超快雷射轉印術於相變化材料奈米結構製作與量測

Nano fabrication and measurement of phase-change thin film by ultrafast laser and atomic force microscopy

曾銘綸(Ming-Lun Tseng)

指導教授 ： 蔡定平

國立臺灣大學/理學院/物理研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.10654

摘要

近年來，相變化材料之應用在學界及工業界都得到極大的注意，原因在於相變化材料在結晶與非結晶態間光電之性質有明顯的差異。相變化材料在眾多領域中已經有廣泛的應用，例如高密度的光儲存、相變化記憶體、奈米微影術、 相變化元件。在此之中，在許多相變化材料中最受到注目的材料為合金鍺銻碲，鍺銻碲具有極短的轉態時間(約為數十奈秒) 、高度的熱穩定性可於室溫下保存數十年，相態間具有性質的變化明顯，轉態過程完全且可逆。 本論文研究雷射轉印術製作相變化材料鍺銻碲結構。使用濺鍍機鍍一層初鍍態鍺銻碲(as-deposited Ge2Sb2Te5 )奈米薄膜於透明基版(稱之為母版)，再經由飛秒雷射( 波長八百奈米，曝光時間一百四十奈秒)曝光後使薄膜上照光區域急速溶化並自透明基版表面轉移至另一側基板之表面(稱之為子版)。本實驗藉由改變寫入雷射功率以及不同厚度之初鍍態鍺銻碲合金薄膜於玻璃基版表面製作一系列不同尺寸以及相態分佈之鍺銻碲奈米點矩陣。我們使用原子力顯微儀以及光學量測系統量測子版表面上長成鍺銻碲奈米點狀結構之尺寸形貌以及性質。藉由這兩種量測工具，我們發現母版上鍺銻碲薄膜的膜厚以及曝光雷射的照度對於子版表面形成之點於尺寸、形貌以及相態有直接的影響。本技術提供一簡易製程供任意形貌之相變化材料鍺銻碲微結構之製作，它具有極大的潛力未來應用於諸如光學元件、微機電、或是相變化記憶體等領域。

關鍵字

雷射轉印術 ； 原子力顯微鏡 ； 相變化材料

並列摘要

Phase change materials has different optical and electrical properties in crystalline and amorphous state, it has been applied to versatile areas such as optical data storage, phase change memory, nanolithography. In this paper, we present a laser-induced forward transfer technique to fabricate the pattern with phase change material Ge2Sb2Te5. The as-deposited Ge2Sb2Te5 alloy films on a transparent substrate are transferred to the receiver substrate after a femto-second laser pulse irradiation (wavelength is 800 nm, and pulse duration is 140 femto-second). The dots patterns are fabricated with different volume and height-width ratio by changing the laser fluence and the thickness of the donor film. The topography of receiver substrate is studied by atomic force microscopy (AFM) and the optical measure system, the transfer properties are analyzed. According to the AFM measured information, we found that the dot diameter is function of Ge2Sb2Te5 donor film thickness and laser fluence. The dot size is around 14 nm (thickness) x 1500 nm (diameter). Fabrication of patterns composed of dots deposited on the receiver substrate was measured. This technique provides a simple way to form arbitrary pattern and has potential in future production of optical components, MEMS and phase-change memory.

並列關鍵字

laser induced forward transfer ； atomic force microscopy ； phase-change material

參考文獻

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