Figure 3
(a) and (b) Two different approaches to cyclic etching of diamond: (a) the relative contribution of Ar to the total gas flow is small throughout the process, but steadily increases within each step in the cycle; (b) one of the two steps has equal flow of argon and oxygen. (c) and (d) Examples of close-up SEM images of two diamond lenses produced via (a) and (b), respectively. |