Carrier transport in amorphous silicon-based thin-film transistors studied by spin-dependent transport

1996 ◽  
Vol 54 (11) ◽  
pp. 7957-7964 ◽  
Author(s):  
Genshiro Kawachi ◽  
Carlos F. O. Graeff ◽  
Martin S. Brandt ◽  
Martin Stutzmann
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Carrier Transport ◽  
Spin Dependent Transport ◽  
Dependent Transport ◽  
Silicon Based

Spin-dependent transport in amorphous silicon thin-film transistors

1996 ◽  
Vol 198-200 ◽  
pp. 1117-1120 ◽  
Author(s):  
C.F.O. Graeff ◽  
G. Kawachi ◽  
M.S. Brandt ◽  
M. Stutzmann ◽  
M.J. Powell
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Silicon Thin Film ◽  
Spin Dependent Transport ◽  
Dependent Transport

Spin-Dependent Transport in Si Thin-Film Transistors

1997 ◽  
Vol 467 ◽  
Author(s):  
G. Kawachi ◽  
C F. O. Graeff ◽  
M. S. Brandt ◽  
M. Stutzmann
Keyword(s):  
Thin Film ◽  
Silicon Nitride ◽  
Thin Film Transistors ◽  
Carrier Transport ◽  
Gate Dielectric ◽  
Signal To Noise Ratio ◽  
Nitride Layer ◽  
Transport Processes ◽  
Spin Dependent Transport ◽  
Dependent Transport

ABSTRACTDefects and carrier transport processes in silicon based thin-film transistors (TFTs) are investigated by spin-dependent transport (SDT). The resonance signal arising from less than 106 defects in the hydrogenated amorphous silicon (a-Si:H) TFT is detected with a sufficient signal-to-noise ratio. The leakage current mechanism in a-Si:H under high source-drain fields is identified by SDT as electron hopping via defect states located at the interface between undoped a-Si:H and the passivation silicon nitride layer. At temperatures below 100K, spin-dependent hopping of electrons in conduction band tail states is observed. The change of the dominant transport path from extended states conduction to variable range hopping with decreasing temperature is confirmed. SDT measurements on polycrystalline silicon (poly-Si) TFTs having silicon nitride and silicon dioxide as the gate dielectric films reveal differences in the defect structure in these devices. The overall results demonstrate that SDT is a powerful method to probe paramagnetic defects and carrier transport in TFTs.

Carrier Transport in Polycrystalline and Amorphous Silicon Thin Film Transistors

1994 ◽  
Vol 358 ◽  
Author(s):  
T. Sameshima ◽  
M. Sekiya ◽  
M. Hara ◽  
N. Sano ◽  
A. Kohno
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Carrier Transport ◽  
Defect Density ◽  
Inversion Layer ◽  
Chemical Vapor ◽  
Laser Crystallization ◽  
Silicon Thin Film ◽  
Plasma Chemical Vapor Deposition

ABSTRACTThe technologies of laser crystallization and methods of SiO2 formation in remote plasma chemical vapor deposition or SiO evaporation with an oxygen ambient realize the fabrication of n-channel polycrystalline and amorphous silicon thin film transistors (poly-Si and a-Si TFTs) at a temperature lower than 300 °C. The defect density was achieved to be 2∼3×1011 cm−2eV−1 and threshold voltage was about IV for both TFTs. The maximum field effect mobility was 600 cm2/Vs for poly-Si TFTs and 2.6 cm2/Vs for a-Si TFTs. The mobility of poly-Si TFT decreased as the gate voltage increases. This is interpreted as that the electrons are confined in the narrow inversion layer and electron scattering with phonon is enhanced for higher normal electric field.

An Amorphous Silicon Thin Film Transistor Fabricated at 125°C by dc Reactive Magnetron Sputtering

1996 ◽  
Vol 424 ◽  
Author(s):  
C. S. McCormick ◽  
C. E. Webe ◽  
J. R. Abelson
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Thin Film Transistor ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
Silicon Thin Film ◽  
Dc Reactive Magnetron Sputtering ◽  
Silicon Based

AbstractWe deposit hydrogenated amorphous silicon-based thin film transistors using dc reactive magnetron sputtering at a substrate temperature of 125°C, which is low enough to allow the use of plastic substrates. We characterize the structural properties of the a-Si:H channel and a-SiNx:H dielectric layers using infra-red absorption, thermal hydrogen evolution, and refractive index measurements, and evaluate the electrical quality using capacitance-voltage and leakage current measurements. Inverted staggered thin film transistors made with these layers exhibit a field effect mobility of 0.3 cm2/V-s, a Ion/Ioff ratio of 5 × 105, a sub-threshold slope of 0.8 V/decade, and a threshold voltage of 3 V.

Defects in Si Thin-Film Transistors Studied by Spin-Dependent Transport

1996 ◽  
Author(s):  
Genshiro KAWACHI ◽  
Carlos F. O. GRAEFF ◽  
Martin S. BRANDT ◽  
Martin STUTZMANN
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Spin Dependent Transport ◽  
Dependent Transport ◽  
Si Thin Film

The Instability Characteristics of Amorphous Silicon Thin Film Transistors with Various Interfacial and Bulk Defect States

1997 ◽  
Vol 36 (Part 1, No. 10) ◽  
pp. 6226-6229 ◽  
Author(s):  
Huang-Chung Cheng ◽  
Jun-Wei Tsai ◽  
Chun-Yao Huang ◽  
Fang-Chen Luo ◽  
Hsing-Chien Tuan
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Defect States ◽  
Silicon Thin Film

Hot-Wire Deposited Amorphous Silicon Thin-Film Transistors

1996 ◽  
Vol 424 ◽  
Author(s):  
R. E. I. Schropp ◽  
K. F. Feenstra ◽  
C. H. M. Van Der Werf ◽  
J. Holleman ◽  
H. Meiling
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Current Crowding ◽  
Hot Wire ◽  
Saturation Regime ◽  
Silicon Thin Film ◽  
Order Of Magnitude

AbstractWe present the first thin film transistors (TFTs) incorporating a low hydrogen content (5 - 9 at.-%) amorphous silicon (a-Si:H) layer deposited by the Hot-Wire Chemical Vapor Deposition (HWCVD) technique. This demonstrates the possibility of utilizing this material in devices. The deposition rate by Hot-Wire CVD is an order of magnitude higher than by Plasma Enhanced CVD. The switching ratio for TFTs based on HWCVD a-Si:H is better than 5 orders of magnitude. The field-effect mobility as determined from the saturation regime of the transfer characteristics is still quite poor. The interface with the gate dielectric needs further optimization. Current crowding effects, however, could be completely eliminated by a H2 plasma treatment of the HW-deposited intrinsic layer. In contrast to the PECVD reference device, the HWCVD device appears to be almost unsensitive to bias voltage stressing. This shows that HW-deposited material might be an approach to much more stable devices.

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