Si基光子器件的p-i-n电学结构模型及分析

Modeling and analysis of p-i-n diodes for Si based waveguide devices

为了设计研制基于载流子色散效应的Si基光子器件,本文针对Si基光子器件的电学结构,利用Silvaco的器件仿真工具Atlas,并根据载流子色散理论,结合有限差分(FD)法,建立了基于pi-n结的电学结构模型。同时,为了提高模型的实际应用水平,采用0.18μm CMOS工艺线制作Si基马赫-曾德尔调制器(MZM),并进行相应的实验验证与分析。本文工作将为从物理层面上优化Si基光子器件设计提供帮助。

Silicon waveguide devices based on free-carrier dispersion are key co mponents for realizing high-speed optical communications and optical interconnections.In thi s paper,the silicon waveguide device using a lateral p-i-n diode configuration is modeled.We nume rically analyze the electrical and optical properties of the silicon waveguide device.A two-dimensional simulation package,Atlas from Silvaco,is employed to simulate the steady state and transient behaviors of the lateral p-i-n diode.According to the change of the electron and hole distributions caused by an applied voltage,the induced real refractive index an d optical absorption coefficient variations produced by free-carrier dispersion at a wavelength of 1.55μm are obtained. From the values of the refractive index and optical absorption coefficient varia tions,the finite-difference （FD） method is then used for the calculation of the effective index and optical losses.Meanwhile,in order to verify the established model,a n electro-optic intensity modulator based on the Mach-Zehnder interferometer,in which phase-sh ifters are embedded with the same p-i-n diodes,is fabricated on a silicon-on-insulator （SOI） wafer by a 0.18μm standard commercial CMOS line.Our calculations indicate that this work can be used to optimize the design of silicon electro-optic device.