Advanced
Semiconductor Dry Etches
We have developed unique advanced dry etches for semiconductors
using DRIE (deep reactive ion etching) in silicon to
fabricate many interesting and useful structures.
Etches similar to DRIE are being developed for a variety
of compound semiconductor materials.
Bulk
and Surface Micromachining
The advanced dry etches enable bulk and surface
micromachining on a variety of materials and make it
possible to produce a range of microsystem components.
Below are examples of a silicon optical shutter
(left) and an optical switch (middle)
fabricated in silicon-on-insulator (SOI) material. The
right panel shows a microhotplate built
on a released silicon nitride membrane.
Pictured below are micromechanical resonator
filters. The micro "teeter totter"
was fabricated in bulk silicon (left) and the micro
xylophone was fabricated using surface micromachining
techniques and amorphous diamond-like carbon dielectrics
(right).
Wafer
Bonding
This type of spiral gas chromatograph column etched
in a silicon chip (using DRIE) and sealed with an anodically
bonded Pyrex cover is a critical component in Sandia's
MicroChemLab technology.
Acoustic
Sensors
The Micro Acoustic Spectrum Analyzer (MASA) comprises
arrays of micromechanical resonators built on silicon
die that are capable of analyzing the power spectrum
of acoustic signals from the audio to ultrasonic range.
The goal is to build an acoustic spectrum analyzer on
a chip that can reduce the power and data communication
requirements for acoustic monitoring applications.
Chemical Sensors
The drawing and micrograph show a gallium-arsenide based
chemical sensor with a released membrane.
Actuators
and Mechanisms
The Bulk Silicon Actuators, pictured below, use thick
electrostatic comb drives that were built in SOI technology.
Alignment and locking mechanisms can be built using
DRIE.
Hybrid
Integration & Assembly
The assembly on the left shows a quartz substrate that
includes an array of three surface acoustic wave (SAW)
chemical sensors in a gas flow channel and serves as
the circuit board for hybrid integration of three GaAs
ASICs that make up the control electronics. This device
is at the heart of Sandia's MicroChemLab.
Sandia's
microrobot driving over a dime, shown above on the right,
carries its own batteries, sensors, and RF communications
electronics. This microsystem was assembled using hybrid
integration techniques and a combination of commercial
and custom fabricated components.
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