Browse Prior Art Database

OLED THRESHOLD VOLTAGE CONTROL

IP.com Disclosure Number: IPCOM000015457D
Original Publication Date: 2001-Dec-23
Included in the Prior Art Database: 2003-Jun-20

Publishing Venue

IBM

Abstract

It is already known in the case of amorphous silicon that after bias temperature stress under about 200C, the Vth shift due to the stress is decreased at room temperature as shown in the left figure in Fig.1 because of the charge detrapping from the amorphous silicon and gate insulator. This phenomenon is called "Bias Temperature Stress test." (BTS) It is also already known that after bias temperature stress over about 200C, the Vth shift is frozen at room temperature as shown in the right figure in Fig.1. This phenomenon was discovered by Martin Powell et al. and is called "Thermal Thermal Bias Annealing." It is supposed that the "Thermal Bias Annealing" is due to the charge redistribution in amorphous silicon as a result of charging state change of Si bonds caused by hydrogen redistribution. As hydrogen is mobile over about 200C in amorphous silicon and is immobile under about 200C, the charging state is frozen after cooling down that result in the Vth change. Temperature Time Time