Preparation And Electrical Characterization Of MgInSnO Thin Film Transistors

Thin film transistor(TFT)is the indispensable parts in the flat-panel display technology.The metal oxide thin film transistors represented by zinc oxide(ZnO)has attracted more and more attention because the advantages such as high mobility and high aperture ratio,thus it is considered to be the next generation thin film transistor technology as alternatives to traditional a-Si and p-Si TFT.However,the ZnO film are usually polycrystal and generate grain-boundary defect easily and generate oxygen vacancy defects in the process of preparation easily,which restricts the improvement of its performance.MgO has strong metal-oxygen bond energy,which can inhibits the formation of oxygen vacancies.However,there are nearly no reports about MgO-based thin film transistors up to now.In this work,we fabricated bottom gate type MgInSnO-TFT for the first time.The device performance can be achieved:the saturate field effect mobility about 12cm2/Vs,the on/off ratio about 107 and the threshold voltage about 0-10V.The main research content is as follows:1.We investigated the effect of annealing temperature and annealing 02 flow rate on the performance of MglnSnO-TFT..The results indicated that best annealing temperature is 750?.Further improve the annealing temperature transforms MglnSnO film from amorphous into poly-crystal state,device performance deteriorates significantly.Annealing O2 flow rate for 400 SCCM device performance is best,O2 flow rate too high or too low will make the device performance decline.2.We investigated the effect of active layer thickness on the performance of MgInSnO-TFT.The results indicated that best active layer thickness is 25nm,the thicker film device performance degraded and the device turn enhanced mode to depletion mode.3.We investigated the influence of W/L ratio and the cdevice scale on MgInSnO-TFT performance.We found that the device with smaller W/L ratio has larger mobility,which because the existence of fringe current effect.And the device with smaller scale has larger mobility,which because smaller scale is,the shorter transport distance carriers pass and less scattering is suffered.