Low temperature process for annealing shallow implanted N+/P junctions
AssigneeWestinghouse Electric Corp.
InventorsAjeet Rohatgi, Prosenjit Rai-Choudhury, Joseph R. Gigante, Ranbir Singh, Stephen J. Fonash
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AssigneeWestinghouse Electric Corp.
InventorsAjeet Rohatgi, Prosenjit Rai-Choudhury, Joseph R. Gigante, Ranbir Singh, Stephen J. Fonash
Estimating the term…
Disclosed is a low temperature technique for annealing implantation damage and activating dopants. Conventional furnace annealing requires temperatures as high as 1000.degree. to 1100.degree. C. to completely anneal the dopant implantation damage; 75 KeV arsenic implantation followed by 550.degree. C. for 75 minutes and 900.degree. C. for 30 minutes in nitrogen for instance is not sufficient to anneal the implantation damage and results in a leakage current of the order of 1 mA per cm.sup.2. If, however, subsequent to the arsenic implantation, 0.4 KeV hydrogen ions are implanted using a Kaufman ion source with an accelerator current of 200 milliamp, then only 500.degree. to 600.degree. C. for one hour anneal in nitrogen is sufficient to eliminate the arsenic implantation damage. This results in a leakage current of the order of 5 to 25 nA per cm.sup.2 and a complete dopant activation is achieved.
A method of low temperature annealing of a silicon semiconductor that has been doped by ion implantation with an element selected from the group consisting of arsenic and phosphorous, said method comprising:
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