Application Of Super Resolution In The Photoelectric Detection

With the rapid development of semiconductor integrated circuit, technology of Optical Critical Dimension(OCD) for microelectronics is coming to the nano field, and it will face a new challenge. The scattering measurement technique is widely used in different kinds of important applications due to its many advantages. OCD, as a non-destructive, convenient, efficient measurement technology has been used as the main method for CD(critical dimension) measurement and analysis for microelectronic structure. However, its resolution is restricted by the diffraction limit that can not exceed half of its operating wavelength. The emerging of super-resolution technologies may improve the resolution of OCD technology as well as measurement accuracy. The title of this article is the application of super-resolution in the photoelectric detection, since the scope of the photodetector is too large, so in this article, super-resolution technology is primarily applied in a OCD technology.Firstly, the thesis introduced the model of Metal lens and its theoretical derivation for breaking diffraction limit. Then, the CST software is used for modeling metal lens, setting up the line light source and the far field antenna to get the time domain and frequency domain information of line source. Based the information received by an antenna, the spectrum of light source be obtained. Compared the performance of anti-metal lens can obtain the effect of super-resolution. By improving the microwave band of the metal lens, the diffraction limit of the simulation results in light wave band is λ/34. Secondly, introduced the electromagnetic theory of anisotropic materials, and the CST software is used for modeling cylindrical lens device that consisting of concentric hyperbolic anisotropic material, using light as a transmission line source, placed it on the inner wall of the cylindrical device, images can be enlarged, in the outer wall, the simulation results of resolution is λ/15. Finally, the metal lens technology is applied in OCD, measured reflection efficiency, and using MATLAB fit the parameters of the grating, as compared to anti-metal lens grating parameters measuring by experiment, the error from the original 8%increasing to 3%.Although super resolution technology mentioned in this thesis are reached λ/34 and λ/15, currently only limited in theoretical simulation, applying it to the project needs further study. Compared with measured parameters of grating disusing super resolution technology by experiment, the error has been reduced to improve the measurement accuracy.