Leakage current mechanisms in top-gate nanocrystalline silicon thin film transistors

2008 ◽  
Vol 92 (8) ◽  
pp. 083509 ◽  
Author(s):  
Hyun Jung Lee ◽  
Andrei Sazonov ◽  
Arokia Nathan
Keyword(s):  
Thin Film ◽  
Leakage Current ◽  
Thin Film Transistors ◽  
Nanocrystalline Silicon ◽  
Silicon Thin Film

Hydrogen in Ultralow Temperature SiO2for Nanocrystalline Silicon Thin Film Transistors

2004 ◽  
Vol 814 ◽  
Author(s):  
Alex Kattamis ◽  
I-Chun Cheng ◽  
Steve Allen ◽  
Sigurd Wagner
Keyword(s):  
Thin Film ◽  
Leakage Current ◽  
Current Density ◽  
Thin Film Transistors ◽  
Secondary Ion Mass Spectrometry ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Film Deposition ◽  
Silicon Thin Film

AbstractNanocrystalline silicon is a candidate material for fabricating thin film transistors with high carrier mobilities on plastic substrates. A major issue in the processing of nanocrystalline silicon thin film transistors (nc-Si:H TFTs) at ultralow temperatures is the quality of the SiO2gate dielectric. SiO2deposited at less than 250°C by radio frequency plasma enhanced chemical vapor deposition (rf-PECVD), and not annealed at high temperature after deposition, exhibits high leakage current and voltage shifts when incorporated into TFT's. Secondary ion mass spectrometry (SIMS) measurements show that the hydrogen concentration (NH) in PECVD oxide deposited at 150°C on crystalline silicon (x-Si) is ∼ 0.8 at. %. This is much higher than in thermal oxides on x-Si, which display concentrations of less than 0.003 at. %. The leakage current density for thermal oxides on x-Si at a bias of 10 V is ∼9×10−6A/cm2whereas for 200°C PECVD oxides on nc-Si:H the current is ∼1×10−4A/cm2. As the temperature of the SiO2deposition is reduced to 150°C the current density rises by up to two orders of magnitude more. The H which is suspected to cause the leakage current across the PECVD oxide originates from the nc-Si:H substrate and the SiH4source gas. We analyzed the 300-nm gate oxide in capacitor structures of Al / SiO2/n+nc-Si:H / Cr / glass, Al / SiO2/ n+nc-Si:H / x-Si, and Al / SiO2/ x-Si. Vacuum annealing the nc-Si:H prior to PECVD of the oxide drives H out of the nc-Si:H film and reduces the amount of H incorporated into the oxide that is deposited on top. SiO2film deposition from SiH4and N2O at high He dilution has a still greater effect on lowering NH. The leakage current at a 10 V bias dropped from ∼1×10−4A/cm2to about ∼2×10−6A/cm2using He dilution at 250°C, and the vacuum anneal of the nc-Si:H lowered it by an additional factor of two. Thus we observe that both the nc-Si:H anneal and the SiO2deposition at high He dilution lessen the gate leakage current.

Study of the Drain Leakage Current in Bottom-Gated Nanocrystalline Silicon Thin-Film Transistors by Conduction and Low-Frequency Noise Measurements

2007 ◽  
Vol 54 (5) ◽  
pp. 1076-1082 ◽  
Author(s):  
Argyrios T. Hatzopoulos ◽  
Nikolaos Arpatzanis ◽  
Dimitrios H. Tassis ◽  
Charalabos A. Dimitriadis ◽  
Maher Oudwan ◽  
...  
Keyword(s):  
Thin Film ◽  
Leakage Current ◽  
Thin Film Transistors ◽  
Low Frequency ◽  
Nanocrystalline Silicon ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Silicon Thin Film ◽  
Noise Measurements

scholarly journals Electromechanical Stability of Flexible Nanocrystalline-Silicon Thin-Film Transistors

2010 ◽  
Vol 31 (3) ◽  
pp. 222-224 ◽  
Author(s):  
I-Chung Chiu ◽  
Jung-Jie Huang ◽  
Yung-Pei Chen ◽  
I-Chun Cheng ◽  
J.Z. Chen ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Nanocrystalline Silicon ◽  
Silicon Thin Film
Sign in / Sign up

Export Citation Format

Share Document