Development of 157 nm positive resists

Itô, Hiroshi; Wallraff, G. M.; Fender, Nicolette; Brock, Phillip J.; Hinsberg, William D.; Mahorowala, Arpan P.; Larson, Carl E.; Truong, Hoa D.; Breyta, Gregory; Allen, Robert D.

doi:10.1116/1.1415512

Cited by 40 publications

(42 citation statements)

References 22 publications

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“…15 The contact angle of Poly͑1͒ with TMAH solution is 20°h igher than with Poly͑4͒. In addition to having lower contact angles, solutions of TMAH that contained surfactants gave increased polymer dissolution rates.…”

Section: Dissolution Studiesmentioning

confidence: 97%

Wetting and dissolution studies of fluoropolymers used in 157 nm photolithography applications

Markley

Marsella

Robertson

et al. 2004

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

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Articles you may be interested inWetting characteristics of the anodic aluminum oxide template and fabrication of cracks using ultraviolet curable resin solution Appl. Phys. Lett.Photolithography using the F 2 excimer laser at 157 nm, a technology to bridge traditional optical lithography and next generation lithographies, promises to enable ultralarge scale integrated devices with sub-70 nm design rules. Chemically amplified resists based on fluoropolymers have previously been shown to be good candidates for 157 nm microlithography. In our research, hexafluoroisopropyl alcohol ͑HFIPA͒ groups have been incorporated into polymers to improve the base solubility and to increase the transparency needed for new photoresists at 157 nm. These new polymers have absorbance values at 157 nm ranging from 1.7 to 3.9 m Ϫ1 . The introduction of fluorine groups increases their hydrophobicity and makes these polymers more difficult to wet at the surface. We have studied the effect of fluorine content on hydrophobicity of fluorinated polymers by measuring contact angle data over short time intervals. The ability to combine fluoropolymer synthesis with extensive contact angle studies has proven to be valuable in understanding solubility characteristics of these resins. These studies indicate that many of the fluorinated polymers have a very hydrophobic surface. Lowering contact angles can help to achieve the desired base solubility. Wetting studies also indicate that addition of certain surfactants to 0.26 N aqueous tetramethylammonium hydroxide ͑TMAH͒ help to reduce the contact angle. In addition to contact angle studies, we have used a quartz crystal microbalance to determine the dissolution rate of polymers in an aqueous base. Preliminary dissolution studies indicate a correlation to contact angle findings. Aqueous base solutions of 0.26 N TMAH containing surfactants were found to significantly lower the contact angle of an HFIPA-containing polymer, and increase the dissolution rate by an order of magnitude.

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Section: Dissolution Studiesmentioning

confidence: 97%

Wetting and dissolution studies of fluoropolymers used in 157 nm photolithography applications

Markley

Marsella

Robertson

et al. 2004

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

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“…The use of EUV has a marked impact on resist design because the energy of the exposure tools exceeds the ionization potential of the resist materials for mass production. [11][12][13][14] Although the usefulness of halogenation has been proven for conventional resists, halogenation demands particular caution for chemically amplified resists for ionizing radiation. 1 Although some excellent EUV resists have been reported, the requirements for nextgeneration resist materials are so strict that technical solutions are still unknown in many categories such as line width roughness.…”

Section: Introductionmentioning

confidence: 99%

Reaction mechanism of fluorinated chemically amplified resists

Yamamoto¹,

Kozawa²,

Okamoto³

et al. 2006

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

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The halogenation of resist materials is a well-known strategy for the improvement in resist performance particularly in electron beam and x-ray resists. However, for chemically amplified resists, the halogenation of polymers requires particular caution because halogenated polymers may interfere with acid generation. In this work, acid generation in poly[4-hydroxystyrene-co-4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropyl)-styrene] films was investigated using steady-state spectroscopy and pulse radiolysis. Acid yield decreased with an increase in the ratio of hexafluoroalcohol units. It was found that the reactivity of polymers with low-energy electrons (∼thermal energy) correlates to the decrease in acid yield.

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“…1 They found that the protected copolymer could beneficially act as a dissolution inhibitor to the homopolymer to provide enhanced patterning capability. 1 They found that the protected copolymer could beneficially act as a dissolution inhibitor to the homopolymer to provide enhanced patterning capability.…”

Section: Introductionmentioning

confidence: 99%