Strain State and Thermal Stability of Strained-Si-on-Insulator Substrates. Yusuke Hoshi, Atsushi Fukumoto, Kentarou Sawano, Ian Cayrefourcq, Makoto Yoshimi, and Yasuhiro Shiraki (Musashi Institute of Technology and Soitec). J. Appl. Phys. 46, No. 11, pp. 7294–7296 (published online November 6, 2007).
The strain state and thermal stability of strained-Si-on-insulator (sSOI) substrates fabricated by the Smart CutTM technique were precisely analyzed by X-ray diffraction reciprocal space mapping and Raman spectroscopy. It was demonstrated that the strain was well maintained even after annealing at temperatures up to 1120 °C in spite of the thickness being larger than the critical thickness. The strain reduction of only 10% was observed at 1150 °C, but the surface smoothness with the RMS roughness below 0.2 nm and high crystal quality did not change. This indicates the high applicability of sSOI to the current Si processes.
Raman spectroscopy study of damage and strain in (001) and (011) Si induced by hydrogen or helium implantation. C. Villeneuve, K. K. Bourdelle, V. Paillard, X. Hebras, and M. Kennard (Soitec, CEMES-CNRS and U. Toulouse). J Appl.Phys. 102, 094905 (14 November 2007). DOI:10.1063/1.2809394.
Raman spectrometry is used to investigate lattice disorder and strain induced by hydrogen or helium implantation in (001) and (011) Si. We observe that the amount of strain increases linearly with the implant dose. For H implants the dependence of strain on crystallographic orientation was discovered. This effect is attributed to the anisotropic morphology of the H-induced extended defects: two-dimensional platelets with preferred orientations versus spherical nanobubbles formed after He implants.
Impact of the transient formation of molecular hydrogen on the microcrack nucleation and evolution in H-implanted Si (001). S. Personnic, K. K. Bourdelle, F. Letertre, A. Tauzin, N. Cherkashin, A. Claverie, R. Fortunier and H. Klocker (Soitec, CEA-Léti, CEMES/CNRS, EMSE). J. Appl. Phys. 103, 023508 (22 January 2008). DOI: 10.1063/1.2829807.
The implant-induced hydrogenated defects responsible for the Smart CutTM layer transfer of Si (001) films is studied. We show that the formation of molecular hydrogen is dominated by a transient phenomenon related to the rapid dissociation of the hydrogenated point defects. The impact of the H2 formation kinetics on the microcrack evolution is described and the physical mechanisms involved in their growth are identified.
Thermally Processed High-Mobility MOS Thin-Film Transistors on Transferable Single-Crystal Elastically Strain-Sharing Si/SiGe/Si Nanomembranes. Hao-Chih Yuan, Michelle M. Kelly (Roberts), Donald E. Savage, Max G. Lagally, George K. Celler, and Zhenqiang Ma (U.Wisconsin/Madison and Soitec). IEEE Transactions on Electron Devices, Vol. 55, No. 3, March 2008. DOI: 10.1109/TED.2007.914833.
Demonstration of high-performance MOS thin-film transistors (TFTs) on elastically strain-sharing single-crystal Si/SiGe/Si nanomembranes (SiNMs) that are transferred to foreign substrates is reported. The transferable SiNMs are realized by first growing pseudomorphic SiGe and Si layers on silicon-on-insulator (SOI) substrates, and then, selectively removing the buried oxide (BOX) layer from the SOI. The results suggest that transferable and thermally stable single-crystal elastically strain-sharing SiNMs can serve as excellent active material for high-speed device application with a simple and scalable transfer method. The demonstration of MOS TFTs on the transferable nanomembranes may create the opportunity for future high-speed Si CMOS heterogeneous integration on any substrate.