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Title: Near surface inversion layer recombination in Al{sub 2}O{sub 3} passivated n-type silicon

On n-type silicon, negatively charged surface passivation layers create a near surface recombination channel, which could significantly reduce the effective carrier lifetime at low injection levels (Δn < 10{sup 14 }cm{sup −3}). This effect is described by Shockley Read Hall recombination at homogeneously distributed defects in the silicon wafer. In the near surface region, fixed charges in the dielectric layer significantly change the carrier concentrations and the recombination rate of defects. Sentaurus device simulations show that the contribution of the near surface recombination to the effective carrier lifetime depends on the properties of the involved defects. The lifetime reduction is strongest when the involved defects have an energy level in the lower half of the band gap and a very high electron to hole capture cross section ratio. For the simulation, a very low defect density in the order of 10{sup 8 }cm{sup −3} is assumed, which is a realistic value in highly pure float zone silicon. Quasi-steady state photoconductance measurements on n-type silicon with Al{sub 2}O{sub 3} passivation are done and fitted with the recombination model. Very good correlation between simulation and experiment is achieved when the involved recombination centers have an electron to hole capture cross section ratio of 10{sup 7} andmore » an energy level of −0.2 eV w.r.t. the intrinsic level. The simulated defect properties are discussed in respect of transition metal and doping related defects reported in literature.« less
Authors:
; ;  [1] ;  [1] ;  [2]
  1. NaMLab gGmbH, Nöthnitzerstr. 64, 01187 Dresden (Germany)
  2. (IHM), 01062 Dresden (Germany)
Publication Date:
OSTI Identifier:
22308549
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; CAPTURE; CARRIER LIFETIME; CORRELATIONS; CROSS SECTIONS; CRYSTAL DEFECTS; DIELECTRIC MATERIALS; INJECTION; LAYERS; N-TYPE CONDUCTORS; PASSIVATION; PHOTOCONDUCTIVITY; RECOMBINATION; REDUCTION; SILICON; SIMULATION; STEADY-STATE CONDITIONS; SURFACES