The Research And Implementation Of Single Chip Integrated Photodetector

With the development of silicon photon integration technology,optical interconnection has become an ideal way of on-chip interconnection and inter-chip interconnection because of its advantages of high bandwidth,low delay,low energy consumption and high anti-interference.Typical optical interconnections include optical modulators at the transmitter,photodetectors at the receiver,and dielectric optical waveguides connecting optical modulators and photodetectors.Optical devices compatible with materials,structures and processes are the key to achieve monolithic integration.However,there is still a lack of more economical and feasible photodetectors for monolithic integrated optical interconnection.Conventional optical interconnection is widely used in the 1.55 ?m near-infrared band,where we propose a novel waveguide optical detector scheme compatible with complementary metal oxide semiconductor integrated circuit processes and designed in structure and process.In structural design,First,Based on the pattern theory,three single mode ridge waveguide structures are analyzed and designed,And then the software Lumerical MODE is used to simulate the three structures,The cross-finger electrode structure and Ti/Au and Pd/Au metal electrode materials were adopted.In process design,First,we designed a set of economical and feasible device process,and the corresponding single step processes such as cleaning,lithography,etching,stripping and graphene transfer were explored,Some feasible experimental parameters were found out,Finally,the Raman test of graphene is carried out,Raman test results show that the use of TTG can transfer graphene well.Meanwhile,In this paper,the visibility of transferred graphene is studied from simulation and experiment,MATLAB simulations show that,At specific silica and silicon nitride film thicknesses,The optical contrast of graphene can increase significantly,When the thickness of silica and silicon nitride is 2547 nm and 320 nm,respectively,A turquoise source of 500 nm as background light,The contrast between graphene and the surrounding medium can exceed 0.3,The contrast experiment of graphene/silicon nitride/silica/silicon dioxide multilayer structure with silica thickness of 2330 nm and 2690 nm,The experimental results are different from the theoretical simulation,The reason is that there is a deviation between the thickness of the material deposition and the wavelength of the light source,It is of guiding significance to improve the fabrication process and test method.For the visible optical band communication,this paper studies photodetectors based on conventional integrated circuit processes.A number of silicon optical detector structures were designed and analyzed using 0.18 ?m process,using photoelectric response test system and finally the test results.Then the photoelectric response test system is used to test the responsivity of these devices.Finally,the test results are analyzed.The test results show that the deeper ldw/psub knot doped with shallow nw/psub junctions in silicon materials has high responsiveness,and the analysis is that light first penetrates the shallow nw_psub junction and then the deeper ldw/psub junction,and the light energy gradually decreases with the penetration depth.The segmented multi-nw/psub junction devices are less responsive than a single nw/psub junction device because the segmented distance extends the carrier collection capacity,making most carriers compound before reaching the electrode.For all devices,the responsiveness is a maximum at a 750 nm visible light wavelength,at about 0.26 A/W.