Solubility Rate of Poly-(Methyl Methacrylate), PMMA, Electron-Resist

Greeneich, James S.

doi:10.1149/1.2401767

Cited by 37 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…15,16 We have also noticed that for a fixed development time in the above developer the RD formation takes place within a 5% change in the exact global exposure dose. With this developer the final resist profiles show less variation with the development time and closely resemble the simulated profiles based on energy threshold criterion.…”

Section: Resultsmentioning

confidence: 68%

Proximity exposure effect analysis using the phenomenon of resist debris formation in electron beam lithography

Deshmukh

2002

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

View full text Add to dashboard Cite

Erratum: "Proximity exposure effect analysis using the phenomenon of resist debris formation in electron beam lithography" [J.Proximity effect correction using pattern shape modification and area density map for electron-beam projection lithography J.The phenomenon of resist debris ͑RD͒ formation is shown to be a useful method for proximity exposure ͑PE͒ effect analysis in electron beam lithography. Some simulation results and corresponding experimental results discussed in this article on RD formation over the electron beam exposed pattern areas before and after PE effect correction reveal certain unique features associated with the method. These unique features of the method have direct relevance with the electron beam exposure parameters assumed in the simulation work, their implementation during the experiments, pattern shape-spacing fidelity, and also the correction scheme used for the PE effect correction.

show abstract

Section: Resultsmentioning

confidence: 68%

Proximity exposure effect analysis using the phenomenon of resist debris formation in electron beam lithography

Deshmukh

2002

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

View full text Add to dashboard Cite

show abstract

“…The exponential dependence on Q contrasts with the often-used linear relation that is obtained by assuming a fixed scission yield, [26][27][28] although Eqs. (40) and (41) are of course linear for small Q.…”

Section: Photochemistry Modelmentioning

confidence: 81%

A model for reaction-assisted polymer dissolution in LIGA.

Larson

2004

View full text Add to dashboard Cite

A new chemically-oriented mathematical model for the development step of the LIGA process is presented. The key assumption is that the developer can react with the polymeric resist material in order to increase the solubility of the latter, thereby partially overcoming the need to reduce the polymer size. The ease with which this reaction takes place is assumed to be determined by the number of side chain scissions that occur during the x-ray exposure phase of the process. The dynamics of the dissolution process are simulated by solving the reaction-diffusion equations for this three-component, two-phase system, the three species being the unreacted and reacted polymers and the solvent. The mass fluxes are described by the multicomponent diffusion (StefanMaxwell) equations, and the chemical potentials are assumed to be given by the Flory-Huggins theory. Sample calculations are used to determine the dependence of the dissolution rate on key system parameters such as the reaction rate constant, polymer size, solid-phase diffusivity, and Flory-Huggins interaction parameters. A simple photochemistry model is used to relate the reaction rate constant and the polymer size to the absorbed x-ray dose. The resulting formula for the dissolution rate as a function of dose and temperature is fit to an extensive experimental data base in order to evaluate a set of unknown global parameters. The results suggest that reaction-assisted dissolution is very important at low doses and low temperatures, the solubility of the unreacted polymer being too small for it to be dissolved at an appreciable rate. However, at high doses or at higher temperatures, the solubility is such that the reaction is no longer needed, and dissolution can take place via the conventional route. These results provide an explanation for the observed dependences of both the dissolution rate and its activation energy on the absorbed dose.3

show abstract

“…The mechanism for development of PMMA is very well known [2,34]. Briefly, PMMA experiences primarily main chain scission when exposed to ionizing radiation.…”

Section: Minimum Feature Sizementioning

confidence: 99%

“…Lower molecular weight (irradiated) PMMA is extremely soluble in the developer solution, whereas higher molecular weight (non irradiated) PMMA is only sparingly soluble. One main chain scission in the middle of a polymer chain will reduce its molecular weight in half, which has a very large effect on its solubility [31,34]. Thus, without development, one bond scission has a negligible effect on contrast when visualizing the patterns by X-ray microscopy, whereas, with development, one bond break can produce a very large contrast change.…”

Section: Minimum Feature Sizementioning

confidence: 99%

Zone plate focused soft X-ray lithography

Leontowich

Hitchcock

2011

Appl. Phys. A

View full text Add to dashboard Cite

The zone plate focused soft X-rays of a scanning transmission X-ray microscope have been used to pattern poly(methyl methacrylate) and poly(dimethylglutarimide) films by a direct write method which is analogous to lithography with a focused electron beam. The lithographic characteristics of both polymers have been determined for 300 eV X-rays. With low doses (1 MGy), developed lines 40 ± 5 nm wide were created in poly(methyl methacrylate). At higher doses an exposure spreading phenomenon substantially increases the lateral dimensions of the developed patterns. The spreading mechanism has been identified as the point-spread function of the zone plate lens. The performance of focused soft X-ray lithography is compared to other direct write methods. The practicality of a dedicated focused soft X-ray writer instrument is discussed.

show abstract

Solubility Rate of Poly-(Methyl Methacrylate), PMMA, Electron-Resist

Cited by 37 publications

References 0 publications

Proximity exposure effect analysis using the phenomenon of resist debris formation in electron beam lithography

Proximity exposure effect analysis using the phenomenon of resist debris formation in electron beam lithography

A model for reaction-assisted polymer dissolution in LIGA.

Zone plate focused soft X-ray lithography

Contact Info

Product

Resources

About