• Title/Summary/Keyword: Gate insulators

Search Result 61, Processing Time 0.025 seconds

ELECTRICAL CHARACTERISTICS OF PENTACENE THIN FILM TRANSISTORS WITH STACKED AND SURFACE-TREATED GATE INSULATORS (러빙 처리된 표면의 적층 절연막을 가지는 Pentacene TFT의 전기적 특성)

  • Kang, Chang-Heon;Lee, Jong-Hyuk;Park, Jae-Hoon;Choi, Jong-Sun
    • Proceedings of the KIEE Conference
    • /
    • 2002.07c
    • /
    • pp.1546-1548
    • /
    • 2002
  • In this paper, the electrical characteristics of pentacene thin film transistors(TFTs) with stacked and surface-treated gate insulators have been investigated. The semiconductor layer of pentacene was thermally evaporated onto the stacked gate insulators. For the gate insulating materials. PVP(PolyvinylPhenol) and polystyrene were spin-coated with two different stacking orders, PVP-polystyrene and polystyrene-PVP. Rapid solvent evaporation during the spin-coating processes of these insulating layers produces non-equilibrium phase morphologies accompanied by surface undulations on gate insulator interfaces. This non-equilibrium phase morphology affects the growth mode of the subsequent pentacene layer. Therefore, in order to smoothen the gate dielectric surfaces, gate dielectric surfaces were rubbed laterally along the direction from the drain to the source TFTs with with stacked and surface-treated gate insulators have provided improved operational characteristics.

  • PDF

Characteristics of Pentacene Thin Film Transistors with Stacked Organic Dielectrics for Gate Insulator

  • Kang, Chang-Heon;Lee, Jong-Hyuk;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.184-187
    • /
    • 2002
  • In this work, the electrical characteristics of organic thin film transistors with the stacked organic gate insulators have been studied. PVP(Polyvinylphenol) and polystyrene were used as gate insulating materials. Both the high dielectric constant of PVP and better insulating capability of polystyrene were compensatorily adopted in two different stacking orders of PVP-polystyrene and polystyrene-PVP. The output characteristics of the device with the stacked gate insulator showed substantial improvement compared with those of the devices with either PVP or polystyrene gate insulator: Furthermore, these stacked organic gate insulators can differently affect the TFT characteristics with the stacking orders. The electrical properties of TFTs with organic gate insulators stacked in different orders are discussed.

  • PDF

Pentacene Thin Film Transistors with Various Polymer Gate Insulators

  • Kim, Jae-Kyoung;Kim, Jung-Min;Yoon, Tae-Sik;Lee, Hyun-Ho;Jeon, D.;Kim, Yong-Sang
    • Journal of Electrical Engineering and Technology
    • /
    • v.4 no.1
    • /
    • pp.118-122
    • /
    • 2009
  • Organic thin film transistors with a pentacene active layer and various polymer gate insulators were fabricated and their performances were investigated. Characteristics of pentacene thin film transistors on different polymer substrates were investigated using an atomic force microscope (AFM) and x-ray diffraction (XRD). The pentacene thin films were deposited by thermal evaporation on the gate insulators of various polymers. Hexamethyldisilazane (HMDS), polyvinyl acetate (PVA) and polymethyl methacrylate (PMMA) were fabricated as the gate insulator where a pentacene layer was deposited at 40, 55, 70, 85, 100 oC. Pentacene thin films on PMMA showed the largest grain size and least trap concentration. In addition, pentacene TFTs of top-contact geometry are compared with PMMA and $SiO_2$ as gate insulators, respectively. We also fabricated pentacene TFT with Poly (3, 4-ethylenedioxythiophene)-Polysturene Sulfonate (PEDOT:PSS) electrode by inkjet printing method. The physical and electrical characteristics of each gate insulator were tested and analyzed by AFM and I-V measurement. It was found that the performance of TFT was mainly determined by morphology of pentacene rather than the physical or chemical structure of the polymer gate insulator

Effects of Gate Insulators on the Operation of ZnO-SnO2 Thin Film Transistors (ZnO-SnO2 투명박막트랜지스터의 동작에 미치는 게이트 절연층의 영향)

  • Cheon, Young Deok;Park, Ki Cheol;Ma, Tae Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.26 no.3
    • /
    • pp.177-182
    • /
    • 2013
  • Transparent thin film transistors (TTFT) were fabricated on $N^+$ Si wafers. $SiO_2$, $Si_3N_4/SiO_2$ and $Al_2O_3/SiO_2$ grown on the wafers were used as gate insulators. The rf magnetron sputtered zinc tin oxide (ZTO) films were adopted as active layers. $N^+$ Si wafers were wet-oxidized to grow $SiO_2$. $Si_3N_4$ and $Al_2O_3$ films were deposited on the $SiO_2$ by plasma enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD), respectively. The mobility, $I_{on}/I_{off}$ and subthreshold swing (SS) were obtained from the transfer characteristics of TTFTs. The properties of gate insulators were analyzed by comparing the characteristics of TTFTs. The property variation of the ZTO TTFTs with time were observed.

Study on the Organic Gate Insulators Using VDP Method (VDP(Vapor Deposition Polymerization) 방법을 이용한 유기 게이트 절연막의 대한 연구)

  • Pyo, Sang-Woo;Shim, Jae-Hoon;Kim, Jung-Soo;Kim, Young-Kwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07a
    • /
    • pp.185-190
    • /
    • 2003
  • In this paper, it was demonstrated that the organic thin film transistors were fabricated by the organic gate insulators with vapor deposition polymerization (VDP) processing. In order to form polyimide as a gate insulator, vapor deposition polymerization process was also introduced instead of spin-coating process, where polyimide film was co-deposited by high-vacuum thermal evaporation from 4,4'-oxydiphthalic anhydride (ODPA) and 4,4'-oxydianiline (ODA) and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and ODA, and cured at $150^{\circ}C$ for 1hr. Electrical output characteristics in our organic thin film transistors using the staggered-inverted top-contact structure obtained to the saturated slop in the saturation region and the subthreshold non-linearity in the triode region. Field effect mobility, threshold voltage, and on-off current ratio in $0.45\;{\mu}m$ thick gate dielectric layer were about $0.17\;cm^2/Vs$, -7 V, and $10^6\;A/A$, respectively. Details on the explanation of compared to organic thin-film transistors (OTFTS) electrical characteristics of ODPA-ODA and 6FDA-ODA as gate insulators by fabricated thermal co-deposition method.

  • PDF

Study on Characteristics of Organic Thin Film Transistors with Rubbed Organic Gate Insulators

  • Lee, Jong-Hyuk;Kang, Chang-Heon;Choi, Jong-Sun;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.717-720
    • /
    • 2002
  • In this work, the electrical characteristics of organic thin film transistors with the surface-treated organic gate insulators have been studied. For the surface treatment, the simple rubbing technique was used. The field effect mobilities of the devices with PVP gate insulator was improved about four times as high as those of TFTs without the insulator surface treatment.

  • PDF

Properties of Poly-Si TFT's using Oxide-Nitride-Oxide Films as Gate Insulators (Oxide-Nitride-Oxide막을 게이트 절연막으로 사용하여 제조한 다결정실리콘 박막트랜지스티의 특성)

  • 이인찬;마대영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.12
    • /
    • pp.1065-1070
    • /
    • 2003
  • HTO(High Temperature Oxide) films are mainly used as a gate insulator for polysilicon thin film transistors(Poly-Si TFT's). The HTO films, however, show the demerits of a high leakage current and a low electric breakdown voltage comparing with conventional thermal oxides even though they have a better surface in roughness than the thermal oxides. In this paper, we propose an ONO(Oxide-Nitride-Oxide) multilayer as the gate insulator for poly-Si TFT's. The leakage current and electric breakdown voltage of the ONO and HTO were measured. The drain current variation of poly-Si TFT's with a variety of gate insulators was observed. The thickness optimization in ONO films was carried out by studying I$\_$on/I$\_$off/ ratio of the poly-Si TFT's as a function of the thickness of ONO film adopted as gate insulator.

Electrical Characteristics of Organic TFTs Using ODPA-ODA and 6FDA-ODA Polyimide Gate Insulators

  • Lee, Min-Woo;Pyo, Sang-Woo;Jung, Lae-Young;Shim, Jae-Hoon;Sohn, Byoung-Chung;Kim, Young-Kwan
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.770-772
    • /
    • 2002
  • A new dry-processing method of organic gate dielectric film in field-effect transistors (FETs) was proposed. The method use vapor deposition polymerization (VDP) that is continuous and low temperature process. It has the advantages of shadow mask patterning and dry processing in flexible low-cost large area applications. Here, 80 nm-thick Al as a gate electrode was evaporated through shadow mask. Gate insulators used two different polyimides. The one material was 4,4'-oxydiphtahlic anhydride (ODPA) and 4,4'-oxydianiline (ODA). Another was 2,2-bis(3,4-dicarboxyphenyl) Hexafluoropropane Dianhydride (6FDA) and 4,4' -oxydianiline (ODA). These were co-deposited by high-vaccum thermal-evapora and cured at 150 $^{\circ}C$ for 1 hour, respectively. Pentacene as a semiconductor and 100 nm-thick Au as a source and drain electrode were evaporated through shadow mask.

  • PDF

Reliability of MOS Capacitors and MOSFET's with Oxide and Reoxidized-Nitrided-Oxide as Gate Insulators (산화막 및 재산화질화산화막의 MOS 캐패시터와 MOSFET의 신뢰성)

  • 노태문;이경수;유병곤;남기수
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.30A no.11
    • /
    • pp.105-112
    • /
    • 1993
  • Oxide and reoxidized-nitrided-oxide were formed by furnace oxidation and rapid thermal processing (RTP). MOS capacitor and n-MOSFET's with those films as gate insulators were fabricated. The electrical characteristics of insulators were evaluated by current-voltage, high-frequency capacitance-voltage (C-V), and time-dependent dielectrical breakdown (TDDB) measurements. The hot carrier effects of MOSFET's were also investigated. Time-dependent dielectrical breakdown (TDDB) characteristics show that the life time of reoxidized-nitrided-oxide films is about 3 times longer than that of oxides. Hot carrier effects reveal that the life time of MOSFET's with reoxidized-nitrided-oxides is about 3 times longer than that of MOSFET's with oxides. Therefore, it is found that the reliability of dielectric films estimated by the hot carrier effects of MOSFET's is consistent with that of dielectric films from TDDB method.

  • PDF

Electrical Characteristics of Pentacene-based TFTs with Stacked Gate Dielectrics

  • Kang, Chang-Heon;Park, Jae-Hoon;Lee, Yong-Soo;Kim, Yeon-Ju;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2003.07a
    • /
    • pp.653-655
    • /
    • 2003
  • Using stacked organic gate insulators and active layer of pentacene deposited at elevated temperatures, pentacene-based organic thin-film transistors(OTFTs) with improved electrical characteristics have been fabricated. Stacked PVP(Polyvinylphenol)-polystyrene gate insulators could compensate the demerits and take advantage of the merits of each other [1]. Also, for the better device performance, moderate substrate heating and high deposition rate of pentacene active layer was adopted [2, 3].

  • PDF