TY - JOUR
T1 - Role of hydrogen and oxygen gas in the growth of carbon thin films by pulsed laser deposition
AU - Yoshitake, Tsuyoshi
AU - Nishiyama, Takashi
AU - Nagayama, Kunihito
N1 - Funding Information:
We would like to acknowledge Dr. M. Tsuji of Kyushu University for valuable discussions. We are very grateful to Mr. Tsuya of Sumitomo Metals for providing Si substrates. The film preparation using the ArF excimer laser was carried out in the Institute for Ionized Gas and Laser Research, Kyushu University. We are very grateful to Dr. M. Bowden, Dr. Y. Hirakawa, Dr. Y. Kajiwara, Prof. K. Uchino and Prof. K. Muraoka for assisting with the experiment including the operation of the ArF excimer laser. We are indebted to Dr. K. Nakata of Kyushu University for the spectrophotometer measurements. The Raman spectrum measurement was made using equipment at the Center of Advanced Instrumental Analysis, Kyushu University. We are very grateful to Mr. K. Sakamoto of Kyushu University for being very helpful with the Raman spectrum measurement. This work is supported by the Nippon Sheet Glass Foundation for Materials Science and Engineering.
PY - 2000
Y1 - 2000
N2 - Carbon thin films of thickness 100 nm were deposited at a substrate temperature of 20 °C by pulsed laser deposition using a graphite target. The laser source used was an ArF excimer laser. The ambient pressure was varied between 10-7 and 1 Torr by adjusting the gas flow of hydrogen or oxygen. Raman spectrum measurement showed a broad peak with a center at 1550 cm-1 for all films deposited in both ambient gases, similar to those of typical diamond-like carbon films prepared using other methods. The absorption coefficients decreased and the optical band gaps increased at pressures higher than 10 mTorr for hydrogen and 0.1 mTorr for oxygen. These results indicate that both hydrogen and oxygen are effective in etching an sp2 bonding fraction. The sp2 etching processes for ambient hydrogen and oxygen could be explained well by the combination of the expected ablation processes and the reaction rate between carbon atoms and the ambient gases.
AB - Carbon thin films of thickness 100 nm were deposited at a substrate temperature of 20 °C by pulsed laser deposition using a graphite target. The laser source used was an ArF excimer laser. The ambient pressure was varied between 10-7 and 1 Torr by adjusting the gas flow of hydrogen or oxygen. Raman spectrum measurement showed a broad peak with a center at 1550 cm-1 for all films deposited in both ambient gases, similar to those of typical diamond-like carbon films prepared using other methods. The absorption coefficients decreased and the optical band gaps increased at pressures higher than 10 mTorr for hydrogen and 0.1 mTorr for oxygen. These results indicate that both hydrogen and oxygen are effective in etching an sp2 bonding fraction. The sp2 etching processes for ambient hydrogen and oxygen could be explained well by the combination of the expected ablation processes and the reaction rate between carbon atoms and the ambient gases.
UR - http://www.scopus.com/inward/record.url?scp=0033738433&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033738433&partnerID=8YFLogxK
U2 - 10.1016/S0925-9635(99)00240-X
DO - 10.1016/S0925-9635(99)00240-X
M3 - Conference article
AN - SCOPUS:0033738433
SN - 0925-9635
VL - 9
SP - 689
EP - 692
JO - Diamond and Related Materials
JF - Diamond and Related Materials
IS - 3
T2 - 10th European Conference on Diamond, Diamond-like Materials, Carbon Nanotubes, Nitrides and Silicon Carbide
Y2 - 12 September 1999 through 17 September 1999
ER -