Laser‐Assisted Thermal Exposure Lithography: Arbitrary Feature Sizes

Abstract

In traditional optical exposure lithography, the feature size is restricted by the Abbe limit, and it is difficult to obtain patterns with a feature size smaller or larger than the optical spot itself. Herein, a laser-assisted thermal exposure lithography technique is reported where the feature size can be arbitrarily tuned and changed, and is not limited to the spot size. The minimum feature size of the obtained patterns is 90 nm, which is %1/7 of the laser spot size (0.62 μm). The corresponding aspect ratio is %1:1. The maximum feature size is 2.7 μm, which is %30 times the minimum feature size. A variety of multiscale and multifunctional structures with different feature sizes are obtained successfully through a highspeed laser-assisted thermal exposure system, where the writing speed is more than 10 m s À1 . This method offers a pathway for direct laser writing with arbitrary feature sizes, high throughput, and low cost.

Nanoscale-Patterned Cr Films by Selective Etching Using a Heat-Mode Resist: Implications for X-ray Beam Splitter

“…Under laser irradiation (exposure), the as-deposited AIST can be changed to the crystalline state. , After development with the alkaline solution, the uncrystallized part of the resist film can be removed Figure a,b shows the two-dimensional (2D) and cross-sectional AFM images of the developed AIST film, respectively.…”

“…Figure a shows the XRD patterns of the laser-exposed, developed, and etched AIST resists. As we have studied before, , the as-deposited AIST can be crystallized under laser irradiation. Strong diffraction peaks can be found in the laser-exposed AIST resist, which corresponds to the mixture of Sb and Ag–In–Te crystallites (including AgIn 3 Te 5 and AgInTe 2 ).…”

“…The feature size of the patterns on the resist film is mainly determined by the distribution of the temperature field, but not limited by the Abbe diffraction limit. 21 By precisely controlling the temperature fields induced by the laser beam, it is feasible to manufacture high-resolution structures with feature sizes at the nanoscale. As shown in Figure 2f, the minimum feature size of the patterns on the Cr layer is ∼100 nm.…”

Electrochemical Strategy for High‐Resolution Nanostructures in Laser‐Heat‐Mode Resist Toward Next Generation Diffractive Optical Elements

“…[13][14][15][16][17][18] Among them, AIST is preferred due to its rapid and stable phase transformation. [19][20][21] In a standard process of laser heat-mode lithography, a laser spot is focused onto the AIST resist. Its phase is changed from an amorphous phase to a crystalline one, which can be used to generate various micro-/ nanoscale patterns.…”

AgGeSbTe thin film as a negative heat-mode resist for dry lithography

“…Currently, nanoscale feature size (smaller than 50 nm) can be achieved in chalcogenide heat-mode resist [14] . Moreover, high density (the duty cycle of 1:1), multiscale (the minimum size varying from 90 nm to 2.7 μm), and arbitrary patterns have also been realized [15] . Besides, chalcogenide heat-mode resist also exhibits high etching resistance, and the patterns can be transferred onto various substrates, including silicon [11,16] , fused silica glass [12,17] , GaAs [18] , etc.…”