Electrical characteristics of Schottky barriers on 4H-SiC: The effects of barrier height nonuniformity

Brian Skromme, E. Luckowski, K. Moore, M. Bhatnagar, C. E. Weitzel, T. Gehoski, D. Ganser

Research output: Contribution to journalArticle

90 Scopus citations

Abstract

Electrical properties, including current-voltage (I-V) and capacitance-voltage (C-V) characteristics, have been measured on a large number of Ti, Ni, and Pt-based Schottky barrier diodes on 4H-SiC epilayers. Various nonideal behaviors are frequently observed, including ideality factors greater than one, anomalously low I-V barrier heights, and excess leakage currents at low forward bias and in reverse bias. The nonidealities are highly nonuniform across individual wafers and from wafer to wafer. We find a pronounced linear correlation between I-V barrier height and ideality factor for each metal, while C-V barrier heights remain constant. Electron beam induced current (EBIC) imaging strongly suggests that the nonidealities result from localized low barrier height patches. These patches are related to discrete crystal defects, which become visible as recombination centers in the EBIC images. Alternative explanations involving generation-recombination current, uniform interfacial layers, and effects related to the periphery are ruled out.

Original languageEnglish (US)
Pages (from-to)376-383
Number of pages8
JournalJournal of Electronic Materials
Volume29
Issue number3
DOIs
StatePublished - Mar 2000

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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