凹球面涂布光刻胶均匀性研究

通过对离心法在凹球面上涂布光刻胶过程进行分析，阐明了离心状态下光刻胶在凹球面基底上的流动机理，结合试验提出影响凹球面涂布光刻胶膜厚均匀性的主要因素有胶液粘度、旋涂速度、旋涂时间，列举了以上因素引起的各种现象，并进行了理论分析。引用凹球面旋涂光刻胶的膜厚公式，建立了膜厚与速度关系数学模型；利用流体力学原理解释了有限圆形空间中流体速度对膜层均匀性的影响，从而解决了大曲率凹球面上制备微细图形结构的关键工艺问题，对非球面上制备微细图形具有借鉴作用。

Uniformity of photoresist film coated on concave sphere

The flow mechanism of the photoresist on the concave sphere under centrifugal state is elaborated by the analysis of the photoresist coating process with centrifugation force. The critical factors that affect the evenness of photosensitive resist and the film forming quality, such as viscosity of photoresist solution, velocity of spin coating and time of spin coating, are investigated with experiments. The various phenomena occurred due to these factors are listed and analyzed theoretically. A mathematic model which describes the relationship between layer thickness and velocity is established by quoting the formula for the spin coating of photoresist film on the concave sphere. The effect of the fluid speed on the uniformity of the layer in the limited circular space is explained according to the principle of fluid mechanics. Accordingly，the key technology for preparing microstructure patterns on the concave spherical surface is achieved.