Chamfering grinding wheel for machining silicon single crystal wafer for thick-layer epitaxy, and chamfering method

Abstract

The invention relates to a chamfering grinding wheel for machining a silicon single crystal wafer for thick-layer epitaxy, and a chamfering method. The diameters of coarse chamfering grooves of the grinding wheel are 120-150 micrometers less than the thickness of the wafer; half angles are 18-22 degrees; the depths are 900-1100 micrometers; the diamond sizes are 600-1000#; the diameters of fine chamfering grooves are 160-180 micrometers less than the thickness of the wafer; half angles are 11 degrees; the depths are 1400-1600 micrometers; the diamond sizes are 1000-2000#; the rotating speed of the coarse chamfering grinding wheel is 2500-5000rpm; machining is conducted for 1-2 rings; the rotating speed of the wafer is 16-20mm / s; the rotating speed of the fine chamfering grinding wheel is 3000-5000rmp; machining is conducted for 2-4 rings; and the rotating speed of the wafer is 10-15mm / s. The edge chamfering is conducted on the wafer by adopting the chamfering grinding wheel, so that the accuracy of an edge contour is high, the consistency of the edge quality is good, and the problem of a slip line due to the defect of the edge of the silicon wafer in a growth process of the thick-layer epitaxy is solved effectively.

Description

technical field [0001] The invention relates to the processing of a silicon single wafer, in particular to a chamfering grinding wheel and a chamfering method for processing a silicon single wafer for thick-layer epitaxy. Background technique [0002] In power electronic devices such as VDMOS and IGBT, silicon single wafers for thick-layer epitaxy are often used as key raw materials. During thick-layer epitaxial growth of silicon single wafers, "epitaxial crowns" or slip line defects are particularly prone to appear at the edges, which will have adverse effects on subsequent applications. [0003] The edge defects of thick-layer epitaxy are mainly caused by the edge quality of silicon single wafer. On the one hand, due to the crystal orientation, the edge of the silicon single wafer has a higher deposition rate than the surface of the silicon single wafer during epitaxial growth. If the area of ​​the edge of the silicon single wafer is too small or the angle is too large, i...

AI Technical Summary

Problems solved by technology

However, the existing chamfering methods cannot meet the needs of silicon substrates for thick-layer epitaxial growth. There are local rough areas on the edge

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