Technique for producing gettering source with dry abrasive blasting on silicon chip back side and eliminating oxidation fog of glazed silicon surface

Abstract

The invention provides a technological method for manufacturing a gettering source on the back surface of a silicon chip by dry sandblasting and removing oxidated fog on the glazed surface of silicon. The method comprises the steps that: according to the back damage gettering principle, sandblasting is carried out on the back surface of the silicon chip to generate crystal lattice damage and manufacture the gettering source; by controlling and regulating sandblasting granularity, sandblasting pressure, operational chip distance and time processes, uniform stacking fault density is promised on the back surface of the silicon chip; namely, that a damage stacking fault of 6 to 38x10<4> / cm<2> is generated on the back surface of the silicon chip to induce stacking faults; emergy determined as W20 is used as sandblasting abrasives; theories and a large number of technological tests decide a sandblasting pressure of 2.3 or 2.7 Kg / cm<3> at atmosphere pressure and a sandblasting chip distance (distance between the nozzle and the silicon chip) of 70mm, and the sandblasting time is controlled between 6 and 8 seconds per chip. By regulating the belt speed of a silicon chip conveying belt, the technology of the invention is ensured with very high feasibility and operability, both low investment and cost and easy implementation, and has better development prospects.

Description

technical field [0001] The invention belongs to the manufacturing technology of IC-level silicon single crystal polished wafers, and mainly relates to a process method for dry sandblasting the back of silicon wafers to manufacture a source of impurities and eliminate oxidized mist on the surface of silicon polished. Background technique [0002] IC-grade silicon single crystal polished wafer is the core material for manufacturing large-scale and ultra-large-scale integrated circuits, and is mainly used in high-tech fields such as high-speed computers and aerospace. The micro-defect "oxidation mist" of silicon polished wafers has always troubled the quality of polished wafers used in military high-reliability devices. This is because P<111> polished wafers are oxidized at 1050°C and oxidized mist is produced after preferential corrosion. Microscopic analysis is heavy metals. It is caused by the deposition of Fe, Ni, Cu, etc. on the front side of the polishing sheet. Fo...

AI Technical Summary

Problems solved by technology

But its equipment is expensive because it has (1) nine groups of SiO 2 The working operation box of the sand spray head; (2) Silicon wafer sending-conveyor belt sending-receiving automatic control system; (3) SiO2 2 Sand liquid preparation operation stirring pump circulation system; three major components

The device occupies a large area, SiO 2 The preparation of sand liquid is complicated and the operation process is complicated. Generally, small enterprises are not easy to implement due to the large investment.