McDermott, Will & Emery
Methodology for repeatable post etch CD in a production tool
A method and apparatus for processing a semiconductor wafer is provided for reducing dimensional variation by feeding forward information relating to photoresist mask CD and profile to adjust the next process the inspected wafer will undergo (e.g., a photoresist trim process). After the processing step, dimensions of a structure formed by the process, such as the CD of a gate formed by the process, are measured, and this information is fed back to the process tool to adjust the process for the next wafer to further reduce dimensional variation. By taking into account photoresist CD and profile variation when choosing a resist trim recipe, post-etch CD is decoupled from pre-etch CD and profile. With automatic compensation for pre-etch CD, a very tight distribution of post-etch CD is achieved. In certain embodiments, the CD and profile measurements, trim, etch processing and post-etch cleaning are performed at a single module in a controlled environment. All of the transfer and processing steps performed by the module are performed in a clean environment, thereby increasing yield by avoiding exposing the wafer to the atmosphere and possible contamination between steps.
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H01L G03F
inventional inventional
Hiroki Wei David S. L.
Sasano Liu Mui