Etching showerhead structure for wafer edge protection

Abstract

The utility model belongs to the field of semiconductor manufacturing technology especially relates to a kind of etching nozzle structure for wafer edge protection, including nozzle main part, nozzle main part end face is sequentially provided with main etching gas flow hole, annular protection gas hole and auxiliary gas flow hole, main etching gas flow hole, annular protection gas hole and auxiliary gas flow hole all have several, several main etching gas flow hole forms main etching gas flow channel, main etching gas flow hole is placed in nozzle main part end face central region, it is arranged in concentric circle, nozzle main part inside is equipped with double-layer heat insulation structure, double-layer heat insulation structure includes the ceramic heat insulation layer towards nozzle main part high temperature surface and the copper base heat dissipation layer towards nozzle main part low temperature surface, cooling runner is integrated in copper base heat dissipation layer;Compared with prior art, the utility model realizes the accurate protection of wafer edge area, significantly improves etching uniformity, reduces edge over-etching and byproduct pollution, improves product yield.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically, to an etching nozzle structure for wafer edge protection. Background Technology

[0002] With the development of IC chip manufacturing technology, wafer diameters have gradually increased to 300mm, and wafer thickness before packaging has become increasingly thinner. To ensure the rigidity of the processed object and reduce the risk of fragmentation, bonding the wafer to a glass substrate before subsequent processing has become a common practice in the semiconductor industry. Using a centrally thinned glass substrate to mount the wafer optimizes subsequent wafer processing. To obtain a ring-shaped glass substrate that is thin in the center and thick at the edges, the surface of the glass substrate needs to be etched using an etching machine.

[0003] In semiconductor lithography and etching processes, wafer edge region control is a key challenge, presenting three major problems: over-etching at the edges due to uneven airflow and photoresist coating issues leading to excessively rapid edge etching, causing structural damage or penetration; residual photoresist at the edges, due to incomplete removal processes, interfering with the uniformity of subsequent etching; and the accumulation of etching byproducts at the edges, forming contamination and degrading the etching environment, all contributing to reduced yield. Existing solutions have significant shortcomings: traditional nozzles with a single gas channel cannot independently control the airflow at the center and edges; although some technologies attempt to adjust the protective gas flow rate to alleviate over-etching, they lack a precise and coordinated control mechanism for airflow direction, spatial distribution, and specific edge regions, failing to effectively address the aforementioned interconnected problems simultaneously. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an etching nozzle structure for wafer edge protection that achieves precise protection of wafer edges through physical isolation and airflow coordinated control, and reduces over-etching and contaminant accumulation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An etching nozzle body structure for wafer edge protection includes a nozzle body. The nozzle body has, sequentially, main etching airflow holes, annular protective airflow holes, and auxiliary airflow holes on its end face. Each of the main etching airflow holes, annular protective airflow holes, and auxiliary airflow holes has a plurality of holes, and the plurality of main etching airflow holes form a main etching airflow channel.

[0007] The main etching airflow holes are located in the central area of ​​the nozzle body end face and are arranged in concentric circles.

[0008] Annular protective vents are coaxially arranged around the main etching gas flow channel. Several annular protective vents form an annular protective gas curtain channel. An annular nozzle is provided at the end of the annular protective gas curtain channel to release inert protective gas to form a vertically downward annular gas curtain barrier.

[0009] The auxiliary airflow holes are evenly distributed in the outer periphery of the annular protective air curtain channel. The nozzle body is equipped with a double-layer heat insulation structure, which includes a ceramic heat insulation layer facing the high-temperature side of the nozzle body and a copper-based heat dissipation layer facing the low-temperature side of the nozzle body. The copper-based heat dissipation layer integrates cooling channels.

[0010] The present invention is further configured such that the central axis of the auxiliary airflow hole is inclined outward relative to the vertical axis of the nozzle, with the inclination angle set to 15° to 30°, for spraying purging gas toward the outer region of the wafer edge.

[0011] The present invention is further configured such that the gas transported in the main etching gas flow channel is selected from... , and At least one of them, the protective gas delivered by the annular protective gas curtain channel is Ar or The purge gas supplied through the auxiliary airflow orifice is He.

[0012] The present invention is further configured such that: the thickness of the ceramic heat insulation layer is set to 2mm to 5mm, and the cross-sectional diameter of the cooling channel integrated in the copper-based heat dissipation layer is set to 0.8mm to 1.2mm.

[0013] The present invention is further configured such that the gas pressure of the annular protective gas curtain channel is 0.3 Pa to 1.0 Pa higher than that of the main etching gas flow channel.

[0014] Compared with the shortcomings of the prior art, the beneficial effects of this utility model are as follows:

[0015] An annular protective gas curtain channel is formed by coaxially setting an annular protective gas hole outside the main etching gas flow hole, and an annular nozzle is set at its end to release inert protective gas, forming a vertically downward annular gas curtain barrier. At the same time, auxiliary gas flow holes inclined outward at 15° to 30° are set in the outer periphery of the annular protective gas curtain channel to spray purge gas to the outer edge of the wafer. A double-layer heat insulation structure consisting of a ceramic heat insulation layer and a copper-based heat dissipation layer with cooling channels is set inside the nozzle body. This allows the annular gas curtain barrier formed by the inert protective gas to effectively isolate the main etching gas flow and provide protection to the wafer edge. The inclined auxiliary gas flow holes can blow etching by-products away from the wafer edge area to prevent accumulation and contamination. The double-layer heat insulation structure ensures the internal temperature of the nozzle is stable and avoids thermal deformation affecting the airflow distribution. Thus, the precise protection of the wafer edge area is achieved in synergy, significantly improving etching uniformity, reducing edge over-etching and by-product contamination, and improving product yield. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0017] Figure 2 This is a cross-sectional view of an embodiment of the present utility model.

[0018] 1. Nozzle body, 2. Main etched airflow hole, 3. Annular protective airflow hole, 4. Auxiliary airflow hole, 5. Ceramic heat insulation layer, 6. Copper-based heat dissipation layer. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Working Principle: During operation, inert protective gas enters the annular protective gas curtain channel through the annular protective gas hole 3 and is released from the annular nozzle at its end, forming a vertically downward annular gas curtain barrier below the end face of the nozzle body 1. Simultaneously, the main etching gas flow hole 2 of the main etching gas flow channel delivers etching gas to the center region of the wafer for etching. This annular gas curtain barrier effectively isolates the main etching gas flow and provides protection to the wafer edge region. The auxiliary gas flow hole 4 continuously sprays purging gas at an angle of 15° to 30° to the outer edge region of the wafer, blowing away the by-products generated by etching from the wafer edge to prevent accumulation and contamination. During this process, the double-layer heat insulation structure inside the nozzle body 1 blocks external high temperatures through its ceramic heat insulation layer 5, while the cooling medium circulating in the cooling channel of the copper-based heat dissipation layer 6 removes heat, maintaining the internal temperature of the nozzle body 1 and avoiding thermal deformation that affects the airflow distribution. Through the coordinated operation of the annular protective gas curtain channel formed by the main etching gas flow hole 2, the annular protective gas hole 3, and the auxiliary gas flow hole 4, stable protection of the wafer edge region is achieved, ensuring etching uniformity.

[0022] like Figures 1 to 2 As shown,

[0023] The device includes a nozzle body 1, with a main etching airflow hole 2, an annular protective airflow hole 3, and an auxiliary airflow hole 4 sequentially on the end face of the nozzle body 1. There are multiple main etching airflow holes 2, annular protective airflow holes 3, and auxiliary airflow holes 4. The multiple main etching airflow holes 2 form a main etching airflow channel, forming a three-layer coordinated airflow control structure from the inside to the outside. This allows the main etching airflow channel to accurately cover the etched area in the center of the wafer. The vertical air curtain barrier formed by the annular protective airflow hole 3 effectively restricts the diffusion of etching gas and protects the edges. Meanwhile, the outer inclined auxiliary airflow hole 4 directionally blows away edge by-products. The three are spatially separated and functionally complementary, which not only avoids mutual interference of airflows, but also solves the problems of center etching, edge protection, and contamination removal simultaneously through zoned coordinated control, significantly improving the wafer edge protection effect and etching uniformity.

[0024] The main etching airflow holes 2 are located in the central area of ​​the end face of the nozzle body 1, arranged in concentric circles. The gas transported by the main etching airflow channel adopts... Alternatively, you can choose and At least one of them, the concentric hole group layout and multi-gas compatible design, can break through the process barrier while ensuring etching uniformity, so that a single nozzle can cover three major etching scenarios, combining technological advancement and engineering economy.

[0025] Annular protective vents 3 are coaxially arranged around the main etching gas flow channel. Several annular protective vents 3 form an annular protective gas curtain channel. An annular nozzle is installed at the end of the annular protective gas curtain channel to release inert protective gas to form a vertically downward annular gas curtain barrier. The protective gas delivered by the annular protective gas curtain channel is Ar, but other gases can also be selected. An annular nozzle is installed at the end of the coaxial annular protective gas curtain channel to release inert gas, forming a vertically downward dense gas curtain barrier that physically isolates the etched area from the edge area, effectively suppressing over-etching at the edges; while Ar and The dual-gas selection design allows the same nozzle to be adapted to different process environments.

[0026] The auxiliary airflow holes 4 are evenly distributed in the outer periphery of the annular protective air curtain channel, and the purging gas delivered by the auxiliary airflow holes 4 is He.

[0027] The central axis of the auxiliary airflow hole 4 is tilted outward relative to the vertical axis of the nozzle, with the tilt angle set to 15° to 30°. It is used to spray purging gas into the outer region of the wafer edge. The auxiliary airflow hole 4 sprays purging gas outward at a tilt angle of 15° to 30°, forming a negative pressure vortex zone on the outer edge of the wafer. This actively removes etching byproducts and prevents them from falling back onto the wafer surface, while also eliminating turbulent disturbances at the end of the gas curtain barrier.

[0028] The gas pressure in the annular protective gas curtain channel is 0.3 Pa to 1.0 Pa higher than that in the main etching gas flow channel. Maintaining this pressure difference creates a centripetal pressure gradient barrier: ① compressing the diffusion of etching gas; ② blocking the migration of byproducts in the reverse flow field; ③ eliminating interfacial turbulence. 0.5 Pa is considered the optimal parameter, simultaneously achieving flow field stability and defect control.

[0029] The nozzle body 1 is equipped with a double-layer heat insulation structure, which includes a ceramic heat insulation layer 5 facing the high-temperature side of the nozzle body 1 and a copper-based heat dissipation layer 6 facing the low-temperature side of the nozzle body 1. The copper-based heat dissipation layer 6 integrates cooling channels.

[0030] The thickness of the ceramic heat insulation layer 5 is set to 2mm to 5mm, and the cross-sectional diameter of the cooling channel integrated in the copper-based heat dissipation layer 6 is set to 0.8mm to 1.2mm. The 2mm to 5mm thickness of the ceramic heat insulation layer 5 precisely balances the heat insulation requirements and space occupation, and attenuates the high temperature conduction of plasma by >90%. The 0.8mm to 1.2mm diameter cooling channel in the copper-based heat dissipation layer 6 achieves turbulent and efficient heat dissipation. The dual structure works together to ensure that the working temperature of the nozzle body 1 is stable within ±1℃, completely eliminating the airflow distribution drift caused by thermal deformation and reducing the fluctuation of etching uniformity.

[0031] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An etching showerhead structure for wafer edge protection, comprising a showerhead body (1), characterized in that: The nozzle body (1) has a main etching airflow hole (2), an annular protective air hole (3), and an auxiliary airflow hole (4) sequentially opened on its end face. There are several main etching airflow holes (2), annular protective air holes (3), and auxiliary airflow holes (4). Several main etching airflow holes (2) form a main etching airflow channel. The main etched airflow holes (2) are located in the center area of ​​the end face of the nozzle body (1) and are arranged in concentric circles. Annular protective vents (3) are coaxially arranged around the main etching gas flow channel. Several annular protective vents (3) form an annular protective gas curtain channel. An annular nozzle is provided at the end of the annular protective gas curtain channel to release inert protective gas to form a vertically downward annular gas curtain barrier. The auxiliary airflow holes (4) are evenly distributed in the outer periphery of the annular protective air curtain channel. The nozzle body (1) is provided with a double-layer heat insulation structure. The double-layer heat insulation structure includes a ceramic heat insulation layer (5) facing the high temperature side of the nozzle body (1) and a copper-based heat dissipation layer (6) facing the low temperature side of the nozzle body (1). The copper-based heat dissipation layer (6) integrates a cooling channel.

2. The etching showerhead structure for wafer edge protection of claim 1, wherein: The central axis of the auxiliary airflow hole (4) is inclined outward relative to the vertical axis of the nozzle, with the inclination angle set to 15° to 30°, for spraying purging gas into the outer region of the wafer edge.

3. The etch showerhead structure for wafer edge protection of claim 1, wherein: The gas delivered by the main etching gas flow channel is selected from at least one of , and , the protective gas delivered by the annular protective gas curtain channel is Ar or , and the purge gas delivered by the auxiliary gas flow hole (4) is He.

4. The etch showerhead structure for wafer edge protection of claim 1, wherein: The thickness of the ceramic heat insulation layer (5) is set to 2mm to 5mm, and the cross-sectional diameter of the cooling channel integrated in the copper-based heat dissipation layer (6) is set to 0.8mm to 1.2mm.

5. The etch showerhead structure for wafer edge protection of claim 1, wherein: The gas pressure in the annular protective gas curtain channel is 0.3 Pa to 1.0 Pa higher than that in the main etching gas flow channel.

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