AVS 58th Annual International Symposium and Exhibition
    Nanomanufacturing Science and Technology Focus Topic Tuesday Sessions
       Session NM-TuP

Paper NM-TuP3
Effect of Growth Temperature on Optical Properties of TiO2 Films by Atomic Layer Deposition

Tuesday, November 1, 2011, 6:00 pm, Room East Exhibit Hall

Session: Nanomanufacturing Science and Technology Poster Session
Presenter: Ming-Hui Chan, National Applied Research Laboratories, Taiwan, Republic of China
Authors: M.H. Chan, National Applied Research Laboratories, Taiwan, Republic of China
C.C. Kei, National Applied Research Laboratories, Taiwan, Republic of China
C.N. Hsiao, National Applied Research Laboratories, Taiwan, Republic of China
W.-H. Cho, National Applied Research Laboratories, Taiwan, Republic of China
C.C. Yu, National Applied Research Laboratories, Taiwan, Republic of China
B.H. Liu, National Applied Research Laboratories, Taiwan, Republic of China
W.C. Chen, National Applied Research Laboratories, Taiwan, Republic of China
D.P. Tsai, National Applied Research Laboratories, Taiwan, Republic of China
Correspondent: Click to Email
Titanium dioxide (TiO2) films were deposited on Si and B270 glass substrates by a horizontal-flow atomic layer deposition (ALD) system. Titanium tetrachloride and deionized water were used as metal precursor and oxidant, respectively. Precursors were separately introduced into the reactor for a pulse length of 40 ms, and the working pressure was kept at 1 torr. Deposition temperature of TiO2 films was varied between 100 and 300oC. Absorption coefficient and refractive index were obtianed by using spectroscopic ellipsometry. Crystal structure of TiO2 films w as acquired by using X-ray diffractometery. Film thickness was obtained by scanning electron microscopy. Curve-fittings of ellipsometric data was also applied to evaluate the film thickness and growth rate if TiO2 films. It was found that the crystallinity of Rutile TiO2 films was significantly improved as increase the processing temperature from 150 to 300 ℃. This might be the reason for an increasing refractive index of TiO2 films prepared at a higher temperature. Beside, increase of precursors’ reactive rate would result in a lower absorption coefficient for samples prepared at a higher temperature. The growth rate of TiO2 film prepared at various temperatures is around 0.6 Å/cycle. However, a slight decrease in the growth rate can be observed due to the faster desorption rate of precursors at higher temperatures.