摘要 |
The present invention addresses this need by providing a method for forming transparent PECVD deposited ashable hardmasks (AHMs) that have high plasma etch selectivity to underlying layers. Methods of the invention involve depositing the AHM using dilute hydrocarbon precursor gas flows and/or low process temperatures. The AHMs produced are transparent (having absorption coefficients of less than 0.1 in certain embodiments). The AHMs also have the property of high selectivity of the hard mask film to the underlying layers for successful integration of the film, and are suitable for use with 193 nm generation and below lithography schemes wherein high selectivity of the hard mask to the underlying layers is required. The lower temperature process also allows reduction of the overall thermal budget for a wafer.
|