Degradation of the surface passivation of plasma-assisted ALD Al2O3 under damp-heat exposure

Wensheng Liang, Dong Chul Suh, Jun X Yu, James Bullock, Klaus Weber

    Research output: Contribution to journalArticlepeer-review

    Abstract

    The effect of humidity on boron diffused and undiffused silicon samples passivated by aluminum oxide (Al2O3) synthesized by plasma-assisted atomic layer deposition (PA-ALD) is investigated. It is found that samples exposed to a saturated humidity ambient show a much higher degradation rate than those exposed to 85% relative humidity (RH). The surface recombination velocity Seff increased by 25% for RH=85% but by more than two orders of magnitude for 100% RH after 10 days of exposure. Moreover, the electrical resistance of Al2O3 film also decreased significantly following saturated humidity exposure. PECVD SiNx:H capping layers are effective at protecting Al2O3 films from damp-heat stress. Two degradation regimes are proposed to explain the degradation: (i) initial reversible degradation at shorter time exposures, which is ascribed to the loss of field effect passivation; (ii) severe degradation after longer term exposure, which is believed to be due to a substantial loss of chemical passivation with the generation of new species from the reaction of Al2O3 and water. The second regime was only observed for saturated humidity conditions.
    Original languageEnglish
    Pages (from-to)274-281
    JournalPhysica Status Solidi A
    Volume212
    Issue number2
    DOIs
    Publication statusPublished - 2015

    Fingerprint

    Dive into the research topics of 'Degradation of the surface passivation of plasma-assisted ALD Al2O3 under damp-heat exposure'. Together they form a unique fingerprint.

    Cite this