Accession Number:

ADA280159

Title:

An Atomic-Resolution Study of Overlayer Formation and Interfacial Mixing in the Interaction of Phosphorus with Si(001)

Descriptive Note:

Interim rept. 1 Jun 1993-31 May 1994

Corporate Author:

WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY

Personal Author(s):

• Wang, Y.
• Chen, X.
• Hamers, R. J.

Report Date:

1994-05-27

Pagination or Media Count:

45.0

Abstract:

Scanning Tunneling Microscopy STM, tunneling spectroscopy, and Auger electron spectroscopy have been used to study the formation of phosphorus- terminated silicon001 surfaces by the thermal decomposition of phosphine PH3 . The STM images show that surface phosphorus atoms readily displace Si from the substrate, dramatically changing the overall surface morphology through the formation of large numbers of islands and an extreme roughening of step edges. The surfaces are terminated with P-P dimers, but also contain large numbers of line defects which act as a strain relief mechanism. STM images are used to determine the symmetry of these line defects and are compared with model defect structures. Line defects in the phosphorus-terminated surface both nucleate islands and also constrain their growth in one dimension, such that the phosphorus-terminated surfaces contain large numbers of extremely anisotropic islands and very rough step edges. At lower phosphorus coverage, the STM experiments are able to identify Si and P atoms individually, revealing the formation of large numbers of Si-P heterodimers and the simultaneous disappearance of the strain-induced line defects. Counting statistics are used to study the equilibrium between SiSi, Si-P, and P-P dimers, showing that the surface is a near random alloy with a slight non-statistical preference for formation of the Si-P heterodimer.

Descriptors:

• *INTERFACES
• *RESOLUTION
• *SILICON
• *ATOMIC STRUCTURE
• *PHOSPHORUS
• *MIXING
• SCANNING
• MODELS
• STRUCTURES
• CHEMICAL VAPOR DEPOSITION
• ATOMS
• MICROSCOPY
• ELECTRONS
• ELECTRON SPECTROSCOPY
• AUGER ELECTRON SPECTROSCOPY
• DECOMPOSITION
• NUMBERS
• TUNNELING
• PHOSPHINE
• IMAGES
• SYMMETRY
• THERMAL ANALYSIS
• PHOSPHORS
• DIMERS
• ISLANDS
• SURFACES
• ALLOYS
• SUBSTRATES
• STATISTICS
• MORPHOLOGY
• SPECTROSCOPY
• INTERACTIONS

Subject Categories:

• Inorganic Chemistry
• Physical Chemistry
• Atomic and Molecular Physics and Spectroscopy
• Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE