CN101038892A - Knife scraping method glass passivation process for silicon current rectifier - Google Patents

Abstract

The invention provides a knife scraping glass passivating process for silicon rectifier which includes: (1) employing mixed acid to erode a diffusion chip which has been photoetched thereby forming PN junction and to remove photoresist; (2) compounding ethyl cellulose and thinner in ratio into solution and then filling the same and glass powder into an eggplant-shaped bottle to stir for making glass plasma; (3) equably coating the glass plasma on the surface of the silicon chip which has been etched with groove, and then removing the redundant glass plasma on electrode face by scraper; (4) pre-firing the coated silicon chip in a furnace for 20 min, 585 DEG C.; (5) taking out the fired silicon chip and erasing the redundant glass powder; (6) glass-melting the erased silicon chip in a furnace for 20 min, 820 DEG C.; (7) executing the procedures of coating, prefiring, erasing, melting for the glass-melted silicon chip once again; (8) plating nickel and gold on the passivated glass and then scribing the same thereby completing the chip of the silicon rectifier. The process can be easily operated, and has less equipment dependence, and is easy for application, and can reduce production cost and operation time.

Description

The knife scraping method glassivation technology of silicon rectification device

Technical field

The present invention relates to a kind of glassivation technology of silicon rectification device, particularly a kind of knife scraping method glassivation technology of silicon rectification device.

Technical background

At present; silicon chip after the many employings of technology of semicon industry manufacturing silicon rectification device will be spread cuts; form up to a hundred chips; after mesa etch and welding lead, cleaning; each chip PN junction table top is carried out the glass coating; reaching the effect of passivation protection, complicated operation, the time is long, efficient is low, production cost is high.

Summary of the invention

The invention provides a kind of knife scraping method glassivation technology of silicon rectification device; elder generation's formulate glass slurry; with knife scraping method glass paste is coated to after the photoetching in the silicon chip PN junction table top groove equably; the way of melting by pre-burning, burning makes glass paste be melt into glass then; play the effect of passivation protection PN junction, make the silicon rectification device chip through technologies such as alloying, scribings again.

The technical scheme that the present invention is taked for achieving the above object is: a kind of knife scraping method glassivation technology of silicon rectification device, and this method comprises following processing step:

(1) silicon chip that will diffuse out PN junction carries out the photoetching process of gluing, preceding baking, exposure, development and post bake according to the dimensions of required chip, carries out litho pattern;

(2) nitric acid, hydrofluoric acid, acetate are mixed with the nitration mixture corrosive liquid by following volume ratio:

Nitric acid: 28～60%

Hydrofluoric acid: 8～50%

Acetate: 10～32%

Then silicon chip after the photoetching is put into the nitration mixture corrosive liquid and corrode, erode away the PN junction table top groove of each chip, keep each chip chamber to connect and not dialysis the cleaning of removing photoresist again;

(3) formulate glass slurry solvent:

With ethyl cellulose and diluent in a certain value among the following ratio:

1g∶5ml～1g∶18ml

Be placed on and heat stirring and dissolving in the beaker, make the glass paste solvent;

(4) formulate glass slurry:

With glass paste with solvent and lead glass frit in 3ml: the 5g ratio is poured in the eggplant-shape bottle and is stirred;

(5) glass paste that stirs is dripped to the silicon chip surface that erodes away groove, apply on silicon chip with the stainless steel spoon, glass paste evenly is coated with in the full groove, with the stainless steel scraper unnecessary glass paste is scraped gently from silicon chip surface again, subsequently this silicon chip is put into quartz boat;

(6) glass pre-burning:

The pre-burning furnace tube temperature is transferred to 575～585 ℃, puts into the quartz ampoule pre-burning with the quartz boat that has applied the glass paste silicon chip is housed, and the time is 20min;

(7) silicon chip after the wiping pre-burning:

With the glass dust wiped clean of the silicon chip surface after the pre-burning, and notice that glass paste is not wiped in the groove;

(8) glass burns till:

The silicon chip of wiping away through the watch crystal brush is carried out glass burn till, the temperature of firing furnace is 820 ℃, and firing time is 20min;

(9) operate again again one time according to the order of (5)～(8);

(10) silicon chip after the glassivation is carried out scribing after nickel plating, gold-plated alloying, make the chip of silicon rectification device.

Characteristics of the present invention are: technological operation is very little to device dependence, has reduced production cost and operating time, has improved production efficiency, and this technological operation is simple, and is easy to implement, can realize the protective effect of glass to the table top groove well.

Embodiment

According to instantiation the invention process process is described below:

The silicon chip that diffuses out PN junction is carried out the photoetching process of gluing, preceding baking, exposure, development and post bake according to the dimensions of required chip, carry out litho pattern;

With nitric acid, hydrofluoric acid, acetate get 3000ml, 2500ml respectively, 1000ml is mixed with the nitration mixture corrosive liquid, silicon chip after the photoetching is put into mixed acid liquid erode away the PN junction table top, with stripper this silicon chip is removed photoresist then, uses the pure water ultrasonic cleaning again;

Get the 50g ethyl cellulose and the 600ml diluent adds thermal agitation in beaker, make solvent, again this solvent 300ml and 500g lead glass frit are mixed to stir and make glass paste;

Glass paste is dripped to the surface of the silicon chip that erodes away groove, evenly apply at silicon chip, make evenly to be coated with full glass paste in the groove, unnecessary glass paste is scraped from silicon chip surface with the stainless steel scraper with the stainless steel spoon;

The silicon chip that has applied glass paste is put on the quartz boat pre-burning 20min in 585 ℃ pre-burning stove;

Use the unnecessary glass dust wiped clean of no fine paper, in 820 ℃ firing furnace, burn again and melt 20min silicon chip surface.

Burn the silicon chip melt and carry out the glass paste coating second time, pre-burning, wiping, fusion again carrying out glass;

Silicon chip after glass burnt till cuts into chip one by one through scribing machine again through nickel plating, gold-plated Alloying Treatment, makes the glassivation chip that silicon rectification device is used.

Claims (1)

1. the knife scraping method glassivation technology of a silicon rectification device, this method comprises following processing step:

(1) silicon chip that will diffuse out PN junction carries out the photoetching process of gluing, preceding baking, exposure, development and post bake according to the dimensions of required chip, carries out litho pattern;

(2) nitric acid, hydrofluoric acid, acetate are mixed with the nitration mixture corrosive liquid by following volume ratio:

Nitric acid: 28～60%

Hydrofluoric acid: 8～50%

Acetate: 10～32%

Then silicon chip after the photoetching is put into the nitration mixture corrosive liquid and corrode, erode away the PN junction table top groove of each chip, keep each chip chamber to connect and not dialysis the cleaning of removing photoresist again;

(3) formulate glass slurry solvent:

With ethyl cellulose and diluent in a certain value among the following ratio:

1g∶5ml～1g∶18ml

Be placed on and heat stirring and dissolving in the beaker, make the glass paste solvent;

(4) formulate glass slurry:

With glass paste with solvent and lead glass frit in 3ml: the 5g ratio is poured in the eggplant-shape bottle and is stirred;

(5) glass paste that stirs is dripped to the silicon chip surface that erodes away groove, apply on silicon chip with the stainless steel spoon, glass paste evenly is coated with in the full groove, with the stainless steel scraper unnecessary glass paste is scraped gently from silicon chip surface again, subsequently this silicon chip is put into quartz boat;

(6) glass pre-burning:

The pre-burning furnace tube temperature is transferred to 575～585 ℃, puts into the quartz ampoule pre-burning with the quartz boat that has applied the glass paste silicon chip is housed, and the time is 20min;

(7) silicon chip after the wiping pre-burning:

With the glass dust wiped clean of the silicon chip surface after the pre-burning, and notice that glass paste is not wiped in the groove;

(8) glass burns till:

The silicon chip of wiping away through the watch crystal brush is carried out glass burn till, the temperature of firing furnace is 820 ℃, and firing time is 20min;

(9) operate again again one time according to the order of (5)～(8);

(10) silicon chip after the glassivation is carried out scribing after nickel plating, gold-plated alloying, make the chip of silicon rectification device.