CMOS Compatible Optical Microring Controller And Fully Differential Photodetector

The 21 st century is the century of information.The rise of big data,cloud computing,internet of things,artificial intelligence and other industries is accompanied by the exponential growth of the volume of data,which brings forward higher request to the transmission and processing of information.With the device size approaching the physical limit,the performance of traditional integrated circuits can't be enhanced as fast as before so that the needs of social development could not be met.However the interconnection and communication technology based on light have advantages that are incomparable to circuits in terms of speed,bandwidth,and anti-jamming ability,which make the integration technology of photonic and electronic the best way to break through the bottleneck of the development of integrated circuits and the key means to improve the performance of integrated circuits in the post-Moore era.Both optical microring resonators and photodetectors are important components of optoelectronic integration technology.The former with simple structure and compact in size has many optical properties,such as filtering,tuning,coherent superposition and so on,and can be widely used in wavelength division multiplexing,resonant filtering and wavelength detection.However,optical microring is very sensitive to thermal fluctuations and process errors so that it can't be used in many applications.The latter plays the role of photoelectric conversion which is the bridge between light and electricity.However,due to the indirect band gap of silicon-based materials,the photosensitivity of silicon-based monolithic integrated photodetectors is low and the full differential detection is seldom reported.In order to help solve the above two problems,this paper based on the standard CMOS technology to study the optical micro-ring stability system and fully differential optical detector,and the main research works are as follows:1.An optical micro-ring temperature control chip is designed by using standard 0.8um CMOS technology.The temperature control principle of the chip and the stability compensation principle of the micro-ring are analyzed theoretically,and tape-out and test are carried out.The temperature control chip consists of three parts: temperature detection,comparative amplification and on-off control of heating.The test results show that the chip has a temperature sensitivity of-5.1 mV/? and a temperature control precision of ±1?.The heating power can be adjusted automatically to keep the chip temperature in the temperature changing environment.2.The fabrication technology of new optoelectronic devices based on two-dimensional materials is studied.Graphene/MoS2 heterojunction photodetector is designed and fabricated on the SiO2/Si substrate by standard microelectronic nanofabrication technology,and the photocurrent response of measurement is analyzed theoretically.Under white light irradiation,the sensitivity of the detector can reach 2435A/W,and the difference characteristics can be observed obviously in the light response curve of Graphene/MoS2 heterojunction photodetector.3.Based on the differential optical response characteristics and the compatibility with silicon-based materials of Graphene/MoS2 heterojunction photodetector,a special differential reading circuit is designed using the standard CMOS process.The differential reading circuit consists of a constant voltage control circuit making the heterojunction detector keep the differential operating state and a differential amplifier circuit which is used to extract the photocurrent to realize differential amplification and voltage conversion.