次微米微影於藍寶石基板圖案化之研究

Abstract

本研究以感應耦合電漿反應離子蝕刻方式進行藍寶石基板蝕刻，並利用奈米球微影、奈米壓印技術、熱微影技術相變化材料、雙層光阻互補性微影四種不同技術製作圖案化蝕刻遮罩，搭配蝕刻製程製備圖案化藍寶石基板。在奈米球微影與奈米壓印技術方面，分別以金屬材料與高分子材料製作蝕刻遮罩；在熱微影相變化材料方面，以鍺、銻、錫、氧（Ge, Sb, Sn, O, GSSO）四元金屬氧化物薄膜材料製作蝕刻遮罩；在雙層光阻互補性微影技術方面，以雙層互補式光阻製作蝕刻遮罩，接續使用感應耦合電漿反應離子蝕刻技術，以合適的蝕刻參數，分別使用上述四種不同技術所製作的蝕刻遮罩，製備圖案化藍寶石基板。完成次微米尺度之圖案化藍寶石基板後，將基板送至LED磊晶廠進行裸晶測試，量測LED的發光效率。 首先在奈米球微影技術製作圖案化藍寶石基板方面，利用調整氧電漿蝕刻時間，將聚苯乙烯的奈米球體的直徑控制於330 nm-600 nm之間，再搭配電子槍鍍膜技術製鍍金屬鉻與鎳作為蝕刻遮罩，以舉離法製作不同間距的金屬蝕刻遮罩，其圓形圖案的直徑及間距控制於330-510 nm以及75-170 nm。並於合適的蝕刻條件下進行蝕刻製程。鉻對藍寶石基板與鎳對藍寶石基板之蝕刻選擇比分別為 1：2 與 1：10。 在奈米壓印技術製作圖案化藍寶石基板方面，以高分子材料作為蝕刻遮罩進行蝕刻製程，圓柱形的高分子蝕刻遮罩的直徑為350 nm、間距280 nm，在上述相同的蝕刻製程條件下，高分子蝕刻遮罩對藍寶石基板之蝕刻選擇比分別為1：0.5，蝕刻製程中可藉由過蝕刻的方式，將結構側壁垂直度由135

In this research, the pattern sapphire substrate was etched by using inductively coupled plasma reactive ion etching (ICP-RIE) method with four patterned masks which produced by different techniques of Nanosphere lithography technology, nanoimprint technology, thermal lithography technology of phase change material, and dual-layer photoresist complementary lithography (DPCL) technology. In Nanosphere lithography technology and nanoimprint technology, metal and polymer materials were used as etching mask to proceed dry etching process, respectively. In thermal lithography technology of phase change material, the etching mask was made by using the oxides of four metal elements of GSSO（Ge, Sb, Se, O, GSSO）. In the DPCL technology, organic and inorganic materials were combined to make etching masks. After the etching processes of sub-micron scale patterned sapphire substrates (PSS) were completed, the testing LED dies with sub-micron scale pattern were evaluated the LED luminous efficiency after the epitaxy process. In the aspect of PSS fabricated by Nanosphere lithography technology, the nanosphere diameter was controlled between 330 nm and 600 nm by adjusting the oxygen plasma etching time. Then the nickel and chromium metal masks with different pitches were made by electron gun evaporation technology and lift-off method. The diameter of circular pattern in metal etch mask can be controlled at 330-510 nm, and the pitch spacing was 75-170 nm. Under suitable etching parameters, the etching selection ratios of chromium and nickel masks versus sapphire substrates are 1:2 and 1:10, respectively. In the aspect of PSS fabricated by nanoimprint technology, the cylindrical pattern of polymer with diameter of 350 nm and spacing of 280 nm was used as the etching mask. With the same etching process mentioned above, the etching selection ratio of polymer mask versus sapphire substrates is 1:0.5. The vertical sidewall angle can be adjusted from 135