Inventor · Fujisawa, JP

Riichiro Shirota

192Patents
35h-index
110Co-inventors
93Inventor score

Filing activity: Nov 17, 1988 → Sep 1, 2023

Most-cited inventions

PatentTitleAreaCited byStatus
US5774397A Non-volatile semiconductor memory device and method of programming a non-volatile memory cell to a predetermined state Physics 622 Expired
US4959812A Electrically erasable programmable read-only memory with NAND cell structure Physics 528 Expired
US7259992B2 Semiconductor memory device with a memory cell array formed on a semiconductor substrate Physics 240 Expired
US8008732B2 Semiconductor memory and method of manufacturing the same Electricity 232 Active
US5602789A Electrically erasable and programmable non-volatile and multi-level memory systemn with write-verify controller Physics 195 Expired
US7696559B2 Semiconductor memory device including pillar-shaped semiconductor layers and a method of fabricating the same Physics 179 Active
US6134140A Nonvolatile semiconductor memory device with soft-programming to adjust erased state of memory cells Physics 179 Expired
US5386422A Electrically erasable and programmable non-volatile memory system with write-verify controller using two reference levels Physics 168 Expired
US5555204A Non-volatile semiconductor memory device Physics 141 Expired
US5469444A Electrically erasable and programmable non-volatile memory system with write-verify controller using two reference levels Physics 140 Expired
US5321699A Electrically erasable and programmable non-volatile memory system with write-verify controller using two reference levels Physics 127 Expired
US6252798A Nonvolatile semiconductor memory device capable of controlling mutual timing of write voltage pulse and transfer voltage pulse Physics 124 Expired
US4939690A Electrically erasable programmable read-only memory with NAND cell structure that suppresses memory cell threshold voltage variation Physics 109 Expired
US6845042B2 Nonvolatile semiconductor memory, fabrication method for the same, semiconductor integrated circuits and systems Electricity 102 Expired
US5946231A Non-volatile semiconductor memory device Physics 82 Expired
US5361227A Non-volatile semiconductor memory device and memory system using the same Physics 75 Expired
US6014330A Non-volatile semiconductor memory device Physics 75 Expired
US6859394B2 NAND type non-volatile semiconductor memory device Physics 74 Expired
US6549464B2 Nonvolatile semiconductor memory device Physics 73 Expired
US6798698B2 Nonvolatile semiconductor memory device Physics 58 Expired
US6493265B2 Nonvolatile semiconductor memory device Physics 57 Expired
US5293337A Electrically erasable programmable read-only memory with electric field decreasing controller Physics 56 Expired
US6151249A NAND-type EEPROM having bit lines and source lines commonly coupled through enhancement and depletion transistors Physics 54 Expired
USRE35838E Electrically erasable programmable read-only memory with NAND cell structure General 52 Expired
US5453955A Non-volatile semiconductor memory device Physics 52 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.