New horizontal boat growth method of undoped, semi-insulating GaAs with low dislocation density

Undoped semi-insulating GaAs single crystals with up to 2 inch diameter and 400 mm length were grown by a horizontal boat growth method using a quartz ampoule, a PBN boat and a B ₂O ₃ encapsulant. A good quality crystal with an average dislocation density of less than 3 000 cm ^-2 was successfuly grown. The resistivity of an as-grown crystal ranged from 10 ⁵ to 10 ⁷ Ω cm, which could be increased up to 10 ⁸ Ω cm through wafer annealing at 1150°C for 5 h under 1 atm arsenic gas pressure. These results indicate that the horizontal boat growth method has potential to provide low EPD, semi-insulating GaAs substrates for advanced electronic devices.