Accelerated current test for fast tunnel oxide evaluation (of EPROMs)

An accelerated method for wafer-level tunnel oxide evaluation and screening is proposed and compared to the widely used constant current test. The dielectric is stressed by an exponentially increasing current flow until breakdown occurs. In a short measurement time a wide current density range is explored, so that both latent defectivity and intrinsic oxide properties can be monitored. It is concluded that sensitivity in charge to breakdown determination and its good correlation with constant current stress results make the ramped current method suitable for routine use in both R&D and production.<>