Determinación del mecanismo de oxigenación del CdTe obtenido por rf sputtering reactivo con magnetrón en un plasma de Ar-N₂O

In this work we did studies to determinate the oxidation site and incorporation mechanism of oxygen to CdTe, when preparing CdTe:O thin films by rf reactive magnetron sputtering, using a CdTe target and a controlled plasma of Ar-N₂O. We study the influence in the oxygen content in films due to the variation of N₂O partial pressure, plasma power and substrate position. We monitored the process in situ by mass spectrometry to determinate the variation of present compounds when varying the N₂O partial pressure and plasma power. Thin films composition was determinated by Auger electron spectroscopy and their structure by X-ray diffraction. We demonstrate that oxygen incorporation has place mainly in the substrate, forming an amorphous CdTe:O film. We found that exists CdTe oxidation without using nitrous oxide, may be due to residual atmosphere. We demonstrate that CdTe oxidation depends on nitrous oxide partial pressure and plasma power. We found that deposition rate of CdTe:O thin films depend on nitrous oxide interactions with CdTe in the target and on the chamber walls. We propose a reaction mechanism to explain the oxygen incorporation to CdTe.