Correlation of roughness and device properties for hydrogen plasma cleaning of Si(100) prior to gate oxidation

J. S. Montgomery, J. P. Barnak, C. Silvestre, J. R. Hauser, Robert Nemanich

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Hydrogen plasma treatment was used as a cleaning and conditioning step prior to gate oxide deposition in the fabrication of cluster-based MOS field effect transistors. Surface roughness was measured by atomic force microscopy and compared to current-voltage characteristics of the MOSFET devices. The MOSFET devices were evaluated on the basis of threshold voltage, peak mobility, interface scattering, and surface roughness coefficient. Following a 10 minute H-plasma exposure at a substrate temperature of 150°C the rms roughness increased from 1.1±0.3 angstrom to 17±9 angstrom. The rms roughness for samples treated for 10 minutes at 700°C was 4±1 angstrom. Analysis of the MOSFET devices treated in the low temperature range (200°C) show significant degradation due to the H-plasma interaction. Threshold voltage for the devices exposed to a 2 minute H-plasma at a temperature of 200°C was 0.72±0.02 V. In contrast the threshold voltage for the 600°C, 2 minute plasma exposure was 0.86±0.03 V. The peak mobility for those devices was 370 cm 2/V·s. Further device analysis was accomplished from the current-voltage measurements to extract a value of interface scattering and surface roughness scattering for each device. Interface scattering and surface roughness scattering do not increase for H-plasma process temperatures of 450 - 700°C. An H-plasma treatment for 2 minutes at 500°C also resulted in no observable increase in rms roughness, a threshold voltage of 0.92±0.03 V, a peak mobility of 410 cm 2/V·s, and no increase in interface scattering and surface roughness scattering.

Original languageEnglish (US)
Title of host publicationMaterials Research Society Symposium - Proceedings
PublisherMaterials Research Society
Number of pages6
StatePublished - 1995
Externally publishedYes
EventProceedings of the 1995 MRS Spring Meeting - San Francisco, CA, USA
Duration: Apr 17 1995Apr 21 1995


OtherProceedings of the 1995 MRS Spring Meeting
CitySan Francisco, CA, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials


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