The Adsorption and Decomposition of NH3 on Si(100) - Detection of the NH2(a) Species
Abstract
The dissociative adsorption of NH3 on Si(100)(2x1) has been studied using accurate coverage measurements, temperature programmed desorption, Auger spectroscopy and digital ESDIAD/LEED methods. It has been found that NH2 surface species (amino species) are produced to a saturation coverage of 1 NH2/Si dimer at 120 K. This is accompanied by the production of a Si-H surface species. Digital ESDIAD measurements of the H+ angular distribution from NH2(a) species indicate that torsional oscillations about the Si-NH2 bond are responsible for the characteristic elliptical H+ pattern whose long axis is perpendicular to the Si-Si dimer bond direction. It has been shown that NH3 dissociatively adsorbs with unity sticking probability at 120 K up to 86% of full coverage, indicative of a mobile precursor adsorption mechanism. The pre-adsorption of atomic H onto the Si dangling bond sites reduces the adsorptive capacity of the Si(100) surface, and 1 H/Si completely passivates the surface for NH3 chemisorption. Ammonia, Silicon nitride, Amino species.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 14, 1988
- Accession Number
- ADA201601
Entities
People
- J. T. Yates Jr.
- M. J. Dresser
- P. A. Taylor
- R. M. Wallace
- Wolfgang J. Wolfgang J. Choyke
Organizations
- University of Pittsburgh