Improvement of selectivity during diamond growth utilizing a new process

A new process, which employs the photoresist or SiO2 as a mask, the CH4-CO2 gas mixtures as the gas source of diamond deposition, and the HF:HNO3:H2O (1:1.1:10) solution as etching solution after the first step deposition, has been developed to improve the selective growth of diamond films. The longer etching time would result in increasing the selectivity during the following step of diamond film growth. The diamond nuclei growth on the undesired region would be removed and a thin SiO2 layer would be formed using the above solution, therefore, increasing the selectivity. Scanning electron microscopy and electron spectroscopy for chemical analysis were used to examine the selective loss and morphological change for the as-grown diamond films.