Through hole mask capable of adsorbing silicon wafer and through hole mask exposure device

Abstract

The utility model relates to a through hole mask capable of adsorbing a silicon wafer and a through hole mask exposure device, and solves the problems of displacement deviation and insufficient precision in symmetrical photoetching of patterns on two sides of a semiconductor silicon wafer. The through hole mask plate comprises a substrate, the substrate is provided with a shading film pattern, the substrate is provided with a through hole in a gap or an outer area of the shading film pattern, and the through hole penetrates through two sides of the substrate. The exposure device comprises an upper vacuum adsorption disc and a lower vacuum adsorption disc, an upper mask plate, a silicon wafer and a lower mask plate are sequentially arranged between the upper vacuum adsorption disc and the lower vacuum adsorption disc from top to bottom, the lower mask plate is a through hole mask plate, and vacuum adsorption cavities are correspondingly formed in through hole areas of the lower vacuum adsorption disc and the lower mask plate. One side of the vacuum adsorption cavity is connected with an adsorption pipe orifice. According to the utility model, the silicon wafer can be stably arranged at the fixed position of the lower mask before and after exposure, so that the efficiency of automatic or manual alignment is improved, and the stability of photoetching is improved.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor manufacturing technology, and relates to a through-hole mask that can adsorb silicon wafers and an exposure device for the through-hole mask. In particular, it relates to an automatic or manual exposure device and the mask used for double-sided pattern alignment photolithography, or single-sided pattern and cut alignment line double-sided photolithography, with an error accuracy range of less than 1µm. Background Technology

[0002] In the manufacturing process of diode chips, situations arise where both the front and back sides need to be photolithographically etched simultaneously, with corresponding patterns. For example, TVS diode chips require photolithography to form symmetrical patterns on both sides of the semiconductor silicon wafer. Similarly, for conventional rectifier diode chips, if both sides are photolithographically etched simultaneously, aligning the cutting lines with the back side (i.e., the cutting surface), it can be adapted to any cutting equipment (including abrasive wheel cutters and laser cutters), facilitating the final chip cutting and separation.

[0003] There are generally two approaches: one is to customize expensive lithography machines, which cost about four times more than traditional domestic lithography machines. These machines can achieve precise flipping and, together with high-precision photomasks, form aligned patterns through two lithography processes. However, even expensive lithography machines cannot guarantee against deviations that occur during wafer flipping in the lithography process, requiring frequent positioning checks and resulting in lower efficiency.

[0004] Another method involves sandwiching two photolithography films with identical top and bottom patterns together. Since the substrate of the films is plastic, they can be aligned and fixed under a microscope. During photolithography, the silicon wafer is placed between the two films for exposure. However, the disadvantages are that the films are susceptible to heat deformation or insufficient processing precision, making it difficult to achieve high consistency in the patterns on both sides of the silicon wafer or easily causing unclear lines. Utility Model Content

[0005] This invention addresses the problems of displacement deviation and insufficient precision in the double-sided patterned symmetrical photolithography of semiconductor silicon wafers described in the background art. It provides a through-hole mask and an exposure device for the through-hole mask that can hold the silicon wafer. Glass masks are used on both sides, and synchronous photolithography of the two sides is achieved through automatic alignment (or real-time alignment inspection using a manual microscope). This achieves a consistency that film cannot reach, effectively reducing the positional deviation of the patterns on both sides and avoiding thermal deformation caused by photolithography. Since the mask lacks an adsorption function, the silicon wafer is prone to sliding after being placed on the mask. Therefore, a glass mask with through-hole adsorption and its photolithography fixing device are designed, ensuring that the silicon wafer is stably placed in a fixed position on the lower mask before and after exposure, improving the efficiency of automatic or manual alignment and further enhancing the stability of photolithography.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a through-hole mask plate that can adsorb silicon wafers, including a substrate, the substrate being provided with a light-shielding film pattern, and the substrate having through holes in the gaps or outer areas of the light-shielding film pattern, the through holes penetrating both sides of the substrate.

[0007] Traditional photomasks only have a light-shielding film pattern on the substrate and no through-hole structure. Therefore, when holding silicon wafers, the wafers are prone to sliding after being fed onto the photomask. This device, however, features a photomask with through-holes. Utilizing negative pressure adsorption, the silicon wafer is fed onto the photomask and then held in place by the through-holes, preventing wafer movement. For specific usage instructions, please refer to the section on through-hole photomask exposure devices described later.

[0008] Preferably, the substrate material is quartz glass or resin.

[0009] Preferably, the pattern on the substrate is formed by photolithography or etching.

[0010] Preferably, the light-shielding film pattern is made of metallic chromium.

[0011] Preferably, the through hole is manufactured by mechanical drilling, laser drilling, dry etching perforation, or wet etching perforation.

[0012] An exposure apparatus for a through-hole mask, using the aforementioned through-hole mask, includes an upper vacuum adsorption disk and a lower vacuum adsorption disk. An upper mask, a silicon wafer, and a lower mask are arranged sequentially from top to bottom between the upper and lower vacuum adsorption disks. The upper vacuum adsorption disk is provided with a plurality of upper vacuum adsorption ports for adsorbing the upper mask. The lower mask is a through-hole mask. The lower vacuum adsorption disk is provided with a vacuum adsorption cavity corresponding to the through-hole area of ​​the lower mask. One side of the vacuum adsorption cavity is connected to an adsorption tube. The lower vacuum adsorption disk is provided with a plurality of lower vacuum adsorption ports for adsorbing the lower mask on the outside of the vacuum adsorption cavity.

[0013] The upper and lower vacuum adsorption ports are used to fix the upper and lower photomasks, preventing them from sliding. The vacuum adsorption chamber is connected to a through-hole, using the through-hole of the lower photomask as an adsorption port to adsorb the silicon wafer on the lower photomask, preventing the silicon wafer from sliding.

[0014] Preferably, the lower wall of the vacuum adsorption chamber is made of transparent quartz glass or resin without any patterns. The lower wall of the vacuum adsorption chamber has a light-transmitting structure, which does not affect the passage of light and ensures the smooth progress of the photolithography process.

[0015] Preferably, the upper mask is a through-hole mask or a regular mask without through holes.

[0016] Preferably, the lower mask plate and the lower vacuum adsorption port are not provided with through holes at the corresponding positions.

[0017] Preferably, the upper vacuum adsorption plate and the lower vacuum adsorption plate are made of transparent quartz glass or resin.

[0018] This invention utilizes the vacuum adsorption of silicon wafers through the through-holes of the lower mask to ensure that the silicon wafers are stably positioned in a fixed position on the lower mask before and after exposure, thereby improving the efficiency of automatic or manual alignment and further enhancing the stability of photolithography. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the structure of a traditional, non-perforated ordinary photomask.

[0021] Figure 2 This is a schematic diagram of the structure of a through-hole mask of this utility model.

[0022] Figure 3 This is a schematic diagram of an exposure device using a through-hole mask according to the present invention.

[0023] In the figure: 1. Substrate, 2. Light-shielding film pattern, 3. Through hole, 4. Upper vacuum adsorption plate, 5. Lower vacuum adsorption plate, 6. Upper mask, 7. Silicon wafer, 8. Lower mask, 9. Upper vacuum adsorption port, 10. Lower vacuum adsorption port, 11. Vacuum adsorption cavity, 12. Adsorption tube opening, 13. Lower cavity wall. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0025] Comparative Example 1: A standard photomask without through holes, such as Figure 1 As shown. A through-hole-free conventional photomask includes a substrate 1. The surface of the substrate 1 has a light-shielding film pattern 2, which is formed by photolithography or etching. The light-shielding film pattern 2 is made of metallic chromium. The substrate 1 is made of transparent quartz glass or resin.

[0026] Example 1: A through-hole mask, such as Figure 2 As shown. The through-hole mask includes a substrate 1, the surface of which has a light-shielding film pattern 2, which is formed by photolithography or etching. The light-shielding film pattern is made of metallic chromium. The substrate 1 is made of transparent quartz glass or resin. Through-holes 3 are formed in the gaps or outer areas of the light-shielding film pattern 2 on the substrate 1, and the through-holes penetrate both sides of the substrate 1. The through-holes 3 must not damage the integrity of the light-shielding film pattern 2. The through-holes 3 are manufactured by mechanical drilling, laser drilling, dry etching, or wet etching.

[0027] Example 2: A through-hole mask exposure apparatus using the through-hole mask of Example 2. This apparatus includes an upper vacuum adsorption disk 4 and a lower vacuum adsorption disk 5. An upper mask 6, a silicon wafer 7, and a lower mask 8 are arranged sequentially from top to bottom between the upper vacuum adsorption disk 4 and the lower vacuum adsorption disk 5. The upper vacuum adsorption disk has several upper vacuum adsorption ports 9 for adsorbing the upper mask. The lower mask 8 is a through-hole mask. Vacuum adsorption chambers 11 are provided on the lower vacuum adsorption disk 5 corresponding to the through-hole areas of the lower mask 8. One side of the vacuum adsorption chamber 11 is connected to an adsorption port 12. The lower vacuum adsorption disk 5 has several lower vacuum adsorption ports 10 on the outside of the vacuum adsorption chamber 11 for adsorbing the lower mask 8. No through-holes are provided on the lower mask 8 at the corresponding positions of the lower vacuum adsorption ports 10.

[0028] The lower cavity wall 13 of the vacuum adsorption chamber is made of the same material as the lower vacuum adsorption disk 5 and the upper vacuum adsorption disk 4. They are all transparent quartz glass or resin without patterns.

[0029] In this example, the upper mask 4 uses either a through-hole mask or a regular mask without through holes.

Claims

1. A through-hole mask capable of adsorbing silicon wafers, comprising a substrate, wherein the substrate is provided with a light-shielding film pattern, characterized in that: The substrate has through holes in the gaps or outer areas of the light-shielding film pattern, and the through holes extend through both sides of the substrate; the substrate material is quartz glass or resin.

2. The through-hole mask for adsorbing silicon wafers according to claim 1, characterized in that: The pattern on the substrate is created using photolithography or etching.

3. The through-hole mask for adsorbing silicon wafers according to claim 1, characterized in that: The light-shielding film pattern is made of metallic chromium.

4. The through-hole mask for adsorbing silicon wafers according to claim 1, characterized in that: The through holes are manufactured by mechanical drilling, laser drilling, dry etching perforation, or wet etching perforation.

5. A through-hole mask exposure apparatus, using the through-hole mask as described in any one of claims 1-4, characterized in that: It includes an upper vacuum adsorption disk and a lower vacuum adsorption disk. An upper mask, a silicon wafer, and a lower mask are arranged sequentially from top to bottom between the upper and lower vacuum adsorption disks. The upper vacuum adsorption disk is provided with several upper vacuum adsorption ports for adsorbing the upper mask. The lower mask is a through-hole mask. The lower vacuum adsorption disk is provided with a vacuum adsorption cavity corresponding to the through-hole area of ​​the lower mask. One side of the vacuum adsorption cavity is connected to an adsorption tube. The lower vacuum adsorption disk is provided with several lower vacuum adsorption ports for adsorbing the lower mask on the outside of the vacuum adsorption cavity.

6. The through-hole mask exposure apparatus according to claim 5, characterized in that: The lower wall of the vacuum adsorption chamber is made of plain transparent quartz glass or resin.

7. The through-hole mask exposure apparatus according to claim 5, characterized in that: The upper mask is either a through-hole mask or a regular mask without through holes.

8. The through-hole mask exposure apparatus according to claim 5, characterized in that: The lower mask plate and the lower vacuum adsorption port are not provided with through holes at the corresponding positions.

9. The through-hole mask exposure apparatus according to claim 5, characterized in that: The upper and lower vacuum adsorption plates are made of transparent quartz glass or resin.

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