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US 4,017,887 AGranted
Method and means for passivation and isolation in semiconductor devices
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsD. Eirug Davies, Sven A. Roosild, Russell P. Dolan, Jr.
Life of this patent
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Abstract
The use of ion implantation to produce low concentrations of chromium, oxygen or iron in a gallium arsenide junction type semiconductor, utilizing the accompanying low resistivity to provide an improved device.
Claims5
A radiation resistant semiconductor device comprising:
- a wafer of n-type gallium arsenide semiconductor material;
- islands of p-type material located in the wafer and forming a portion of the surface thereof, said p and n material so positioned as to form p-n junctions;
- implanted regions of compensating chromium ions having a concentration between 10.sup.14 to 10.sup.18 ions per cubic centimeter, said ions being of insufficient concentration to form a new compound, but of sufficient concentration to form a semi-insulating layer of carrier depleted gallium arsenide, having a resistivity of between 10.sup.6 and 10.sup.9 ohm centimeters, extending to the surface of the wafer and surrounding said islands of p material;
- and contact means affixed to the n and p material for attaching electrical conductors.
1 more element
A radiation resistant semiconductor device comprising;
- a wafer of gallium arsenide semiconductor material, having a first layer containing n type dopants and a second layer containing p type dopants and together said portions forming a p-n junction;
- a region of compensating chromium ions having a concentration between 10.sup.14 to 10.sup.18 ions per cubic centimeter implanted in said n type portion, said ions being of insufficient concentration to form a new compound, but of sufficient concentration to form a semi-insulating layer of carrier depleted gallium arsenide having a resistivity of between 10.sup.6 and 10.sup.19 ohm-centimeters, parallel and in close spaced relation to the p-n junction, and contact means affixed to the first and second portions for affixing electrical conductors thereto.
A method of forming radiation resistant gallium arsenide semiconductor devices comprising the steps of:
- forming areas of p type material on an n doped semiconductor wafer;
- covering the p type areas with an ion impervious mask;
- placing the wafer in an ion accelerating means;
- implanting compensating chromium ions in the n type wafer having a concentration between 10.sup.14 and 10.sup.18 ions per cubic centimeter, whereby said implanted ions form a layer surrounding said areas of p type material having ions of insufficient concentration to form a new compound, but of sufficient concentration to form a semi-insulating layer having a resistivity of between 10.sup.6 and 10.sup.9 ohm-centimeters, causing a reduced number of photo induced ions to be generated by intense radiation;
- removing the mask, and affixing electrical contacts.
2 more elements
Dependencies are inferred from the claim text.