Deep Silicon Etching™
MEMS and Nanotechnology applications frequently require features to be created in silicon with relatively high aspect ratios and anisotropic profiles.
These objectives are usually accomplished using the Bosch process, also commonly
known as Deep Silicon Etching (DSE) or Deep Reactive Ion Etching (DRIE). Plasma-Therm
offers DSE technology on the
The DSE process
alternates between deposition and isotropic
etching in a chamber with an ICP configuration. During the deposition process, a polymer is deposited such that it is conformal
over the surface. Following deposition, the polymer is removed only from the
horizontal surfaces, allowing isotropic etching during the next step. The deposition
gas is typically C4F8 and the etching gas is commonly SF6.
The alternation of process steps can produce features with vertical profiles and sidewall
morphology that often referred to as "scalloped." However, by using specialized hardware and
software, switching between deposition and etching steps can be accomplished very
quickly. With “fast switching” of power, pressure, and gases in each step, the
scalloped effect can be virtually eliminated.
Plasma-Therm has developed DSE that has been demonstrated to have the widest
process latitude. This process latitude, coupled with the high mask selectivity, low
SOI notching, and fast process switching, has made Plasma-Therm the leader in
providing DSE technology.