A review was presented of recent results and analyses of the effects of uniaxial compressive stress on the electronic states and atomic configurations of a Pt–H2 defect in Si, and discuss the results on the basis of a structural model. A technique of isothermal deep-level transient spectroscopy  was applied, combined with the application of uniaxial compressive stress. The experiments showed that <111> and <100> stresses split the isothermal deep-level transient spectroscopy peak of the Pt–H2 defect into 2 components, and a <110> stress split it into 3 components. Such a splitting pattern and the observed intensity ratios of split components uniquely determined that the defect had C2v symmetry, on which this structural model was based. It was found that the electronic levels corresponding to split components varied linearly with <111> stress. Subtracting the stress shift of the conduction band minima, 36meV/GPa was obtained as being the net increase in energy for the level with the higher energy with respect to the applied stress. This result strongly suggested that compressive stress raised the energy of the Pt–H2 level, indicating its anti-bonding character. It was observed that the Pt–H2 defect was aligned above 80K under uniaxial stress to the configuration with the higher electronic level. This indicated that the stress-induced increase of level energy was overcome by the energy gain due to electronic bonding and atomic relaxation, resulting in the decrease of the total energy of the Pt–H2 defect system. It was found that the intensity ratio of split components of the IT-deep-level transient spectroscopy peak was described by a Boltzmann factor, where the activation energy was proportional to the magnitude of the applied stress up to 0.4GPa with a proportional factor, 49meV/GPa, from which an element A3 of the piezospectroscopic tensor was determined to be −37meV/GPa.

Effects of Compressive Stress on the Electronic States and Atomic Configurations of the Pt–H2 Defect in Silicon. Y.Kamiura, K.Sato, Y.Yamashita, T.Ishiyama: Materials Science and Engineering B, 2006, 134[2-3], 213-7