Ge−Sb Thin Films Patterned by Heat‐Mode Lithography

Abstract

A binary Te-free phase-change material Ge 9.15 Sb 90.85 (GS) is investigated as the heat-mode resist. A high etching selectivity ratio can be achieved by matching a suitable developer. A reasonable explanation for the positive development is proposed based on the chemical binding energy analysis. High-resolution relief patterns are fabricated on the GS films by laser direct writing and wet etching. It reveals that GS is a promising heat-mode resist for the fabrication of photonic devices.

Mechanism of Corrosion Selectivity of NSb2Te Thin Films in the H3PO4/HNO3 Developer for Direct Laser Writing Nanolithography

“…On the other hand, the as-deposited thin film has the constant developing rate of 0.4–0.6 nm/min at a HNO 3 concentration of 0.2–1.0 mol/L (shown in the inset of Figure b). Thus, the maximum corrosion selectivity of 500 can be determined at a HNO 3 concentration of 0.7 mol/L, which is much larger than those of GeSb (corrosion selectivity of 12), BiSb (corrosion selectivity of 15), and AgInSbTe thin films (corrosion selectivity of 30). Figures c–e, S1, and S2 show the uniform grating structures with different periods and linewidths.…”

“…So far, various heat-mode resists have been investigated such as metallic glass, , polymeric photoresist, and copper–hydrazone–complex thin films . Among others, the SbTe phase change thin film, as a heat-mode resist, is a promising candidate owing to the simple fabrication procedure and clear phase change thermal threshold. − Currently, Wang et al successfully achieved multiscale structural fabrication with the feature size from 90 nm to 2.7 μm in the AgInSbTe resist. A high corrosion selectivity of 30:1 and high-resolution nanostructures with a minimum feature size of 41 nm are further obtained in the same resist via an electrochemical strategy .…”

Ge2Sb2Te5 Thin Film as a Promising Heat‐Mode Resist for High‐Resolution Direct Laser Writing Lithography

“…obtained after developed at H 2 SO 4 solution. [27] It suffers from serious environmental pollution and high cost of wastewater treatment. Moreover, high-resolution lithography is difficult to be implemented due to the high line-edge roughness.…”

Defocusing detection of high-speed imaging for samples with arbitrary pattern structures

“…Such as Foucault knife-edge method, Eccentric light beam method, Critical angle method, Astigmatic method, etc [17][18] . However, when these methods are applied to transparent or semi-transparent samples, errors will occur due to the low reflectivity of the sample surface [19][20] . In this work, a defocusing detection method based on transmitted light spot signal is proposed.…”