Manufacturing large diameter GaAs substrates for epitaxial devices by VB method

The vertical boat (VB) method has advantages in the growth of substrates for epitaxial devices. Low residual strain and low dislocation four inch GaAs crystals are manufactured with good reproducibility. Low residual strain reduces slip line occurrence and low dislocation density enables growth of low defects in epitaxial layers. FETs fabricated on carbon doped high resistivity VB substrates show high breakdown voltage. Vth was stable at higher drain voltages. Six inch GaAs crystals are also grown by VB and show adequate characteristics.