Published online by Cambridge University Press: 22 February 2011
The electrical properties of IR radiation transient annealed Si implanted semi-insulating GaAs are presented for 100 keV ion doses from 3 × 1012 to 3 × 1014 cm−2. For wafers implanted with 3 × 1012 cm−2 doses, suitable for FET channel layers, carrier concentration and drift mobility profiles were determined from C-V and transconductance measurements on fat FET structures. Optimum electrical activation and carrier concentration profiles were obtained for peak pulse temperatures of 930–950°C. Van der Pauw measurements were made on substrates implanted with Si doses ≥ 1 × 1013 cm−2 to determine sheet carrier concentration and Hall mobility. The peak pulse temperature required to give optimum activation efficiency is found to increase with dose. The results presented here demonstrate that undoped substrates are preferable to Cr-doped substrates for low dose device applications.