Abstract The diode is formed in a bell-jar system using a vapordeposition technique to deposit a sandwich of thin-films on a glass substrate, the films including aluminum, aluminum oxide, manganese, manganese oxide and lead. Thus a five-layer diode system M/1/M/1/M is provided in which the 1/M/1 is a barrier member formed of the oxides and the manganese and having a thickness about 200 A. The electrodes are the aluminum and lead, i.e., the metals ''''M'''' which sandwich the barrier 1/M/1. Critically, the manganese oxide film is formed by a two-step process in which the deposited manganese film first is permitted to oxidize slowly, preferably, in the residual air of a reduced atmosphere of about 2- 8 X 10 5 torr. This oxidizing exposure, which may last for about 5 minutes, is followed by a relatively rapid oxidation of the manganese at atmosphere pressure.
The method of claim 1 wherein said limited amount of heat is applied to said manganese source for a period of no less then about 20 seconds and the heat applied does not exceed about 350* K. when measured at the filmless surface of the substrate.
Claim 2
Dependent Claim
42 words
The method of claim 1 wherein said limited heat applied to said manganese source is controlled by monitoring the heat-responsive decrease in manganese resistance to attain a gradual decrease to about 3 X 104 ohms/square in no less than about 20 seconds.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said slow oxidation of the manganese is maintained for about 5 minutes.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein said counterelectrode is lead and wherein the thickness of the aluminum and lead films are about 2,000-3,000 A.
Claim 5
Dependent Claim
146 words
A vapor-deposited thin-film varistor diode having Schottky-emission I-V characteristics comprising: a substrate, an aluminum base electrode film deposited on said substrate, an aluminum oxide film of about 10-50 -A. thickness formed on said aluminum film, a manganese film formed on said oxide, a manganese oxide film formed on said manganese film, and a counterelectrode film formed on said manganese oxide, said manganese and manganese oxide films providing a barrier system having a combined film thickness of about 150-190 A. and said system having a film resistivity about 104 times larger than the bulk resistivity of manganese, said manganese oxide film being a type resulting from a two-step vapor-deposition process in which the first step is a slow oxidation in a reduced atmospheric pressure of about 2-8 X 10 5 torr for a period of about 5 minutes and the second step is a relatively rapid oxidation.
Claim 6
Dependent Claim
22 words
The diode of claim 6 wherein said counterelectrode is lead and the aluminum and lead both are about 2,000-3,000 A. in thickness.