Diffused Emitter and Base Silicon Transistors

The necessity of thin base layers for high-frequency operation of transistors has long been apparent. One of the most appealing techniques for controlling the distribution of impurities in a semiconductor is the diffusion of the impurity into the solid semiconductor. The diffusion coefficients of Group III acceptors and Group V donors into germanium and silicon are sufficiently low at judiciously selected temperatures so * A portion of t h e material of this p a p e r was p r e s e n t e d at t h e Semiconductor Device Conference of t h e I n s t i t u t e of R a d i o E n g i n e e r s , P h i l a d e l p h i a , Pa., J u n e , 1955.