Measurement of photoacid generation kinetics in photoresist thin films via capacitance techniques

Berger, Cody M.; Henderson, Clifford L.

doi:10.1117/12.485081

Cited by 3 publications

(1 citation statement)

References 14 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Typically, two areas of photoacid behavior are studied when trying to characterize a CAR: photoacid generation from a PAG, and photoacid diffusion through the matrix polymer. We have previously reported the use of interdigitated electrodes (IDEs) as a novel tool for measuring the kinetics of photoacid generation 2,3 . In this technique, a polymer film loaded with a photoacid generator is coated on top of the interdigitated electrode structures.…”

Section: Introductionmentioning

confidence: 99%

Chemically amplified photoresist characterization using interdigitated electrodes: an improved method for determining the Dill C parameter

Berger

Henderson

2004

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

We have recently developed a technique that utilizes capacitance data from resist coated interdigitated electrodes to measure the kinetic rate constant of photoacid generation (commonly referred to as the Dill C parameter) for photoacid generators in chemically amplified resists. The work presented in this paper focuses on a recently improved version of the IDE Dill C measurement technique. The original version of the technique required coating several IDEs with resist films containing different loadings of photoacid generator and then using the capacitance data from these IDEs to calculate linear mixing relationships between IDE capacitance and the content of PAG or photoproducts within the resist film. The improved version of the technique reported here totally eliminates the need for this "calibration process" through the use of normalized capacitance data. Elimination of the need to measure linear mixing relationships independently for each PAG and polymer combination gives the improved technique many advantages over the prior version. These include improved curve fitting and accuracy of Dill C calculations; fewer raw materials, IDEs, and experimental time; and most importantly, the potential to measure the Dill C for a resist from a single IDE with no prior knowledge of the resist's photoacid generator type or loading. A detailed derivation of the normalization scheme is presented in this paper, along with evidence of the dramatic improvement in model curve fit that can be achieved using this technique. In addition, Dill C parameters measured for five different photoacid generators with both the original and normalized version of the IDE technique are presented to demonstrate that both techniques measure the same Dill C parameter and hence are describing the same physical phenomena.

show abstract

Section: Introductionmentioning

confidence: 99%

Chemically amplified photoresist characterization using interdigitated electrodes: an improved method for determining the Dill C parameter

Berger

Henderson

2004

SPIE Proceedings

Self Cite

View full text Add to dashboard Cite

show abstract

Improved method for measuring photoacid generator kinetics in polymer thin films using normalized interdigitated electrode capacitance data

Berger

Henderson

2004

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

Self Cite

View full text Add to dashboard Cite

Articles you may be interested inOn the design of capacitive sensors using flexible electrodes for multipurpose measurements Rev. Sci. Instrum. 78, 043903 (2007); A high precision method for measuring very small capacitance changes Rev.A precision capacitance cell for measurement of thin film out-of-plane expansion. I. Thermal expansion Rev.A data analysis method is presented that can be used to calculate kinetic rate constants for photoacid generation ͑Dill C values͒ in polymer and chemically amplified photoresist thin films using capacitance versus exposure dose data from resist coated interdigitated electrode ͑IDE͒ sensors. It is shown that the use of normalized IDE capacitance data can reduce or eliminate errors and variations in measured Dill C values obtained from our previous analysis method that are created by environmental factors such as humidity fluctuations and IDE factors such as variations in electrode geometry and size. Using this normalization method, the Dill C rate constants for 248 nm exposure of triphenylsulfonium triflate ͑TPS-Tf͒, triphenylsulfonium perfluoro-1-butanesulfonate ͑TPS-Nf͒, bis͑4-tert-butylphenyl͒iodonium triflate ͑TBI-Tf͒, and bis͑4-tert-butylphenyl͒iodonium perfluoro-1-butanesulfonate ͑TBI-Nf͒ in poly͑p-hydroxystyrene͒ ͑PHOST͒ were found to be 0.046, 0.040, 0.055, and 0.056 cm 2 /mJ, respectively. These results are shown to compare well with values obtained for these same systems using our original IDE data analysis method ͑0.045 cm 2 /mJ for TPS-Tf/PHOST, 0.039 cm 2 /mJ for TPS-Nf/PHOST, 0.056 cm 2 /mJ for TBI-Tf/PHOST, and 0.054 cm 2 /mJ for TBI-Nf/PHOST͒. The normalization method has a significant advantage in that it permits the determination of a Dill C parameter for a particular polymer-photoacid generator system using a single resist film coated IDE and a single exposure experiment.

show abstract

Quantifying acid generation efficiency for photoresist applications

Tsiartas

Schmid

Johnson

et al. 2005

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

A direct analytical technique for measuring the solution quantum efficiencies of photoacid generators (PAGs) is presented. The technique is based on the nonaqueous potentiometric titration of the photogenerated acid and does not require separate calibrations, or the addition of sensing materials such as dyes or bases. Solutions of PAGs in acetonitrile were irradiated at 248 nm and subsequently titrated with known concentrations of triethanolamine base. The only quantities required for an accurate determination of the quantum efficiency are the incident radiation energy and the titration equivalence point. A mathematical analysis that enables this calculation is derived, and a table with calculated quantum efficiency values for three classes of PAGs having a variety of counterions is presented. The method is simple, accurate, and applicable to any class of PAG molecules.

show abstract

Measurement of photoacid generation kinetics in photoresist thin films via capacitance techniques

Cited by 3 publications

References 14 publications

Chemically amplified photoresist characterization using interdigitated electrodes: an improved method for determining the Dill C parameter

Chemically amplified photoresist characterization using interdigitated electrodes: an improved method for determining the Dill C parameter

Improved method for measuring photoacid generator kinetics in polymer thin films using normalized interdigitated electrode capacitance data

Quantifying acid generation efficiency for photoresist applications

Contact Info

Product

Resources

About