| 摘要: | 隨著技術的不斷進步，矽光子學正在不斷發展和演進，此技術的優勢在與能與傳統CMOS半導體製程實現光子與電子元件的高度集成。而群速度色散對於高速光通訊、數據傳輸和非線性光學方面舉足輕重。因此本論文首先使用有限元法(FEM)對我們所需要的波導結構進行色散模擬，第一部分，我們透過模擬在不同高度及不同寬度的情況下，觀察幾何形狀調製色散的利弊；第二部分，在確認了氮化矽波導幾何形狀後，使用不同披覆層材料並在上方逐漸增加披覆層的厚度，模擬其沉積色散調製後的變化。接著我們介紹微環形共振腔的製程步驟，並且驗證了原子層沉積不會對波導造成額外損耗及品質因子產生影響。
在色散量測上，我們使用了二氧化鉿(HfO2)及氧化鋁(Al2O3)兩種材料披覆在氮化矽微環形共振腔上，透過原子層沉積能精確控制沉積厚度，能精準的調製色散。在沉積了二氧化鉿披覆層後，我們能將氮化矽波導的色散從-274 ps/ nm-km調製到-205 ps/nm-km ;除此之外，在沉積氧化鋁披覆層後，能將波導色散從-213 ps/nm-km調製到46 ps/nm-km，實驗結果顯示:使用氧化鋁披覆層能將波導色散調製到近零色散，並且在增加披覆層厚度後，更能將正常色散調製為異常色散，這意味著我們能更靈活的進行色散調製。
最後我們也研究了如何提高微環形共振腔的品質，透過飛秒雷射對微環形共振腔進行局部退火，其中也使用拉曼(Raman)光譜及原子力顯微鏡(Atomic force microscope)來尋找對氮化矽薄膜最有幫助的退火功率，我們發現特定功率對於微環形共振腔的品質因子提升有幫助，幅度約為1.3倍。
本論文透過雷射退火來提高微環形共腔的品質，並且提供了不會對波導增加額外損耗、精準及靈活調製色散的方式。
;With the continuous advancement of technology, silicon photonics is undergoing constant development and evolution. One of the key advantages of this technology lies in the high integration of both photonic and electronic components within the traditional CMOS semiconductor fabrication process. Group velocity dispersion plays a crucial role in high-speed optical communication, data transmission, and nonlinear optics. Therefore, in this thesis, we first conducted dispersion simulations using finite element method on the required waveguide structures. In the first part, we observed the pros and cons of geometric modulation of dispersion under different heights and widths. In the second part, after confirming the geometry of the silicon nitride waveguide, we simulated the variation in deposited dispersion modulation by using different coating materials and gradually increasing the thickness of the coating layer.
Next, we introduced the fabrication steps of the micro-ring resonator and verified that atomic layer deposition does not cause additional losses or affect the quality factor of the waveguide. For dispersion measurement, we used two materials, Hafnium Dioxide (HfO2) and Aluminum Oxide (Al2O3), coated on the silicon nitride micro-ring resonator.
Through atomic layer deposition, we could precisely control the deposition thickness and accurately modulate the dispersion. With the deposition of Hafnium Dioxide coating, we were able to modulate the dispersion of the silicon nitride waveguide from -274 ps/nm km to -205 ps/nm-km. Furthermore, with the deposition of Aluminum Oxide coating, we could modulate the waveguide dispersion from -213 ps/nm-km to 46 ps/nm-km. The experimental results showed that using Aluminum Oxide coating could tune the waveguide dispersion to near-zero dispersion. Additionally, increasing the coating thickness could further transform normal dispersion into anomalous dispersion, indicating greater flexibility in dispersion tuning.
Finally, we investigated methods to enhance the quality of the micro-ring resonator. Through femtosecond laser annealing, we conducted localized annealing on the micro ring resonator. Raman spectroscopy and Atomic Force Microscope were utilized to identify the annealing power most beneficial to the silicon nitride film. We found that
specific power levels contributed to a 1.3-fold improvement in the quality factor of the micro-ring resonator.
This thesis demonstrates the enhancement of micro-ring resonator quality through laser annealing, providing a means of precise and flexible dispersion modulation without
introducing additional losses to the waveguide. |
