Growth of Polycrystalline Silicon films at low Temperature by Remote Plasma CVD

1992 ◽  
Vol 283 ◽  
Author(s):  
Sung Chul Kim ◽  
Kyu Chang Park ◽  
Sung Ki Kim ◽  
Jung Mok Jun ◽  
Jin Jang
Keyword(s):  
Substrate Temperature ◽  
Polycrystalline Silicon ◽  
Volume Fraction ◽  
Power Level ◽  
Chemical Vapour ◽  
Rf Power ◽  
Crystalline Volume Fraction ◽  
Remote Plasma ◽  
Chemical Vapour Deposition Technique ◽  
Polycrystalline Silicon Films

ABSTRACTWe studied the growth of polycrystalline silicon by using remote plasma chemical vapour deposition technique. The effects of RF power and the substrate temperature on the structural properties have been investigated. With increasing the RF power, the crystalline volume fraction and the grain size increase up to 100W, but decrease for the further increase in power level. We obtained the poly-Si with the crystalline volume fraction of about 74 at.% at the substrate temperature of 330°C.

Boron-Doped Nanocrystalline Silicon Thin Films Prepared by PECVD

2012 ◽  
Vol 503 ◽  
pp. 386-390
Author(s):  
Xiu Qin Wang ◽  
Jian Ning Ding ◽  
Ning Yi Yuan ◽  
Shu Bo Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Substrate Temperature ◽  
Volume Fraction ◽  
Chemical Vapour ◽  
Nanocrystalline Silicon ◽  
Process Conditions ◽  
Rf Power ◽  
Silicon Thin Films ◽  
Boron Doped

Boron-doped nanocrystalline silicon thin films(p-nc-Si:H) were deposited on glass substrates by plasma enhanced chemical vapour deposition (PECVD) using SiH4/ H2/ B2H6. The effects of substrate temperature, rf power and diborane flow on the microstructure, the electrical properties of nanocrystalline silicon thin films have been investigated. The results show that, increasing substrate temperature, rf power and B2H6flow can improve the conductivity of P-Si thin film. However, exceeding one value, they are not advantageous to improve the conductivity due to the decrystallization of films. Hence, appropriate process conditions are crucial for the preparation of high quality p layer. crystalline volume fraction (Xc) 26.2 %, mean grain size (d) 3.5nm and conductivity 0.374S/cm, p-nc-Si:H thin film was deposited.

Intrinsic and Doped m c-Si:H TFT Layers using 13.56 MHz PECVD at 250°C

2004 ◽  
Vol 808 ◽  
Author(s):  
Czang-Ho Lee ◽  
Denis Striakhilev ◽  
Arokia Nathan
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Rf Power ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Bias Stress ◽  
Hydrogen Dilution ◽  
Low Threshold

ABSTRACTUndoped and n+ hydrogenated microcrystalline silicon (μc-Si:H) films for thin film transistors (TFTs) were deposited at a temperature of 250°C with 99 ∼ 99.6 % hydrogen dilution of silane by standard 13.56 MHz plasma enhanced chemical vapor deposition (PECVD). High crystallinity m c-Si:H films were achieved at 99.6 % hydrogen dilution and at low rf power. An undoped 80 nm thick m c-Si:H film showed a dark conductivity of the order of 10−7 S/cm, the photosensitivity of an order of 102, and a crystalline volume fraction of 80 %. However, a 60 nm thick n+ μc-Si:H film deposited using a seed layer showed a high dark conductivity of 35 S/cm and a crystalline volume fraction of 60 %. Using n+ μc-Si:H films as drain and source contact layers in a-Si:H TFTs provides substantial performance improvement over n+ a-Si:H contacts. Finally, fully μ c-Si:H TFTs incorporating intrinsic m c-Si:H films as channel layers and n+ μc-Si:H films as contact layers have been fabricated and characterized. These TFTs exhibit a low threshold voltage and a field effect mobility of 0.85 cm2/Vs, and are far more stable under gate bias stress than a-Si:H TFTs.

Microcrystalline Silicon for Solar Cells at High Deposition Rates by Hot Wire Cvd

2002 ◽  
Vol 715 ◽  
Author(s):  
R. E. I. Schropp ◽  
Y. Xu ◽  
E. Iwaniczko ◽  
G. A. Zaharias ◽  
A. H. Mahan
Keyword(s):  
Solar Cells ◽  
Substrate Temperature ◽  
Volume Fraction ◽  
Silicon Layer ◽  
Hot Wire ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Deposition Rates ◽  
Deposition Parameters ◽  
Si Films

AbstractWe have explored which deposition parameters in Hot Wire CVD have the largest impact on the quality of microcrystalline silicon (μc-Si) made at deposition rates (Rd) < 10 Å/s for use in thin film solar cells. Among all parameters, the filament temperature (Tfil) appears to be crucial for making device quality films. Using two filaments and a filament-substrate spacing of 3.2 cm, μc-Si films, using seed layers, can be deposited at high Tfil (∼2000°C) with a crystalline volume fraction < 70-80 % at Rd's < 30 Å/s. Although the photoresponse of these layers is high (< 100), they appear not to be suitable for incorporation into solar cells, due to their porous nature. n-i-p cells fabricated on stainless steel with these i-layers suffer from large resistive effects or barriers, most likely due to the oxidation of interconnected pores in the silicon layer. The porosity is evident from FTIR measurements showing a large oxygen concentration at ∼1050 cm-1, and is correlated with the 2100 cm-1 signature of most of the Si-H stretching bonds. Using a Tfil of 1750°C, however, the films are more compact, as seen from the absence of the 2100 cm-1 SiH mode and the disappearance of the FTIR Si-O signal, while the high crystalline volume fraction (< 70-80 %) is maintained. Using this Tfil and a substrate temperature of 400°C, we obtain an efficiency of 4.9 % for cells with a Ag/ZnO back reflector, with an i-layer thickness of only ∼0.7 μm. High values for the quantum efficiency extend to very long wavelengths, with values of 33 % at 800 nm and 15 % at 900 nm, which are unequalled by a-SiGe:H alloys. Further, by varying the substrate temperature to enable deposition near the microcrystalline to amorphous transition (‘edge’) and incorporating variations in H2 dilution during deposition of the bulk, efficiencies of 6.0 % have been obtained. The Rd's of these i-layers are 8-10 Å/s, and are the highest to date obtained with HWCVD for microcrystalline layers used in cells with efficiencies of ∼6 %.

Fast Deposition of Polycrystalline Silicon Films by Hot-Wire CVD

1995 ◽  
Vol 377 ◽  
Author(s):  
A. R. Middya ◽  
A. Lloret ◽  
J. Perrin ◽  
J. Huc ◽  
J. L. Moncel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Polycrystalline Silicon ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Hot Wire ◽  
Crystalline Orientation ◽  
Silicon Thin Films ◽  
Hydrogen Dilution ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTPolycrystalline silicon thin films have been deposited at fast growth rates (50 Å/s) by hotwire chemical vapour deposition (HW-CVD) from SiH4/H2 gas mixtures at low substrate temperature (400–500°C). The surface morphology of these films consists of 0.5 – 2.0μm dendritic grains as seen by electron microscopy. The films have a columnar morphology with grains starting from the substrate either on glass or c-Si. Even the 150 nm thick initial layer is polycrystalline. The preferential crystalline orientation of the poly-Si film is apparently not governed by the radiative source but strongly depends on the type and orientation of the substrate. A strong hydrogen dilution (>90%) of silane is essential to obtain poly-Si films with optimal crystalline structure.

Structure of Polycrystalline Silicon Films by Glow-Discharge Decomposition using SiH4/H2/SiF4 at Low Temperature

1999 ◽  
Vol 581 ◽  
Author(s):  
R. Tsuchida ◽  
M. Syed ◽  
T. Inokuma ◽  
Y. Kurata ◽  
S. Hasegawa
Keyword(s):  
Power Supply ◽  
Vapor Deposition ◽  
Local Structure ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
High Angle Boundary ◽  
Rf Power ◽  
Nanocrystalline Structures ◽  
Si Films ◽  
Polycrystalline Silicon Films

ABSTRACTFor poly-Si films prepared by a plasma-enhanced chemical vapor deposition, we examined the changes in the local structure caused by adding H2 and/or SiF4 in the SiH4 feed gases and by changing supplied rf power values. The conditions of low rf power supply, low H2 addition, and SiF4 addition allow formation of films with microcrystalline or nanocrystalline structures. In addition, the H2 or SiF4 addition was found to be effective in promotive growth of <111> or <110> grains, respectively. In such low crystallized films, it was suggested that high-angle boundary would be formed, leading to a decrease in the density of SiH2 and Si dangling bonds, and to an increase in g values.

Electronic Properties of Microcrystalline Silicon

1997 ◽  
Vol 467 ◽  
Author(s):  
R. Carius ◽  
F. Finger ◽  
U. Backhausen ◽  
M. Luysberg ◽  
P. Hapke ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Chemical Vapour ◽  
Structural Defects ◽  
Photoluminescence Properties ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

ABSTRACTThe electronic and optical properties of microcrys tall ine silicon films prepared by plasma enhanced chemical vapour deposition are investigated with Hall-effect, electrical conductivity, photothermal deflection spectroscopy and photoluminescence measurements. In particular, the influence of the grain size and the crystalline volume fraction on the conductivity, the carrier density and the Hall mobility is investigated in highly doped films. A percolation model is proposed to describe the observed transport data. Photoluminescence properties were studied in un-doped films. It is proposed that the photoluminescence is due to recombination at structural defects similar to those observed in crystalline silicon.

Hydrogenated Silicon Films Prepared by Remote Plasma CVD

1990 ◽  
Vol 192 ◽  
Author(s):  
Sung Chul Kim ◽  
Seung Kyu Lee ◽  
Sung Mo Soe ◽  
Sung Ok Koh ◽  
Sung Shil Ihm ◽  
...  
Keyword(s):  
Chemical Vapour ◽  
Substrate Bias ◽  
Rf Power ◽  
Remote Plasma ◽  
Substrate Bias Voltage ◽  
Hydrogenated Silicon ◽  
Gas Concentration ◽  
Hydrogen Dilution ◽  
Plasma Chemical Vapour Deposition

ABSTRACTWe have studied the improvement of the quality of undoped a-Si:H deposited by remote-plasma chemical vapour deposition. The effects of reactant gas concentration, rf power, substrate bias voltage on the electrical and optical properties have been investigated. Some hydrogen dilution of si lane improves the photoeletric property and a high rf power gives rise to the defect creation due to the ion bombardment on the growing surface. The positive substrate bias improves the quality of undoped a-Si:H.

The Study of Microcrystalline Silicon Thin Films Prepared by PECVD

2013 ◽  
Vol 537 ◽  
pp. 197-200
Author(s):  
Chun Ya Li ◽  
Hao Zhang ◽  
Jun Li ◽  
Xi Feng Li ◽  
Jian Hua Zhang
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Process Parameters ◽  
Volume Fraction ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Crystalline Volume Fraction ◽  
Microcrystalline Silicon ◽  
Reaction Pressure ◽  
Silicon Thin Films

Under different growth conditions, microcrystalline silicon thin films are deposited successfully on glass substrates by the double-frequency plasma enhanced chemical vapor deposition (PECVD). We report the systematic investigation of the effect of process parameters (hydrogen dilution, substrate temperature, forward power, reaction pressure, et al.) on the growth characteristics of microcrystalline silicon thin films. Raman scattering spectra are used to analyze the crystalline condition of the films and the experimental results. Optimizing the process parameters, the highest crystalline volume fraction of microcrystalline silicon films was achieved. It is found that the crystalline volume fraction of microcrystalline silicon films reaches 72.2% at the reaction pressure of 450 Pa, H2/SiH4 flow ratio of 800sccm/10sccm, power of 400 W and substrate temperature of 350 °C.

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