Semiconducting highly indium doped silicon prodn. - by doping melt with indium alloy to reduce indium vapour pressure and drawing

摘要

Prodn. of semiconducting, highly In-doped Si (I) entails first producing a metallic alloy (II) contg. In, then fusing this with Si in a crucible and drawing a highly doped Si rod or bar from this. Pref. (II) is an alloy of In (1 pt.) with Au (3 pts.), Ag (5 pts.), Sn (3 pts.) or Si (9 pts.). In is incorporated in a concn. of ca. 10 exp. 19 or 10 exp. 20 In atoms/cm3. Ar under slight over-pressure is used as protective gas. (I) is specified for making opto-electronic devices and IR sensors. The use of (II) as dopant greatly reduces the In vapour pressure and hence increases the possible In concn.