Highly indium doped silicon semiconductor prodn. - using metal alloy contg. indium to reduce vapour pressure, useful for opto:electronic device and IR sensor

摘要

Prodn. of highly In-doped Si (I) with semiconductor properties involves doping a Si rod or bar with a metal alloy contg. In. Pref. doping is carried out by noncrucible zone melting, using an alloy of In (1 pt.) with Sn (3 pts.), Ag (5 pts.), Au (3 pts.), or Si (9 pts.). The In concn. in the Si is 10 exp. 19 or 10 exp. 20 In atoms/cm3. Doping is carried out with a suitable moulding, e.g. a die or cylinder, placed at the starting point of zone melting or at continuous or discrete points along the rod. (I) is specified for use in the prodn. of optoelectronic devices and IR sensors. The vapour pressure of the In is greatly reduced, allowing a much higher level of doping than usual to be attained.