Stress-induced splitting of the electronic level related to a platinum-hydrogen complex in silicon

We have applied deep-level transient spectroscopy (DLTS) under uniaxial compressive stress to study the structure of a platinum- and hydrogen-related defect, which has a gap state at 0.14eV below the conduction band minima in Si. The application of 〈100〉 and 〈111〉 stresses split the DLTS peak of the defect into two components with intensity ratios of 2.7:1 and 1.4:1, respectively, which were the ratios of the low-temperature peak to the high-temperature peak. Under 〈110〉 stress, this peak split into three components as an intensity ratio of two lower-temperature peaks to the high-temperature peak was 1.4:5:1. In addition, we observed the stress-induced alignment of the defect to the configuration corresponding to the low-temperature DLTS peak during the DLTS scan in the temperature range of 65-100K, for all stress directions. Our results provide the first evidence to connect the electronic level at E_c-0.14eV to the atomic configuration of the Pt-H₂ complex with the C_2v symmetry previously identified by EPR.