In-Situ Diffraction and Imaging Studies of Heteroepitaxial Growth of Semi-Conductors
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 Si(100), 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 Si(100) 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 Si(100); Determination of surface diffusion and binding energies related to nucleation and growth processes for Ge on Si(100).
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 17, 1990
- Accession Number
- ADA231568
Entities
People
- J. A. Venables
- P. A. Bennett
Organizations
- Arizona State University