Fabricating a high-resolution mask with improved line-edge roughness by using a nonchemically amplified resist and a postexposure bake

Abstract

The authors have developed a high-resolution technique for fabricating photomasks at the 10-nm halfpitch logic nodes and beyond. Current mask-manufacturing techniques use a chemically amplified resist (CAR) that has a complex mechanism of acid generation, complicating the criteria for selecting the polymer and the quencher for industrial purposes. Thus, it is important to study fabricating masks with non-CARs. The authors exposed a non-CAR, diluted ZEP520A, to variable-shaped electronbeam lithography and used a postexposure bake (PEB) to modify the resist. Studying how the PEB temperature affected the non-CAR and resultant masks, the authors demonstrate that their technique can produce high-resolution structures. By measuring the critical dimensions (CDs), the authors show that the PEB shrunk, enlarged, and retained the size of 1:1 line-and-space, isolated space, and isolated line patterns, respectively. By optimizing the PEB temperature, the authors improved the line-edge roughness (LER) of the 1:1 line-and-space and isolated space CDs by $40%. To understand how the PEB affected the resultant structures, the authors measured the hardness of cured resists with and without a PEB at various temperatures. Optimizing the PEB temperature of the non-CAR increased the resist contrast, annealing the resist and improving the LER. As such, their technique is capable of high resolutions on the order of 20 nm. The insights the authors gained from optimizing the PEB might be useful when fabricating next-generation masks.

Organotin in Nonchemically Amplified Polymeric Hybrid Resist Imparts Better Resolution with Sensitivity for Next-Generation Lithography

“…LER and inspection of energy fluence effect in MAPDST- co -ADSM resist formulations with variation in dose. After exposure, the resist films were optimized to postexposure bake (PEB) at different temperatures of 30, 70, 110, and 150 °C for 60 s to minimize the LER/LWR and patter surface roughness . Finally, the negative tone nanofeatures were achieved after the development of resist films using aqueous TMAH developer of different concentrations (varied from 0.0026 to 0.26 N)…”

“…After exposure, the resist films were optimized to postexposure bake (PEB) at different temperatures of 30, 70, 110, and 150 °C for 60 s to minimize the LER/LWR and patter surface roughness. 22 Finally, the negative tone nanofeatures were achieved after the development of resist films using aqueous TMAH developer of different concentrations (varied from 0.0026 to 0.26 N). 23 2. of the photoresist was analyzed using atomic force microscopy (AFM) and sensitivity-contrast relation was plotted.…”

Effect of molecular weight on the EUV-printability of main chain scission type polymers

“…It prints via main chain scission of the polymer backbone, similar to PMMA, but with higher sensitivity and resolution for EUV. 35,36 The results are provided in the section below.…”

Tailoring potentials by simulation-aided design of gate layouts for spin qubit applications

“…However, the consideration of process constrains promises higher functionality and device yields. To that extend, fabricational variations such as line-edge roughness on the order of a few new nanometers [28], and the limitations of patterning with electron beam lithography at non-vertical angles need to be considered [29].…”