Pressure-dependent real-time investigations on the rapid thermal sulfurization of Cu–In thin films

Abstract

Rapid thermal processing (RTP) under high sulfur partial pressure of copper rich Cu–In alloy thin films is investigated using in situ energy dispersive X-ray diffraction (EDXRD). Cu–In precursors are sulfurized at S vapor pressures in the 1 mbar range. Diffraction of white synchrotron light and recording of EDXRD spectra every 10 s at the EDDI beamline of the BESSY facility is used to monitor in situ the solid phases during the sulfurization and the subsequent cool-down. Ternary CuInS 2 forms via the binary InS and CuS and the ternary CuIn 5S 8 phases. The concentration of copper in the secondary Cu 2− x S phase, which segregates on the surface of the CuInS 2, shows a strong dependence on the maximum sulfur pressure during the RTP-like process.