Lithographic Feasibility of ESCAP Beyond Quarter Micron.

Abstract

A production-worthy deep UV resist system built on the ESCAP platform is described. The resist consists of a thermally and hydrolytically stable resin and acid generator and thus can be heated at high temperatures for free volume reduction, which provides stabilization toward airborne base contamination. The film densification in conjunction with the use of a bulky acid reduces acid diffusion during postexposure bake, contributing to high lithographic performance. Robust 0.25 µm process latitudes have been demonstrated. Furthermore, the resist has produced excellent 175 nm line/space images with a depth-of-focus of 0.3 p m on a KrF excimer laser stepper with a numerical aperture of 0.60, indicating that the resist allows the use of the current exposure tool in the early 1 Gbit generation.

Measuring acid generation efficiency in chemically amplified resists with all three beams

“…Sixteen chemically amplified resists were prepared in a 4ϫ4 experimental array utilizing four PAGs of concentration 80 mol/cm 3 based on solids ͑see Table I͒, [22][23][24][25][26][27][28][29][30][31][32][33][34][35] and four levels of base ͓1,8-diazabicyclo͓5.4.0͔undec-7-ene ͑DBU͒ at 0, 3, 6, and 10 mol % versus PAG͔. The polymer is an advanced ESCAP-type material composed primarily of p-hydroxystyrene and t-butyl acrylate monomers.…”

Development of 157 nm positive resists

“…11,12 a͒ Electronic mail: hiroshi@almaden.ibm.com C. Measurements 1 H ͑250 MHz͒ and 13 C ͑62.9 MHz͒ NMR spectra were recorded on a Bruker AF250 spectrometer at room temperature. [13][14][15] A liquid scintillation counting technique was used to measure residual radiolabeled PGMEA in spin-cast films. 19 F NMR spectra ͑470 MHz͒ were obtained for polymer composition analysis on a Bruker AM500 spectrometer using perfluorobenzene as an internal standard.…”

Contribution of photoacid generator to material roughness

“…9 It was postulated that hydrogen bonding between the PAG and acidic protons of either phenol-or hexafluoroisopropanol-bearing polymers was responsible for both the NMR shift and dissolution behavior. The additional roughness imparted on a test polymer by incorporation of a series of iodonium, sulfonium, diazo, and imido PAGs was measured.…”