Fujio Masuoka

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Fujio Masuoka (舛岡 富士雄)
BornMay 8, 1943 (1943-05-08) (age 77)
Alma materTohokù University
Known forFlash memory
NOR flash
NAND flash
AwardsIEEE Morris N. Liebmann Memorial Award
Scientific career
FieldsElectrical engineering
Tohoku University
Doctoral advisorJun-ichi Nishizawa

Fujio Masuoka (舛岡 富士雄, Masuoka Fujio, born May 8, 1943) is a Japanese engineer, who has worked for Toshiba and Tohoku University, and is currently chief technical officer (CTO) of Unisantis Electronics. He is best known as the inventor of flash memory, including the development of both the NOR flash and NAND flash types in the 1980s.[1] He also invented the first gate-all-around (GAA) MOSFET (GAAFET) transistor, an early non-planar 3D transistor, in 1988.


Masuoka attended Tohoku University in Sendai, Japan, where he earned an undergraduate degree in engineering in 1966 and doctorate in 1971.[2] He joined Toshiba in 1971. There, he invented stacked-gate avalanche-injection metal–oxide–semiconductor (SAMOS) memory, a precursor to electrically erasable programmable read-only memory (EEPROM) and flash memory.[3][4] In 1976, he developed dynamic random-access memory (DRAM) with a double poly-Si structure. In 1977 he moved to Toshiba Semiconductor Business Division, where he developed 1 Mb DRAM.[3]

Masuoka was excited mostly by the idea of non-volatile memory, memory that would last even when power was turned off. The EEPROM of the time took very long to erase. He developed the "floating gate" technology that could be erased much faster. He filed a patent in 1980 along with Hisakazu Iizuka.[5][3] His colleague Shoji Ariizumi suggested the word "flash" because the erasure process reminded him of the flash of a camera.[6] The results (with capacity of only 8192 bytes) were published in 1984, and became the basis for flash memory technology of much larger capacities.[7][8] Masuoka and colleagues presented the invention of NOR flash in 1984,[9] and then NAND flash at the IEEE 1987 International Electron Devices Meeting (IEDM) held in San Francisco.[10] Toshiba commercially launched NAND flash memory in 1987.[11][12] Toshiba gave Masuoka a small bonus for the invention, but it was American company Intel which made billions of dollars in sales on related technology.[13]

In 1988, a Toshiba research team led by Masuoka demonstrated the first gate-all-around (GAA) MOSFET (GAAFET) transistor. It was an early non-planar 3D transistor, and they called it a "surrounding gate transistor" (SGT).[14][15][16][17][18] He became a professor at Tohoku University in 1994.[13] Masuoka received the 1997 IEEE Morris N. Liebmann Memorial Award of the Institute of Electrical and Electronics Engineers.[19] In 2004, Masuoka became the chief technical officer of Unisantis Electronics aiming to develop a three-dimensional transistor, based on his earlier surrounding-gate transistor (SGT) invention from 1988.[17][2] In 2006, he settled a lawsuit with Toshiba for ¥87m (about US$758,000).[20]

He has a total of 270 registered patents and 71 additional pending patents.[3] He has been suggested as a potential candidate for the Nobel Prize in Physics, along with Robert H. Dennard who invented single-transistor DRAM.[21]



  1. ^ Jeff Katz (September 21, 2012). "Oral History of Fujio Masuoka" (PDF). Computer History Museum. Retrieved March 20, 2017.
  2. ^ a b "Company profile". Unisantis-Electronics (Japan) Ltd. Retrieved March 20, 2017.
  3. ^ a b c d "Fujio Masuoka". IEEE Explore. IEEE. Retrieved 17 July 2019.
  4. ^ Masuoka, Fujio (31 August 1972). "Avalanche injection type mos memory". Cite journal requires |journal= (help)
  5. ^ "Semiconductor memory device and method for manufacturing the same". US Patent 4531203 A. November 13, 1981. Retrieved March 20, 2017.
  6. ^ Detlev Richter (2013). Flash Memories: Economic Principles of Performance, Cost and Reliability. Springer Series in Advanced Microelectronics. 40. Springer Science and Business Media. pp. 5–6. doi:10.1007/978-94-007-6082-0. ISBN 978-94-007-6081-3.
  7. ^ F. Masuoka, M. Asano, H. Iwahashi, T. Komuro and S. Tanaka (December 9, 1984). "A new flash E2PROM cell using triple polysilicon technology". International Electronic Devices Meeting. IEEE: 464–467. doi:10.1109/IEDM.1984.190752.CS1 maint: uses authors parameter (link)
  8. ^ "A 256K Flash EEPROM using Triple Polysilicon Technology" (PDF). IEEE historic photo repository. Retrieved March 20, 2017.
  9. ^ "Toshiba: Inventor of Flash Memory". Toshiba. Retrieved 20 June 2019.
  10. ^ Masuoka, F.; Momodomi, M.; Iwata, Y.; Shirota, R. (1987). "New ultra high density EPROM and flash EEPROM with NAND structure cell". Electron Devices Meeting, 1987 International. IEDM 1987. IEEE. doi:10.1109/IEDM.1987.191485.
  11. ^ "1987: Toshiba Launches NAND Flash". eWeek. April 11, 2012. Retrieved 20 June 2019.
  12. ^ "1971: Reusable semiconductor ROM introduced". Computer History Museum. Retrieved 19 June 2019.
  13. ^ a b Fulford, Benjamin (June 24, 2002). "Unsung hero". Forbes. Retrieved March 20, 2017.
  14. ^ Masuoka, Fujio; Takato, H.; Sunouchi, K.; Okabe, N.; Nitayama, A.; Hieda, K.; Horiguchi, F. (December 1988). "High performance CMOS surrounding-gate transistor (SGT) for ultra high density LSIs". Technical Digest., International Electron Devices Meeting: 222–225. doi:10.1109/IEDM.1988.32796.
  15. ^ Brozek, Tomasz (2017). Micro- and Nanoelectronics: Emerging Device Challenges and Solutions. CRC Press. p. 117. ISBN 9781351831345.
  16. ^ Ishikawa, Fumitaro; Buyanova, Irina (2017). Novel Compound Semiconductor Nanowires: Materials, Devices, and Applications. CRC Press. p. 457. ISBN 9781315340722.
  17. ^ a b "Company Profile". Unisantis Electronics. Archived from the original on 22 February 2007. Retrieved 17 July 2019.
  18. ^ Yang, B.; Buddharaju, K. D.; Teo, S. H. G.; Fu, J.; Singh, N.; Lo, G. Q.; Kwong, D. L. (2008). "CMOS compatible Gate-All-Around Vertical silicon-nanowire MOSFETs". ESSDERC 2008 - 38th European Solid-State Device Research Conference: 318–321. doi:10.1109/ESSDERC.2008.4681762. ISBN 978-1-4244-2363-7.
  19. ^ "IEEE Morris N. Liebmann Memorial Award Recipients". Archived from the original on June 6, 2008. Retrieved March 20, 2017.
  20. ^ Tony Smith (July 31, 2006). "Toshiba settles spat with Flash memory inventor: Boffin gets ¥87m but wanted ¥1bn". The Register. Retrieved March 20, 2017.
  21. ^ Kristin Lewotsky (July 2, 2013). "Why Does the Nobel Prize Keep Forgetting Memory?". EE Times. Retrieved March 20, 2017.