Effects of constant voltage stressing on HfTaOx/SiGe gate stack

S. Mallik, C. Mahata, M. K. Hota, C. K. Sarkar, C. K. Maiti

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Ultrathin HfTaOx gate dielectric has been deposited on Si 0.81Ge0.19by RF co-sputtering of HfO2 and Ta2O5 targets. X-ray photoelectron spectroscopic (XPS) analyses indicate an interfacial layer containing GeOx, Hf silicate, SiO x (layer of Hf- Si-Ge-O) formation during deposition of HfTaO x. No evidence of Ta-silicate or Ta incorporation was found at the interface. X-ray diffraction (GIXRD) measurements show that as-deposited HfTaOx films are amorphous; however, the crystallization temperature of HfTaOx film is found to increase significantly after annealing beyond 500°C (for 5 min) along with the incorporation of Ta (with 18% Ta). It has been found that HfTaOx gate dielectric on Si 0.81Ge0.19 exhibit excellent electrical properties with low interface state density (∼6.0×1011 cm-2eV-1) and hysteresis voltage (<70 mV). Charge trapping/detrapping behavior of the gate stacks has been studied under constant voltage stressing and the degradation mechanism of the dielectrics has been studied in detail.

Original languageEnglish
Title of host publication16th International Workshop on Physics of Semiconductor Devices
PublisherSPIE
ISBN (Print)9780819493002
DOIs
StatePublished - 2012
Event16th International Workshop on Physics of Semiconductor Devices, IWPSD 2011 - Kanpur, India
Duration: 19 Dec 201122 Dec 2011

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8549
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

Conference16th International Workshop on Physics of Semiconductor Devices, IWPSD 2011
Country/TerritoryIndia
CityKanpur
Period19/12/1122/12/11

Keywords

  • Constant voltage Stress
  • MOS Capacitor
  • SiGe

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