Metal-Semiconductor Reaction Phenomena and Microstructural Investigations of Laser Induced Regrowth of Silicon on Insulators.
Abstract
Solid phase regrowth of Silicon-on-sapphire has been investigated in the Si (amorphous)/Al(poly) Al2O3 (crystal) system. Using transmission electron microscopy, scanning electron microscopy, Auger electron spectroscopy and Hall effect measurements, it has been shown that Si is transported through an Al film at 550 C to produce p-type Si films on the sapphire substrate. The growth process has been shown to be initiated at Si nucleation sites on the substrate. These sites expand by mass accretion forming island structures that coalesce to yield continuous large grained polycrystalline Si films on the sapphire surface. The defect structure in CVD Si layers on sapphire were investigated before and after scanning laser annealing. Prior to laser annealing, the films were characterized by the presence of stacking faults, twinning zones and dislocation lines producing large regions of high disorder. Subsequent to laser annealing under conditions to produce total melting of the Si layers it was shown that liquid phase epitaxial regrowth occurred resulting in regions of defect-free Si and a total absence of twinning regions. Single-crystal Si sheets (0.2 micrometer in thickness) of (100) orientation and of maximum dimensions, 100 x 10,000 micrometer, have been recrystallized by cw laser annealing of polycrystalline Si films deposited over parallel 3- micrometer-wide SiO2 bars adjacent to 3- micrometer Si (100) substrate openings. The recrystallized films are free of cracks, mosaic structure, stacking faults or excessive mass flow at the oxide edges.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1982
- Accession Number
- ADA112842
Entities
People
- Calvin Leung
- R. A. Armistead
- R. D. Ormond
- T. J. Magee