| Title |
The Fabrication and Electrical Characteristics of Pentacene TFT using Polyimide and Polyacryl as a Gate Dielectric Layer |
| Authors |
김윤명(Kim, Yun-Myoung) ; 김옥병(Kim, Ok-Byoung) ; 김영관(Kim, Young-Kwan) ; 김정수(Kim, Jung-Soo) |
| Keywords |
Organic Thin Film Transistor ; Pentacene ; Gate Insulator ; Field Effect Mobility ; On/Off Current Ratio ; Output Characteristics ; Transfer Characteristics |
| Abstract |
Organic thin film transitors(TFTs) are of interest for use in broad area electronic applications. For example, in active matrix liquid crystal displays(AMLCDs), organic TFTs would allow the use of inexpensive, light-weight, flexible, and mechanically rugged plastic substrates as an alternative to the glass substrates needed for commonly used hydrogenated amorphous silicon(a-Si:H). Recently pentacene TFTs with carrier field effect, mobility as large as 2 cm^2V^{-1}s^{-1} have been reported for TFTs fabricated on silicon substrates, and it is higher than that of a-Si:H. But these TFTs are fabricated on silicon wafer and SiO_2 was used as a gate insulator. SiO_2 deposition process requires a high insulator which is polyimide and photo acryl. We investigated trasfer and output characteristics of the thin film transistors having active layer of pentacene. We calculated field effect mobility and on/off ratio from transfer characteristics of pentacene thin film transistor, and measured IR absorption spectrum of polymide used as the gate dielectric layer. It was found that using the photo acryl as a gate insulator, threshold voltage decreased from -12.5 V to -7 V, field effect mobility increased from 0.012 cm^2V^{-1}s^{-1} to 0.039 cm^2V^{-1}s^{-1} , and on/off current ratio increased from 10^5 to 10^6. It seems that TFTs using photo acryl gate insulator is apt to form channel than TFTs using polyimide gate insulator. |