Statistical Breakdown Measurement Technique for Monitoring Diode-Switch Reliability in Active Matrix LCD Production

An important aspect in the production of high quality active matrix addressed liquid crystal displays (AMILCDs) is the operational reliability of the electrical switching devices in the active matrix. Failing pixels in the display may occur if the switches on the glass substrate are subject to electrical breakdown. In this study, a measurement method is presented that uses forced electrical breakdown on many samples (103-104) of thin film diodes (TFDs), that are used as switches in TFD-R displays. The method allows us to obtain information on extrinsic defect densities and failure modes related to the production process, as well as the limits of electrical reliability of the switches.