An investigation was made of Pt-related defects in Si, based upon measurements of their optical absorption and found optical absorption peaks related to Pt clusters. The Pt and H were separately doped into float-zone Si by heating at 1000 to 1300C, followed by quenching in water. Optical absorption spectra were measured at about 5K with a Fourier transform infrared spectrometer. In a specimen doped with a higher concentration of H than of Pt, optical absorption peaks were observed which were due to 4 types of Pt–H complexes. In specimens with a higher concentration of Pt than of H, peaks were observed in the region from 1300 to 1700/cm. Based on the peak shift due to the H

 
isotope and the dependence on excitation energy and the annealing behavior, these peaks were thought to be due to the electronic transitions of Pt-related defects such as Pt clusters, rather than the local vibrational modes of H. The defect centers which gave rise to optical absorption at about 1301, 1318, 1452 and 1474/cm were IR-active centers under illumination and the optical threshold energy was determined to be about 0.34eV by applying Lucovsky's model.

Platinum-Related Defects in Silicon Observed by Optical Absorption Measurements. N.Fukata, M.Suezawa, K.Saito, A.Kasuya: Journal of Applied Physics, 2003, 93[1], 143-7