Insulated-gate thin film transistor with low leakage current

An insulated-gate thin film transistor comprising:

• A. a substrate having opposed major surfaces and including electrically insulating material adjoining at least a part of one major surface;
• B. a conductor layer of an electrically conductive material on at least one major surface of the substrate adjoining an electrically insulating material to form a gate electrode;
• C. an insulator layer of an electrically insulating and thermally conductive material disposed on the conductor layer;
• D. source and drain electrodes of electrically conductive material disposed on said insulator layer, said source and drain electrodes being spaced apart from each other;
• E. a thin semiconductor layer of semiconductor material in contact with the source and drain electrodes and in contact with the insulator layer at least between the source and drain electrodes;
• and
• F. a metal layer in contact with the source electrode without contacting said drain electrode and in contact with said semiconductor layer at least between said source and drain electrodes, said metal layer of a material forming a Schottky-barrier junction with said semiconductor layer at least between the source and drain electrodes.

An insulated-gate thin film transistor comprising:

• A. a substrate having opposed major surfaces and including an electrically insulating material adjoining at least part of one said major surface;
• B. a first thin semiconductor layer of semiconductor material disposed on at least one major surface of the substrate adjoining electrically insulating material;
• C. a second thin semiconductor layer of semiconductor material disposed on the first semiconductor layer, said semiconductor layer being of an opposite type conductivity from the first semiconductor layer and forming a PN junction with the first semiconductor layer;
• D. source and drain electrodes of electrically conductive material disposed in contact with the second semiconductor layer, said source and drain electrodes being spaced apart from each other, and said source electrode also being in contact with the first semiconductor layer without said first semiconductor layer contacting said drain electrode;
• E. an insulator layer of an electrically insulating material in contact with said source and drain electrodes and the second semiconductor layer at least between the source and drain electrodes;
• and
• F. a conductor layer of electrically conductive material disposed on the insulator layer at least between the source and drain electrodes to form a gate electrode.

An insulated-gate thin film transistor comprising:

• A. a substrate having opposed major surfaces and including electrically insulating material adjoining at least part of one of said major surface;
• B. a layer of electrically conductive material disposed on at least one major surface of the substrate adjoining an electrically insulating material;
• C. a thin semiconductor layer of semiconductor material disposed on the metal layer, said semiconductor layer forming a Schottky-barrier junction with said metal layer;
• D. source and drain electrodes of electrically conductive material disposed on the semiconductor layer, said source and drain electrodes being spaced away from each other, and said source electrode also being in contact with said metal layer without said metal layer contacting said drain electrode;
• E. an insulator layer of an electrically insulating material in contact with said source and drain electrodes and the semiconductor layer at least between the source and drain electrodes;
• and
• F. a conductor layer of electrically conductive material disposed on the insulator layer at least between the source and drain electrodes to form a gate electrode.