基于双缝隙结构的电光调制器设计与工艺实现

Design and Process Implement of EO Modulator Based on the Dual-Slot Structure

受铜线带宽小、延时大、功耗高的限制,下一代芯片互连较为可行的一种解决方式是采用光互连。调制器作为其中的关键器件,有重要的研究意义。设计了一种新型的硅基双缝隙波导电光调制器,该调制器结构采用法布里珀罗微谐振器,依靠缝隙内高非线性聚合物的快速电光效应,通过外加电压达到调制效果。调制器结构包含了新型的一般微纳波导到双缝隙波导的模式转换器,降低了传输损耗,也更利于电极的工艺制作。首先对设计结构进行仿真分析,得到合适的设计参数。然后,对调制器所需的工艺进行反复验证,包括工艺制备中参数的优化等,通过使用电子显微镜已观测到较好的光刻线宽、刻蚀深度以及侧壁粗糙度。初步完成了调制器硅基部分的制备,为下一步聚合物工艺打下基础。

With the development of microelectronics, metal interconnect has become the major limitation for the further im- provement of the integrated circuits performance, due to the relatively low bandwidth, high delay and large power consump- tion of metal wires. Optical interconnect is one of the feasible solution for the next generation integrated circuits. Optical modulator, as a basic building block for optical interconnect, has attracted much research interest in recent years. In this pa- per, we propose a novel duabslot silicon electr^optic modulator, consisting of a Fabry-Perot microresonator in a waveguide. The modulation is enabled by using the high linear electro-optic effect in the polymer material filled in the slots. To reduce the mode conversion loss and to simplify the electrode design, a mode converter is used to connect the regular silicon ridge waveguide to the dual-slot waveguide. The device performances are analyzed using numerical simulations and optimum design parameters are given. We also present the preliminary fabrication results for the device with SEM images showing that waveguide width, etch depth and side wall roughness can be well controlled usin~ CMOS fabrication facilities.