Wafer wet etching reaction chamber
By introducing a shielding structure into the wafer wet etching reaction chamber, the problem of atomized particles adhering back to the back of the wafer was solved, improving product quality and yield, and reducing rework losses.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SJ SEMICONDUCTOR (JIANGYIN) CORP
- Filing Date
- 2025-04-29
- Publication Date
- 2026-05-01
AI Technical Summary
In existing wet etching processes for wafers, atomized particles tend to adhere back to the back of the wafer, leading to product quality risks and batch rework. Existing technologies cannot effectively solve the problem of atomized particle re-adhesion.
Design a wafer wet etching reaction chamber, including a shielding structure to shield the back of the wafer and reduce the exposed area, combined with a corrosion-resistant shielding and an etching solution recovery lifting unit to prevent atomized particles from adhering back.
It effectively prevents atomized particles from re-adhering, reduces contamination in subsequent processes, improves product quality, reduces rework losses, and enhances process precision and yield.
Smart Images
Figure CN224192389U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wafer wet etching technology, and in particular to a wafer wet etching reaction chamber. Background Technology
[0002] In semiconductor manufacturing processes, wet etching technology is widely used for patterning metal layers (such as copper, aluminum, and titanium) and dielectric layers (such as silicon dioxide) due to its high selectivity and process simplicity. Traditional wet etching processes remove material by immersing the wafer in a chemical etching solution or using a spray chamber. However, in actual production, it has been found that the atomized particles generated during this process adhere back to the back of the wafer, becoming a significant factor limiting yield improvement. Specifically, under the influence of high-speed spraying, bubble bursting, or high-temperature volatilization, the etching solution forms micron-sized atomized particles containing metal salts, reaction byproducts, and chemical reagents. These particles are easily deposited on the back side of the wafer under the influence of airflow disturbance or electrostatic adsorption inside the chamber, forming irreversible dirt marks and causing the following serious defects: (1) Post-process contamination: The atomized particles on the back side of the wafer may fall off and contaminate the equipment or front functional layer during subsequent laser (laser marking, cutting) or thin film deposition processes, causing reliability risks such as short circuits and poor contact; (2) Deterioration of process accuracy: Particle adhesion leads to a decrease in the flatness of the wafer surface, laser focus shift or uneven energy distribution, resulting in pattern alignment deviation or uncontrolled cutting depth; (3) Batch rework loss: Due to back side contamination, the entire batch of wafers needs to be reworked and cleaned, which not only increases the consumption of chemical liquid and labor costs, but may also cause surface scratches or oxide layer damage, further reducing product yield.
[0003] Although the industry has proposed some improvement solutions to this problem (such as enhancing exhaust efficiency and optimizing cleaning process), the existing technology still has significant limitations: (1) Insufficient exhaust system design: Traditional chambers mostly use unidirectional exhaust, which easily forms a dead airflow angle on the back of the wafer, making it difficult to discharge suspended particles in time; (2) Lack of particle interception mechanism: Most devices are not equipped with high-efficiency filters or multi-stage adsorption devices, which cannot effectively intercept submicron particles; (3) Crude wafer loading method: Horizontal placement or fixed clamp design exposes the back of the wafer directly to the diffusion path of atomized particles, lacking a physical isolation barrier.
[0004] Therefore, there is an urgent need to develop an improved solution to address the problem of atomized particles adhering back to the back of the wafer. Utility Model Content
[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a wafer wet etching reaction chamber to solve the problems in the prior art.
[0006] To achieve the above-mentioned and other related objectives, this utility model is obtained through the following technical solution.
[0007] This utility model provides a wafer wet etching reaction chamber, including a reaction chamber body. The reaction chamber body is provided with a base for supporting the wafer and a shield for blocking the etching liquid that is partially reflected back onto the back of the wafer. The shield is a hollow structure with a circular top surface. The shield is fitted onto the base and does not protrude from the top surface of the base.
[0008] In one specific embodiment, the bottom surface of the shield is circular or elliptical.
[0009] In one specific embodiment, the shield is frustum-shaped, cylindrical, or obliquely shaped cone.
[0010] In one specific embodiment, the outer diameter L1 of the top surface of the shield is 80% to 107% of the wafer diameter.
[0011] In one specific embodiment, the top surface of the base is provided with a chuck for fixing the wafer.
[0012] In one specific embodiment, the shield is a central axis symmetrical structure.
[0013] In one specific embodiment, when used for a wafer with a diameter of 300 mm, the outer diameter L1 of the top surface of the shield is 240 to 322 mm.
[0014] In one specific embodiment, the distance d between the top surface of the shield and the bearing surface of the chuck is 0.5 to 2 cm.
[0015] In one specific embodiment, the reaction chamber body is provided with an etching solution recovery lifting part, the diameter of which is 102% to 110% of the wafer diameter.
[0016] In one specific embodiment, when used for a wafer with a diameter of 300 mm, the diameter of the opening end of the etching solution recovery lifting section is 308-330 mm.
[0017] In one specific embodiment, the top surface of the shield also extends radially outward to form a horizontal shielding awning.
[0018] In one specific embodiment, the shield is a corrosion-resistant shield.
[0019] In one specific embodiment, the width D of the horizontal shielding eaves is 0.17 to 1.7% of the wafer diameter.
[0020] In one specific embodiment, when used for a wafer with a diameter of 300 mm, the width D of the horizontal shielding ledge is 0.5 to 5 mm.
[0021] In one specific embodiment, the bottom surface of the shield is located on the side of the base or the bottom surface of the reaction chamber body; or, the inner side surface of the shield is fixed to the side surface of the base.
[0022] This invention provides a wafer wet etching reaction chamber that can shield the back side of the wafer, reduce the exposed area of the back side of the wafer, physically isolate the atomized particles generated by wet etching, and prevent the contamination caused by particle re-adhesion from affecting subsequent laser etching, thereby causing product quality risks and batch rework.
[0023] Instruction manual illustrations
[0024] Figure 1 This diagram shows the operational status of the wafer wet etching reaction chamber.
[0025] Figure 2 This is a cross-sectional view of the wafer wet etching reaction chamber in use.
[0026] Figure 3 This is a 3D view of the wafer wet etching reaction chamber.
[0027] Figures 4-5 Displayed as a 3D image with a mask.
[0028] Explanation of reference numerals in the attached figures:
[0029] 11 bases;
[0030] 12 shields;
[0031] 121 Horizontal eaves;
[0032] 13. Etching solution recovery lifting unit;
[0033] 14. Rinse the nozzle;
[0034] 15 cassettes. Detailed Implementation
[0035] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0036] Please see Figures 1 to 5It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.
[0037] like Figures 1-2 As shown, this utility model discloses a wafer wet etching reaction chamber, including a reaction chamber body. The reaction chamber body is provided with a base 11 for supporting the wafer and a shield 12 for blocking the etching liquid that is partially reflected back onto the back of the wafer. The shield 12 has a hollow structure and a circular top surface. The shield 12 is sleeved on the base 11 and does not protrude from the top surface of the base 11.
[0038] The aforementioned wafer wet etching reaction chamber can shield the back side of the wafer, reducing the exposed area of the back side of the wafer and physically isolating the atomized particles generated by wet etching (including the etching liquid thrown out by the wafer rotation during spray etching). This prevents the contamination caused by particle re-adhesion from affecting subsequent laser processes, thereby causing product quality risks and batch rework.
[0039] In one specific embodiment, the bottom surface of the shield 12 is circular or elliptical. As an example, such as... Figures 4-5 As shown, the bottom surface of the shield 12 is circular.
[0040] In one specific embodiment, the shield 12 is frustum-shaped, cylindrical, or obliquely shaped. As an example, such as... Figures 4-5 As shown, the shield 12 is truncated cone in shape. The oblique cut surface of the oblique cone is elliptical and serves as the bottom surface of the shield 12.
[0041] In a more specific embodiment, the shield 12 has a central axis symmetric structure. Specifically, the shield 12 is frustum-shaped or cylindrical.
[0042] In a like Figure 2 , 4 In a more specific embodiment shown, the outer diameter L1 of the top surface of the shield 12 is not less than the outer diameter of the bottom surface of the shield 12. The shape of the shield 12 includes, but is not limited to, an inverted frustum shape and a cylindrical shape. As an example, such as... Figure 4As shown, the shield 12 is shaped like an inverted frustum.
[0043] In a like Figure 5 In the specific embodiment shown, the outer diameter L1 of the top of the shield 12 is smaller than the outer diameter of the bottom surface of the shield 12. In this case, the shape of the shield 12 is a frustum of a circle.
[0044] In one specific embodiment, the outer diameter L1 of the top surface of the shield 12 is 80% to 107% of the wafer diameter. In a more specific embodiment, when used for a wafer with a diameter of 300 mm, the outer diameter L1 of the top surface of the shield 12 is 240 to 322 mm. For example, the outer diameter L1 of the top surface of the shield 12 can be 80% to 90%, 90% to 100%, or 100% to 107% of the wafer diameter. Figure 2 As shown, the outer diameter L1 of the upper bottom surface of the shield 12 is equal to the diameter of the wafer. If the outer diameter of the top surface of the shield 12 is too large, it will affect the raising and lowering of the etching solution recovery lifting section 13 in the wafer wet etching reaction chamber. This is because: the etching solution recovery lifting section 13 has a cavity for receiving and recovering the etching solution. During wet etching, the opening end of the etching solution recovery lifting section 13 rises above the wafer to recover the etching solution. After wet etching is completed, the opening end of the etching solution recovery lifting section 13 descends to be flush with or slightly higher than the shield 12. If the outer diameter of the top surface of the shield 12 is too small, it will cause particles to re-adhere to the back of the wafer, bringing contamination. The rinsing nozzle 14 of the wafer wet etching reaction chamber can be used to rinse the contamination within 30mm of the wafer edge on the back of the wafer. Beyond this range, physical isolation is required with the help of the shield 12.
[0045] In one specific embodiment, a chuck 15 for fixing the wafer is provided on the top surface of the base 11. The chuck 15 has a vacuum channel inside, which uses negative pressure to adsorb the wafer onto the support surface.
[0046] In a more specific embodiment, the distance d between the top surface of the shield 12 and the bearing surface of the chuck 15 is 0.5–2 cm. For example, it can be 0.5–1 cm, 1–1.5 cm, or 1.5–2 cm. As an example, such as… Figure 2 As shown, the upper bottom surface of the shield 12 is 1 cm away from the bearing surface of the chuck 15. If the distance is too large, particles will stick to the back of the wafer, causing dirt; if the distance is too small, it will affect the placement and removal of the wafer.
[0047] In a like Figure 2In the specific embodiment shown, the reaction chamber body is provided with an etchant recovery lifting section 13, the diameter of which is 102% to 110% of the wafer diameter. In a more specific embodiment, when used for a wafer with a diameter of 300 mm, the diameter of the opening end of the etchant recovery lifting section 13 is 308 to 330 mm. The etchant recovery lifting section 13 is selected according to the wafer size; for example, the diameter of the opening end of the etchant recovery lifting section 13 can be 102 to 105%, 105 to 108%, or 108 to 110% of the wafer diameter.
[0048] In a like Figure 2 In the specific embodiment shown, the top surface of the shield 12 also extends radially outward to form a horizontal shielding awning 121. The horizontal shielding awning 121 is used to increase the shielding area of the shield 12.
[0049] In a more specific embodiment, the width D of the horizontal shielding ledge 121 is 0.17% to 1.7% of the wafer diameter. In a further specific embodiment, when used for a wafer with a diameter of 300 mm, the width D of the horizontal shielding ledge 121 is 0.5% to 5 mm. For example, the width D of the horizontal shielding ledge 121 can be 0.17% to 0.2%, 0.2% to 0.5%, 0.5% to 1.0%, 1.0% to 1.5%, or 1.5% to 1.7% of the wafer diameter.
[0050] In one specific embodiment, the shield 12 is a corrosion-resistant shield 12. The corrosion-resistant shield 12 must not only meet the requirements of resistance to strong acid and strong alkali corrosion, but also prevent contamination of the wafer. Specifically, the material of the corrosion-resistant shield 12 can be PFA, PVDF, polypropylene, or PTFE can be sprayed onto the surface of a metal (such as stainless steel) or ceramic substrate.
[0051] In one specific embodiment, the bottom surface of the shield 12 rests on the side of the base or the bottom surface of the reaction chamber body; or, the inner side surface of the shield 12 is fixed to the side of the base. These measures ensure that the shield 12 can be placed stably, thus ensuring the shielding effect. As an example, such as... Figure 2 As shown, the bottom surface of the shield 12 is mounted on the side of the base. The fixing methods include, but are not limited to, sleeve or snap-fit.
[0052] In one specific embodiment, the upper and / or lower bottom surfaces of the shield 12 are parallel to the bearing surface of the chuck 15. In this application, the upper bottom surface of the shield 12 may or may not be parallel to the bearing surface of the chuck 15, as long as it facilitates wafer loading and unloading. In this application, the lower bottom surface of the shield may or may not be parallel to the bearing surface of the chuck 15. When the bottom surface of the shield sits on the side of the base 11, the bottom surface of the shield can be set to be parallel or not parallel to the bearing surface of the chuck 15; when the bottom opening of the shield sits on the bottom surface of the reaction chamber body, the lower bottom surface of the shield is parallel to the bearing surface of the chuck 15. As a specific example, such as... Figure 2 As shown, the upper and lower bottom surfaces of the shield 12 are both parallel to the bearing surface of the chuck 15.
[0053] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A wafer wet etch reaction chamber, comprising: The reaction chamber body includes a base (11) for supporting the wafer and a shield (12) for blocking the etching liquid that is partially reflected back onto the back of the wafer. The shield (12) is a hollow structure with a circular top surface. The shield (12) is fitted onto the base (11) and does not protrude from the top surface of the base (11).
2. The wafer wet etch reaction chamber of claim 1, wherein, The bottom surface of the shield (12) is circular or elliptical; and / or, the shield (12) is frustum-shaped, cylindrical or obliquely shaped cone; and / or, the outer diameter L1 of the top surface of the shield (12) is 80% to 107% of the wafer diameter; and / or, the top surface of the base (11) is provided with a chuck (15) for fixing the wafer.
3. The wafer wet etching reaction chamber according to claim 2, characterized in that, The shield (12) has a central axis symmetric structure; and / or, when used for a wafer with a diameter of 300 mm, the outer diameter L1 of the top surface of the shield (12) is 240 to 322 mm.
4. The wafer wet etching reaction chamber according to claim 2, characterized in that, The distance d between the top surface of the shield (12) and the bearing surface of the chuck (15) is 0.5 to 2 cm.
5. The wafer wet etch reaction chamber of claim 1, wherein, The reaction chamber is equipped with an etching solution recovery lifting part (13), the diameter of which is 102% to 110% of the wafer diameter.
6. The wafer wet etching reaction chamber according to claim 5, characterized in that, When used for wafers with a diameter of 300 mm, the diameter of the opening end of the etching solution recovery lifting part (13) is 308-330 mm.
7. The wafer wet etch reaction chamber of claim 1, wherein, The top surface of the shield (12) also extends radially outward to form a horizontal shielding awning (121); and / or, the shield (12) is a corrosion-resistant shield (12).
8. The wafer wet etch reaction chamber of claim 7, wherein, The width D of the horizontal shielding awning (121) is 0.17 to 1.7% of the wafer diameter.
9. The wafer wet etch reaction chamber of claim 7, wherein, When used for wafers with a diameter of 300 mm, the width D of the horizontal shielding awning (121) is 0.5 to 5 mm.
10. The wafer wet etch reaction chamber of claim 1, wherein, The bottom surface of the shield (12) is located on the side of the base or the bottom surface of the reaction chamber body; or, the inner side surface of the shield (12) is fixed to the side surface of the base.