METHOD FOR ROUGHNESS IMPROVEMENT AND SELECTIVITY ENHANCEMENT DURING ARC LAYER ETCH USING CARBON

摘要

A method of patterning a silicon containing ARC (anti-reflective coating) layer underlying a patterned layer is described that includes establishing a flow of a process gas to a plasma processing system, selecting a process condition that increases an etch selectivity of the silicon containing ARC layer relative to the patterned layer, igniting plasma from the process gas using a plasma source in accordance with the process condition, and exposing the substrate to the plasma to extend the feature pattern of the patterned layer into the silicon containing ARC layer. The process gas includes a first gaseous molecular constituent composed of C, F and optionally H, a second gaseous molecular constituent composed of C, F, and optionally H, and a third gaseous molecular constituent composed of C and an element selected from the group consisting of H and F.

主权项

1. A method of dry developing a multi-layer mask on a substrate, comprising:
disposing a substrate comprising a multi-layer mask in a plasma processing system, wherein the multi-layer mask has a patterned layer defining an open feature pattern overlying a silicon containing ARC (anti-reflective coating) layer; establishing a flow of a process gas to the plasma processing system, the process gas containing:
a first gaseous molecular constituent composed of C, F and optionally H,a second gaseous molecular constituent composed of C, F, and optionally H, the second gaseous molecular constituent having a different carbon-to-fluorine ratio than the first gaseous molecular constituent, anda third gaseous molecular constituent composed of C and an element selected from the group consisting of H and F, wherein the carbon-to-fluorine ratio of the third gaseous molecular constituent is greater than the maximum carbon-to-fluorine ratio of the first and second gaseous molecular constituents; selecting a process condition specifying a flow rate for each gaseous molecular constituent that increases an etch selectivity, measured as the ratio of the etch rate of the silicon containing ARC layer to the etch rate of the patterned lithographic layer, relative to a nominal etch selectivity achievable using the process condition while introducing only the first and second gaseous molecular constituents; igniting plasma from the process gas using a plasma source in accordance with the process condition; and exposing the substrate to the plasma to extend the open feature pattern of the patterned layer into the silicon containing ARC layer.