Evaluation technique of gate oxide reliability with electrical and optical measurements

Techniques combining optical and electrical measurements have been developed for the evaluation of gate oxide reliability. The authors have found that uniformity of the injection current across an electrode is degraded beyond a certain current density which coincides with the onset of Q_BD lowering under high current density. The authors describe the system architecture and measuring theory and give an application example to show the effectiveness of the method. They also describe the general characteristics of oxide found by using this method.