Browsing by Author "Liu, Cheng-Chin"

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Advanced gate-all-around fin-like poly-Si TFTs with multiple nanowire channels
(2008)
Tu, Shih-Wei
;
Liao, Ta-Chuan
;
Lin, Wei-Kai
;
Liu, Cheng-Chin
;
Tai, Ya-Hsiang
The gate-all-around (GAA) fin-like poly-Si TFTs (FinTFTs) with multiple nanowire channels (MNCs) have been fabricated using a simple process to demonstrate high performance electrical characteristics. The fin-like nanowire (NW) channel with high body thickness-to-width ratio (T-Fin/W-Fin), approximately equals to one, was realized only with a sidewall-spacer formation. The unique suspending MNCs were also achieved to build the GAA structure. By the way, the GAA-MNC Fin TFTs showed outstanding three-dimensional gate controllability and excellent electrical characteristics, which revealed a high ON/OFF current ratio (>10(8)), a low threshold voltage, a steep subthreshold swing, a near-free drain-induced barrier lowering and a good reliability. Therefore, such the high-performance GAA-MNC FinTFTs are vet-v suitable for the applications in the system-on-panel (SOP) and three-dimensional (3D) circuits.
High-performance poly(3-hexylthiophene) transistors with thermally cured and photo-cured PVP gate dielectrics
(2008)
Yang, Feng-Yu
;
Chang, Kuo-Jui
;
Hsu, Meei-Yu
;
Liu, Cheng-Chin
;
電子工程學系及電子研究所
We have fabricated poly(3-hexylthiophene) organic field-effect transistors (P3HT-OFETs) with either high-temperature (200 degrees C) thermally cured PVP gate dielectrics or low-temperature (120 degrees C) photo-cured PVP gate dielectrics. We prepared the thermally cured PVP dielectric layer from a blend of poly(4-vinylphenol) (PVP) and poly(melamine-co-formaldehyde) (PMF); the photo-cured PVP dielectric formulation contained an additional photo-acid generator (PAG), which allowed the temperature for the cross-linking reaction to be reduced. We examined the intrinsic dielectric properties (e.g., the dielectric constant, the electrical insulating properties) and surface properties (e.g., morphology, surface energy) of the formulations loaded with various amounts of PAG (from 0 to 2.4 wt%). The P3HT-OFETs with the thermally cured PVP gate dielectrics exhibited an excellent carrier mobility of ca. 0.1 cm(2) V(-1) s(-1), a sub-threshold swing of 2.0 V decade(-1), and an on/off ratio of 1.2 x 10(4). For comparison, the P3HT-OFET devices with the photo-cured PVP gate dielectrics also exhibited good electrical characteristics, including carrier mobilities as high as 0.06 cm(2) V(-1) s(-1), sub-threshold swings as low as 1.4 V decade(-1), and on/off ratios as large as 3.0 x 10(4). To take advantage of the photo-cured PVP films, we also fabricated OFETs on a flexible, cheap ITO/PET substrate.
Low-operating-voltage polymeric transistor with solution-processed low-k polymer/high-k metal-oxide bilayer insulators
(2008-10-01)
Yang, Feng-Yu
;
Chang, Kuo-Jui
;
Hsu, Meei-Yu
;
Liu, Cheng-Chin
;
電子工程學系及電子研究所
We have successfully demonstrated a polymeric semiconductor-based transistor with low-k polymer/high-k metal-oxide (TiO2) bilayer as gate dielectric. The TiO2 layers are readily processable from solution and cured at low temperature, instead of traditionally sputtering or high temperature sintering process, thus may suitable for a low-cost organic field effect transistors (FETs) manufacture. The low-k polymer capped on TiO2 layer could further smooth the TiO2 dielectric surface and suppress the leakage current from grain boundary of TiO2 films. The resulting unpatented P3HT-OFETs could operate with supply voltage less than 10 V and the mobility and threshold voltage were 0.0140 cm(2)/V s and 1.14 V, respectively. The on/off ratio was 1.0 x 10(3). (C) 2008 Elsevier B.V. All rights reserved.
Novel gate-all-around poly-Si TFTs with multiple nanowire channels
(2008-08-01)
Liao, Ta-Chuan
;
Tu, Shih-Wei
;
Yu, Ming H.
;
Lin, Wei-Kai
;
Liu, Cheng-Chin
The novel gate-all-around (GAA) poly-Si thin-film transistors (TFTs) with multiple nanowire channels (MNCs) have been, for the first time, fabricated using a simple process to demonstrate high-performance electrical characteristics and high immunity to short-channel effects (SCEs). The nanowire channel with high body-thickness-to-width ratio (T(Fin)/W(Fin)), which is approximately equal to one, was realized only with a sidewall-spacer formation. Moreover, the unique suspending MNCs were also achieved to build the GAA structure. The resultant GAA-MNC TFTs showed outstanding three-dimensional (3-D) gate controllability and excellent electrical characteristics, which revealed a high on/off current ratio (> 10(8)), a low threshold voltage, a steep subthreshold swing, a near-free drain-induced barrier lowering, as well as an excellent SCE suppression. Therefore, such high-performance GAA-MNC TFTs are very suitable for applications in system-on-panel and 3-D circuits.
Self-patterning of high-performance thin film transistors
(2009-08-01)
Chang, Kuo-Jui
;
Yang, Feng-Yu
;
Liu, Cheng-Chin
;
Hsu, Meei-Yu
;
Liao, Ta-Chuan
We have developed a technique for the preparation of thin film transistors (TFTs) through the self-patterning of various organic and inorganic materials via solution processing using a wide range of solvents. To obtain selectively self-patterned layers, we treated the oxide dielectric with two-phase patterned self-assembled monolayers of hexamethyldisilazane (HMDS) and octyltrichlorosilane. The conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid) in water and the dielectric polymer poly(vinyl phenol) in propylene glycol methyl ether acetate were both selectively deposited and patterned on the HMDS regions with high-quality feature shapes. When source and drain electrodes were patterned on the bottom-gate oxide wafer, we also self-patterned organic and inorganic semiconductors around the channel (HMDS) regions. These TFT devices exhibited moderate to good electronic characteristics. This method has great potential for the economical full solution processing of large-area electronic devices. The selectivity in the patterning phenomena can be understood in terms of surface energy interactions. (C) 2009 Elsevier B.V. All rights reserved.