Lanthanum‐modified lead titanate thin film formed by low‐temperature chemical vapor deposition and subsequent annealing

1993 ◽  
Vol 62 (25) ◽  
pp. 3377-3379 ◽  
Author(s):  
Shunji Watanabe ◽  
Takamitsu Fujiu ◽  
Akira Tanaka
MRS Advances ◽  
2016 ◽  
Vol 2 (29) ◽  
pp. 1533-1538 ◽  
Author(s):  
S. Ishihara ◽  
Y. Hibino ◽  
N. Sawamoto ◽  
T. Ohashi ◽  
K. Matsuura ◽  
...  

ABSTRACTMolybdenum disulfide (MoS2) thin films were fabricated by two-step chemical vapor deposition (CVD) using (t-C4H9)2S2 and the effects of temperature, gas flow rate, and atmosphere on the formation were investigated in order to achieve high-speed low-temperature MoS2 film formation. From the results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) investigations, it was confirmed that c-axis orientation of the pre-deposited Mo film has a significant involvement in the crystal orientation after the reaction low temperature sulfurization annealing and we successfully obtained 3 nm c-axis oriented MoS2 thin film. From the S/Mo ratios in the films, it was revealed that the sulfurization reaction proceeds faster with increase in the sulfurization temperature and the gas flow rate. Moreover, the sulfurization under the H2 atmosphere promotes decomposition reaction of (t-C4H9)2S2, which were confirmed by XPS and density functional theory (DFT) simulation.


2003 ◽  
Vol 18 (4) ◽  
pp. 973-978 ◽  
Author(s):  
U. C. Oh ◽  
Kwang Nam Kim ◽  
Sung Chul Kim ◽  
Hye Dong Kim ◽  
Ho Kyoon Chung

Metal contamination in Si and SiO2 films deposited by plasma-enhanced chemical vapor deposition (PECVD) in the fabrication of low-temperature poly Si thin-film transitor was investigated. Aluminum was the major metal impurity to have the highest concentration. Segregation of Al was always observed in the films deposited at temperatures above 400 °C. The impurity level in the segregated region was 1018 ∼ 1020 atoms/cm3 for Al, while the concentration in matrix was about 1016 atoms/cm3. From the transmission electron microscopy image, the Al segregated region contains small-size Al precipitates. Although the Al impurity level of 1016 atoms/cm3 did not cause any serious degradation of device performance, the level of 1018 atom/cm3 and higher can induce a fatal degradation of the threshold voltage. This study revealed that the Al originated from the PECVD chamber, carbon precipitates provided the preferred sites for Al precipitates, and the solubility and diffusivity of Al in Si accelerated the segregation of Al.


2001 ◽  
Vol 686 ◽  
Author(s):  
Kousaku Shimizu ◽  
Jianjun Zhang ◽  
Jeong-woo Lee ◽  
Jun-ichi Hanna

AbstractLow temperature growth of poly-SiGe has been investigated by reactive thermal chemical vapor deposition technique, which is a newly developed technique for preparing polycrystalline materials with using redox reactions in a set of source materials, Si2H6 and GeF4.. In order to prepare high uniformity and reproducibility of Si-rich poly-SiGe, total pressure, gas flow ratio, and residence time are optimized at 450°C of substrate temperature. Through optimizing the conditions, poly-Si1−xGex (x<0.04) films have been prepared in the reproducibility more than 90% and uniformity more than 88%. Bottom gate type of n-channel thin film transistors has been fabricated in various grain size of poly-Si1−xGex on SiO2 (100nm)/Si substrates. 5-36 cm2/Vs of field effect mobility of thin film transistors (L/W = 50μm/50μm) have been achieved after hydrogenation, whose threshold voltage is around 2±0.5V, and on/off ratio is more than 104.


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