Study On Coating Process Of Photoresist And Its Application Based On Piezoelectric Spray Coating

The rapid development of the integrated circuit makes lithography get more and more attention,lithography is a new micro-fabrication technology.Its coating is a key link,which plays an important role in the quality of the subsequent lithography process and gradually becomes a hot research topic recently.Because of high utilization rate of materials,good repeatability,large area of coating and no influence of substrate morphology,piezoelectric spray coating has been widely used in various fields.Due to thickness,uniformity and adhesion of photoresist film made by piezoelectric spray coating are required difference in various fields,the research for the influence of related process parameters on the quality index and adhesion of the photoresist film made by piezoelectric spray coating is of great significance,which can improve the quality and application value of the photoresist film.Firstly,the process of piezoelectric spray coating was expounded in detail through analysis of the working principle on piezoelectric transducer and cavitation effect.The physical model of film was analyzed and the mathematical model of film thickness was established,which provided theoretical basis for the study on process of photoresist film made by piezoelectric spray coating.Secondly,the paper set up a set of the photoresist coating system of piezoelectric spray coating,with the characteristics of separation modularization and vacuum seal.The system consists of three parts:hardware,software and electric,which could meet the requirement of the experiment and reduced the cost of the equipment.In addition,the system was assembled and debugged,which realized the functions of the gathering atomization of nozzle and the photoresist coating under different substrates.Thirdly,the research for the quality index of positive and negative photoresist film made by piezoelectric spray coating through different dilution ratio and flow volume,different preheating temperature and air pressure,different distance and power,different speed and substrates and different dilution solvent and layers based on the system set up.The result showed that the regularity for quality index of positive photoresist film influenced by these parameters was consistent with negative photoresist film,and due to the intrinsic properties of negative photoresist,the numerical value of positive photoresist film influenced by these parameters was different from negative photoresist film.In addition,the research for the adhesion of positive and negative photoresist film made by piezoelectric spray coating through different dilution volume ratio and preheating temperature,different prebake temperature and time and different substrates and dilution solvent.The result showed that the adhesion of positive and negative photoresist film had some significant changes influenced by these parameters.Finally,the application of photoresist film made by piezoelectric spray coating was explored.The application of photoresist film in lithography needed to be explored,because the subsequent process of lithography was influenced by the quality of the photoresist film.Meanwhile,compared with spin coating,the research for coating photoresist on silicon with square structure,boss structure and three-dimensional zigzag section through piezoelectric spray coating,which proved coating photoresist based on piezoelectric spray coating could be applied in the substrate with irregular shape and showed the great potential in the integrated circuit and 3D structure.However,the thickness of photoresist film made by piezoelectric spray coating was not controllable,and its surface was not uniform,so the process still needed to be further studied.