Spin coating is used by several industries to apply thin but uniform liquid films to a given substrate. While this method produces very uniform coatings over much of the substrate, near the periphery of the substrate, defects in the coating, sometimes referred to as edge beading, often occur. This paper explores the usage of a two-axis spin coating technology that leads to a more uniform film thickness near the edge of the substrate. By rotating the substrate on an axis parallel to the substrate, centrifugal forces are generated that act both normal and parallel to the substrate. These forces are known as elevated gravity and act to even out any existing coating irregularities and also to drain liquid toward the edge of the substrate. This study investigates the effect of elevated gravity on the coating dynamics of a photoresist liquid film on a circular silicon wafer. Using lubrication theory, we derive a modified evolution equation that includes the effects of elevated gravity. We solve this equation numerically using implicit finite differences. Four layers of a photoresist film are spin coated on 3-inch circular wafers using a two-axes spin technology under various elevated gravity conditions. The thickness of the dried coating layers near the periphery of the substrate is measured using a SEM device. Both the experiments and the simulations show that edge beading defects can be substantially reduced for the 500g elevated gravity case compared to the normal 1g gravity case.

旋涂被多个行业用于将薄而均匀的液膜施加到给定的基材上。虽然这种方法在大部分基材上产生非常均匀的涂层，但在基材周边附近，涂层中经常出现缺陷，有时称为边缘卷边。本文探讨了双轴旋涂技术的使用，该技术可在基板边缘附近形成更均匀的薄膜厚度。通过在平行于基板的轴上旋转基板，产生垂直于和平行于基板作用的离心力。这些力被称为升高的重力，用于消除任何现有的不规则涂层，并将液体排向基材的边缘。本研究调查了重力升高对圆形硅晶片上光刻胶液膜涂层动力学的影响。使用润滑理论，我们推导出一个修改后的演化方程，其中包括重力升高的影响。我们使用隐式有限差分对这个方程进行数值求解。在各种升高的重力条件下，使用双轴旋转技术将四层光刻胶膜旋涂在 3 英寸圆形晶圆上。使用SEM装置测量基底周边附近的干燥涂层的厚度。实验和模拟均表明，对于 500 我们使用隐式有限差分对这个方程进行数值求解。在各种升高的重力条件下，使用双轴旋转技术将四层光刻胶膜旋涂在 3 英寸圆形晶圆上。使用SEM装置测量基底周边附近的干燥涂层的厚度。实验和模拟均表明，对于 500 我们使用隐式有限差分对这个方程进行数值求解。在各种升高的重力条件下，使用双轴旋转技术将四层光刻胶膜旋涂在 3 英寸圆形晶圆上。使用SEM装置测量基底周边附近的干燥涂层的厚度。实验和模拟均表明，对于 500g升高的重力案例与正常的 1 g重力案例相比。