Advanced Diamond Technologies
(ADT) is making broadly available an etch recipe which enables engineers
and product developers to reliably and affordably design micro devices and sensors
out of diamond.
Based on research published in the November/December 2009 issue of the peer-reviewed
Journal of Vacuum Science & Technology B (JVST B), the etch recipe is available
for download from ADT’s website at http://www.thindiamond.com.
Using standard processes available in most foundries, this dry etch recipe enables
designers to develop cutting-edge diamond micro devices and sensors while eliminating
the complexity traditionally associated with diamond.
“The process to make diamond available, accessible, and affordable is
complete. We have published this recipe so diamond can be incorporated into
process flows using the same equipment and materials used to process silicon.
We’ve eliminated the risk—and mystery—of how to make diamond
devices and we hope to stimulate the creativity and ingenuity of designers to
make diamond devices without having them worry about processing steps,”
said ADT’s president, Neil Kane.
The article, “Nanofabrication of Sharp Diamond Tips by E-beam Lithography
and Inductively Coupled Plasma Reactive Ion Etching,” describes the etch
recipe developed while creating sharp diamond tips for atomic force microscopy
(AFM) probes. The dry etch recipe was optimized to achieve a maximum etch rate
of 650 nm/min using ADT’s UNCD® Wafers. Parameters to achieve slower
etch rates are also outlined which are applicable for developing delicate nano-structures.
Process steps for creating and patterning the hard mask, a 350 nm thick plasma-enhanced
chemical vapor deposited SiOx layer, are also detailed.
“We have customers using our UNCD Wafers to make diamond products as
diverse as AFM probes, switches for phased-array radar, biosensors to detect
E. coli in water, LED lighting, and boron-doped diamond electrodes for water
purification. A simple, optimized etch recipe makes the adoption of diamond
very straightforward,” says ADT’s chief technical officer Dr. John
Carlisle. “A whole generation of 2D and 3D diamond structures are now
conceivable such as high performance RF MEMS devices and accelerometers,”
said ADT’s MEMS lead scientist and lead author of the JVST B article,
Dr. Nicolaie Moldovan.
The development of an optimized dry etch capability is part of ADT’s
ongoing research to advance its 2009 R&D100 Award winning NaDiaProbes®,
the world’s first all-diamond AFM probes, which are created using UNCD
Wafers as a starting material. NaDiaProbes are not diamond-coated probes or
pieces of diamond mounted on cantilevers; rather the entire cantilever and tip
assembly is made of UNCD, a thin-film form of nanocrystalline diamond.
ADT gratefully acknowledges its continuing collaboration with Argonne National
Laboratory (Argonne) which is a co-author of the JVST B article. NaDiaProbes
were developed with a grant from the National Science Foundation’s SBIR/STTR
Formed to commercialize the ultrananocrystalline diamond technology developed
at Argonne, ADT is the exclusive licensee to its portfolio of diamond patents.
ADT is a World Economic Forum 2007 Technology Pioneer, a recipient of a 2008
EuroAsia IC Award in the Materials Enabling category from EuroAsia Semiconductor
magazine, a 2008 R&D 100 Award winner for mechanical seals faces for fluid
pumps, and a 2009 R&D 100 Award winner for NaDiaProbes.