| 摘要: | 矽光子電路利用黃光微影技術，將大尺寸的光纖光路架構縮小至微米乃至奈米級的波導結構，並與矽晶圓的CMOS製程相容。矽基半導體結構的相容性提供了一個將光路與電路結合的平台。調製器是矽光子不可或缺的組件，通過不同手段改變材料的折射率，進而影響光譜在外界環境變化下的響應。
本論文利用在環形共振腔上疊加一層微型金屬加熱電阻結構，通過歐姆效應產生熱量，使其穿透光譜產生紅移現象，並探討不同結構對調製效率和調製速率的影響。首先，以Ansys LUMERICAL軟體模擬熱流傳輸，對相同結構但不同金屬材質的微加熱器，以及相同金屬但不同結構的微加熱器進行溫度分布的模擬。結合FDTD與FDE solver的方法，討論上述情況。
隨後，利用國家實驗研究院台灣半導體研究中心(Taiwan Semiconductor Research Institute, TSRI)的步進式曝光機製作並測量各種波導結構，最終驗證在DC直流信號和AC交流信號調製驅動下，鋁微加熱器相比鈦微加熱器僅需要較小的驅動電壓便足以提供同等的調製效率。在不同結構的波導中，驗證了在DC直流信號調製下，脊型波導因其特殊的隔熱特性而具有高熱調製係數；而低限制波導中，DC直流和AC交流調製能力較弱。
此外，鑒於環形共振腔諧振器對製程線寬的要求，通常需要高解析度的曝光機（例如步進式曝光機、電子束微影曝光機）支持，這無疑增加了製作環形共振腔或其他高精度元件的難度。因此，本論文利用AZ5214光阻，結合其正光阻與負光阻的特性，在同一基板上同時使用兩種相反的光阻，最終將解析度從常規的2μm微縮至1μmu以下，一定程度上提高接觸式曝光的解析度。
;Silicon photonic circuits utilize photolithography with yellow light to miniaturize large-scale optical fiber pathways into micron- and nanometer-scale waveguide structures, while also being compatible with CMOS processes on silicon wafers. The compatibility of silicon-based semiconductor structures provides a platform for integrating optical and electrical circuits. Modulators are indispensable components in silicon photonics, affecting the final spectral response to external environmental changes by altering the refractive index of the materials through various means.
This thesis employs a micro metal heating resistor structure layered on a ring resonator. By generating heat through the Ohmic effect, a redshift phenomenon in the transmission spectrum is observed. The study explores the impact of different structures on modulation efficiency and rate. Initially, thermal flow transmission is simulated using Ansys LUMERICAL software. Simulations are performed to observe the temperature distribution differences for micro-heaters made of various metals with identical structures, as well as for micro-heaters made of the same metal but with different structures. The FDTD and FDE solvers are combined to discuss these scenarios.
Subsequently, various waveguide structures are fabricated and measured using a stepper at the National Applied Research Laboratories Taiwan Semiconductor Research Institute (TSRI). It is verified that under DC and AC signal modulation, aluminum micro-heaters require a lower driving voltage compared to titanium micro-heaters to achieve the same modulation efficiency. Among different waveguide structures, it is confirmed that under DC signal modulation, rib waveguides have a high thermal modulation coefficient due to their unique insulation properties, whereas the modulation capabilities of DC and AC signals in low confinement waveguides are weaker.
Additionally, due to the smaller linewidth requirements of ring resonator resonators, high-resolution exposure tools (such as steppers and electron beam lithography tools) are usually necessary, which undoubtedly increases the complexity of fabricating ring resonators or other high-resolution components. Therefore, this thesis aims to use AZ5214 photoresist, which possesses both positive and negative photoresist characteristics, to simultaneously use two opposite photoresists on the same substrate. This approach enhances the resolution in contact lithography to a certain extent, ultimately improving the resolution from the conventional 2μm to below 1μm. |
