矽絕緣層基板上實作垂直進光鍺吸收臨界耦合光偵測器

Critically Coupled Germanium Photodetector Fulfill on SOI Wafer with Vertical Illumination

劉宇軒(Liu, Yu Hsuan)

指導教授 ： 鄭克勇

國立清華大學/電機資訊學院/光電工程研究所/碩士(2016年)

摘要

利用Ⅳ族的鍺作為吸收層的光偵測器在積體電路有高度的整合性，其吸收波段更是與目前光通訊的主要波段相符，我們利用傳統的p-i-n結構並引進臨界耦合的概念設計出高頻率響應、高頻寬的光偵測器，入射的光訊號其所有能量會在共振腔中形成建設性干涉，共振腔外的地方形成破壞性干涉，因此入射光的能量會完全被吸收層吸收，只需要數百奈米的鍺，就可以有90%以上的量子效率，也由於吸收層厚度較傳統的鍺光偵測器薄，頻寬可以大幅提升到50GHz，其缺點是頻譜線寬只有約15奈米，但透過反常色散關係設計進行頻率補償，可以使頻譜線寬增加到50奈米，我們利用SOI基板進行鍺吸收臨界耦合光偵測器的實作，並採取背面進光的設計，分析討論並傳統的矽、鍺光偵測器進行比較，目標是得到高頻率響應、高頻寬的光偵測器。

關鍵字

臨界耦合 ； 鍺吸收光偵測器 ； 光通訊

並列摘要

Using Germanium as absorption layer for photodetector has highly integrity in IC, which has same wavelength in optical communication. We used critical couple theory combined with traditional p-i-n structure, designed a high frequency response and high bandwidth photodetector. The incident light source would be constructive interference in the cavity, and outside the cavity, the signal would be destructive interference. So the power of incident light source would totally be absorbed by Germanium layer, it could reach up to 90% quantum efficiency and just need a few hundred nanometers Ge absorption layer. Comparing with traditional Ge p-i-n photodetector, our PD’s bandwidth could up to 50GHz, but the disadvantage is that linewidth is just 15nm. To conquer this problem, we made another design, which is anomalous dispersion mirror. By AD mirror’s phase compensation, our PD’s linewidth could increase to 50nm. About process, we use SOI wafer to manufacture Germanium absorbed critical couple photodetector, which design for backside incident, can reach high frequency response and high bandwidth compare with traditional Si and Ge photodetectors.

並列關鍵字

Critically coupled ； Ge photodetector ； optical communication

參考文獻

Yariv, A., “Critical coupling and its control in optical waveguide-ring resonator systems,” Photonics Technology Letters, IEEE, 2002. 14(4): p.483-485.

Casalino, M., et al., “Critically coupled silicon Fabry-Perot photodetectors based on the internal photoemission effect at 1550 nm,” Optics Express, 2012. 20(11): p.12599-12609.

Lumerical Solutions, Inc., http://www.lumerical.com/.

C.Y. Chou, “Critically coupled Germanium photodetector under vertical illumination,” MS thesis of National Tsing-Hua University, 2013.

Y.T. Yang, T.K. Won, S.Y. Choi, Takako Takegara, Yasunori Nishimura, and John M. White, “The Latest Plasma-Enhanced Chemical-Vapor Deposition Technology for Large-Size Processing,” Journal of Display Technology, Vol.3, No.4, December 2007.