| 摘要 |
1,134,656. Semi-conductor devices. RADIO CORPORATION OF AMERICA. 31 March, 1966 [15 April, 1965], No. 14406/66. Heading H1K. In an insulated-gate FET comprising a body of single crystal bandgap material, the gate insulation comprises a crystalline material having an average atomic spacing between 0À9 and 1À1 times that of the body material. The insulator should have a conductance less than 10<SP>-3</SP> times that of the body and a bandgap of at least 1À1 eV. and at least 0À4 eV. greater than that of the body. N-type source and drain regions (25, 27) are produced in a wafer (23) of gallium arsenide by masking the surface and heating in sulphur vapour, Fig. 5B (not shown). The surface is then remasked and again heated in sulphur vapour to produce an N-type channel region (31), Fig. 5C (not shown). An epitaxial layer (29) of pure gallium phosphide is grown by a halogen or oxygen transport technique, Fig. 5D (not shown), and a degenerate gallium phosphide layer (33) is deposited by using a source heavily doped with tellurium or by adding sulphur to the hydrogen ambient. These two layers serve as the gate insulation and gate electrode respectively. The gallium phosphide layers are then masked and etched to expose parts of the source and drain regions which are contacted by means of lead wires or evaporated gold layers (35, 37), Fig. 5E (not shown). Gallium phosphide may also be used as the insulator on a silicon wafer, and gallium arsenide may be used as the insulator on wafers of germanium, indium arsenide and indium antimonide. The insulator may be polycrystalline. The body may be provided with a contact and biased with either D.C. or A.C., and if the body is thin and resistive an auxiliary gate electrode may be applied to the lower face of the wafer. |
