1887
banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Resist reflow minimization via viscosity control by exposure
Rent:
Rent this article for
USD
10.1116/1.4832155
/content/avs/journal/jvstb/31/6/10.1116/1.4832155
http://aip.metastore.ingenta.com/content/avs/journal/jvstb/31/6/10.1116/1.4832155
View: Figures

Figures

Image of FIG. 1.
FIG. 1.

(Color online) Hybrid lithography process according to scheme A (see text), sketch (left), experimental details (right): after substrate treatment, the photoresist is spin-coated (  = 200 nm), imprinted (  = 90 °C,  = 5 min, and  = 100 bar), exposed through a photomask ( = 500 mJ/cm2), and finally developed (  = 3 min). (a) 260 nm lines and spaces after imprint, the residual layer amounts to about  = 30 nm. (b) Exposure through a photomask. Standing wave profiles within a plane resist film of 300 nm under broadband and i-line exposure including absorption. For broadband illumination, the Hg lines were summed-up (weighting: i: 40%, h: 28%, and g: 32%). Similar sensitivity for all three lines was assumed. Absorption was considered with an absorption coefficient of 1.2 m−1. (c) Hybrid lithography result after development. Without PEB and without antireflective films below the photoresist, standing waves are present at the lithographic edges. Three distinct levels are observed in accordance with the relative intensity distribution [see (b)].

Image of FIG. 2.
FIG. 2.

(Color online) Transition between exposed and unexposed region of preimprinted pattern (400 nm lines and spaces) subjected to hybrid lithography (500 mJ/cm2) with an additional PEB (100 °C and 1 min) to reduce standing wave effects. (a) Without the development step: strong reflow in unexposed region. (b) After 2 min development time: porous residues (can be removed by prolonged development time) and interconnected elevated patterns along the lithography edge (cavity loss, cannot be removed even with a prolonged development time).

Image of FIG. 3.
FIG. 3.

(Color online) Demonstration of the viscosity increase due to exposure by means of an imprint experiment. The photoresist was locally exposed through a photomask ( = 350 mJ/cm2) before thermal imprint (  = 90 °C,  = 5 min, and  = 100 bar). The exposed region shows an increased viscosity, which is indicative of a molecular weight increase and/or partial cross-linking. Partially filled cavities make the viscosity difference visible. (a) Wide cavities, low filling level, regular filling: increased imprint depth in unexposed regions. (b) Small cavities, increased filling level: self-assembly defects in unexposed regions.

Image of FIG. 4.
FIG. 4.

(Color online) Evaluation of the reflow response during PEB to exposure dose via UV-light and typical reflow examples (line width 260 nm, cavity width 260 nm, and residual layer 50 nm). (a) and (b) Typical sample cross sections with definition of evaluation parameters, (c) evaluation (see text). With increasing exposure dose the reflow is reduced, with doses higher than about 60 mJ/cm2 the imprinted patterns are stabilized.

Image of FIG. 5.
FIG. 5.

Hybrid lithography results obtained with the negative tone resist ma-N 405 (  = 90 °C,  = 40 mJ/cm2,  = 180 mJ/cm2,  = 100 °C,  = 1 min, and  = 10 min). The standing waves are minimized and reflow is avoided. Flood exposure was applied after imprint before PEB. The residual layer is removed during development without any additional process step. (a) Line width 460 nm and cavity width 810 nm, (b) line width 260 nm and cavity width 360 nm.

Image of FIG. 6.
FIG. 6.

Lift-off results obtained with ma-N 405 after a hybrid lithography process with a flood exposure before PEB. The lift-off (30 nm Au is sputtered and lifted in an ultrasonic bath at 50 °C) was performed without any additional step for residual layer removal. The 460 nm (a) and 260 nm (b) wide metal lines are well connected to the large, micron-sized metal film; there is no distinct narrowing of the metal line width, especially in the transition region at the line ends.

Loading

Article metrics loading...

/content/avs/journal/jvstb/31/6/10.1116/1.4832155
2013-11-15
2014-04-20
Loading

Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Resist reflow minimization via viscosity control by exposure
http://aip.metastore.ingenta.com/content/avs/journal/jvstb/31/6/10.1116/1.4832155
10.1116/1.4832155
SEARCH_EXPAND_ITEM