E.
Kohn, M. Adamschik, P. Schmid, S. Ertl*
Dept.
of Electron Devices and Circuits
University
of Ulm
Ulm,
Germany
*
present address: GFD, 89081 Ulm, Germany
Abstract
At the European 1998
Diamond conference we had first discussed Diamond MEMS based on HOD films on
silicon as an emerging technology. Key elements for electro-mechanical as well
as electro-thermal applications were discussed, namely membrane and cantilever
structures and a diamond inkjet element.
Meanwhile several
demonstrators have found their way into specific applications and the
structures have been optimized and their static and dynamic performance
characterized and compared to that of conventional microsystems technologies.
Three of these
applications will be discussed:
- the CVD
diamond scalpel used in surgery, the technology of which has been extended to a
temperature controlled heated blade,
- the
diamond micro switch, which has been the basis for the devlopment of a
microwave power switch, which will be integrated into a coplanar waveguide, and
- a diamond
inkjet, which has been adopted to a piko-litre dispenser system for biochemical
processes like the DNA synthesis.
These examples show,
that diamond is indeed an exceptional MEMS material for extreme conditions.
However, in most cases such extreme conditions are not required and the
advantages are not obvious. Thus, it has often been questioned whether diamond
can be an enabling material. On the other hand, its wide bandgap electronic
properties allow to use this material simultaneously in a variety of different
active and passive functions. This multi-functionality simplifies the
fabrication technology essentially and improves performance and reliability at
the same time.
Thus, initial windows
can be found, where diamond based micro-devices exhibit distinct advantages
over devices using conventional materials. Due to improved substrate quality
manufacturability is not in question anymore. The next step on the road map
will be the integration with Si-based electronics to expand the present device
technology to a systems technology.