Degradation Mechanisms of MILC P-Channel Poly-Si TFTs under Dynamic Hot-Carrier Stress Using a Novel Test Structure

Abstract

In this study, dynamic hot carrier effect in the MILC p-channel TFT device has been characterized by the unique struture. This novel structure is capable of spatially resolving the hot carrier effect and is highly sensitive to detect the defect-rich region. The dynamic hot carrier stress has been focused on the impacts of the frequency, the rise time and the fall time. In varied frequency stress condition, the degradation in the drain-sided monitor transistor (DMT) increases monotonically with increasing frequency, infering that more defects are generated by extra dynamic stress contribution in the drain side and degrade the characteristic of device. Under varied fall time stress condition, the oncurrent degradtion is severe with decreasing fall time due to the extra voltage drop during voltage switch. The final part is effect of rise time. While device switches, the large voltage drop exists in the junction between the channel and the drain, which resulted in anothor hot carrier degradation.