Experimentation relating to drift-intrinsic transistors

Design theory for a silicon diffused-base drift-intrinsic transistor of the tabbed type will be briefly reviewed. Experimental fabrication and problems will be described. A sealed quartz tube gaseous diffusion technique is utilized. Convenient mechanisms for obtaining the desired low vapor pressures are (1) introducing microquantities of solid impurities (2) utilizing the low vapor pressure of impurity elements in equilibrium with the molten liquid reservoir. Surface preparation is of extreme importance. Collector and emitter contacts may be simultaneously evaporated and alloyed in vacuo.