Title
Silicon Carbide heteroepitaxy on large diameter Silicon substrates
Description
Silicon carbide (SiC) is a wide band gap semiconductor attractive for high power and high
frequency electronic devices, due to its excellent physical properties such as high thermal
conductivity, high breakdown field and high saturation velocity. It is also very attractive for
applications in photonic, bio-compatible electronic and optoelectronic devices, and large variety
of sensors for harsh and medical environments. SiC has numerous polytypes, among which the
hexagonal structured 4H- and 6H-SiC are used to fabricate electronic devices. 4H and 6H-SiC
films of good crystal quality can be obtained by homoepitaxy at a growth temperature over
1600°C. The largest 4H- and 6H-SiC wafers available commercially are 150 and 100 mm in
diameter, respectively, limited by the size of SiC substrates for homoepitaxy. The production
cost of SiC is high since the SiC substrate cannot be replaced by the Si wafer for the growth of
4H- and 6H-SiC. Unlike 4H- and 6H-SiC, the cubic structured polytype 3C-SiC can be
heteroepitaxially grown on Si. The heteroepitaxial growth of 3C-SiC on Si has thus attracted
attention in the past years due to lower production cost and larger SiC wafer size. Nowadays, Si
wafers up to 450 mm diameter are commercially available. The difficulty in growing a
heteroepitaxial SiC layer of good quality on Si arises due to the large lattice-mismatch (19.7%)
and the difference in thermal expansion coefficients (∼8%) between Si and SiC. Recently, a
historical breakthrough has been made by researchers from the Nano-Silicon Group, which
underpins low-temperature 3C-SiC heteroepitaxial growth on large diameter Si substrates for
mass production. It opens an opportunity for application of low-cost 3C-SiC epitaxial materials
in various highly demanding solid state semiconductor devices.
The project is an exciting opportunity to be involved in development of new concepts in
3C-SiC heteroepitaxial growth for the realization of high quality SiC epilayers on large diameter
Si substrates. Epitaxial growth of the structures will be developed in-house, using a state of the
art industrial type Si based Chemical Vapour Deposition (CVD) reactor, unique among UK
Universities. Material properties will be researched by a variety of in-house cutting edge
experimental techniques including Hall effect and resistivity measurements, defects revealing,
Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Scanning
Electron Microscopy (SEM), Fourier Transfer Infrared Spectroscopy (FTIR) and X-ray
diffraction and others. Complex characterization of new epitaxial materials will provide an indepth analysis and understanding of 3C-SiC heteroepitaxy and properties of new materials.
Successful outcomes from the project will lead to high impact publications in international
scientific journals and the application of developed materials in a variety of devices using both
in-house device fabrication techniques and the capabilities of industrial collaborators. During the
project the student will gain valuable knowledge and hands-on experience that will put them in
an excellent position to start a career in academia or industry.
To discuss this project further contact:
Dr Maksym Myronov (M.Myronov@warwick.ac.uk)