The etching mechanism of deep (∼10 μm) submicron diameter holes with high aspect ratios (>10) using plasmas maintained in mixtures of SF 6 and O 2 gases was investigated. A low-pressure, high-density, inductively coupled plasma etching reactor with a planar coil was used for the etching. The influence of SF 6-to-O 2 gas ratio, pressure, and rf-bias voltage on the etch rate and selectivity was also analyzed using Si wafers, which were patterned with 0.35-0.5 μm diameter holes in a SiO 2 mask. The etch rate and anisotropy were determined using the F-to-ion flux ratio and F-to-O flux ratio.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|State||Published - May 1 2004|