An artificial fingerprint device (AFD): A study of identification number applications utilizing characteristics variation of polycrystalline silicon TFTs

Shigenobu Maeda, Hirotada Kuriyama, Takashi Ipposhi, Shigeto Maegawa, Yasuo Inoue, Masahide Inuishi, Norihiko Kotani, Tadashi Nishimura

Research output: Contribution to journalArticle

20 Citations (Scopus)


An idea for obtaining unique identification (ID) numbers using polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with a logic LSI compatible process is proposed. Like an actual human fingerprint, the characteristic variations of poly-Si TFTs are utilized for ID numbers in LSIs. The variation of poly-Si TFT characteristics is random, and this method offers unique, nonalterable, and nonduplicable numbers without any special processes, unlike other methods such as flash memory and mask ROM. These characteristics are highly suitable for ID number applications. The device physics of poly-Si TFTs for realizing the stable recognition of ID numbers was studied and a recognition circuit is proposed. The design guidelines for the grain size of poly-Si and AFD applications are also discussed.

Original languageEnglish
Pages (from-to)1451-1458
Number of pages8
JournalIEEE Transactions on Electron Devices
Issue number6
Publication statusPublished - 2003 Jun 1



  • Crystals
  • Identification
  • Random number generation
  • Silicon
  • Silicon on insulator technology
  • Thin-film transistors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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