在一般半導體製程中，大多採用光微影的方式達到圖形轉移的目的，而光微影所能製作出的最小線寬會受到光學繞射極限的物理現象，使得線寬尺寸受到限制。利用熱微影的方式以熱傳導的形式來傳遞能量將可避免光繞射的限制，除此之外，熱的傳導速度遠低於光波的傳輸速度，因此具有控制傳輸距離的可行性。本文主要對光阻劑在加熱時結構產生交聯反應(cross-link)作為探討，實驗利用薄膜加熱器配合脈衝熱源，控制不同的脈衝寬度及週期，觀察光阻劑輪廓隨著加熱時間及溫度的變化，以及厚度的趨勢，並討論光阻劑加熱時的化學反應對於光阻劑結構交聯的程度，及顯影後留下被加熱區域的光阻劑所達到圖形轉移的效果，製作出不同厚度之微結構。另外透過有限元素分析軟體COMSOL建立模型，探討溫度分佈的影響，進而了解熱於高分子阻劑中的暫態傳輸現象。Photolithography is widely used in semiconductor industry and many micro/nano-manufacturing. Its resolution is usually limited by the wavelength of the light source. Thermal lithography use heat as the exposure source which has the possibility to generate patterns with minimum feature size exceeding the diffraction limit in photolithography. In addition, heat transport is much slower than light which allows us to control the transport distance. In this manuscript, we use transient heating to generate resist patterns with different thicknesses and study the heat transport and crosslinking in polymer thin films. The experiments use thin film heaters with pulsed Joule heating. Different pulse widths and periods are used to control the temperature rises and accumulated heating durations. The trend of the resulting resist thicknesses reveals the important role of the relaxation time in the cross-linking reaction. In addition, through the finite element analysis, we can simulate temperature distribution, and then to understand the thermal transient transport phenomena in polymer resists.
