Research On DMD Control System Of Lithography Machine Based On FPGA

Lithography technology is one of the core technologies in the development of modern electronic information.DMD(Digital Micromiror Device),as the core device of the lithography machine,has the advantages of high speed,flexibility and secondary development.It has broad application prospects in the semiconductor integrated circuit,3D digital lithography and other industries.With the improvement of DMD drive control technology,continuous scrolling scanning exposure mode is realized.At present,DMDbased lithography technology has problems such as low exposure speed and insufficient accuracy in actual production applications.This article is based on FPGA to study the DMD digital lithography system.Realize the optimization of the processing and exposure control of the exposure image of the lithography machine based on FPGA.Aiming at the low efficiency problem of existing DMD digital lithography in scanning exposure work,a DMD high-speed image exposure method is designed.This paper adjusts the image processing of the host computer to FPGA-based image processing,and realizes the cutting of exposed images by FPGA,which solves the problem of insufficient FPGA resources.The SDRAM memory module is designed to pre-store the processed binary image data.When receiving the synchronization signal of the motion platform,the FPGA reads the data in real time and transmits it to the DMD at high speed and flips it to achieve high-speed exposure.Finally,a single-strip scanning exposure was realized on the experimental platform,and the traditional exposure and high-speed exposure time were tested and compared.The exposure rate was increased by 4 to 5 times compared with the traditional exposure rate.Exposure accuracy is also an important index that lithography equipment needs to meet.In this paper,an improved gray-scale modulation technology is designed,through the DMD tilting a certain angle and the displacement compensation of the moving platform,to realize the superposition of the exposure image misalignment.In this paper,the tilt angle of 45? is taken as an example.The superimposed pixel width of two adjacent frames of data is ?2/2 times the size of the micromirror unit,and the theoretical accuracy value can reach 7.6 ?m.It can be analyzed by the tilt principle.The smaller the tilt angle,the realization the higher the exposure accuracy,the more complicated the corresponding compensation algorithm.The simulation of the single pixel of the exposure image with DMD tilt angle of 0? and 45? was carried out.Finally,the experiment verified that after the DMD was tilted 45?,the accuracy of the exposure line width of the movement platform displacement compensation was increased by 30% to 40%.This article implements a high-performance DMD scanning exposure controller based on FPGA in the Vivado development platform.Make full use of FPGA's powerful timing control and high-speed data transmission capabilities,optimize the DMD control system process,and control the DMD to refresh data at the maximum speed.Through the analysis of DMD data loading and control sequence,the rationality and feasibility of the design are verified.The experimental results show that the FPGA-based DMD control system of the lithography machine designed in this paper effectively improves the exposure efficiency and accuracy of the lithography machine.