Plasma Etching and Patterning of CVD Diamond at <100° for Microelectronics Application

AbstractOxidation resistance of diamond is an important characteristic to be considered in many high temperature microelectronics and other applications. We have tested the stability of CVD diamong by exposing to Ground State Atomic Oxygen (GSAO) at a temperature of 70°C. Polycrystalline diamond is quite stable at this temperature using GSAO. We have tested the stability of diamond using Excited State Atomic Oxygen (ESAO). Initially, CVD diamond was exposed to ESAO for 15 mind at 63°C and noted that the diamond was etched. We have also carried out the experiments at different time intervals such as 30 and mine. Etching rate of the diamond using ESAO is ≈ 0.2 – 0.25 μm/min at 63°C. We have successfully patterned the diamond using a Ni mask by exposing the sample to ESAO for longer time. ESAO has etched the diamond uniformly in all the directions of the diamond crystal as opposed to the molecular oxygen. Stability of the single crystal diamond has been tested using ESAO by using Ni mask material. We were able to etch the single crystal diamond (type Iia, 100 orientation) quite uniformly. An etching rate of single crystal diamond using ESAO was observed to be 0.3 μm/min.