Transistor and its method of manufacture

摘要

A transistor includes a substrate, a source terminal and a drain terminal, each terminal being supported by the substrate, and the source and drain terminal being separated by a portion of the substrate, a layer of semiconductive material deposited so as to cover the portion of the substrate and to connect the source terminal to the drain terminal, a layer of dielectric material deposited so as to cover at least a portion of the layer of semiconductive material, and a layer of electrically conductive material deposited so as to cover at least a portion of the layer of dielectric material. The layer of electrically conductive material providing a gate terminal to which a potential may be applied to control a conductivity of the layer of semiconductive material connecting the source and drain terminals.

主权项

1. A method of manufacturing a transistor, the method comprising:
providing a substrate and a region of electrically conductive material supported by the substrate; forming at least one layer of resist material over said region to form a covering of resist material over said region; forming a depression in a surface of the covering of resist material, said depression extending over a first portion of said region, said first portion separating a second portion of the region from a third portion of the region; removing resist material located under said depression so as to form a window, through said covering, exposing said first portion of the electrically conductive region; removing said first portion to expose a portion of substrate separating the second portion from the third portion of the region; depositing semiconductive material at least inside the window to form a layer of semiconductive material connecting the second portion to the third portion; depositing dielectric material to form a layer of dielectric material over said layer of semiconductive material; depositing electrically conductive material to form a layer of electrically conductive material over said layer of dielectric material; removing resist material at least from around said window so as to expose the second and third portions, wherein said second and third portions provide a source terminal and a drain terminal respectively and the layer of electrically conductive material provides a gate terminal to which a potential may be applied to control a conductivity of the layer of semiconductive material connecting the second and third portions; undercutting the covering of resist material around the window before said depositing of semiconductive material so as to expose a part of an upper surface of the second portion adjacent the separating portion of substrate and expose a part of an upper surface of the third portion adjacent the separating portion of substrate; and forming a step in said exposed part of the second portion and a step in said exposed part of the third portion before depositing said semiconductive material.