Double diffused high speed Ge transistors

The recent progress on pyrolytic deposition of masking films on semiconductor surfaces allows one to adopt double diffused technologies for Ge similar to that used for Si. Because of the more favorable material properties, Ge offers the possibility of higher speed and frequency devices. This paper describes the process of double diffused npn and npn planar transistors. The lateral dimensions of the three stripe transistors are such that conventional photoresist processes can be applied. The emitter stripe width is 5 , emitter and base are separated by 5 . Impurity profiles are discussed for both types of transistors. To obtain high speed transistors, the diffused structures are rather shallow. The emitter depth and base width are 2/ .