CN111816574A - A kind of UV film template and method for realizing clean glass passivation using UV film template - Google Patents

Abstract

The invention belongs to the technical field of semiconductors, and in particular relates to a UV film template and a method for realizing clean glass passivation by using the UV film template. The UV film template includes a UV film. A UV film connecting region is formed between the parts. The invention utilizes that the UV film itself is sticky to the surface of the silicon wafer, and the hollow area is used to selectively fill the glass into the chip groove during scraping. In the prior art, there is a technical problem that the surface of the silicon wafer is not clean during the passivation of the scraped glass; the present invention obtains a good glass passivation effect, and can protect the PN junction interface very well; the glass of the present invention effectively protects the upper edge, The problem of poor photoresist coating is avoided.

Description

A kind of UV film template and method for realizing clean glass passivation using UV film template

technical field

The invention belongs to the technical field of semiconductors, and in particular relates to a UV film template and a method for realizing clean glass passivation by using the UV film template.

Background technique

At present, the main way to realize the withstand voltage of devices in the semiconductor industry is passivation. Among them, typical mesa devices rely on filling glass in the mesa grooves to achieve reliable voltage resistance. There are three main methods for passivation with glass: knife scraping method, photoresist method and electrophoresis method. Among them, photoresist and electrophoresis have high equipment requirements, large investment, complex process control, poor process stability, high cost and low penetration rate. . The knife scraping method has the advantages of simple equipment, low investment, simple operation and the highest penetration rate.

Although the knife scraping method has many advantages, it also has disadvantages. Typically, this method requires surface cleaning (because there is glass on the entire surface when the knife is scraped), which is not easy to remove completely, and at the same time, cleaning will cause damage to the glass in the chip groove, resulting in the loss of the interface glass to be protected. Defects will lead to voltage deterioration, product scrap or early failure, resulting in poor chip electrical properties, reduced reliability, and hidden dangers to quality. In addition, multiple lithography is required during the production process of silicon wafers, and liquid photoresist needs to be applied. In order to block the corrosion of the acid solution, the conventional glass has an incomplete boundary where the photoresist is difficult to protect, resulting in the damage of the glass layer during the later corrosion, which will eventually lead to product scrap or early failure.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a UV film template and a method for realizing clean glass passivation by using the UV film template, which solves the problems of uncleanness on the surface of the silicon wafer and the glass in the chip groove when the glass passivation by the scraping method is adopted in the prior art. Technical issues prone to damage.

The UV film template of the present invention includes a UV film, and the UV film is provided with several hollow areas, and UV film connecting areas are formed between the ends of adjacent hollow areas.

The shapes formed by all hollow areas and all UV film connection areas correspond to the chip grooves on the silicon wafer.

The width of the UV film attachment area is greater than 0 mm and less than 0.3 mm.

The silicon wafer is one of GPP diodes, triodes, and thyristor chips.

The UV film connecting area is 2-4.

The method for realizing clean glass passivation using UV film template according to the present invention comprises the following steps:

(1) Multi-segment hollow areas are hollowed out on the UV film according to the pattern of the silicon chip groove, and a UV film connection area is formed between the ends of the adjacent hollow areas. The UV film is cut according to the position of the chip pattern on the silicon wafer. The shape of the silicon wafer is consistent with the size, and the UV film is pasted on the silicon wafer using a microscope, and the hollow area corresponds to the chip groove on the silicon wafer;

(2) Scratch the glass powder on the surface of the UV film, and the glass powder enters the chip groove. After the scraping is completed, dry the silicon wafer with the UV film and place it under the UV lamp to irradiate the UV film. The UV film can be removed, except for the chip. The glass is completely removed from the area outside the tank.

The method of hollowing out is laser or abrasive hollowing out.

The drying process is as follows: the temperature is 80-100°C, and the time is 3-10min.

The light power of the UV film is 80-120mW/cm, and the irradiation time is 40-45s.

The principle of the present invention is as follows: the present invention utilizes the feature that the UV film itself is sticky, and the stickiness is basically eliminated after UV illumination, and realizes selective filling. Fill in the UV film connection area between the hollow areas to ensure the integrity of the entire film and not easy to deform. When the UV film template is pasted and covered on the surface of the silicon wafer, the width of the UV film connection area is limited to be greater than 0mm and less than 0.3mm. , when the glass paste-latex is filled, it will automatically enter the chip groove below the connection area.

Compared with the prior art, the present invention has the following beneficial effects.

(1) The present invention utilizes that the UV film itself is sticky to the surface of the silicon wafer, and the hollow area is used to selectively fill the glass into the chip groove during scraping, and the UV film template is removed after the chip groove is filled, which can completely remove the residual glass powder , which solves the technical problem that the surface of the silicon wafer is not clean during the passivation of the scraped glass in the prior art;

(2) The present invention obtains a good glass passivation effect, and can protect the PN junction interface very well;

(3) The glass of the present invention effectively protects the upper edge and avoids the problem of poor photoresist coating.

Description of drawings

1 is a schematic structural diagram of a UV film template in Example 1 of the present invention;

FIG. 2 is a schematic view of the structure after passivation of silicon wafer glass in implementation 2 of the present invention, wherein: a is conventional glass passivation; b is glass passivation using UV film template.

In the figure: 1, UV film 2, hollow area 3, UV film connection area 4, N-Si silicon wafer 5, glass passivation layer 6, chip groove 7, the upper edge of the glass passivation layer.

Detailed ways

The present invention will be further described below in conjunction with the embodiments and the accompanying drawings of the description

Example 1

As shown in FIG. 1 , the UV film 1 of the present invention is provided with 4-segment hollow regions 2 , and UV film connecting regions 3 are formed between the ends of adjacent hollow regions 2 .

The shapes formed by all hollow regions 2 and all UV film connecting regions 3 correspond to the chip grooves on the silicon wafer.

The width of the UV film connecting region 3 is 0.2 mm.

The UV film connection area 3 is 4 places.

The silicon wafer for glass passivation in this embodiment is a thyristor chip of type BTB16, 3.92mm*3.92mm.

Example 2

The method for realizing clean glass passivation using UV film template according to the present invention comprises the following steps:

(1) Four sections of hollow area 2 are hollowed out on the UV film 1 according to the pattern of the silicon chip groove, and a UV film connection area 3 is formed between the ends of the adjacent hollow areas 2. According to the position of the chip pattern on the silicon wafer, UV The film 1 is cut into a shape consistent with the size of the silicon wafer, and the UV film 1 is pasted on the silicon wafer using a microscope, and the hollow area 2 corresponds to the chip groove on the silicon wafer;

(2) Scratch the glass latex on the surface of the UV film 1, and the glass latex enters the chip tank. After the scraping is completed, dry the silicon wafer with the UV film 1 and place it under the UV lamp for irradiation, and then the UV film 1 can be irradiated. Removed, and the glass in the area other than the chip groove is completely removed.

The method of hollowing out is laser hollowing out.

The drying process is as follows: the temperature is 90°C and the time is 7min.

The light power of UV film 1 was 100 mW/cm, and the irradiation time was 43 s.

As shown in FIG. 2 , a glass passivation layer 5 is formed after the glass of the chip groove 6 on the surface of the N-Si silicon wafer 4 is passivated. In Figure a, after conventional passivation, the upper edge of the glass passivation layer of the glass passivation layer 5 is formed. 7 places, because the glass latex powder is not easy to hang during scraping, and the glass is not well hung, so that the upper edge of the glass passivation layer is thinner at 7 places, which is not good for the protection of the PN junction. In Figure b, after UV template treatment , UV film 1 has UV glue on the back, which can be adhered to N-Si silicon wafer 4. After the glass latex is dried by scraping, and UV light (ultraviolet light) is added, the viscosity of the UV glue decreases sharply. The film is easily removed, and the upper edge 7 of the glass passivation layer 7 of the glass passivation layer 5 forms a thick protrusion, which is beneficial to protect the glass passivation layer 5 .

Example 3

The method for realizing clean glass passivation using UV film template according to the present invention comprises the following steps:

(1) Four sections of hollow area 2 are hollowed out on the UV film 1 according to the pattern of the silicon chip groove, and a UV film connection area 3 is formed between the ends of the adjacent hollow areas 2. According to the position of the chip pattern on the silicon wafer, UV The film 1 is cut into a shape consistent with the size of the silicon wafer, and the UV film 1 is pasted on the silicon wafer using a microscope, and the hollow area 2 corresponds to the chip groove on the silicon wafer;

(2) Scratch the glass latex on the surface of the UV film 1, and the glass latex enters the chip tank. After the scraping is completed, dry the silicon wafer with the UV film 1 and place it under the UV lamp for irradiation, and then the UV film 1 can be irradiated. Removed, and the glass in the area other than the chip groove is completely removed.

The method of hollowing out is laser hollowing out.

The drying process is as follows: the temperature is 80°C and the time is 3min.

The light power of UV film 1 is 80mW/cm, and the irradiation time is 40s.

Example 4

The method for realizing clean glass passivation using UV film template according to the present invention comprises the following steps:

(1) Four sections of hollow area 2 are hollowed out on the UV film 1 according to the pattern of the silicon chip groove, and a UV film connection area 3 is formed between the ends of the adjacent hollow areas 2. According to the position of the chip pattern on the silicon wafer, UV The film 1 is cut into a shape consistent with the size of the silicon wafer, and the UV film 1 is pasted on the silicon wafer using a microscope, and the hollow area 2 corresponds to the chip groove on the silicon wafer;

(2) Scratch the glass latex on the surface of the UV film 1, and the glass latex enters the chip tank. After the scraping is completed, dry the silicon wafer with the UV film 1 and place it under the UV lamp for irradiation, and then the UV film 1 can be irradiated. Removed, and the glass in the area other than the chip groove is completely removed.

The method of hollowing out is abrasive hollowing.

The drying process is as follows: the temperature is 100°C, and the time is 10 minutes.

The light power of UV film 1 was 120 mW/cm, and the irradiation time was 45 s.

Claims (9)

1. A UV film template, comprising a UV film (1), characterized in that: the UV film (1) is provided with several hollowed-out regions (2), and UV film connections are formed between the ends of adjacent hollowed-out regions (2). District (3). 2 . The UV film template according to claim 1 , wherein the shapes formed by all hollow regions ( 2 ) and all UV film connecting regions ( 3 ) correspond to the chip grooves on the silicon wafer. 3 . 3. The UV film template according to claim 1, wherein the width of the UV film connecting region (3) is greater than 0 mm and less than 0.3 mm. 4 . The UV film template according to claim 2 , wherein the silicon wafer is one of GPP diodes, triodes, and thyristor chips. 5 . 5. The UV film template according to claim 1, wherein the UV film connecting region (3) is 2-4. 6. a kind of method that utilizes any described UV film template of claim 1-5 to realize clean glass passivation, it is characterized in that: comprise the steps: (1) On the UV film (1), according to the pattern of the silicon wafer chip groove, a plurality of hollow areas (2) are hollowed out, and a UV film connecting area (3) is formed between the ends of the adjacent hollow areas (2). Position on the silicon wafer Cut the UV film (1) into a shape consistent with the size of the silicon wafer, and stick the UV film (1) on the silicon wafer using a microscope, and the hollow area (2) corresponds to the chip groove on the silicon wafer; (2) Scratch the glass powder latex on the surface of the UV film (1), and the glass powder latex will flow into the chip groove under the hollow area of the UV film along the scraper. After the scraping is completed, the glass powder latex will be dried. The UV film (1) can be removed by placing the silicon wafer with the UV film (1) under a UV lamp for irradiation, and the glass in the area other than the chip groove can be completely removed. 7 . The method for realizing clean glass passivation by using a UV film template according to claim 6 , wherein the hollowing process is one of laser, grinding tool hollowing, and screen printing. 8 . 8 . The method for realizing clean glass passivation by using a UV film template according to claim 6 , wherein the drying process is as follows: the temperature is 80-100° C. and the time is 3-10 min. 9 . 9 . The method for realizing clean glass passivation by using a UV film template according to claim 6 , wherein the light power of the UV film (1) is 80-120 mW/cm, and the irradiation time is 40-45 s. 10 .

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