Capless rapid thermal annealing of GaAs using a graphite susceptor

The results of experiments performed to evaluate the use of a commercially available rapid thermal annealer (RTA) with a graphite susceptor for capless rapid thermal annealing to activate implants in GaAs are reported. The interior of the susceptor was easily charged with As by annealing a sacrificial GaAs wafer. Wafers annealed face up in the charged susceptor showed no evidence of surface degradation (due to preferential loss of As) and no decrease in implant activation (peak doping) when compared to dielectric (SiO₂) capped anneals. Over 50 wafers have been annealed without recharging the susceptor. In addition, slip on 3-in wafers was almost completely eliminated due to the reduction of radial temperature gradients. It is concluded that capless RTA in a commercially available graphite susceptor appears to be a viable annealing technique for activating implants in GaAs and related III-V materials and is suitable for a production environment