Aspect ratio dependent plasma polymer deposition of fluorocarbons

Abstract

The plasma polymer deposition of fluorocarbons on structured silicon samples with trenches with aspect ratios from 0 to 17 was experimentally investigated for sample temperatures from 0 to 100 °C under low dc-bias conditions (30 V) and for 0 °C sample temperature under high dc-bias conditions (80 V). It was found that for the low dc-bias conditions, the deposition rate decreases from 32 to 8 nm/min as the sample temperature increases from 0 to 100 °C, while the distribution of the deposited polymer inside the trenches does not significantly vary with temperature. The deposition rate at the high dc-bias conditions is higher (39 nm/min) than for the low dc-bias conditions, while the polymer thickness distribution does not significantly differ from the distributions of the low dc-bias conditions. A simple diffuse-reflection model was applied to describe the plasma polymer thickness distribution inside the trenches for the aspect ratio range covered by the experiments.