Wafer soft baking processing device for optimizing high film thickness surface uniformity

Abstract

The utility model relates to a wafer soft baking processing device for optimizing high film thickness surface uniformity, which comprises a shell, a heating disc, a top cover and a plurality of air inlets, and is characterized in that the top cover is positioned at the top of the shell and is provided with an extraction opening; the heating disc is located in the shell, and the multiple air inlet holes are distributed between the shell and the heating disc in an annular array mode. The utility model has the advantages that the improvement cost is low, the nitrogen inlet holes are used for simultaneously feeding air, so that the air inlet quantity and the air inlet flow velocity are more uniform, and the condition that the air flow near the nitrogen inlet holes is larger is avoided, so that the film thickness uniformity is controlled.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to a wafer soft baking device for optimizing the uniformity of high film thickness surface. Background Technology

[0002] Wafer soft baking (also known as soft roasting or pre-baking) is an important step in semiconductor processing, especially in photolithography. The main purpose of soft baking is to densify the photoresist film on the wafer and remove residual solvent. This step helps improve the photoresist's processing performance, including reducing free volume and polymer relaxation, improving photoresist adhesion to the substrate, promoting photoresist uniformity on the wafer, and better controlling linewidth during subsequent etching.

[0003] However, during high-film-thickness soft baking processes such as TIV and C4, a closed-coverage operation is often used to ensure baking effect and wafer yield. This results in higher baking temperatures, more volatile solvents, and longer operation times. During this process, nitrogen needs to be continuously replenished to extract the volatile solvents in the processing chamber, forming an upward-extraction and downward-intake air path. However, the nitrogen inlet has a large airflow rate, which causes the solvents near the inlet to evaporate faster than in other areas of the wafer, resulting in surface depressions and poor film thickness uniformity. Utility Model Content

[0004] The purpose of this invention is to provide a wafer soft baking process device that optimizes the uniformity of high film thickness surface, thereby improving film thickness uniformity.

[0005] To achieve the above-mentioned utility model objectives, this utility model provides a wafer soft baking device for optimizing high film thickness surface uniformity, including a housing, a heating plate, a top cover, and a plurality of air inlets. The top cover is located on the top of the housing and is provided with an air extraction port. The heating plate is located inside the housing, and the plurality of air inlets are arranged in a ring-shaped array between the housing and the heating plate.

[0006] Preferably, the cross-section of the air inlet is an inverted trapezoid.

[0007] As a further improvement to the utility model, the air extraction port is equipped with a one-way valve.

[0008] As a further improvement of the utility model, a flow equalization mesh is provided between the housing and the heating plate, and the flow equalization mesh is located above the air inlet.

[0009] As a further improvement to the utility model, a guide plate is provided above the air inlet.

[0010] Furthermore, the guide plate extends inward, with one end of the guide plate connected to the inner wall of the housing, and the other end of the guide plate forming an air outlet with the side wall of the heating plate.

[0011] Furthermore, the opening size of the air outlet is A, and the distance between the housing and the heating plate is B, with A accounting for 25%-50% of B.

[0012] Furthermore, the guide plate is inclinedly disposed above the air inlet, with the end of the guide plate closest to the heating plate being the highest position.

[0013] Furthermore, the tilt angle of the guide plate in the horizontal position is 45°±10°.

[0014] This invention provides a wafer soft-bake processing device that optimizes the uniformity of high film thickness. The device evenly distributes air inlets around the outer ring of the heating plate, effectively controlling the uniform flow rate of nitrogen gas through each inlet, ensuring uniform solvent evaporation across all areas of the wafer. Without altering the original formulation, it improves wafer film thickness uniformity, reduces operational difficulties at subsequent process stations, and is compatible with existing processing equipment structures, resulting in low modification costs.

[0015] This utility model provides an optimized wafer soft baking process device for high film thickness surface uniformity, which has the following advantages compared with the prior art:

[0016] The improvement is low-cost, and multiple nitrogen inlets allow for simultaneous air intake, resulting in more uniform air intake volume and flow rate. This avoids excessive airflow near the nitrogen inlets, thus controlling film thickness uniformity. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a wafer soft baking device for optimizing the surface uniformity of high film thickness according to the present invention;

[0018] Figure 2 This is a schematic diagram of the air intake port distribution structure;

[0019] Figure 3 This is a schematic diagram of the flow equalization network structure;

[0020] Figure 4 This is a schematic diagram of the guide vane structure. Detailed Implementation

[0021] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0022] like Figure 1-2 As shown, the present invention provides a wafer soft baking device for optimizing the surface uniformity of high film thickness, including a housing 1, a heating plate 2, a top cover 3, and a plurality of air inlets 4. The top cover 3 is located on the top of the housing 1 and is provided with an air extraction port 31. The heating plate 2 is located inside the housing 1, and the plurality of air inlets 4 are arranged in a ring-shaped array between the housing 1 and the heating plate 2.

[0023] This invention provides a wafer soft-bake processing device that optimizes the uniformity of high film thickness. The device evenly distributes air inlets 4 around the outer ring of the heating plate, effectively controlling the uniform flow rate of nitrogen gas through each inlet, ensuring uniform solvent evaporation across all areas of the wafer. Without altering the original formulation, it improves wafer film thickness uniformity, reduces operational difficulties at subsequent process stations, and is compatible with existing processing equipment structures, resulting in low modification costs.

[0024] The cross-section of the air inlet 4 is an inverted trapezoid, which slows down the nitrogen flow rate, further improves the uniformity of nitrogen distribution, slows down the solvent evaporation rate at the wafer edge, and optimizes the uniformity of wafer film thickness. The film thickness uniformity deviation can be controlled to below 5%.

[0025] The exhaust port 31 is equipped with a one-way valve 5 to control the direction of gas flow and ensure that nitrogen and volatile solvents are quickly discharged from the exhaust port 31.

[0026] like Figure 3 As shown, a flow equalization mesh 6 is provided between the housing 1 and the heating plate 2, and the flow equalization mesh 6 is located above the air inlet 4. The honeycomb mesh structure of the flow equalization mesh 6 can make the gas flow from the lower air inlet 4 more uniform, which largely ensures that the nitrogen flow rate in different areas of the wafer remains consistent.

[0027] like Figure 4 As shown, a guide plate 7 is provided above the air inlet 4. The guide plate 7 guides the nitrogen gas coming out of the air inlet 4, allowing more gas to flow directly to the wafer area and reducing gas loss.

[0028] The guide plate 7 extends inward, with one end connected to the inner wall of the housing 1 and the other end forming an air outlet with the side wall of the heating plate 2. Compared to nitrogen being directly transmitted from the air inlet 4, the nitrogen from the air inlet 4 is transmitted to the wafer surface from the air outlet, making the nitrogen more concentrated and in contact with the wafer surface, further improving the uniformity of solvent evaporation on the wafer surface.

[0029] The opening size of the air outlet is A, and the distance between the housing 1 and the heating plate 2 is B. A accounts for 25%-50% of B. If the opening size of the air outlet is too large, it will affect the gas guiding effect; if the opening size of the air outlet is too small, it will affect the nitrogen flow rate.

[0030] The guide plate 7 is inclined and positioned above the air inlet 4, with the end of the guide plate 7 closest to the heating plate 2 being the highest point. Nitrogen gas is transported along the inclined surface of the guide plate 7, creating a funnel-shaped airflow channel. This reduces the amount of nitrogen gas near the inner wall of the housing 1, concentrating the nitrogen gas near the heating plate 2 and improving nitrogen utilization. The optimal guiding effect is achieved when the guide plate 7 is inclined at a horizontal angle of 45°±10°.

[0031] The preferred embodiments of this utility model have been described in detail above, but this utility model is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this utility model, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A wafer soft bake processing apparatus for optimizing high film thickness surface uniformity, characterized in that, It includes a housing, a heating plate, a top cover, and several air inlets. The top cover is located on top of the housing and has an air extraction port. The heating plate is located inside the housing, and the several air inlets are arranged in a ring between the housing and the heating plate.

2. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 1, characterized in that, The cross-section of the air inlet is an inverted trapezoid.

3. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 1, characterized in that, The air extraction port is equipped with a one-way valve.

4. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 1, characterized in that, A flow equalization mesh is provided between the housing and the heating plate, and the flow equalization mesh is located above the air inlet.

5. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 1, characterized in that, A guide plate is provided above the air intake.

6. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 5, characterized in that, The guide plate extends inward, with one end connected to the inner wall of the housing and the other end forming an air outlet with the side wall of the heating plate.

7. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 6, characterized in that, The opening size of the air outlet is A, and the distance between the housing and the heating plate is B, where A occupies 25%-50% of B.

8. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 5, characterized in that, The guide plate is inclinedly disposed above the air inlet, with the end of the guide plate closest to the heating plate being the highest position.

9. The wafer soft bake processing apparatus for optimizing high film thickness surface uniformity as described in claim 8, characterized in that, The guide vane is tilted at an angle of 45°±10° in the horizontal position.

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