Technique for Determining Breakdown Voltage and Leakage of Thin Insulator Films
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
This article describes a new technique for determining breakdown voltage of thin insulator films. The dielectric strength and breakdown statistics are important parameters for thin insulator films used in MOS integrated circuits because they determine the maximum operating electric field in the MOSFETs and affect the circuit yield. These parameters are commonly measured by ramping the voltage across an MOS capacitor and registering its value as the current through the insulator exceeds a preset level, typically between 1 and 50 mA. This technique works reasonably well for SiO2 films thicker than 500 A but becomes inefficient for thinner films, as explained below. Fig. 1 illustrates different I-V characteristics observed in thin-oxide p-type substrate capacitors by ramping the electrode voltage in the negative direction.