Ak. Chu et al., Silicon V grooves fabricated using Ta2O5 etch mask prepared by room-temperature magnetron sputtering, J VAC SCI B, 19(4), 2001, pp. 1169-1172
A tantalum pentoxide (Ta2O5) etch mask process has been developed in the fa
brication of silicon V grooves for precision positioning of optical fibers.
The relationship between the Ta2O5 etch mask undercutting and the etching
temperature of a mixture of ethylenediamine, pyrocatechol, and water (EDP)
was studied. The Ta2O5 etch mask with a thickness of 500 nm was deposited b
y radio-frequency magnetron sputtering at room temperature on both sides of
a 4 in. (100) Si substrate. Desired patterns were formed on the substrate
using a dielectric lift-off technique. Etching temperatures of EDP ranging
from 90 to 120 degreesC have been tested for the process. The undercut was
found to decrease with the increasing etching temperature of EDP. At the et
ching temperature of 120 degreesC, an undercut of 1.61 +/- 131 mum using th
e Ta2O5 etch mask was achieved. (C) 2001 American Vacuum Society.