Research On OTFT By Simulation

Thin film transistor is different from the traditional MOS transistor, it charges through the accumulation of carriers. Because the thin film transistor can be made easily, it becomes popular with all the world when it comes to the world. And the organic thin film transistor has more advantages, such as environment friendly, its material is easy to be made, and it can be made into flexible device, which make it becomes an important subject for the researchers. Even though a big progress has been made in the field of mobility, the theory study of the organic thin film transistor is still immature. In this article, a few models which cover the transfer of the carriers and the direct characteristics of the single gate transistors and the double gate transistors are listed. The simulaton tool Silvaco is used to simulate the electrical characteristics of the organic thin film transistors.The importance of device simulation is to simulate and study the physical and electrical characteristics without making out the actual devices, so the the cost of fabrication can be saved. In this article, a few aspects of the oaganic thin film transistrs are simulated with Silvaco:(1)The influence of the channel length, the active layer thickness, the insulator layer thickness, the insulator layer permittivity to the device output characteristics. And the effect of the defects is also simulated, which covers the interface fixed charge and the bulk defect. The output characteristics of single and double gate organic thin film transistors are specially analysed,and the influence of electrode thickness on the double gate device output characteristic is also discussed.(2)The simulation of the small size devices, the way of reducing the short channel effect is researched, and the effect of the overlay length of the gate electrode and the source,drain electrode is also simulated.(3)The inverter circuits which are made of organic thin film transistor are realized. Four kinds of inverters are studied with the mixmode method of atlas, one is made of p-type organic thin film transistor and n-type IGZO thin film transistor, one is only made of two p-type single gate organic thin film transistors,one is made of four p-type single gate organic thin film transistors and the last one is made of two p-type double gate organic thin film transistors. And in the basic of the inverter circuits, other gate circuits such as NAND gate circuit and NOR gate circuit are also relazied only with p-type organic thin film transistors. And the simulation results indicate the double gate organic thin film transistor is better than the single gate transistor in the aspects of output characteristic, short channel characteristics and the realization of gate circuits.