Research And Simulation On Heat Flow Of Electrostatic Chuck In HDPCVD Equipment

Electrostatic chucks are commonly used for wafer adsorption and temperature control in advanced semiconductor manufacturing equipment.In the High Density Plasma Chemical Vapor Deposition(HDPCVD)process,it is necessary to precisely control the wafer temperature through the electrostatic chuck to deposit higher quality films without damaging the internal wiring of the wafer.Therefore,it is very important to analyze the heat transfer characteristics of the electrostatic chuck system and establish the heat flow theory and simulation model of the wafer and electrostatic chuck system.This paper focuses on the analysis of the development of integrated circuit manufacturing technology and chip manufacturing process,as well as the main equipment used in it.The structure and application of electrostatic chucks are summarized,and electrostatic chucks are classified according to their working principles.In this study,after referring to a large number of research results and methods,the theoretical study of the thin gas heat transfer and contact heat transfer between the wafer and the electrostatic chuck was carried out,and the steady-state theoretical heat transfer model of the electrostatic chuck system in the HDPCVD chamber was established.An in-situ experimental platform for HDPCVD chamber was built,which can accurately measure the wafer temperature under high-density plasma.Using the existing electrostatic chuck samples,the heat transfer characteristics between the wafer and the electrostatic chuck were experimentally studied by controlling the pressure of heat-conducting helium and the RF power,and the steady-state temperature data of the wafer were obtained.At the same time,combined with the theoretical model,the heat transfer coefficient of heatconducting helium and the contact heat transfer coefficient between the wafer and the electrostatic chuck are obtained under typical working conditions.The heat transfer characteristics of the electrostatic chuck system were analyzed and summarized by drawing the relationship curves of heat transfer coefficient,RF power and helium pressure.Combined with the theoretical model parameters,the heat flow simulation model of the electrostatic chuck system was established through the multi-physics coupling simulation software COMSOL,and the correctness of the model was verified by comparing with the experimental results.Further,through the simulation model,the temperature uniformity of the wafer under the contact condition and the heat conduction helium is studied,and the main factors affecting the temperature uniformity of the wafer are analyzed.A low-cost verification method and design direction are provided for further improving wafer temperature uniformity.