Accession Number:

ADA231568

Title:

In-Situ Diffraction and Imaging Studies of Heteroepitaxial Growth of Semi-Conductors

Descriptive Note:

Final rept. 1 Aug 1987-31 Jul 1990,

Corporate Author:

ARIZONA STATE UNIV TEMPE DEPT OF PHYSICS

Personal Author(s):

Report Date:

1990-10-17

Pagination or Media Count:

9.0

Abstract:

The work emphasizes in-situ characterization of the initial stages of heteroepitaxial growth of semiconductors and ultrathin film silicides using advanced instrumentation and techniques, including high resolution reflection high energy electron diffraction RHEED, a UHV scanning electron microscope with micro-probe RHEED and a UHV scanning transmission electron microscope UHV- STEM. Systems of interest include vicinal Si100, germanium on silicon, and ultrathin film silicides. Specific instrument and technique developments include Demonstration that Auger lineshapes can be used to separate coexisting silicide phases in a partially reacted ultrathin film Demonstration that quasi-kinematic RHEED intensity calculations can be used to identify epitaxial structures Imaging of single atomic height steps with STEM Visualization of submonolayers of germanium and various metals using biassed secondary electron imaging Auger imaging at the highest spatial resolution obtained anywhere. Specific scientific accomplishments include Measurement of a kinetic phase formation diagram for contact reactions in ultrathin film silicides showing previously overlooked thickness dependence Identification of Ni2Si-theta as a precursor structure responsible for the much studied B- to A-type transition in NiSi2 overlayers Demonstration that single layer steps on Si100 are favored over double layer steps due to strain rather than entropic effects, as previously believed Identification of novel strained island structures for Ge on Si100 Determination of surface diffusion and binding energies related to nucleation and growth processes for Ge on Si100.

Subject Categories:

  • Inorganic Chemistry
  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE