line - The University of Texas at Austin

Figure 2.13: Cross section SEM images of dense 70 nm (a) and 100 nm (b) lines..39
Figure 2.14: SEM micrographs of an oxide/ITO template after resist development
(a) and after oxide etch and resist strip (b). ......................................................40
Figure 2.15: Requirements of film stacks (a) during template production and (b)
during imprinting. .............................................................................................41
Figure 2.16: Optical constants for materials used in template fabrication. (a) ITO, 65
(b) 6.35 mm fused silica plate, (c) PECVD SiO2, (d) ZEP520, and (e) NEB22.
Extinction coefficients were calculated to be zero in the data range unless
noted..................................................................................................................42
Figure 2.17: Optical constants for materials used during SFIL imprinting not listed
in Figure 2.16. (a) SFIL A4 etch barrier, (b) DUV30J-11 transfer layer, and (c)
Si (from reference 57).......................................................................................43
Figure 2.18: Optical coefficients for 780 nm exposure corresponding to the film
stack shown in Figure 2.15b using ZEP520 as the e-beam resist. The height
sensor beam is incident on the substrate at 75° from normal, hence the
difference in p- and s-polarizations...................................................................45
Figure 2.19: Optical coefficients for 365 nm exposure at normal incidence,
corresponding to the film stack shown in Figure 2.15a. The plots are different
for areas of the template that possess SiO2 features (left) and those that do not
possess features (right)......................................................................................47
Figure 2.20: Cross-sections of imprints using Cr-based templates showing (left to
right) 50, 40, 30, and 20 nm lines. ....................................................................48
Figure 2.21: Iso-dense features imprinted with SFIL-32-ITO-01 template. a) 90 nm,
b) 80 nm, c) 70 nm............................................................................................49
Figure 2.22: Cross-section SEMs of imprinted features. a) 90 nm, b) 80 nm, c) 70
nm. ....................................................................................................................49
Figure 2.23: Features imprinted using a SiO2-encapsulated ITO template. a) nested
and b) isolated 20 nm lines. 26 ............................................................................50
Figure 3.1: Dramatic profile improvements are observed in all etch barrier
formulations with increasing crosslinker concentration. Formulation M2 did
not print.............................................................................................................62
Figure 3.2: F1s XPS peak area as a function of sputter depth for imprinted film
containing 1% (w/w) fluorinated acrylate.........................................................64
Figure 4.1: Idealized reaction of alkyltrichlorosilane on hydroxylated silica. ........67
Figure 4.2: From Chuang, et al. 16 Side views of specific silicon planes (dashed lines
representing an edge of such a plane) of β-cristobalite. Drawn approximately to
scale: (a) 111-face; (b) 100-face; (c) vicinal sites from dehydration of the 100face....................................................................................................................72
Figure 5.1: Illustration of perfect and imperfect separation of imprint template from
substrate. ...........................................................................................................98
Figure 5.2: Comparison of (a) water contact angle and (b) F:Si XPS peak area ratio
for samples treates at 20 °C for various reaction times. .................................106
xv