Reduction of plasma-induced damage during HDP-CVD oxide deposition in the inter layer dielectric (ILD) process

The degradation of the gate oxide in terms of plasma-induced damage was investigated in the dielectric deposition process on the basis of the photoconduction mechanism. Major damage was induced in the HDP-CVD process for filling a gap after the formation of the bit line. We observed the gate oxide degradation of the thick gate oxide PMOSFET without protection diodes in I-G-V-G curves. We also discovered that the breakdown voltage of the PMOSFET without protection diodes was correlated with deep power down current failure in electrical die sorting tests. Thus, we measured improvement of plasma-induced damage by the portion of deep power down current failure. We observed approximately 93% improvement of deep power down current failure by changing solely quantities of gas elements than the reference group. This result compared to outcomes that showed about 92% reduction of DPD current failure than the reference group as reducing preheating time and plasma power in the preheating step. First of all, we newly verified the reduction of plasma-induced damage without altering materials, but by adjusting only the quantity of gas elements during the preheating step. (C) 2011 Elsevier B.V. All rights reserved.