Accession Number : ADA296177

Title :   Reaction of Atomic Hydrogen with Hydrogenated Porous Silicon - Detection of Precursor to Silane Formation.

Descriptive Note : Technical rept.,

Corporate Author : PITTSBURGH UNIV PA DEPT OF CHEMISTRY

Personal Author(s) : Glass, John A., Jr. ; Wovchko, Edward A. ; Yates, John T., Jr

PDF Url : ADA296177

Report Date : 16 JUN 1995

Pagination or Media Count : 29

Abstract : The reaction of electrochemically formed porous silicon with atomic hydrogen or atomic deuterlum flas been studied at cryogenic temperatures and at room temperature. Cryogenic temperatures were chosen in order to kinetically suppress silane formation (silicon etching) and to spectroscopically observe the snrface precursor to SiH4 formation. By comparing developments in the Si-H and Si-D stretd%ing mode regions of the infrared spectrum, it is demonstrated that SiH3 is stabilized at 133 K without formation of Sill4 (g). Warming to near 200 K and above evolves SiH4 (g) as SiH3 reacts with neighbor SiHx species. It is demonstrated that the reaction SiH3 + H --> SiH4 (g) does not proceed rapidly at 133 K. This suggests that disproportionation of SiH3 and SiHx surface species to make SiH4 (g) dominates in the etching process on porous silicon at lower temperatures.

Descriptors :   *HYDROGEN, *SILICON, *SILANES, *ATOMIC STRUCTURE, LOW TEMPERATURE, DETECTION, ETCHING, ROOM TEMPERATURE, SURFACES, RESPONSE, HEATING, CRYOGENICS, INFRARED SPECTRA, POROUS MATERIALS.

Subject Categories : Physical Chemistry
      Inorganic Chemistry
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE