Epitaxial overgrowth method and devices

摘要

Method of epitaxial overgrowth of AB semiconductor on non-planar AB substrate containing grooves, the sidewalls of which have an equivalent orientation to that of the substrate. This method is applied to the fabrication of an heterobipolar transistor and of a vertical field effect transistor (700) and with buried gates (704) having gate sidewall crystal orientation the same as the substrate surface and a low index substrate crystal orientation without tilt to a higher index direction. The gate (704) may have modulated doping along the channel (706), and the drain (708) may have a lighter doping level than the channel which may be accomplished by an epitaxial overgrowth of the gates (704) to form the channels (706).