Design of Alloyed Junction Germanium Transistors for High-Speed Switching

Alloyed-junction transistors have been critically evaluated with respect to their potential use as high-speed switching devices. Limitations are found to result from avalanche multiplication and space charge layer widening which necessitate design compromises between high frequency and high voltage circuit requirements. It is shown in this article that n-p-n germanium transistors have an advantage over p-n-p type beyond that expected from mobility considerations. The additional advantage derives from differences in avalanche multiplication.