基于紫外光刻的双轴张应变Ge/SiGe多量子阱电吸收调制器

Biaxially tensile-strained Ge/SiGe multiple quantum wells electro-absorption modulator based on ultraviolet lithography

采用紫外光刻工艺(ultraviolet lithography technique,UVL),在互补金属氧化物半导体(complementary metal oxide semiconductor,CMOS)兼容的硅基平台上制作了基于悬空微桥结构在Ge/SiGe多量子阱材料中引入双轴张应变的低偏振相关电吸收调制器。利用拉曼光谱测试了器件引入双轴张应变的大小,并对器件在横电(transverse electric,TE)偏振和横磁(transverse magnetic,TM)偏振下的光电流响应、调制消光比和高频响应等性能进行了测试。器件的低偏振相关消光比在0 V/4 V工作电压下可达5.8 dB,3 dB调制带宽在4 V反向偏置电压时为8.3 GHz。与电子束光刻工艺(electron beam lithography technique,EBL)相比,采用UVL制作的器件在调制消光比、高频响应带宽等性能上略差一点,但具有曝光时间短、成本低和可大批量生产等优势,应用前景广阔。

A low polarization-dependent Ge/SiGe multiple quantum wells electro-absorption modulator by introducing biaxial tensile strain through suspended microbridge structure is fabricated on complementary-metal-oxide-semiconductor(CMOS)compatible silicon platform using ultraviolet lithography technique(UVL).The biaxial tensile strain of the fabricated device is measured through Raman spectroscopy,and the photocurrent response,modulation extinction ratio and high frequency response of the device are tested under both of transverse electric(TE)and transverse magnetic(TM)polarization.The device presents a low polarization-dependent extinction ratio of 5.8 dB under 0 V/4 V operation,together with a 3 dB modulation bandwidth of 8.3 GHz at 4 V reverse bias voltages.Compared with electron beam lithography technique(EBL),although the device fabricated through UVL performs a little worse in modulation extinction ratio and high frequency response bandwidth,it has the advantages of short exposure time,low cost and enabling mass production,which has broad application prospects.