Abstract
The electrical properties of sulphur 32 implanted gallium arsenide were investigated using the capacitance-voltage, Copeland and Hall measurement techniques. N-type epitaxial gallium arsenide was implanted with a range of sulphur ion doses from 10[12] ions/cm[2] to 10[15] ions/cm[2], with energies from 100 keV to 400 keV and afterwards annealed at temperatures up to 800°C. The implantations were carried out with the specimens held at temperatures up to 180°C. Deep concentration profiles were observed, with super-tails extending three or four microns into the material. These deep profiles were considered to be due to diffusion during subsequent annealing. A saturation in the peak concentration was also observed, with a maximum electrically active peak concentration of 1.7 x 10[16] atoms/cm3. A range of percentage electrical activities, from zero to 86%, was obtained. The resultant concentration profiles were dominated by the effects of the structural damage produced by the implantation process. In order to study the effects of damage further, gallium arsenide was implanted with doses of both protons and argon.