| Title |
The Study of Fluoride Film Properties for Thin Film Transistor Gate Insulator Application |
| Authors |
김도영(Kim, Do-Yeong) ; 최석원(Choe, Seok-Won) ; 안병재(An, Byeong-Jae) ; 이준신(Lee, Jun-Sin) |
| Keywords |
박막트랜지스터 ; 게이트 절연막 ; 불화막 ; 계면포획전하 ; MIS 소자 ; |
| Abstract |
Various fluoride films were investigated for a gate insulator of thin film transistor application. Conventional oxide containing materials like SiO_2 Ta_2O_5 and Al_2O_3 exhibited high interface states which lead to an increased threshold voltage and poor stability of TFT. In this paper, we investigated gate insulators using a binary matrix system of fluoride such as CaF_2, SrF_2 MgF_2, and BaF_2. These materials exhibited an improvement in lattice mismatch, interface state and electrical stability. MIM and MIS devices were employed for an electrical characterization and structural property examination. Among the various fluoride materials, CaF_2 film showed an excellent lattice mismatch of 5%, breakdown electric field higher than 1.2MV/cm and leakage current density of 10^{-7}A/cm^2. MIS diode having Ca_2 film as an insulation layer exhibited the interface states as low as 1.58×10^{11}cm^{-2}eV^{-1}. This paper probes a possibility of new gate insulator materials for TFT applications. |