Time Dependent Dielectric Breakdown of Silicon Dioxide under Constant Tunneling Current Stress

This report describes a study of the time dependent dielectric break down characteristics of oxides in the 200 Angstrom, 100 Angstrom, and 50 Angstrom thickness range, under constant current stress. Current level and temperature were the main stress variables used. The test vehicle was a small less than .001 square centimeter polysilicon, silicon dioxide, silicon capacitor fabricated with a process similar to that used in commercial dynamic random access memory DRAM products. The test matrix included 34 wafers of test capacitors, arranged in 17 cells, with about 1200 individual capacitors per cell. An automated wafer level system was used to control stress and log data. Sample voltage was monitored during stress, and C-V curves were taken initially and after partial stress. Life-time statistics, trapped charge density, and trap generation rate were extracted from the data. Silicon dioxide, Accelerated life testing, Constant current, Wafer level testing, Trapping, Latent defects, Electron beam, Induced current, Transmission electron.