Influence of Oxide Breakdown Percolation Resistance on MOSFETs (Invited Paper)

Abstract

A method is developed to measure the effective resistance associated with a percolation path formed during gate oxide breakdown (BD). The evolution of percolation resistance (Rperc) and channel resistance (Rch) during progressive BD (PBD) is studied in details. Our results reveal that PBD is constituted by the Rperc- and the Rch-controlled region. Additionally, Rperc is found to be a temperature- and voltage-dependent parameter, implying that PBD under different stressing conditions could be governed by different mechanisms. According to finite element analysis and infrared photoemission microscopy, a high localized temperature in the vicinity of the BD spot could exist to trigger dopant redistribution and microstructural damages. The change in diode I-V characteristics at the substrate-source/drain junction acts as a signature for the occurrence of dopant redistribution. This is confirmed by the simulation results of TSUPREM. The narrow device structures further enhance the localized heating effect during BD due to heat confinement.