Studies On Microelectronic Optical Measurement System Technology Based On Coherent Light

The increasing integration of integrated circuits poses a huge challenge to microelectronic measurement technology.Optical critical dimension(OCD)measurement technology is one of the main technologies in the field of microelectronic structure measurement.Along with the critical size reduction of the microelectronic structure,the sensitivity of the OCD measurement system is reduced,and there are also measurement limits and resolution problems.To solve this problem,we applies the optical system based on coherent light to the OCD measurement system,and uses coherent light to improve the sensitivity of the OCD measurement system.First,scatterometry has important applications in critical dimension measurement of microelectronic structures,especially as an important application for OCD measurement techniques.In-depth discussion and analysis of the positive and inverse problems of the OCD measurement system.The microscopic measurement techniques commonly used in the measurement of microelectronic structures in the industry are further introduced.The advantages and disadvantages of each measurement method are compared and analyzed.Secondly,the causes of the diffraction limit of the optical measuring system are explained.The application of the existing coherent optical optical measurement system in the measurement of critical dimensions of microelectronic structures is analyzed.On this basis,the scheme of OCD measurement system combined with coherent optical system is given,and the coherent optical system is applied in OCD measurement system.And the corresponding theoretical analysis is given.The OCD measurement system combined with coherent light is discussed and analyzed in terms of interference results and system sensitivity.And compared with the existing OCD measurement system results.The MATLAB tool was used to simulate the optical measurement system based on coherent light.In the simulation calculation of the light reflection field of the periodic grating structure,the rigorous coupled wave analysis method(RCWA)is utilized.In the optical path simulation,the theory of wave optics is mainly applied.Finally,in order to better illustrate the scheme,the measurement results of the OCD measurement system based on coherent light are given when the sample to be tested is a one-dimensional periodic grating structure.The system sensitivity underdifferent parameters is given.At the same time,the sensitivity of the traditional OCD measurement system was compared and analyzed.From the comparison results,it is explained that the method of using coherent light effectively improves the sensitivity of the measurement system,and the sensitivity is increased by four times when only adjacent angle interference occurs.Through theoretical analysis and simulation data,it is finally concluded that the coherent optical system is applied to the OCD measurement system,which effectively improves the sensitivity of the measurement system.At the same time,by comparing the inversion results of key dimensions,it can be concluded that the coherent optical system is applied to the OCD measurement system,which improves the measurement accuracy.