DIFFUSED ALLOYED EMITTER AND THE LIKE AND A METHOD OF MANUFACTURE THEREOF

摘要

In a germanium transistor wherein an aluminum emitter is selectively diffused from an aluminum trichloride vapor phase chemical displacement reaction with germanium and is localized by a patterned or windowed silicon dioxide mask, the surface concentration of said emitter is increased substantially by alloying into said aluminum diffusion, in a nondestructive manner, a film of aluminum evaporated over said diffusion. The surface concentration of aluminum in the emitter can be increased from about 5x1019 atoms per cubic centimeter for the diffused emitter to 5x1020 atoms per cubic centimeter for the diffused alloyed emitter. Consequently, the efficiency of the aluminum diffused emitter is substantially increased by the subsequent alloying.