Research On Automatic Control Of Nano-films Preparation And Online Measurement Of Thickness

Nano-films are widely used for surface modification and protection of semiconductor materials.At present,magnetron sputtering is the main method for preparing nano-films.Due to the error of the film thickness generated by magnetron sputtering due to random factors,the development of a nano-scale film thickness online detection system and realtime adjustment of process parameters is a technical bottleneck to improve the accuracy and efficiency of similar equipment.Using the flatness detection method and statistical principles of parts as the theoretical basis of the thin-film thickness on-line detection system;the comprehensive use of mechatronics integration technology to complete the development of the on-line detection system.The implementation process mainly includes:(1)learning the theoretical knowledge of topics such as mechanical design,mathematical statistics,and intelligent control of equipment;in-depth understanding of the main working principles of magnetron sputtering equipment;the impact of changes in various process parameters on film performance;The group has an in-depth understanding of the performance of small magnetron sputtering equipment,analyzes the current defects of the equipment,and formulates an overall improved design scheme.(2)According to the specific conditions of the equipment,analyze the advantages and disadvantages of different nano-film thickness detection methods,and determine that the thin-film thickness online detection system uses a laser micro-cantilever detection technology scheme.Improve the design of existing equipment and optimize the design of key components of the equipment.(3)Analyze the key technologies of the laser micro-cantilever,complete the overall design of the online inspection platform,and select the key components.A variety of measurement methods are used to calibrate the accuracy of the detection system,and the host computer design of the online detection system is completed.(4)Comprehensive analysis of the functional requirements of the equipment Complete the selection of the main control PLC and the allocation of the I / O ports.Aiming at the problem that the temperature control accuracy of the existing magnetron sputtering equipment is not high,a high-precision temperature control and temperature measurement module was independently designed.Use SIMATIC Win CC to compile the upper computer,and complete the overall design of the intelligent control system.(5)Complete the assembly and commissioning of the thin-film thickness online detection system and magnetron sputtering equipment.Silver nano-films with different target thicknesses were prepared,and the error between the detection value and the theoretical value was verified by a line detection system.The parameters of the film were verified by 3D optical microscope and SEM to verify the error of the measured value and the actual value of the online detection system.The experiments show that the new equipment runs stably and the functional modules of the online detection system work normally.When the nano-scale thin film of different thicknesses is prepared at one time,the maximum comprehensive error of the film thickness is 4.13%,and its control accuracy and production efficiency have reached the expected goals.