Nature of D-defect in CZ silicon: D-defect dissolution and D-defect related TDDB

The nature of D-defects in CZ Si, including defect dissolution thermodynamic/kinetics and electrical behavior, was investigated. After a dry oxidation at 1200 degrees C for 2hr, the D-defect density decreases with depth from the surface up to some critical depth, determined by the injection rate of interstitial silicons, and then increases toward that in as-grown wafer. During oxidation, the D-defect density profile exactly follows the vacancy concentration porfile, indicating that the driving force for the D-defect dissolution is vacancy undersaturation caused by annihilation between injected interstitial silicons and vacancies in the matrix. The D-defect dissolution improves B-mode type of oxide breakdown failures for Tox approximate to 100nm, which is a function of the injection rare of interstitial silicons. Although the presence of D-defects does not influence time zero oxide breakdown of approximate to 17nm, it degrades the time dependent dielectric oxide breakdown characteristic, which is associated with oxidation induced resolved shear stresses.