Design and Analysis of Metal-Oxide-Semiconductor-Capacitor Microring Optical Modulator with Solid-Phase-Crystallization Poly-Silicon Gate

具固相晶化多晶矽之MOS電容微環型光調變器設計與分析

石志聰

《光學工程》 113期 (2011/04) Pp. 7-18

https://doi.org/10.30011/OE.201104.0002

摘要

對於具有金屬氧化半導體電容結構的電光微環型光調變器：我們目標是利用自由載子效應在一個具有金屬氧化半導體橫截面的微環型調變器用以達到高速的電光調變；首先，爲了最佳化橫截面尺寸，我們提出一容易理解的優化程序用以達到容易耦光、單模條件、傳播常數匹配、忽略彎曲損失以及進而達到最大化自由載子色散效應的需求；第二，利用上述的方法與二維的MEDICI模擬工具與藉由自由載子色散效應，我們針對一具有金屬氧化半導體結構的單臂微環形光調變器，在矽、二氧化矽與絕緣體(SOI)的晶片上，提出嚴格又廣泛的電性與光性分析。我們針對調變器之SPC的p型多晶矽半導體與n型單晶矽在各個不同的參雜濃度下，操作在3.3伏特電壓下之調變速度、操作功率與插入損失作分析。對於p型多晶矽半導體與n型單晶矽半導體的參雜濃度皆為3×10^18cm^(-3)下，調變器操作在74 GHz的調變速度下，切換一次所需4.6×10^(-2)pJ/平方公分的操作功率可以達到。對於40 GHz的操作，在SPC的p型多晶矽半導體，10-12 dB的插入損失可以達到，且在退火良好的p型多晶矽半導體，意即沒有光學損失的p型多晶矽半導體，9 dB的插入損失可以達到。

關鍵字

金屬氧化半導體電容 ； 矽光調變器 ； 自由載子色散效應

並列摘要

For silicon-based electro-optical microring modulator with MOS cross-section: We aim for employing the free-carrier dispersion effect in a microring modulator that has a MOS cross-section for high-speed electro-optical modulation. First, in order to optimize the cross-section dimensions, we present a comprehensive optimization process in the design of the MOS micro-ring modulator to meet the requirements of easy butt-coupling, single-mode condition, propagation constant matching, negligible bending loss, and hence maximizing the free-carrier dispersion effect. Second, by employing the free-carrier dispersion effect, we present rigorous and extensive electrical and optical analyses for a MOS-capacitor single-arm microring optical modulator on a silicon-on-insulator (SOI) wafer with above-mentioned methods together with the 2-D MEDICI simulation tool. Modulation speed, operating power at 3.3 V operating voltage, and insertion loss (IL) for the modulator were analyzed with respect to the doping level of the SPC p-polysilicon gate and the n-crystalline silicon channel. 4.6×10^(-2) pJ/cm^2 operating power per switch can be achieved with 74 GHz modulation speed for 3×10^18 cm^(-3) doping level in both the SPC p-polysilicon gate and the n-crystalline silicon channel. For 40 GHz operation, 10-12 dB IL is achievable with the solid phase crystallization (SPC) polysilicon, and 9 dB IL is achievable with the well-annealed polysilicon that is lossless.

並列關鍵字

MOS-capacitor ； Silicon Optical Modulator ； Free-carrier Dispersion