Linewidth Of Maskless Lithography Theory And Technology Research

The study of this dissertation consists of three parts: the principle and design of focusing unit in maskless lithographic system, the theory of defocusing lithography for width-variable line, and the reality and application of maskless lithographic system.In order to get an appropriate focusing approach, the stability analysis for defocusing signal based on energy information is firstly proposed. Astigmatic lens approach based on quad-quadrant detector and confocal approach based on single-quadrant detector are then analyzed. Finally, off-axis approach based on dual-quadrant detector is chosen. The detailed research and analysis to the new focusing approach contain algorithm of focus error signal, optimization for optical parameters, elliptic laser spot, physical model of micro-displacement platform, etc.For research of the relationship between linewidth and defocusing lithography, the mathematical model of linewidth in laser scanning is first constructed, and then three linewidth-defocus models are established, which are symmetric linear model, static Gaussian model and dynamic Gaussian model. The relationship between stabilizing linewidth and overexposure theory is also discussed. Those theory and models are well agreed with experimental data.As for the reality and application of maskless lithography, this paper studies the micro-actuator, defocusing sources, dynamic focusing characteristics, system hardware, system software, fabrication of rotation symmetric figure, etc.