Crystallinity, strain, and thermal stability of heteroepitaxial Si1−xGex/Si (100) layers created using pulsed laser induced epitaxy
- 17 August 1992
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 61 (7) , 769-771
- https://doi.org/10.1063/1.107793
Abstract
Heteroepitaxy of Si1−xGex/Si alloy layers on Si (100) substrates has been achieved using pulsed laser induced epitaxy (PLIE). The energy of 1 to 20 pulses from a spatially homogenized XeCl excimer laser beam is used to melt a structure consisting of electron-beam evaporated Ge on Si (100) substrates. Alloy films with different Ge fractions are investigated and films with up to 21% Ge content are found to exhibit excellent crystallinity, as confirmed by MeV-ion channeling along the 〈100〉 direction. MeV-ion channeling is also used to determine the level of strain in the layers. This is done by comparing angular yield curves around the 〈110〉 direction for the substrate and alloy layer. The strain values obtained match with calculations for an ideally strained layer state. The strain is also measured for layers that have been subjected to different thermal cycles. A high level of strain is preserved in the alloy layer even after heating to 950 °C for 1 h. This unusual thermal stability is believed to be due to two process features, the ultrarapid nature of the process and the interfacial grading of the Ge fraction created during the melt-regrowth process.Keywords
This publication has 15 references indexed in Scilit:
- Pulsed laser assisted epitaxy of GexSi1−x alloys on Si 〈100〉Applied Physics Letters, 1991
- Strain measurements and thermal stability of Si1−xGex/Si strained layersJournal of Materials Research, 1989
- X-ray diffraction of strain relaxation in Si-Si1−xGex heterostructuresApplied Physics Letters, 1989
- Epitaxial GexSi1−x/Si (100) structures produced by pulsed laser mixing of evaporated Ge on Si (100) substratesApplied Physics Letters, 1988
- Properties of a‐Si,Ge:H,F alloys prepared by rf glow discharge in an ultrahigh vacuum reactorJournal of Vacuum Science & Technology A, 1986
- A semiautomatic algorithm for rutherford backscattering analysisNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1986
- A new self-aligned GaAs FET with a Mo/WSixT-gateIEEE Electron Device Letters, 1985
- GexSi1−x/Si strained-layer superlattice grown by molecular beam epitaxyJournal of Vacuum Science & Technology A, 1984
- Strain relaxation mechanisms of thin deposited filmsCritical Reviews in Solid State and Materials Sciences, 1983
- Defects in epitaxial multilayersJournal of Crystal Growth, 1976