ABSTRACT
The field of silicon (Si)-based heterostructures solidly rests on the shoulders of materials scientists and crystal growers, those purveyors of the semiconductor “black arts” associated with the deposition of pristine films of nanoscale dimensionality onto enormous Si wafers with near infinite precision. Once the move to Si-based processing occurred, the field of Si epitaxy was launched, the first serious investigation of which was reported in 1963. The basic idea of using an electric field to modify the surface properties of materials, and hence construct a “field-effect” device, is remarkably old, predating even the quest for a solid-state amplifier. The first functional silicon–germanium (SiGe) p-channel metal-oxide-semiconductor field-effect transistors (pMOSFET) was published in 1991, and shortly thereafter, a wide variety of other approaches aimed at obtaining the best SiGe pMOSFETs. It is ironic that the practical demonstration of the bipolar junction transistor preceded that of the MOSFET by 9 years.
