Investigations on etching resistance of undoped and boron doped polycrystalline diamond films by oxygen plasma etching

•The difference of surface damages generated by pure O2 RIE of undoped and BDD film was analyzed.•The effects of boron within the BDD layers on the etch performances were investigated.•The much superior etching resistance of BDD film can be ascribed to the existence of boron within the film.•The (111) planes of BDD films were more etching resistant than (100) planes due to much higher boron concentration.

The reactive ion etching (RIE) technique was used to etch the undoped and boron-doped diamond (BDD) polycrystalline films using oxygen plasma. The effect of boron within the BDD coatings on the morphology was investigated. BDD films exhibited much superior etching resistance than the undoped diamond films, wherein the (111) planes of BDD films were more etching resistant than (100) planes due to much higher boron concentration. However, this is in contradiction to undoped diamond films whose (111) planes were etched more quickly. The results would help to better design a particular and efficient etching method for undoped and BDD films to get a well-patterned microstructures.