No abstract

No abstract

This paper presents data obtained in developing a process using 193 nm lithography and the RELACS contact hole shrink technique. For the line/space levels, process windows showing resist performance using chrome on glass masks are presented. Data showing feature size linearity and the requirements for optical proximity correction (OPC) are presented. Some ofthe OPC trends observed are discussed and compared to results obtained using 248nm lithography. Image shortening data also compares the results obtained in 193 and 248 lithography. Etch results for the new 1 93 resists are given and show the etch resistance of this relatively new class ofphotoresist materials.For contact hole and via levels, results using 193 lithography and COG masks show the importance ofthe mask error enhancement factor (MEEF), print bias and resolution. Due to the relative immaturity and performance of contact hole resists for 1 93 lithography, Clariant's RELACS process was investigated with 248nm resists. In this process contact holes are printed larger than required and then reduced to the desired size by a chemical shrink process. Results obtained with 248 lithography using state ofthe art resists and phase shift masks are discussed. It was found that l4Onm contact holes with at least O.Sum depth offocus could be obtained. Cross sections and process windows are shown.

In the processing of chemically amplified resist systems, two "dose" parameters must be considered. The exposure dose dictates the amount of photoacid generated, and the thermal dose that is administered during the post-exposure bake (PEB) governs the extent to which the resin is chemically transformed by the acid. An Arrhenius relationship exists between these two dose variables, and the magnitude of the effective activation energy determines the degree of PEB temperature control required for a particular Iinewidth budget. PEB characteristics are presented for a chemically amplified positive-tone DUV resist used by IBM in the manufacture of 0.5-jim 16-Mb DRAMs. The effect of PEB temperature and time on resist sensitivity, contrast, resolution, and process lattitude is presented. The influence of exposure and thermal dose on the chemical contamination effect is also discussed.

No abstract