Correlation between plasma-induced gate oxide damage and charging sensor measurements

Abstract

This paper describes for the first time a methodology which allows direct correlation between charging potential, measured under actual process conditions using a flash memory cell as a charging sensor, and latent oxide damage revealed through FN injection on transistors. The methodology was used to study charging effects in a transformer-coupled plasma (TCP) metal etcher under actual process conditions, as a function of antenna shape. Significant V/sub th/ shifts after FN injection were found only with very dense finger antennas, revealing enhanced oxide damage due to the electron shading effects. The oxide damage is strictly correlated with charging potential using flash memory cells with the same antenna structures as the transistors.