Photoelectric characteristics of contacts In-semiconductor A3B5

摘要

s The effect of annealing structures on the electrical and photoelectric properties of metal-semiconductor contacts was investigated. Metal/semiconductor structures have been fabricted by method of electrochemically deposition of In on the electrochemically cleaned surface of the semiconductors A3B5 (GaP, GaAs). The dark capacitance-voltage, current-voltage characteristics and the photoelectric spectra of zero bias for front-illuminated contact show near-ideal Schottky barrier diode properties for annealing temperature up to 250-3000C. Was found that the spectra of zero bias photocurrent of In/GaP besides the region photoconductivity resulting from band to band excitation, contains, also, separated of them the region photoconductivity in a long wavelength of spectra, which is related to the interaction between the metal and semiconductor. Samples used for the fabrication of In/GaP diodes were growing by Chochralski method especially undoped n-type GaP into (Ⅲ) oriented wafers. The thickness and carrier concentration was 200-250 mmic and (2-4). 10 exp17 atom/cm3 respectively. At first ohmical contact to the one side of wafer was formed by alloying of indium at the temperature 500 ℃ for GaAs and 600℃ for GaP during 5 min in hydrogen. Then the sample with ohmic contact and wire for preceding the power was coaled with chemical stable polystyrene solution except the area where the metal will be deposited. The wafers were then ached chemically, rinsed in distilled water and were transferred immediately into electrolyte for deposition of In.