Study of chucking force distribution according to substrate pattern and deformation characteristics of electrostatic chuck for deposition

An electrostatic chuck is a device used for the force between charges applied between two parallel plates to attract and secure substrates, such as wafers or OLED panels. Unlike mechanical adhesion methods, which rely on physical fixation, this method uses electrostatic forces for adhesion, making it crucial to verify the chucking force. As the size of the substrate increased, deformation due to gravity or the chucking force also increased, and the chucking force decreased sharply as the distance between the chuck and the substrate increased. This distance between the chuck and the substrate is represented by an Air Gap. With the trend of displays shifting from small to large OLEDs, the consideration of substrate deformation has become necessary. In this study, to verify substrate deformation through various patterns, a simplified 2D model using Maxwell, an electromagnetic field analysis program, and Mechanical, a static structural analysis program, both by Ansys, was utilized to observe changes in adhesive force. Additionally, 3D modeling was applied to verify the adhesive force and deformation according to the voltage and size of various patterns. • As the substrate size increases, deformation also increases, making it crucial to minimize air gaps to maintain optimal chucking force. • Changing the substrate shape rather than the electrode pattern was found to be more effective in increasing chucking force. • The analysis results indicate that the deformation is influenced more by the shape of the electrode than by the chucking force.