also be adjusted adaptively.
[0041] In addition, the outlet of each branch pipeline is a fan-shaped nozzle, which can increase the coverage area of the airflow flowing out of the branch pipeline, increase the dispersion area of the gas, and can better improve the uniformity of the gas concentration and the uniformity of the film thickness on the surface of the wafer W.
[0042] In the present invention, the main pipeline 340 in the thin film deposition device is connected with an MFC, which is used to control and adjust the total gas flow rate entering the processing chamber 100. By selecting branch pipelines with different inner diameters and extending them to different positions in the height direction of the susceptor 200, the gas flow rate at different height positions of the susceptor 200 can be accurately adjusted, so as to make the uniformity of the film thickness formed on the wafer surfaces at different heights of the susceptor 200 better.
[0043] The above embodiments are only used to illustrate the principle and its effects of the present invention by way of example, rather than to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.
Claims
1. A thin film deposition device, characterized in that, comprising: a processing chamber; a susceptor located in the processing chamber for horizontally placing a plurality of wafers, and the plurality of wafers are arranged at intervals along the height direction of the susceptor; an intake pipeline, including a main pipeline and a plurality of branch pipelines connected to the main pipeline and in parallel with each other. The plurality of branch pipelines are arranged on the side of the susceptor, and the ends of the plurality of branch pipelines are respectively provided with air outlets for introducing process gas into the processing chamber, and the air outlets are respectively located at different positions in the height direction of the susceptor; wherein the inner diameters of the plurality of branch pipelines are different and satisfy the following relationship: n represents the number of branch pipelines, and the gas flow rates to be set for the multiple branch pipelines are q v1 , q v2 , …, q vn , the lengths of the multiple branch pipelines are respectively (l + ∑l e ) 1 , (l + ∑l e ) 2 , …, (l + ∑l e ) n , the inner diameters of the multiple branch pipelines are respectively d1, d2, …, dn, and the resistance coefficients of the multiple branch pipelines are respectively λ 1 , λ 2 , …, λ n .
2. The thin film deposition device according to claim 1, characterized in that, the plurality of branch pipelines are fixedly connected to the main pipeline.
3. The thin film deposition device according to claim 1, characterized in that, the plurality of branch pipelines are detachably connected to the main pipeline.
4. The thin film deposition device according to claim 1, characterized in that, it further includes a connection MFC with the main pipeline for controlling and regulating the total gas flow rate entering the processing chamber.
5. The thin film deposition device according to claim 1, characterized in that, the plurality of branch pipelines include a first branch pipeline, a second branch pipeline and a third branch pipeline, and the air outlet positions of the first branch pipeline, the second branch pipeline and the third branch pipeline increase in sequence along the height direction of the susceptor.
6. The thin film deposition device according to claim 5, characterized in that, the flow rate of the second branch pipeline is lower than the flow rates of the first branch pipeline and the third branch pipeline.
7. The thin film deposition device according to claim 1, characterized in that, the air outlets of the plurality of branch pipelines are fan-shaped nozzles.
8. The thin film deposition device according to claim 1, characterized in that, the plurality of branch pipelines include a first branch pipeline and other branch pipelines whose air outlet positions increase in sequence along the height direction of the susceptor, and the flow rate of the first branch pipeline is greater than the flow rates of the other branch pipelines.