Contact Effects in High Mobility Microcrystalline Silicon Thin-Film Transistors

2007 ◽  
Vol 989 ◽  
Author(s):  
Kah Yoong Chan ◽  
Eerke Bunte ◽  
Helmut Stiebig ◽  
Dietmar Knipp
Keyword(s):  
Thin Film ◽  
Threshold Voltage ◽  
Thin Film Transistors ◽  
High Mobility ◽  
Chemical Vapor ◽  
Channel Length ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film ◽  
Short Channel ◽  
Long Channel

AbstractMicrocrystalline silicon (mc-Si:H) has recently been proven to be a promising material for thin-film transistors (TFTs). We present mc-Si:H TFTs fabricated by plasma-enhanced chemical vapor deposition at temperatures below 200°C in a condition similar to the fabrication of amorphous silicon TFTs. The mc-Si:H TFTs exhibit device mobilities exceeding 30 cm2/Vs and threshold voltages in the range of 2.5V. Such high mobilities are observed for long channel devices (50-200 mm). For short channel device (2 mm), the mobility reduces to 7 cm2/Vs. Furthermore the threshold voltage of the TFTs decreases with decreasing channel length. A simple model is developed, which explains the observed reduction of the device mobility and threshold voltage with decreasing channel length by the influence of drain and source contacts.

Analysis of threshold voltage of short channel polycrystalline silicon thin-film transistors fabricated on large grains

2006 ◽  
Vol 100 (11) ◽  
pp. 114507 ◽  
Author(s):  
Genshiro Kawachi ◽  
Shinzo Tsuboi ◽  
Takashi Okada ◽  
Masahiro Mitani ◽  
Masakiyo Matsumura
Keyword(s):  
Thin Film ◽  
Threshold Voltage ◽  
Thin Film Transistors ◽  
Polycrystalline Silicon ◽  
Silicon Thin Film ◽  
Short Channel

High-mobility microcrystalline silicon thin-film transistors prepared near the transition to amorphous growth

2008 ◽  
Vol 104 (5) ◽  
pp. 054506 ◽  
Author(s):  
Kah-Yoong Chan ◽  
Dietmar Knipp ◽  
Aad Gordijn ◽  
Helmut Stiebig
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
High Mobility ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film

Role of field enhanced mechanisms and impact ionization on the threshold voltage of short channel polycrystalline silicon thin film transistors

2008 ◽  
Vol 93 (19) ◽  
pp. 193512 ◽  
Author(s):  
P. Gaucci ◽  
A. Valletta ◽  
L. Mariucci ◽  
A. Pecora ◽  
M. Cuscunà ◽  
...  
Keyword(s):  
Thin Film ◽  
Threshold Voltage ◽  
Thin Film Transistors ◽  
Polycrystalline Silicon ◽  
Impact Ionization ◽  
Silicon Thin Film ◽  
Short Channel

Exploration of Amorphous Silicon Thin Film Transistor Degradation with Thermal Anneal

1993 ◽  
Vol 297 ◽  
Author(s):  
R.F. Kwasnick ◽  
G.E. Possin ◽  
W.L. Hill II
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Substrate Surface ◽  
Thin Film Transistor ◽  
Transfer Characteristic ◽  
Channel Length ◽  
Silicon Thin Film ◽  
Short Channel ◽  
Effective Mobility ◽  
Long Channel

We have measured the device characterisics of short and long channel inverted- staggered hydrogenated amorphous silicon thin film transistors (TFTs) with either Mo or Cr source/drain metal after annealing at temperatures from 225 C to 275 C. The TFT deposition temperature at the substrate surface was about 270 C. From the slope of the transfer characteristic an effective mobility is extracted. Devices with Mo source/drain metal exhibit an initial effective mobility increase at short times (within about 30 min), while those with Cr do not. At long times the mobility of all devices decreases. The mobility changes are greatest for short channel length devices because of contact effects. The channel length dependence of the behavior permits a separation of the device behavior into contact and intrinsic mobility components.

Effect of Dynamic Bias Stress (AC) In Short-Channel (L=1.5μm) p-Type polycrystalline Silicon (poly-Si) Thin Film Transistors (TFTs) on the glass substrate

2011 ◽  
Vol 1321 ◽  
Author(s):  
Sung-Hwan Choi ◽  
Yeon-Gon Mo ◽  
Min-Koo Han
Keyword(s):  
Thin Film ◽  
Threshold Voltage ◽  
Glass Substrate ◽  
Thin Film Transistors ◽  
Polycrystalline Silicon ◽  
Short Channel ◽  
Bias Stress ◽  
P Type ◽  
Long Channel ◽  
Si Thin Film

ABSTRACTWe have investigated the stability of short channel (1.5μm) p-Type polycrystalline silicon (poly-Si) Thin Film Transistors (TFTs) on the glass substrate under AC bias stress. The variation of threshold voltage in short channel poly-Si TFT was considerably higher than that of long channel poly-Si TFT. Threshold voltage of the short channel TFT was considerably moved to the positive direction during AC bias stress, whereas the threshold voltage of a long channel was rarely moved. The variation of threshold voltage in the short channel p-type TFT under AC bias stess was more compared to that under DC bias stress. The threshold voltage of short channel (L=1.5μm) poly-Si TFT was increased about -7.44V from -0.305V to -7.745V when VGS = 5 (base value) ~ -15V (peak value), VDS = -15V was applied for 3,000 seconds. This positive shift of threshold voltage and significantly degraded s-swing value in the short channel TFT under dynamic stress (AC) may be due to the increase of the stress-induced trap state density at gate insulator / channel interface region.

Properties of Amorphous Silicon Thin Film Transistors with Phosphorous-Doped Hydrogenated Microcrystalline Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
J. H. Choi ◽  
C. W. Kim ◽  
H. G. Yang ◽  
J. H. Souk
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Thin Film Transistors ◽  
Field Effect ◽  
Chemical Vapor ◽  
Field Effect Mobility ◽  
Rf Power ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film ◽  
Threshold Voltages

AbstractPhosphorous (P) doped hydrogenated microcrystallme silicon (n+μ c-Si:H) films have been prepared by using the hydrogen-diluted plasma enhanced chemical vapor deposition (PECVD) method. The crystallinity of films deposited over the range of SiH4/H2 flow ratios and RF-power is studied by Raman spectroscopy. For a 900 Å thick film deposited at 250°C, a conductivity of 71Ω−1cm−1 and an average crystallinity of 49% is obtained. n+ μ c-Si:H films as well as n+ a-Si:H films are used for both etch stopper and back channel etch type TFTs and the I4-V8 characteristics are compared. For the etch stopper type TFT, the field effect mobility of 0.85 cm2/V.sec, threshold voltages of 2 – 3 V and Ion/Ioff ratio of ∼107 are obtained.

Thin-film inverters based on high mobility microcrystalline silicon thin-film transistors

2008 ◽  
Vol 52 (6) ◽  
pp. 914-918 ◽  
Author(s):  
Kah-Yoong Chan ◽  
Eerke Bunte ◽  
Dietmar Knipp ◽  
Helmut Stiebig
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
High Mobility ◽  
Microcrystalline Silicon ◽  
Silicon Thin Film
Sign in / Sign up

Export Citation Format

Share Document