TY - JOUR
T1 - Effects of annealing conditions and thickness ratio of Si/Al films on the Hall carrier mobility, Al carrier concentration, and nanovoids formed in the metal-induced Si crystallization of Si/Al/Si/SiO2/glass specimens
AU - Peng, Cheng Chang
AU - Chung, Chen Kuei
AU - Wu, Bo Hsiung
AU - Weng, Min Hang
AU - Huang, Chil Chieh
AU - Lin, Jen Fin
N1 - Funding Information:
This work was partially sponsored by the Bureau of Energy, Ministry of Economic Affairs, R.O.C. , under grant 99-D0204-2 . We would like to thank the Center for Micro/Nano Science and Technology (CMNST) and the Center for precious instruments at National Cheng Kung University (NCKU), Tainan, Taiwan, for access to analysis equipment and technical support.
PY - 2011/6/25
Y1 - 2011/6/25
N2 - In the present study, a-Si/μc-Al/a-Si/SiO2/glass specimens were prepared with various combinations of thicknesses of the μc-Al layer and the two a-Si layers. The effects of μc-Al film thickness, a-Si film thickness, the thickness ratio of Al film to Si films, and the annealing temperature on the metal-induced Si crystallization and void defects formed in the sandwich composite specimens were investigated. A transmission electron microscope (TEM) and an X-ray photoelectron spectroscope (XPS) were used to investigate the diffusion mechanism and efficiency of Si crystallization. When the annealing temperature was sufficiently high, the μc-Al grains diffused into the two adjacent Si layers with a fairly even distribution over the entire sandwich structure. Si crystallization was thus significantly enhanced by the sandwich structure. The Hall carrier mobility of the specimen with a structure of a-Si(500nm)/μc-Al(50nm)/a-Si(500nm) was 80.1cm2/Vs and the Al carrier concentration was 1.5×1018/cm3 at an annealing temperature of 600°C; no voids were found in the sandwich structure. An increase in the top layer (a-Si) thickness is advantageous for Si crystallization; however, an increase in the third layer (a-Si) thickness degrades Si crystallization. For a given Al film thickness, an excessive increase in the thicknesses of the two a-Si layers degrades Si crystallization even at high annealing temperatures. A thick Al film in combination with two thick a-Si layers leads to a high Hall carrier mobility when the annealing temperature is sufficiently high. An increase in the Si/Al thickness ratio increases the Hall carrier mobility and decreases the Al carrier concentration.
AB - In the present study, a-Si/μc-Al/a-Si/SiO2/glass specimens were prepared with various combinations of thicknesses of the μc-Al layer and the two a-Si layers. The effects of μc-Al film thickness, a-Si film thickness, the thickness ratio of Al film to Si films, and the annealing temperature on the metal-induced Si crystallization and void defects formed in the sandwich composite specimens were investigated. A transmission electron microscope (TEM) and an X-ray photoelectron spectroscope (XPS) were used to investigate the diffusion mechanism and efficiency of Si crystallization. When the annealing temperature was sufficiently high, the μc-Al grains diffused into the two adjacent Si layers with a fairly even distribution over the entire sandwich structure. Si crystallization was thus significantly enhanced by the sandwich structure. The Hall carrier mobility of the specimen with a structure of a-Si(500nm)/μc-Al(50nm)/a-Si(500nm) was 80.1cm2/Vs and the Al carrier concentration was 1.5×1018/cm3 at an annealing temperature of 600°C; no voids were found in the sandwich structure. An increase in the top layer (a-Si) thickness is advantageous for Si crystallization; however, an increase in the third layer (a-Si) thickness degrades Si crystallization. For a given Al film thickness, an excessive increase in the thicknesses of the two a-Si layers degrades Si crystallization even at high annealing temperatures. A thick Al film in combination with two thick a-Si layers leads to a high Hall carrier mobility when the annealing temperature is sufficiently high. An increase in the Si/Al thickness ratio increases the Hall carrier mobility and decreases the Al carrier concentration.
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U2 - 10.1016/j.surfcoat.2011.04.032
DO - 10.1016/j.surfcoat.2011.04.032
M3 - Article
AN - SCOPUS:79955897983
VL - 205
SP - 4672
EP - 4682
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
IS - 19
ER -