STRESS-FREE GAAS ON SI BY LASER-PULSE IRRADIATION

A novel method to relieve the stress in GaAs on a Ge-coated Si substrate using YAG (Yttrium Aluminum Garnet) laser pulse irradiation (the wavelength is 1.064-mu-m) is described. The stress decreases with increasing number of shots or shortening pulse width while keeping pulse energy per shot constant. The residual stress in the GaAs on Si after irradiation of 5 shots of the laser pulse (the pulse width is 2 ns and pulse energy is 0.36 J/pulse) is almost zero.