ABSTRACT
We have employed the vertical boat (VB) method for growing semiinsulating GaAs crystals with 6-inch diameters, and single crystals have been successfully obtained. A semi-insulating property and good controllability of resistivity have been achieved by the carbon doping technique in the VB system. The 6-inch VB substrates have low dislocation density (about 3,000cm-2), low residual strain and high uniformity of resistivity compared to LEC substrates. Furthermore, the evaluation of ion-implanted layers did not show significant difference between the VB and LEC substrates. Consequently, the 6-inch VB substrates are suitable for device applications with the ion-implantation process.
