ELECTRICAL CHARACTERISTICS OF 100 MEV SI-28 IMPLANTED LEC GROWN GAAS(100)

Undoped semi-insulating gallium arsenide single crystals were grown in pBN crucible using LEC technique. Si-28 implantation at various fluen ces was carried out using 100 MeV 28Si ion. Implanted samples were cha racterised using four probe and Hall measurements. In-situ resistance measurements were carried out for samples implanted with various fluen ces. The electrical characterisation results of 100 MeV Si-28 implante d GaAs samples show an increase in mobility 5774 cm(2)/V.s (3800 cm(2) /V.s) and a decrease in sheet resistivity of the order of 2 x 10(2) Om ega/square. The increase in mobility at 300 K may be due to better ele ctrical homogeneity in the implanted layer, than in the virgin substra te. The implanted samples (100 MeV/1.5 x 10(13) cm(-2)) were annealed at different temperatures in the range of 200-400 degrees C and charac terised using Hall measurements at different temperatures (300-380 K). The implantation profile of the two buried layers by 100 MeV/1 x 10(1 2) cm(-2) and 80 MeV/1 x 10(12) cm(-2) for Si-28 ion were observed and analysed using Scanning Electron Microscopy.