Double-diffused silicon and germanium microwave amplifier transistors

This paper is a comparison of both germanium and silicon NPN double-diffused transistors used as small, signal, low noise amplifiers in the frequency range of 1-6 GHz. With the development of the necessary oxide masking and shallow diffusion technologies, it has been possible to fabricate NPN double-diffused planar germanium transistors using the more sophisticated multi-stripe transistor geometries which have been used in the fabrication of microwave silicon transistors.