Electrochemical technology of silicon surface alloyed diffused transistors

Electrochemical techniques combined with solid state diffusion and surface alloying have been utilized to produce a high frequency, high speed NPN silicon switching transistor. Special jet etching and plating solutions with a newly developed infrared controlled etching action are used to precisely place the emitter and collector electrodes in the graded-base region. Gotd whisker wire contacts are fused directly to the 3.5 and 6.5 mil diameter gold-antimony-silicon electrodes without any solder or contaminating fluxes. As in the germanium MADT, the etnire process is readily adaptable to fast automatic transfer production with step-to-step feedback of information for immediate unit-to-unit in-process control.