Array Test Structures for Gate Dielectric Integrity Measurements and Statistics

An array test structure for highly parallelized stressing and measurements of ultrathin MOS gate dielectrics is presented. The array test structure consisting of thousands of NMOS devices under test (DUTs) provides a large and significant statistical base for analysis of dielectric breakdown and the stress induced degradation of transistor parameters. The test array has been fabricated in a standard mixed-mode 130 nm CMOS technology. As such technologies offer both thin and thick gate dielectrics for MOS transistors, different gate dielectric thicknesses have been chosen for DUTs and digital control logic which gives the possibility to stress the DUTs with high gate voltages and prevent the control logic from degradation.