Dependence of Ideality Factor in Lateral PNP Transistors on Surface Carrier Concentration

Xingji Li, Jianqun Yang, Hugh Barnaby, Kenneth F. Galloway, Ronald D. Schrimpf, Daniel M. Fleetwood, Chaoming Liu

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


The influence of surface carrier concentration on the ideality factor of excess base current (Δ IB) in gated lateral PNP (GLPNP) bipolar junction transistors (BJTs) induced by 1-MeV electrons is investigated. ΔIB in LPNP BJTs is impacted by the surface carrier density and radiation-induced interface traps. In GLPNP BJTs, the surface carrier concentration can be controlled by the voltage applied to a gate over the base region. The ideality factor changes after irradiation, and its dependence on emitter-base voltage (VEB) is a function of gate voltage. For the irradiated devices, as the gate voltage decreases from +20 to -5 V, the ideality factor for excess base current changes from a single slope to two-slope behavior. The majority carrier concentration at the surface of the base, controlled by the gate voltage, impacts the excess base current and its ideality factor.

Original languageEnglish (US)
Article number7929388
Pages (from-to)1549-1553
Number of pages5
JournalIEEE Transactions on Nuclear Science
Issue number6
StatePublished - Jun 2017


  • Bipolar junction transistor (BJT)
  • electron irradiation
  • ideality factor
  • interface traps
  • radiation effects

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering


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