A single-energy isolation scheme was applied to n-type GaAs by using He ion irradiation at 25, 100 or 200C to create thermally-stable highly resistive regions. It was found that optimum isolation, and its persistence during further heat treatment, was highly influenced by the implantation temperature. Isolation caused by hot implants in GaAs layers was more effective and had an improved thermal stability over room-temperature implants, due to the formation of thermally stable defects during implantation at high temperatures.

Electrical Isolation of n-Type GaAs and InP Using Helium Ion Irradiation at Variable Target Temperatures. S.Ahmed, P.Too, R.Gwilliam, B.J.Sealy: Applied Physics Letters, 2001, 79[21], 3533-5