Method of making substantially linear field-effect transistor

A method of making a field-effect transistor, CHARACTERIZED BY THE STEPS OF:

• forming on a substrate a plurality of alternating donor and conduction layers arranged from top to bottom, each layer having a thickness, the donor layer having a wider bandgap than the conduction layer and having donor impurities therein for providing carriers to channels in the conduction layers, the thicknesses of the conduction layers decreasing from the top to bottom layers;
• forming a gate on the top conduction layer;
• implanting into the donor and conduction layers, masked by the gate, to form self-aligned source and drain regions;
• and,
• contacting the so formed source and drain regions;
• wherein each of the channels are at different depths below the gate;
• and
• wherein the thickness of the conduction layers, the depths of the channels, and the charge carrier concentrations therein are selected to provide a substantially linear transistor gate input voltage-to-output drain current transfer characteristic over substantially all gate input voltages between pinch-off and channel saturation.