The new Queensland Microtechnology Facility at Griffith University has
ordered
a Gamma sputtering system from Surrey
NanoSystems, to support commercially-backed research into advanced
semiconductor
devices.
Queensland Microtechnology Facility staff with their own 200 and 150 mm SiC-on-Si wafers produced using the facility's unique epitaxial deposition process.
The prime application for the system is to research, develop and
establish
pilot production procedures for silicon-carbide-on-silicon (SiC-on-Si)
devices
- on wafers of up to 200 mm diameter. Established with support from the
Queensland
State Government, Queensland Microtechnology Facility (QMF) has developed
a
unique epitaxial SiC-on-Si wafer deposition process. By combining the
superior
semiconductor and physical properties of SiC with low cost silicon wafers,
QMF
is creating a platform technology that has the potential to enable radical
new
generations of semiconductor devices - and electronics products.
One of the many performance advantages of SiC is its low leakage, and
superior
new forms of semiconductor memory for non-volatile and volatile
applications
are some of the researchers' ambitious targets. The markets for these
devices
alone are massive: today's Flash memory business alone is worth over $22
billion
annually - and the total semiconductor memory market exceeds $60 billion.
QMF's
memory research and development is funded by Qs Semiconductor Corporation.
A novel SiC-on-Si non-volatile memory cell with a performance exceeding
today's
commercial criteria has already been demonstrated. QMF's memory cell
architecture
is very simple and the researchers believe it has the potential to be
integrated
easily with current silicon fabrication technology - allowing a fast
transition
into production at 65 nm or smaller node geometries.
Surrey NanoSystems won the competitive tender for three main reasons: the
ability
of the hardware and its control system to replicate commercial production
processes,
the flexibility of the system to support wide-ranging research, and the
high
quality vacuum engineering.
The Gamma sputtering system was specified and chosen by Alan Iacopi,
Manager
and Deputy Director of the Queensland Microtechnology Facility, whose
background
includes wafer fabrication experience as a process engineer and more than
15
years in the development of semiconductor production equipment. Surrey
NanoSystems'
control architecture, which employs a combination of a dedicated real-time
PLC
controller for the processing hardware with an industrial PC front-end for
the
user interface, was a big plus point for him compared with the standard
PCs
used on some other systems. He also liked the system's operating software,
GammaSoft,
which is purpose designed and provides a simple graphical means of
constructing
and modifying custom processing 'recipes'.
"We carry out commercially funded projects, and so porting of
research
into production to minimize time to market is of paramount importance to
our
investors," says Alan Iacopi. "Gamma was a system I could get
excited
about as it met the sophisticated design and processing attributes we
require
to support our wide-ranging research and development goals, including the
deposition
of complex aluminium interconnect metallization to replicate commercial
production
processes. The control software was also the most feature-rich of all
reviewed."
The superior electrical, thermal, optical and mechanical properties of
crystalline
SiC make it an interesting material to support progress not only in
semiconductor
device performance, but also in numerous other emerging technologies.
Developing
device-quality SiC films on silicon wafers is a very promising means for
silicon
carbide to enter mainstream electronics markets. The Queensland
Microtechnology
Facility has some unique ideas for successfully fabricating this materials
combination
at temperatures low enough for integrated circuit manufacturing, and
following
its success with non-volatile memory, it is targeting research at a broad
range
of advanced semiconductor devices and other technologies that could
benefit
from SiC-on-Si. These include power electronics, solar cells, devices for
micro-electro-mechanical
systems, and optoelectronics.
The equipment chosen is a configuration of Surrey NanoSystems' Gamma
sputtering
tool, an advanced PVD (physical vapor deposition) sputtering system that
is
highly optimized for both performance and versatility of use, and is
widely
used in R&D and pilot production applications. Capable of deposition
over
200 mm diameter wafers or substrates, the system's very high vacuum
capability
of 5 x 10-9 Torr, which is as much as two orders of magnitude higher than
some
other commercially available sputtering systems, provides an exceptionally
pure
environment to aid uniform film deposition. Developed and refined over
almost
10 years, the company uses a number of novel materials and system building
ideas
to reduce out-gassing, and enhance the level of cleanliness that can be
achieved.
Surrey NanoSystems is also fitting a brand new reactive gas control
system
- which is believed to be a first for commercial sputtering systems.
Instead
of a conventional DC pulse controlled process, the Gamma system will use
optical
emission spectroscopy to dynamically control a high performance gas
injection
system. Reactive gas control provides a much faster alternative to radio
frequency
(RF) deposition, combined with comprehensive control over the
stoichiometry
of the deposited films. The integrated optical emission spectroscopy
capability
allows users to monitor the process and modify it dynamically - providing
the
means to avoid the common problem of 'target poisoning'.