High-Efficiency Metal-Base Transistor Prepared by MBE or LPCVD Using a Composite Epitaxial Base
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
The main advantages of metal-base transistors (MBTs) are that only majority carriers participate in the ballistic current transport through the base thus eliminating the carrier storage time present in minority carrier devices and the resistivity of epitaxial metal bases is minimal thus allowing the use of ultrathin layers which reduces the carrier transit time, both yielding very fast response times of the device. Another very important aspect is its integrability in monolithic structures. The very high frequencies that should be realizable with MBTs can make this kind of device a serious competitor with GaAs- based devices. To reduce scattering of electrons in the metal base, the base material has to be made as perfect as possible, i.e., epitaxial.