Low-temperature photo-hydro-modification of II–VI and III–V semiconductors

The purpose of this paper was the investigation of a photostimulated modification of optical properties of semiconductors subsurface region, to create elements and devices of integrated optics. The experiments have been carried out in II–VI (CdS, CdTe) and III–V (GaAs) semiconductor single crystals. It was shown that during the photostimulated process the enriching of cadmium occurs in the subsurface region of, e.g., CdS single crystals, and thus, the complex refractive index is strongly changed. For the first time this phenomenon was detected and investigated in CdS single crystals [1,2] and was named low temperature photo-hydromodification (LTPHM) method. In this paper the LTPHM-phenomenon was shown to take place in GaAs and CdTe single crystals too. It was theoretically shown that the subsurface region refractive index changes take place due to an increase of clusters concentration, consisting of interstitial atoms. Clusters change their forms during the LTPHM-process.