Comparative Study of Solid-Phase Crystallization of Amorphous Silicon Deposited by Hot-wire CVD, Plasma-Enhanced CVD, and Electron-Beam Evaporation

2007 ◽  
Vol 989 ◽  
Author(s):  
Paul Stradins ◽  
Oliver Kunz ◽  
David L. Young ◽  
Yanfa Yan ◽  
Kim M. Jones ◽  
...  

AbstractSolid-phase crystallization (SPC) rates are compared in amorphous silicon films prepared by three different methods: hot-wire chemical vapor deposition (HWCVD), plasma-enhanced chemical vapor deposition (PECVD), and electron-beam physical vapor deposition (e-beam). Random SPC proceeds approximately 5 and 13 times slower in PECVD and e-beam films, respectively, as compared to HWCVD films. Doping accelerates random SPC in e-beam films but has little effect on the SPC rate of HWCVD films. In contrast, the crystalline growth front in solid-phase epitaxy experiments propagates at similar speed in HWCVD, PECVD, and e-beam amorphous Si films. This strongly suggests that the observed large differences in random SPC rates originate from different nucleation rates in these materials while the grain growth rates are relatively similar. The larger grain sizes observed for films that exhibit slower random SPC support this suggestion.

1999 ◽  
Vol 85 (9) ◽  
pp. 6843-6852 ◽  
Author(s):  
K. F. Feenstra ◽  
R. E. I. Schropp ◽  
W. F. Van der Weg

2006 ◽  
Vol 910 ◽  
Author(s):  
Farhad Taghibakhsh ◽  
K.S. Karim

AbstractFabrication of hot-wire chemical vapor deposition (HWCVD) of amorphous silicon (a-Si) thin film transistors (TFT) on thin polyamide sheets is reported. A single graphite filament at 1500 °C was used for HWCVD and device quality amorphous silicon films were deposited with no thermal damage to plastic substrate. Top-gate staggered thin film transistors (TFTs) were fabricated at 150°C using hot-wire deposited a-Si channel, Plasma enhanced chemical vapor deposition (PECVD) silicon nitride gate dielectric, and microcrystalline n+ drain/source contacts. Low leakage current of 5×10-13 A, high switching current ratio of 1.3×107, and small sub threshold swing of 0.3 V/dec was obtained for TFTs with aspect ratio of 1300μm/100μm. The field effect mobility was extracted to be 0.34 cm2/V.s.


10.30544/128 ◽  
2015 ◽  
Vol 21 (1) ◽  
pp. 7-14
Author(s):  
Meysam Zarchi ◽  
Shahrokh Ahangarani

The effect of new growth techniques on the mobility and stability of amorphous silicon (a-Si:H) thin film transistors (TFTs) has been studied. It was suggested that the key parameter controlling the field-effect mobility and stability is the intrinsic stress in the a-Si:H layer. Amorphous and microcrystalline silicon films were deposited by radiofrequency plasma enhanced chemical vapor deposition (RF-PECVD) and hot-wire chemical vapor deposition (HW-CVD) at 100 ºC and 25 ºC. Structural properties of these films were measured by Raman Spectroscopy. Electronic properties were measured by dark conductivity, σd, and photoconductivity, σph. For amorphous silicon films deposited by RF-PECVD on PET, photosensitivity's of >105 were obtained at both 100 º C and 25 ºC. For amorphous silicon films deposited by HW-CVD, a photosensitivity of > 105 was obtained at 100 ºC. Microcrystalline silicon films deposited by HW-CVD at 95% hydrogen dilution show σph~ 10-4 Ω-1cm-1, while maintaining a photosensitivity of ~102 at both 100 ºC and 25 ºC. Microcrystalline silicon films with a large crystalline fraction (> 50%) can be deposited by HW-CVD all the way down to room temperature.


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