Hydrogen sensitivity of InP HEMTs with WSiN-based gate stack

Samuel D. Mertens, Jesús A. del Alamo, Tetsuya Suemitsu, Takatomo Enoki

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We have experimentally investigated the hydrogen sensitivity of InP high- electron mobility transistors (HEMTs) with a WSiN-Ti-Pt-Au gate stack. We have found that exposure to hydrogen produces a shift in the threshold voltage of these devices that is one order of magnitude smaller than published data on conventional Ti-Pt-Au gate HEMTs. We have studied this markedly improved reliability through a set of quasi-two-dimensional mechanical and electrostatic simulations. These showed that there are two main causes for the improvement of the hydrogen sensitivity. First, the separation of the Ti-layer from the semiconductor by a thick WSiN layer significantly reduces the stress in the heterostructure underneath the gate. Additionally, the relatively thinner heterostructure used in this study and the presence of an InP etch-stop layer with a small piezoelectric constant underneath the gate reduces the amount of threshold voltage shift that is caused by the mechanical stress.

Original languageEnglish
Pages (from-to)305-310
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number3
Publication statusPublished - 2005 Mar
Externally publishedYes


  • High-electron mobility transistors (HEMTs)
  • Hydrogen
  • InP
  • Piezoelectric effect
  • Reliability

ASJC Scopus subject areas

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


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