Si ion implantation into LEC semi-insulating GaAs

The implantations were performed at room temperature on LEC semi-insulating GaAs substrates to form n-type layers at energies of 80-130 keV with doses of 3-8 x 1012 cm-2 and an n- layer at lower energy of 40 keV with a higher dose of 1 x 1014 cm-2. I-V characteristic, capacity-voltage profiling, and Hall effect measurements were used to investigate the electrical properties of the implanted layers after annealing. The carrier mobilities and electrical activities measured in the n-type layers are 2500-3000 cm2 V-1 s-1 and 55-88%, respectively, and the maximum carrier density of the n+/n structure, which is used to fabricate GaAs MESFET's and DIC's, is as high as 2 x 1018 cm-3 and is desirable to decrease the resistances of source and drain contacts. Damage removal and carrier activation in the annealed implanted regions are discussed and device application results are presented in this paper. (author)