Oxygen ion beam assisted etching of single crystal diamond chips using reactive oxygen gas

The etching characteristics of single crystal diamond chips processed using an oxygen ion beam with reactive oxygen gas flux were investigated. The specific etching rate increased linearly with increasing ion energy in the range of 250 to 1000 eV. The specific etching rates processed in a 1000-eV oxygen ion beam with oxygen gas was approximately twice that processed only in a 1000-eV oxygen ion beam. The angular dependences of only a 500-eV oxygen ion beam (no assist), and a 500-eV argon ion beam with oxygen gas were quite different from that of the other conditions. The specific etching rates were almost constant as a function of ion incident angle in the range of 0 to 50°. Those for the other conditions first increased with increasing ion incident angle, and reached a maximum rate at an ion incident angle of 40° or 50°, and then decreased gradually with further increase in ion incident angle. The specific etching rates using an argon ion beam with oxygen gas first increased with increasing gas partial pressure and then reached a saturation level at a gas partial pressure above 0.015 Pa, whereas those for the other conditions increased linearly with increasing gas partial pressure in the range of 0 to 0.06 Pa. The specific etching rates using an oxygen ion beam increased linearly with increasing substrate temperature in the range of 100 to 500 °C. The specific surface roughness was almost constant as a function of the substrate temperature, in the range of 100 to 500 °C. The specific surface roughness after assisted etching using oxygen or hydrogen gases was approximately half that processed in only oxygen or argon ion beams (no assist). © 2001 Kluwer Academic Publishers