THE EFFECT OF SULPHUR VAPOUR TREATMENT ON THE SPEED OF INP THERMAL OXIDATION, COMPOSITION, SURFACE MORPHOLOGY, AND PROPERTIES OF FILMS

Abstract

Purpose. At present, AIIIBV type compounds are considered to be the most promising semiconductors in modern electronics. They are widely used to create high-speed optoelectronic and microelectronic devices. One way to protect the surface of semiconductors is chalcogenide passivation, which to some extent prevents the negative effects of self-oxidation and reduces the density of surface states at the internal interface. The proposed method for modifying the InP surface is the simplest, since it does not require ultra-high vacuum conditions and allows controlling the process parameters. The purpose of this work is to establish the effect of the pre-treatment of the InP surface with sulphur vapours on the oxidation speed, the distribution of components in the fi lm, and the morphological characteristics and electrophysical properties. Methods and methodology. The modifi cation from the gas phase with sulphur vapour was carried out at the temperature of 170°C for 60 minutes, followed by thermal annealing of the samples for 10 minutes at the temperatures of 280 °C and 360 °C. Thermal oxidation of sulphurmodifi ed InP was carried out at a temperature of 530 °C for 60 minutes. Results. The modifi cation from the gas phase with sulphur vapour followed by thermal annealing of the samples for 10 minutes at the temperatures of 280 °C and 360 °C results in fi xing of the sulphur layer on the InP surface (the content is about 7 at. %). The study of the kinetic data of thermal oxidation of sulphur-modifi ed InP established the effect on the growth rate of the formed oxide fi lms. According to the AES data, the sulphur content in the synthesized fi lms was not detected, however, the difference in the distribution profi les of the substrate components and oxygen with the reference indicated the effect of preliminary surface treatment with sulphur on the process of thermal oxidation. The surface morphology of the fi lms formed by thermal oxidation of sulphur-modifi ed InP after annealing at 360 °C improves, which is manifested in an increase in grain order and decrease in fi lm roughness compared to both the controlled and modifi ed InP after annealing at 280 °C. Conclusions. The modifi cation by sulphur vapour of the InP surface positively affects the parameters of fi lm formation and improves their morphology. Films synthesized by thermal oxidation of surface-modifi ed InP possess semiconductor properties.

Keywords

• indium phosphide
• surface
• sulphur
• nanoscale fi lms
• thermal oxidation
• modifi cation.