<s>
Advanced	B-Algorithm
silicon	I-Algorithm
etching	I-Algorithm
(	O
ASE	O
)	O
is	O
a	O
deep	B-Algorithm
reactive-ion	I-Algorithm
etching	I-Algorithm
(	O
DRIE	B-Algorithm
)	O
technique	O
to	O
etch	O
deep	O
and	O
high	O
aspect	O
ratio	O
structures	O
in	O
silicon	O
.	O
</s>
<s>
ASE	O
consists	O
in	O
combining	O
the	O
faster	O
etch	O
rates	O
achieved	O
in	O
an	O
isotropic	O
Si	O
etch	O
(	O
usually	O
making	O
use	O
of	O
an	O
SF6	O
plasma	O
)	O
with	O
a	O
deposition	O
or	O
passivation	B-Application
process	O
(	O
usually	O
utilising	O
a	O
C4F8	O
plasma	O
condensation	O
process	O
)	O
by	O
alternating	O
the	O
two	O
process	O
steps	O
.	O
</s>
<s>
This	O
approach	O
achieves	O
the	O
fastest	O
etch	O
rates	O
while	O
maintaining	O
the	O
ability	O
to	O
etch	O
anisotropically	O
,	O
typically	O
vertically	O
in	O
Microelectromechanical	B-Architecture
Systems	I-Architecture
(	O
microelectromechanical	B-Architecture
systems	I-Architecture
(	O
MEMS	B-Architecture
)	O
)	O
applications	O
.	O
</s>
