矽因具有高折射率，其表面於可見光波段之正向入射反射率高達三成以上，於光電元件應用上構成損失。以表面結構降低反射率並同時調控其潤濕性，可使元件於戶外或潮濕環境中維持穩定之光學表現。本研究以飛秒雷射燒蝕結合連續波雷射誘導鉻薄膜去濕遮罩之複合製程，於矽基板上製作階層式矽奈米結構，並探討其抗反射表現與潤濕行為。
本研究建立三種製程並逐一比較。製程一以三波長飛秒雷射直接粗糙化矽基板，涵蓋 IR、Green 與 UV 三種光源及 125、625 與 1250 kHz 三種調變器頻率，共九組參數。製程二先以電子束蒸鍍機沉積十奈米之鉻薄膜，再以 CW 雷射於氬氣環境中誘導其鉻薄膜去濕，形成鉻奈米金屬顆粒遮罩，經感應耦合電漿之 Bosch 製程蝕刻後移除鉻層，共四組掃描速度參數。製程三結合前兩者，先以飛秒雷射粗糙化，再施以 CW 雷射去濕以形成遮罩並蝕刻，形成兼具微米與奈米尺度之階層式結構，共三十六組參數。
於抗反射部分，製程二之平均反射率隨掃描速度提高而由 23.56% 單調下降至 18.47%。製程三之抗反射表現以紫外光粗糙化之複合結構為最佳，其調變器頻率 625 kHz 與 1250 kHz 兩組降至 3.20% 至 4.86%，為全部參數中之最低，較裸矽之 30% 以上大幅降低。以綠光粗糙化者穩定落於 12.11% 至 14.75% 之間，以紅外光粗糙化者則隨調變器頻率提高而由 11.85% 上升至 25.39%，其成因為紅外光於高調變器頻率下使表層熔融而趨於平滑，孔洞消失，該組之固液接觸面積分率 f₁ 亦同步升至全部參數之最高值 0.601。
於潤濕性分析部分，其結果顯示三種製程呈現截然不同之行為。製程一之樣品於清洗前均呈超親水，經緩衝氧化物蝕刻液清洗移除表面氧化層後，接觸角回升至 44.726 度至 66.308 度之間，其潤濕行為符合 Wenzel 模型，液滴完全填滿結構凹槽。製程二之四組接觸角介於 102.224 度至 111.454 度，均高於平坦矽之本徵接觸角 63.84 度，可以 Cassie–Baxter 模型描述，反推所得之固液接觸面積分率 f₁ 介於 0.440 至 0.547，並隨掃描速度提高而下降。製程三之接觸角範圍擴大至 98.556 度至 131.492 度，固液接觸面積分率涵蓋 0.272 至 0.601，其中以飛秒雷射光源 Green、調變器頻率 125 kHz、CW 雷射掃描速度 3 m/s 一組為最低，該組同時具有全部參數中最高之接觸角 131.492 度。
本研究確認孔洞之尺度與密度為同時決定抗反射表現與潤濕狀態之共同因素。孔洞細密者可於液滴下方維持氣墊並有效捕捉入射光，孔洞過大或表面過度平滑者則兩項表現同時劣化。以此為依據，複合製程得以在單一製程視窗內同時達成低反射率與高接觸角。

Silicon reflects more than 30% of visible light at normal incidence because of its high refractive index, and this loss limits the efficiency of silicon-based optoelectronic devices. In this study, hierarchical silicon nanostructures were fabricated by combining femtosecond laser ablation with a chromium dewetting mask induced by a continuous-wave (CW) laser, and their antireflection and wetting behavior were examined.
Three routes were compared. Process I roughened bare silicon with IR, green and UV femtosecond beams at three modulation frequencies, giving nine parameter sets. Process II deposited a 10 nm chromium film by electron-beam evaporation, dewetted it into nanoparticles with a 1070 nm CW laser under argon, and transferred the mask into the silicon by inductively coupled plasma Bosch etching before stripping the residual chromium, giving four parameter sets. Process III applied the Process II sequence to substrates already roughened by Process I, combining micrometer-scale laser texture with nanometer-scale etched features, giving thirty-six parameter sets.
Within Process III, the series roughened with the ultraviolet beam performed best, reaching 3.20% to 4.86% at 625 and 1250 kHz, the lowest of all parameter sets. Process II and Process III surfaces were both in the Cassie–Baxter state, with contact angles of 102.224°–111.454° and 98.556°–131.492° and solid–liquid contact area fractions of 0.440–0.547 and 0.272–0.601 respectively.
The hybrid process reaches low reflectance and a high contact angle within a single process window.

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