Application of compact microwave ion source to low temperature growth of transition metal nitride thin films for vacuum microelectronics devices

Abstract

A compact microwave ion source was applied to the low temperature growth of transition metal nitride thin films for the cathode of vacuum microelectronics devices. An ion beam assisted deposition system consisted of a compact microwave ion source and an electron beam evaporator was developed. Depositions of zirconium nitride and niobium nitride thin films were performed and the film properties were investigated. As a result, it was found that polycrystalline films of zirconium nitride and niobium nitride were prepared at the substrate temperature as low as 500 °C, which was almost 200 °C lower than the results shown in the literature. The reason for this reduction of substrate temperature might be attributed to low gas pressure during deposition, due to the use of a single aperture ion source. The control of film composition by controlling the ion-atom arrival rate ratio achieved the control of work function. It was concluded that the ion beam assisted deposition with microwave ion source provides a possible process of cathode deposition.