Hot-carrier- and constant-voltage-stress-induced low-frequency noise in nitrided high-k dielectric MOSFETs

M. Shahriar Rahman, Tanvir Hasan Morshed, Zeynep Çelik-Butler, M. A. Quevedo-Lopez, A. Shanware, Luigi Colombo

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4 Scopus citations


Understanding and minimization of low-frequency noise (LFN) originating from high- k (HK) gate dielectrics in newgeneration MOSFETs are of critical importance to applications in RF, analog, and digital circuits. To understand the effect of stress conditions on noise, nMOSFETs were subjected to accelerated hot-carrier stress (HCS) and positive constant-voltage stress (CVS). The additional LFN introduced through stressing was evaluated on nMOSFETs with TiN metal gate and HfSiON gate dielectric. Nitridation of HfSiO gate-dielectric MOSFETs was achieved by either a high-temperature \hbox{NH}-{3} anneal or a lower temperature plasma anneal. Influence of different dielectric nitridation procedures on the stress-induced degradation of transconductance, threshold properties, and LFN was studied. Worst degradation conditions, i.e., V-{g} = V-{d}, were used for HCS, whereas for CVS, the vertical field was fixed at 10 MV/cm for all transistors to achieve comparable stressing conditions. Plasma-nitrided devices showed less increase in their noise in the linear operation region than the thermally nitrided devices. This difference in noise behavior is attributed to the nitrogen profile across the HK/Si interface and in the bulk of the HK oxide caused by different nitridation techniques. The dielectric defect profile resultant from different annealing techniques was consistent with the spectral form of the observed drain-voltage LFN.

Original languageEnglish
Article number4808167
Pages (from-to)203-208
Number of pages6
JournalIEEE Transactions on Device and Materials Reliability
Issue number2
StatePublished - Jun 2009
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received October 10, 2008; revised January 23, 2009 and February 27, 2009. First published March 31, 2009; current version published June 5, 2009. This work was supported in part by the Semiconductor Research Corporation under Contract 2004-VJ-1193.


  • Hafnium silicon oxynitride (HfSiON)
  • High-k (HK)
  • Hot-carrier stress (HCS)
  • Low-frequency noise (LFN) ( 1/f noise)
  • Reliability


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