Title: Thermal Chemical Vapor Deposition of Silicon Carbide Films for Optoelectronic Applications
1Thermal Chemical Vapor Deposition of Silicon
Carbide Films for Optoelectronic Applications
Aaron Angerami Mame Diop, Spyros Gallis,
and Harry Efstathiadis, Ph.D.School of
NanoSciences and NanoEngineeringUniversity at
Albany - SUNY
2Outline
- Introduction
- Motivation Why SiC?
- Experimental procedure
- TCVD1 process of SiC films
- Results
- Effect of Substrate Temperature on Film
Composition - Conclusions
- Future Directions
- 1 TCVD- Thermal Chemical Vapor Deposition
3Motivation Why SiC?
- Due to its wide band gap and excellentmechanical
, chemical, and physical properties, SiC has
emerged as a promising material for advanced
electronic devices that can be used under
extremelyharsh conditions. - SiC has also been considered as a good candidate
for novel optoelectronic devices producing light
in the visible spectral range from blue to
yellow.
I. G. Ivanov, et.al., Phys. Rev. B 64, (2001) T.
Ma, et.al., J. Appl. Phys. 88, 6408 (2000)
4Summer internship objectives
- Become familiar with CVD processes
- Gain hands-on experience with various analytical
techniques, such as Fourier Transform Infrared
(FTIR), Ellipsometry, Auger Electron Spectroscopy
(AES). - Use a stand alone CVD tool to deposit SiC films.
- Employ a nonhalide precursor from the family of
polysilyenemethylenes (PSMs), known as SP-4000,
as the silicon and carbon source to grow SiC
films. - Determine the effects of varying the substrate
temperature on the film characteristics using
FTIR and AES.
5Experimental setup and process parameters for SiC
film deposition
6Experimental procedure (contd)
- Nonhalide precursor from family of
polysilyenemethylenes (PSMs), -SiH2-CH2-n , n
2 8, as Si and C source - Substrates used Si pieces
7Typical AES depth profile of a 225 nm-thick film
Results
- Typical spectra show
- SiC ratio 11
- Low atomic percentage of N and O
- Uniform composition throughout the bulk of the
film
8Typical FTIR spectrum of a 225 nm-thick SiC film
Si -C
CO2
- A Typical spectra should exhibit
- a prominent peak around 800 cm-1 which is
indicative of Si-C - No peak related to C-H (s) near 3000 cm-1
9Effect of Substrate Temperature on Film
Composition
- Films were deposited at substrate temperatures of
700 C, 800 C and 900C. - These films were then analyzed with AES and FTIR.
Relative at. Carbon
Temperature C
- The amount of carbon in the films was found to
increase with substrate temperature by as
determined AES.
10Results
Films grown at a substrate temperature of
900C
700C
C-H, C-C
Si-C
O-H
CH2
Si-H
Si-H
O-H
Si-C
C-H, C-C
CO2
CO2
CH2
- FTIR provides information on bonding
configuration - Films grown at 900C were found to be carbon rich
which is consistent with AES measurements
11Conclusions
- Acquired hands-on experience with TCVD of SiC,
FTIR, AES. - Deposited SiC films with a non-halide precursor
at temperatures as low as 700ºC. - Performed structural and chemical
characterization of the resulting SiC films
deposited on Si substrates. - Films grown at the substrate temperature 800ºC
were found with SiC 1.0 and lt 5 at. O and N. - Investigated the effect of substrate temperature
on film composition
12Future Directions
- Systematically investigate TCVD processing
parameters and their effect on the a-SiC film
characteristics. In particular, optimize film
characteristics for Er doping. - Perform annealing of the a-SiC films at
different temperatures.
Acknowledgements
Work supported by the New York State Center for
Advanced Thin Film Technology at the University
at Albany SUNY and The Research Foundation of
State University of New York. Richard Moore at
the School of NanoSciences and NanoEngineering of
the University at Albany - SUNY. Denise
Wilson. Starfire Systems, Inc.