Flash Memories

  • Authors
  • Paulo Cappelletti
  • Carla Golla
  • Piero Olivo
  • Enrico Zanoni

Table of contents

  1. Front Matter
    Pages i-xi
  2. Piero Olivo, Enrico Zanoni
    Pages 1-35
  3. Paolo Pavan, Roberto Bez
    Pages 37-90
  4. Boaz Eitan, Anirban Roy
    Pages 91-152
  5. Luca Selmi, Claudio Fiegna
    Pages 153-239
  6. Maurizio Branchetti, Giovanni Campardo, Stefano Commodaro, Stefano Ghezzi, Andrea Ghilardelli, Carla Golla et al.
    Pages 241-360
  7. Guido Torelli, Massimo Lanzoni, Alessandro Manstretta, Bruno Riccò
    Pages 361-397
  8. Paolo Cappelletti, Alberto Modelli
    Pages 399-441
  9. Giulio Casagrande
    Pages 443-479
  10. Bruno Beverina, Philippe Bergé, C. Kunkel, G. Moy, A. Damiano, R. Ferrara et al.
    Pages 481-526
  11. Back Matter
    Pages 527-540

About this book


A Flash memory is a Non Volatile Memory (NVM) whose "unit cells" are fabricated in CMOS technology and programmed and erased electrically. In 1971, Frohman-Bentchkowsky developed a folating polysilicon gate tran­ sistor [1, 2], in which hot electrons were injected in the floating gate and removed by either Ultra-Violet (UV) internal photoemission or by Fowler­ Nordheim tunneling. This is the "unit cell" of EPROM (Electrically Pro­ grammable Read Only Memory), which, consisting of a single transistor, can be very densely integrated. EPROM memories are electrically programmed and erased by UV exposure for 20-30 mins. In the late 1970s, there have been many efforts to develop an electrically erasable EPROM, which resulted in EEPROMs (Electrically Erasable Programmable ROMs). EEPROMs use hot electron tunneling for program and Fowler-Nordheim tunneling for erase. The EEPROM cell consists of two transistors and a tunnel oxide, thus it is two or three times the size of an EPROM. Successively, the combination of hot carrier programming and tunnel erase was rediscovered to achieve a single transistor EEPROM, called Flash EEPROM. The first cell based on this concept has been presented in 1979 [3]; the first commercial product, a 256K memory chip, has been presented by Toshiba in 1984 [4]. The market did not take off until this technology was proven to be reliable and manufacturable [5].


CMOS EEPROM electrons EPROM non-volatile memory programming PROM reliability Standard testing transistor

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