Quantum well mosfet channels having uni-axial strain caused by metal source/drains, and conformal regrowth source/drains

A transistor comprising:

• a quantum well in a substrate, the quantum well comprising a channel layer between a top barrier layer and a bottom buffer layer, wherein the top barrier layer and the bottom buffer layer each comprise a material having a lattice spacing different than a lattice spacing of a channel material of the channel layer and each causing a bi-axial strain in the channel layer;
• a first junction region adjacent to the quantum well, the first junction region through the channel layer, and to the bottom buffer layer;
• a different second junction region adjacent to the quantum well, the second junction region through the channel layer, and to the bottom buffer layer;
• a junction material in the first junction region and in the second junction region having a lattice spacing different than a lattice spacing of the channel material, and causing a uni-axial strain in the channel layer, in addition to the bi-axial strain.

An apparatus comprising:

• a transistor quantum well in a substrate, the quantum well comprising a channel layer between a top barrier layer and a bottom buffer layer, wherein the top barrier layer and the bottom buffer layer each comprise a material having a lattice spacing smaller than a lattice spacing of a channel material of the channel layer to each cause a bi-axial compressive strain in the channel layer;
• a first junction region adjacent to a portion of the quantum well, the first junction region extending through the top barrier layer, through the channel layer, and to the bottom buffer layer;
• a different second junction region adjacent to the portion of the quantum well, the second junction region extending through the top barrier layer, through the channel layer, and to the bottom buffer layer;
• a junction material in the first junction region and in the second junction region, the junction material having a lattice spacing greater than a lattice spacing of the channel material to cause a uni-axial compressive strain in the channel layer, in addition to the bi-axial compressive strain.