Abstract A method of manufacturing a thin-film solid state devices comprising a body of bandgap-material, preferably aluminium oxide, sandwiched between two conductive electrodes and containing between about 1018 - 1020 impurity atoms per cm3, said impurity atoms being selected from the group of Cu, Cd, Zn, Ag, Ni, and I. The preferred method of manufacture comprises the steps of providing an electrically conductive substate, forming a layer of bandgap material on said substrate, said layer having an effective thickness between about 15 and 300 Angstrom units, introducing into said layer ions of said impurity material by exposing a surface of said layer opposite to said substrate to a fluid (which may be a liquid or a gas under reduced pressure) containing ions of said impurity material, applying a voltage across said layer, said voltage having a polarity and magnitude such that said ions are accelerated and drawn into said layer without forming a deposit of said impurity material on said expsoed surface, and providing electrodes on said substrate and said exposed surface.
The method according to claim 1 wherein: said substrate is formed by evaporating, under reduced pressure, a metal film onto a surface of a support body; said layer of bandgap material is formed by oxidizing a surface region of said metal layer by subjecting the exposed surface of said metal layer to an electrical discharge in an oxygen containing gas of reduced pressure; and a second metal layer is evaporated, under reduced pressure, onto the exposed surface of said oxide layer for forming the electrode.
Claim 2
Dependent Claim
20 words
The method according to claim 1 wherein said layer has an effective thickness of between 15 and 30 Angstrom units.
Claim 3
Dependent Claim
17 words
The method according to claim 1 wherein said d.c. voltage is between approximately 1.5 and 3 volts.
Claim 4
Dependent Claim
28 words
The method according to claim 1 wherein said layer of bandgap material is formed by anodizing a surface region of an anodically oxidable metal in an electrolytic bath.
Claim 5
Dependent Claim
11 words
The method according to claim 5 wherein said metal is aluminum.
Claim 6
Dependent Claim
12 words
The method according to claim 6 wherein said impurity material is copper.
Claim 7
Dependent Claim
24 words
The method according to claim 6 wherein said impurity material is selected from the group consisting of cadmium, copper, zinc, silver, nickel and iodine.