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US 5,328,858 AGranted
Method for producing the bipolar transistor
AssigneeSharp Kabushiki Kaisha
InventorSatoshi Hikida
Life of this patent
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Abstract
A silicon oxide film is formed at a surface of a silicon substrate of a first conductive type, and then patterned to have an opening. PSG is deposited on the silicon substrate having the insulating film thereon, and then etched to leave the PSG only on a side wall of the opening. An impurity is implanted to the silicon substrate through the opening, and then thermal treatment is effected.
Claims6
A method for producing a semiconductor device, comprising the steps of:
- forming an insulating film at a surface of a semiconductor substrate of a first conductive type;
- forming an opening in the insulating film by removing a portion thereof where a buried layer of a second conductive type is to be formed;
- depositing an insulating glass containing phosphorus at a high concentration on the semiconductor substrate so as to cover the insulating film;
- anisotropically etching the insulating glass to leave the insulating glass only on a side wall of the opening;
- and
- implanting an impurity of a second conductive type into the semiconductor substrate through the opening and then affecting thermal treatment.
3 more elements
Dependencies are inferred from the claim text.