Charge storage type semiconductor device and method for producing same
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsHirokazu Sekine, Katuhiko Morimune, Masaharu Watanabe, Nobuo Suzuki
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Abstract
A charge storage type semiconductor device comprising a semiconductor substrate and means for accumulating charge in those portions of the substrate which are located in the vicinity of one of the major surfaces of the substrate. The substrate has a defect region of a high defect density and at least one defect free region having no crystal defects or a low defect density and formed in the vicinity of at least the major surface of the substrate. The defect region prevents unnecessary minority carriers from flowing into charge storage regions.
Claims9
A charge storage type semiconductor device comprising:
- a semiconductor substrate comprised of a single, crystal, said substrate having an interior short carrier diffusion length region with a crystal defect density of from 10.sup.5 /cm.sup.2 to 10.sup.7 /cm.sup.2, and at least one long carrier diffusion length region, said long carrier diffusion length region being formed in the vicinity of at least one of the major surfaces of the substrate, said long carrier diffusion length region having a thickness of from about 5 to 60 microns;
- and
- means for accumlating charge in those portions of the substrate which are located in the vicinity of one of the major surfaces of the substrate, said interior region being separated from said charge accumulating means.
A charge storage type semiconductor device comprising:
- a substrate of semiconductor material in the form of a singe crystal, said substrate having an interior portion having a crystal-defect density of from 10.sup.5 /cm.sup.2 to 10.sup.7 /cm.sup.2, and at least one relatively defect free region adjacent one surface of said substrate, said region having a relatively low defect density with respect to said interior portion and a thickness of about 5 to 60 microns;
- and
- means for accumulating charge in locations in said defect-free regions adjacent said surface of said substrate, said interior portion being separated from said location in said defect free regions.
Dependencies are inferred from the claim text.