Ohmic Aluminum-n-Type Silicon Contact

A method of making an ohmic alloyed contact to n-type silicon using aluminum has been developed. In the usual procedures for alloying aluminum to silicon a regrowth region of β-aluminum-silicon alloy is formed which is monocrystalline with the parent silicon. As a result of the junction formed between the n-type silicon and the p-type regrowth, the contact is rectifying. However, by the careful control of the heating and cooling cycles, it is possible to prevent the deposition of the β phase onto the surface of the parent silicon. Thus, an ohmic contact is obtained. The theory of the process is discussed. By this technique it has been possible to develop a ``ruggedized'' solar energy converter for use in space vehicles.