Patent ID: 9721809
Date: 2017-08-01
CPC Classifications: H01L

Claim:
1. A method of forming a gettering layer configured to capture metallic ions on a back-side surface of a semiconductor wafer formed with a plurality of devices on a face-side surface thereof, the method comprising: irradiating the back-side surface of the semiconductor wafer with a pulsed laser beam to form the gettering layer of a depth of 10 to 230 nm, wherein the gettering layer is formed from the same material as the remainder of the semiconductor wafer, wherein the semiconductor wafer is a silicon wafer, and a pulse width of the pulsed laser beam is set in the range from 1 to 500 ps, and wherein a relation of v/h≦2d is established, where h (kHz) is the repetition frequency of the pulsed laser beam, v (mm/sec) is the feed rate of the pulsed laser beam, and d (micron) is the spot diameter of the pulsed laser beam.