2198 results about "Electron mobility" patented technology

There are provided a higher-performance compound semiconductor epitaxial substrate having improved electron mobility characteristics and its production method. The compound semiconductor epitaxial substrate includes a channel layer in which electrons travel and an epitaxial layer on each of a front side and a back side of the channel layer, wherein a total p-type carrier concentration A ( / cm2) per unit area in the epitaxial layer on the back side of the channel layer and a total p-type carrier concentration B ( / cm2) per unit area in the epitaxial layer on the front side of the channel layer satisfy the following expression (1):0<A / B≦3.5  (1)wherein A=(a concentration of all p-type carriers in an active state due to an acceptor impurity contained in the epitaxial layer on the back side of the channel layer)×(a total thickness of the epitaxial layer on the back side), and B=(a concentration of all p-type carriers in an active state due to an acceptor impurity contained in the epitaxial layer on the front side of the channel layer)×(a total thickness of the epitaxial layer on the front side).

A multi-layer structure for use in the fabrication of integrated circuit devices is adapted for the formation of enhancement mode high electron mobility transistors, depletion mode high electron mobility transistors, and power high electron mobility transistors. The structure has, on a substrate, a channel layer, spacer layer on the channel layer, a first Schottky layer, a second Schottky layer on the first Schottky layer, and a third Schottky layer on the second Schottky layer, and a contact layer on the third Schottky layer. Etch stops are defined intermediate the first and second Schottky layers, intermediate the second and third Schottky layers, and intermediate the third Schottky layer and the contact layer.