Title :
Anomalous breakdown behavior in ultrathin oxides and oxynitrides under dynamic electrical stress
Author :
Hwang, Hyunsang ; Lee, Jack
Author_Institution :
Microelectron. Res. Center, Texas Univ., Austin, TX, USA
Abstract :
Time-dependent dielectric breakdown (TDDB) and high-field stress-induced leakage behavior of ultrathin oxide (40-110 AA) under static and dynamic electrical stress conditions were investigated. Both thermally grown oxides and oxynitrides prepared by oxidation in N/sub 2/O were used for comparison. For thicker dielectrics, it was found that the charge-to-breakdown (Q/sub BD/) values are much larger when the dielectrics were stressed under bipolar waveform than those under unipolar. However, for thinner oxides (<60 AA), TBBD behavior is significantly worse under bipolar stressing. The anomalous behavior can be explained by the weak spot region of a fixed thickness at the polycrystalline silicon/oxide interface.<>
Keywords :
dielectric thin films; electric breakdown of solids; leakage currents; metal-insulator-semiconductor devices; nitridation; oxidation; silicon compounds; MOS capacitors; N/sub 2/O; Si-SiO/sub 2/; Si-SiO/sub x/N/sub y/; TDDB; anomalous behavior; bipolar waveform; charge-to-breakdown; dynamic electrical stress; high-field stress-induced leakage behavior; oxidation; thermally grown oxides; ultrathin oxides; ultrathin oxynitrides; unipolar waveform; weak spot region; Current density; Dielectric breakdown; Electric breakdown; Etching; Lifting equipment; MOS capacitors; Oxidation; Rapid thermal processing; Silicon; Thermal stresses;
Journal_Title :
Electron Device Letters, IEEE
