Physical Characteristic Effects of Contact Hole Reflow

Abstract

The thermal reflow process is one of many processes used for pattern shrinkage and resolution enhancement technology. In this study, we try to describe the shrinkage phenomena of linear static in contact hole patterns by the finite element method. The resist of thermal flow is designed as a circular saw blade for linear conduction thermal analysis. Using a commercial tool such as I-DEAS, the values of the modeled parameters corresponding to the resist parameters of shrinkage and deformation due to thermal reflow are extracted from a comparison of the experimental results. The contact hole patterns are linearly reduced due to the increase in temperature and the increase in heat flux. Hence, for the linear static phenomena, these mechanical simulations predict the contact hole patterns after thermal reflow. Also, we describe the effect of surface tension during the thermal reflow. In the thermal reflow process, as the temperature increases, the bottom corner edges of the resist profile are sharper below a specific temperature and more round above the same temperature. Using the description of surface tension effects in spin coating, it is shown that these phenomena are due to the surface tension.