Trench etching technology and diode production method

Abstract

The invention relates to a trench etching technology and diode production method, and belongs to the field of diode production. A trencher is used for trenching, rinsing is carried out, a mixed acid including a mixture of nitric acid, hydrofluoric acid, acetic acid and sulfuric acid is used for corrosion for 1.8-2.2 min after once drying, and secondary drying is carried out after washing. Trenching is used for form a V-shaped trench in the depth of 13.5-140 micron and with the top opening width of 250-300 micron. A wafer trench can be etched with simple technology and short time completely needless of photo-etching, a tedious yellow light process is avoided, use of expensive photoresist and photo-etching device is not needed, the efficiency is improved greatly, the yield rate is high, timeand energy are saved and the environment is protected. The invention also provides a diode production method, and a prepared diode is high in performance.

Description

technical field [0001] The invention belongs to the field of diode production, and in particular relates to a groove etching processing technology and a production method of diodes. Background technique [0002] At present, the production process of high-frequency rectifier diodes includes three times of yellow light lithography. The purpose of the first yellow light lithography is to etch the groove on the wafer to expose the PN node, provide conditions for the passivation protection of the glass, and also divide the wafer into several parts. An independent grain, easy to cut and separate. However, as we all know, the photolithography process steps are cumbersome, including coating, exposure, development, fixing, hardening, degumming, and rinsing. The current traditional yellow lithography groove process is: 1. Take the cleaning sheet into the lithography station, 2. Apply glue on the surface of the silicon wafer, 3. Pre-baking (soft baking), 4. Alignment and exposure, 5. ...

AI Technical Summary

Problems solved by technology

However, as we all know, the photolithography process steps are cumbersome, including coating, exposure, development, fixing, hardening, degumming and rinsing, etc.

The current traditional yellow lithography groove process is: 1. Take the cleaning sheet into the lithography station, 2. Apply glue on the surface of the silicon wafer, 3. Pre-baking (soft baking), 4. Alignment and exposure, 5. Developing and fixing , 6. Hard film (hard baking), 7. Inspection, record filling and finishing work, 8. Quality control inspection, 9. Primary photolithography corrosion, 10. Rinse residual acid with pure water, 11. Drying and drying Roasting, 12. Inspection, filling in records, 13. Quality control inspection, 14. Phosphorus surface glue filling, 15. Baking, 16. Taking materials to Taiwan rot station, 17. Inspection preparation work, 18. Second photolithography Corrosion, 19. Flushing with pure water, 20. Sulfuric acid degumming, 21. Flushing, 22. Drying and drying, 23. Checking film collection and finishing, 24. Quality control inspection, 25. Testing TRR value, 26 .There are as many as 26 steps in the whole process from trenching material to cleaning station, the process is complicated, and the completion time of trench etching by yellow light lithography is as long as 2-3 hours

[0003] The coating integrity of the photoresist, the firmness of the adhesion, and the stability of the development and fixing process involved all determine the etching quality of the groove, and the influencing factors are complex

Yellow light lithography is used for groove etching, not only the process steps are complicated and demanding, but also the quality of photoresist and lithography equipment are relatively high. Good photoresist generally needs to be imported, and lithography equipment is relatively expensive. The above factors mean that There are many requirements for manpower, raw materials and equipment, so the production cost remains high

At the same time, the use of photoresist, developing and fixing chemicals involved in the photolithography process, and the subsequent degumming and cleaning process will pollute the environment

However, trench etching by yellow light lithography is the current solution, and there is no better alternative process, which is a difficult problem in the current silicon diode production process.

The current research is all about the improvement of the yellow light lithography process, and there is no report on the high-quality trench etching without the use of yellow light lithography.

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