Improvement of interfacial adhesion of Al/Cr films deposited on indium tin oxide coated glasses by interfacial oxidation

Metallization of aluminum (Al)/chromium (Cr) composite thin metal film on indium-tin-oxide (ITO) coated glass has been carried out to improve the bondability of optoelectronic devices. In this study, we have introduced various amounts of oxygen at the Cr/ITO interface during the early stage of Cr deposition to form the intermediate oxide layer, which enhances interfacial adhesion strength between Cr/ITO. The results show that the adhesion strength is increased as the flow rate of oxygen increases. Maximum improvement occurs as the flow rate of oxygen reached 6 standard cubic centimeter/minute (sccm), which is dependent on the chemical composition and interphase boundary structure of Cr/ITO interface. The interfacial layer thickness and chemical composition of metal/oxide interface have been analyzed by the Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The results indicate maximum improvement of adhesion strength is probably due to the presence of higher thickness of interfacial Cr2O3 oxide contained strong oxide-to-oxide bonding on the interface of Cr/ITO surface.