Wafer edge protection device

Abstract

The application provides a wafer edge protection device, which comprises a cavity and a base, a hot table is arranged in the cavity, the bottom of the hot table is fixed on the base, a wafer placing position is arranged in the middle of the surface of the hot table, a process gas inlet is arranged on the outer wall of the cavity, and an inner lining is arranged around the hot table on the inner wall of the cavity; a ceramic ring, the inner ring surface edge of the ceramic ring is provided with a protection edge, the protection edge is used for covering the edge of a wafer to be treated; the inner ring edge of the inner lining is provided with a limiting clamping groove, the outer ring of the ceramic ring is provided with a guide protrusion matched with the limiting clamping groove, the guide protrusion is embedded in the limiting clamping groove, and the ceramic ring is overlapped on the inner ring of the inner lining; and a lifting mechanism, the driving end of the lifting mechanism is connected with the base, so as to drive the hot table to move upward / downward in the cavity. The device is convenient to operate, and can accurately and effectively protect the edge of the wafer in the deposition process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to a wafer edge protection device. Background Technology

[0002] Chemical vapor deposition (CVD) is a method of synthesizing coatings or nanomaterials by reacting chemical gases or vapors on the surface of a substrate. It is the most widely used technology in the semiconductor industry for depositing a variety of materials, including a wide range of insulating materials, most metallic materials, and metal alloys.

[0003] In metal chemical vapor deposition (MCVD), the wafer edges need to be protected. If the edges are not protected, metal will deposit on the wafer edges and back side, which is unacceptable in the process. Current MCVD processes typically use physical shielding methods such as protective capping plates and protective films to protect the wafer edges. However, this method suffers from inconvenience in operation and inaccurate coverage, failing to provide precise and effective protection for the wafer edges. This results in uneven metal deposition on the inner side of the wafer edges, affecting the deposition process. Summary of the Invention

[0004] In view of this, embodiments of this application provide a wafer edge protection device to achieve the purpose of accurately and effectively protecting the wafer edge from metal deposition.

[0005] This application provides the following technical solution: a wafer edge protection device, comprising:

[0006] The process chamber includes a cavity and a base. A hot stage is disposed inside the cavity. The bottom of the hot stage is fixedly disposed on the base. A wafer placement position is provided in the middle of the surface of the hot stage. A process gas inlet is opened on the outer wall of the cavity above the surface of the hot stage. A cavity liner is provided around the hot stage on the inner wall of the cavity.

[0007] A ceramic ring, which has a ring-shaped structure, has an inner ring surface edge extending towards the center of the ceramic ring to form a protective edge. The inner side of the protective edge forms a wafer edge receiving cavity, which is used to cover the edge of the wafer to be processed. The inner ring edge of the cavity liner is provided with a limiting groove, and the outer ring of the ceramic ring is provided with a guide protrusion adapted to the limiting groove. The guide protrusion is embedded in the limiting groove, so that the ceramic ring overlaps the inner ring of the cavity liner.

[0008] A lifting mechanism is provided, with its drive end connected to the base to drive the heating stage to move up and down within the cavity. When the lifting mechanism drives the heating stage upward, the surface of the heating stage causes the ceramic ring to move upward and detach from the cavity liner, so that the protective edge of the ceramic ring covers the edge of the wafer to be processed. When the lifting mechanism drives the heating stage downward, the guide protrusion on the outer ring of the ceramic ring is embedded in the limiting groove of the cavity liner, so that the ceramic ring detaches from the surface of the heating stage and overlaps the inner ring of the cavity liner.

[0009] According to one embodiment of this application, the ceramic ring has an annular groove formed from the bottom wall inward, and a communicating channel is formed between the annular groove and the wafer edge receiving cavity, the communicating channel connecting the annular groove and the wafer edge receiving cavity;

[0010] The base opens a gas channel into the interior of the hot stage. The outlet end of the gas channel is connected to the annular groove, and the inlet end of the gas channel is supplied with protective gas. The protective gas enters the annular groove from the gas channel, passes through the connecting channel, and enters the wafer edge receiving cavity to purge the edge of the wafer to be processed.

[0011] According to one embodiment of this application, the height H and width W of the connecting channel satisfy W / H>4.

[0012] According to one embodiment of this application, the gas channel is provided with a plurality of gas outlets, which are evenly distributed within the annular groove.

[0013] According to one embodiment of this application, the inner edge of the protective ring of the ceramic ring is chamfered.

[0014] According to one embodiment of this application, the angle θ at the chamfer is 30-60°.

[0015] According to one embodiment of this application, a gas equalization device is further provided in the cavity. The gas equalization device is fixed between the hot stage surface and the process gas inlet, so that the process gas entering the cavity through the process gas inlet passes through the gas equalization device and is then deposited on the wafer to be processed at the wafer placement position on the hot stage surface.

[0016] According to one embodiment of this application, the hot stage includes a horizontal platform and a vertical support base, making the side profile of the hot stage T-shaped. The bottom of the vertical support base is fixed to the base, and a corrugated pipe is sealed around the base. The corrugated pipe connects the side wall of the cavity and the base, together forming the process cavity. The corrugated pipe can be compressed or extended by the lifting mechanism driving the base.

[0017] According to one embodiment of this application, a plurality of limiting slots are evenly spaced on the inner edge of the cavity liner, and a plurality of guide protrusions are correspondingly spaced on the outer edge of the ceramic ring.

[0018] According to one embodiment of this application, the width L of the protective edge of the ceramic ring is 3-6 mm.

[0019] Compared with existing technologies, the wafer edge protection device in this invention achieves effective protection of the wafer edge through the structural design of the ceramic ring. During metal chemical vapor deposition, the process gas enters the process chamber and can be uniformly deposited on the wafer surface. The wafer edge is protected by the ceramic ring, preventing metal deposition. The mating structure between the ceramic ring and the chamber liner makes the wafer edge protection operation very convenient, with good protection effect and high yield. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the wafer edge protection device according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the ceramic ring and the cavity liner in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the separation of the ceramic ring from the cavity liner in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the ceramic ring structure according to an embodiment of the present invention;

[0025] Figure 5 yes Figure 4 Sectional view of the EE plane;

[0026] Figure 6 yes Figure 5 Partial view at point F;

[0027] Among them, 1-cavity, 2-gas equalization device, 3-wafer, 4-cavity liner, 5-ceramic ring, 6-heating stage, 7-corrugated pipe, 8-base. Detailed Implementation

[0028] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments, providing a clear and complete description of the technical solutions of the present invention. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, an embodiment of the present invention provides a wafer edge protection device, comprising:

[0031] The process cavity includes a cavity body 1 and a base 8. A hot stage 6 is provided inside the cavity body 1. The bottom of the hot stage 6 is fixedly mounted on the base 8. A wafer placement position is provided in the middle of the surface of the hot stage 6. A process gas inlet is opened on the outer wall of the cavity body 1 above the surface of the hot stage 6. A cavity liner 4 is provided around the hot stage 6 on the inner wall of the cavity body 1.

[0032] The ceramic ring 5 has a ring-shaped structure. The inner edge of the ceramic ring 5 extends towards the center of the ceramic ring 5 to form a protective edge. The inner side of the protective edge forms a wafer edge receiving cavity. The protective edge is used to cover the edge of the wafer to be processed. The inner edge of the cavity liner 4 is provided with a limiting groove. The outer ring of the ceramic ring 5 is provided with a guide protrusion that matches the limiting groove. The guide protrusion is embedded in the limiting groove, so that the ceramic ring 5 overlaps the inner ring of the cavity liner 4.

[0033] A lifting mechanism (not shown in the figure) is connected to the base 8 at its drive end to drive the hot stage 6 to move up / down within the cavity 1. When the lifting mechanism drives the hot stage 6 to move upward, the surface of the hot stage 6 causes the ceramic ring 5 to move upward and detach from the cavity liner 4, so that the protective edge of the ceramic ring 5 covers the edge of the wafer to be processed. When the lifting mechanism drives the hot stage 6 to move downward, the guide protrusion on the outer ring of the ceramic ring 5 is embedded in the limiting groove of the cavity liner 4, so that the ceramic ring 5 detaches from the surface of the hot stage 6 and overlaps the inner ring of the cavity liner 4.

[0034] In this embodiment, during the metal chemical vapor deposition process, the hot stage 6 moves up and down, causing the ceramic ring 5 to separate and reconnect with the cavity liner 4. Figures 2-3As shown. The lifting mechanism drives the hot stage 6 downwards. During this downward movement, the outer ring of the ceramic ring 5 overlaps with the inner ring of the cavity liner 4, detaching from the surface of the hot stage 6. At this point, the hot stage 6 descends to a certain height, and the robotic arm for transporting wafers places the wafer to be processed onto the wafer placement position on the surface of the hot stage 6. After placement, the lifting mechanism drives the hot stage 6 upwards. During this upward movement, the inner ring of the ceramic ring 5 overlaps with the surface of the hot stage 6, and the protective edge of the ceramic ring 5 covers the edge of the wafer to be processed. Based on the deposition process parameters of the wafer to be processed, the lifting mechanism drives the hot stage 6 upwards, adjusting the wafer to be processed to a suitable height. Process gas enters the cavity 1 from the process gas inlet at the top of the cavity 1, completing the deposition process on the surface of the wafer to be processed. An exhaust port is opened on the bottom side wall of the cavity 1.

[0035] The matching structure of the limiting groove set in the inner ring of the cavity liner 4 and the guide protrusion set in the outer ring of the ceramic ring 5 not only serves to support the ceramic ring 5, but also to guide and limit the ceramic ring 5, which can effectively achieve centering, ensure the installation accuracy of the ceramic ring, and thus ensure the accuracy of the protective edge of the ceramic ring 5 covering the edge of the wafer, thereby ensuring the quality of the deposition process.

[0036] In one embodiment, the inner edge of the cavity liner 4 is provided with a plurality of limiting grooves at even intervals, and the outer edge of the ceramic ring 5 is provided with a plurality of guide protrusions at corresponding intervals. Figures 2-4 As shown, in this embodiment, three limiting slots are preferably provided. These three limiting slots are evenly distributed on the inner ring of the cavity liner 4, and three guide protrusions are evenly provided on the outer ring of the ceramic ring 5, which can effectively ensure that the ceramic ring 5 is centered.

[0037] The lifting mechanism can be a servo motor driving a lead screw, or a hydraulic lifting mechanism, etc. Any method that can achieve the lifting and driving function can be used in this invention.

[0038] To further ensure that metal is not deposited at the wafer edges, in one embodiment, such as Figures 5-6 As shown, the ceramic ring 5 has an annular groove formed from the bottom wall inward, and a connecting channel is formed between the annular groove and the wafer edge receiving cavity, the connecting channel connecting the annular groove and the wafer edge receiving cavity;

[0039] The base 8 opens a gas channel into the interior of the hot stage 6. The outlet end of the gas channel is connected to the annular groove, and the inlet end of the gas channel is supplied with protective gas. The protective gas enters the annular groove from the gas channel, passes through the connecting channel, and enters the wafer edge receiving cavity. The edge of the wafer to be processed is purged to prevent metal deposition on the wafer edge.

[0040] To ensure the uniformity of the protective gas distribution at the wafer edge, in one embodiment, the gas channel is provided with a plurality of gas outlets, which are evenly distributed within the annular groove.

[0041] In practical implementation, a single gas channel can be provided, with multiple branch ports at its outlet end. These branch ports are evenly distributed within the annular groove to ensure uniform gas purging. Alternatively, multiple gas channels can be provided, each evenly distributed circumferentially within the hot platen, ensuring that the outlet ports of each gas channel are uniformly distributed within the annular groove. The protective gas is an inert gas such as argon.

[0042] The protective gas enters the annular groove through the gas channel and then enters the wafer edge receiving cavity through the connecting channel. Since the width of the ceramic ring 5 itself is small, the height of the connecting channel is very small when the connecting channel is opened, which is equivalent to a very small gap. In order to reduce the influence of the surface accuracy of the connecting channel on the airflow uniformity, in one embodiment, the height H and width W of the connecting channel satisfy W / H>4. That is, when the width W of the connecting channel is greater than 4 times the height H, the influence of the design accuracy of the connecting channel on the airflow uniformity can be ignored, ensuring the uniformity of airflow in the circumferential direction.

[0043] According to one embodiment, the inner edge of the protective ring of the ceramic ring 5 is chamfered. This chamfered design reduces the impact of the inner edge of the ceramic ring 5 on the process gas flow, thereby ensuring the uniformity of wafer surface deposition. Based on process experience parameters, the preferred chamfer angle θ in this embodiment is 30-60°, which is considered the optimal design.

[0044] According to one embodiment, a gas equalization device 2 is also provided in the cavity 1. The gas equalization device 2 is fixed between the surface of the hot stage 6 and the process gas inlet, so that the process gas entering the cavity 1 through the process gas inlet passes through the gas equalization device 2 and then undergoes a chemical reaction on the surface of the wafer 3 to be processed at the wafer placement position on the surface of the hot stage 6 to deposit metal.

[0045] According to one embodiment, the hot platform 6 includes a horizontal platform surface and a vertical support base, making the side profile of the hot platform 6 T-shaped. The bottom of the vertical support base is fixed to the base 8. A bellows 7 is sealed and fixed around the base 8. The bellows 7 connects the side wall of the cavity 1 and the base 8, together forming the process cavity. The bellows 7 can be compressed or extended as the lifting mechanism drives the base 8, cooperating with the lifting movement of the hot platform 6.

[0046] The size of the protective edge of the ceramic ring 5 can be designed according to the specific edge size of the wafer to be processed. In this embodiment, the width L of the protective edge of the ceramic ring is preferably 3-6mm, which is in line with the universality of most wafer sizes.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wafer edge protection device, characterized in that, include: The process chamber includes a cavity and a base. A hot stage is disposed inside the cavity. The bottom of the hot stage is fixedly disposed on the base. A wafer placement position is provided in the middle of the surface of the hot stage. A process gas inlet is opened on the outer wall of the cavity above the surface of the hot stage. A cavity liner is provided around the hot stage on the inner wall of the cavity. A ceramic ring, which has a ring-shaped structure, has an inner ring surface edge extending towards the center of the ceramic ring to form a protective edge. The inner side of the protective edge forms a wafer edge receiving cavity, which is used to cover the edge of the wafer to be processed. The inner ring edge of the cavity liner is provided with a limiting groove, and the outer ring of the ceramic ring is provided with a guide protrusion adapted to the limiting groove. The guide protrusion is embedded in the limiting groove, so that the ceramic ring overlaps the inner ring of the cavity liner. A lifting mechanism is provided, with its drive end connected to the base to drive the heating stage to move up and down within the cavity. When the lifting mechanism drives the heating stage upward, the surface of the heating stage causes the ceramic ring to move upward and detach from the cavity liner, so that the protective edge of the ceramic ring covers the edge of the wafer to be processed. When the lifting mechanism drives the heating stage downward, the guide protrusion on the outer ring of the ceramic ring is embedded in the limiting groove of the cavity liner, so that the ceramic ring detaches from the surface of the heating stage and overlaps the inner ring of the cavity liner. The ceramic ring has an annular groove formed from the bottom wall inwards, and a connecting channel is formed between the annular groove and the wafer edge receiving cavity. The height H and width W of the connecting channel satisfy W / H>4, and the connecting channel connects the annular groove and the wafer edge receiving cavity. The base opens a gas channel into the interior of the hot stage. The outlet end of the gas channel is connected to the annular groove, and the inlet end of the gas channel is supplied with protective gas. The protective gas enters the annular groove from the gas channel, passes through the connecting channel, and enters the wafer edge receiving cavity to purge the edge of the wafer to be processed.

2. The wafer edge protection device according to claim 1, characterized in that, The gas channel is provided with multiple gas outlets, which are evenly distributed within the annular groove.

3. The wafer edge protection device according to claim 1, characterized in that, The inner edge of the protective ring of the ceramic ring is chamfered.

4. The wafer edge protection device according to claim 3, characterized in that, The angle θ at the chamfer is 30-60°.

5. The wafer edge protection device according to claim 1, characterized in that, The cavity is also equipped with a gas equalization device, which is fixed between the hot stage surface and the process gas inlet, so that the process gas entering the cavity through the process gas inlet passes through the gas equalization device and is then deposited on the wafer to be processed at the wafer placement position on the hot stage surface.

6. The wafer edge protection device according to claim 1, characterized in that, The hot platform includes a horizontal platform surface and a vertical support base, making the side profile of the hot platform T-shaped. The bottom of the vertical support base is fixed to the base. A bellows is sealed around the base. The bellows connects the side wall of the cavity and the base, together forming the process cavity. The bellows can be compressed or extended as the lifting mechanism drives the base.

7. The wafer edge protection device according to claim 1, characterized in that, The inner edge of the cavity liner is provided with a plurality of limiting slots at even intervals, and the outer ring of the ceramic ring is provided with a plurality of guide protrusions at corresponding intervals.

8. The wafer edge protection device according to claim 1, characterized in that, The width L of the protective edge of the ceramic ring is 3-6 mm.

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