Patent ID: 7632696
Filing Date: 2009-12-15
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor chip where the method includes steps (1) to (4) and step (3) includes a stain etching method, comprising the steps: (1) forming semiconductor device regions at respective positions on a main surface of a semiconductor wafer; (2) grinding the back side of the semiconductor wafer to a predetermined thickness; (3) providing a porous single crystal layer on the backside of the semiconductor wafer, wherein the stain etching method is performed by causing a HF/HNO the HF/HNO and the ratio by volume of the 49% HF aqueous solution to concentrated nitric acid is in the range of 10:1 to 5000:1 with reference to the volume before mixing; and (4) dicing the processed semiconductor wafer obtained from steps (1) to (3).