Wafer face shape control model based on automatic spindle inclination adjustment

Abstract

The total thickness variation (TTV) of a wafer is an important indicator of the quality of the wafer grinding process, and the control technology of wafer face shape is the bottleneck of chip manufacturing. However, the existing mathematical models for wafer surface shape control are limited by specific adjustment layouts, making it difficult to achieve automatic control of wafer surface shape. This paper proposes a wafer surface shape control model based on automatic adjustment of the spindle inclination angle, which is suitable for the single-variable automatic adjustment layout of the workpiece spindle. First, this paper explains the limitations of the current adjustment layout in the automatic control of wafer surface shape and presents a new architectural framework for automatic inclination angle adjustment. Secondly, it analyzes the geometric relationship between the wafer face shape characteristic components and the spindle inclination angle, integrates with the principle of coordinate system translation transformation, and constructs the mathematical model of wafer face shape control. Then, through simulation and experiment, the relative error between the simulated value and the actual value reaches 13%, which verifies the accuracy of the mathematical model. Finally, this paper discusses the diversity of inclination adjustment layouts, reveals the advantages of four special inclination adjustment layouts in withstanding the interference of external errors, and proposes the corresponding adjustment strategies.