Electrostatic chuck (E-Chuck) | Application

Release: 2020-04-22, Update: 2025-05-07, N.T.

An electrostatic chuck (E-Chuck, ESC) is a chuck that absorbs and fixes (chucks) a workpiece by using an electrical force that causes objects to attract each other with static electricity. E-Chucks are primarily used in semiconductor manufacturing equipment to clamp semiconductor wafers. When positive and negative voltages are applied to the internal electrodes of the chuck while the workpiece is placed on the chuck, the electric charges in the workpiece move so that they are attracted to the internal electrodes. This generates a Coulomb force between the electrodes and the workpiece, and the workpiece is adsorbed to the chuck.

Electrostatic chucks are divided into two types based on their chucking method. One is the Coulomb force type, which uses an insulating material as the dielectric. The other is the Johnsen-Rahbek-force type, in which a small current flows through a small gap at the interface between the object and the dielectric, causing electrostatic polarization and induction. The Coulomb-force type ESC is used slightly more often, accounting for about 60% of cases.

Since electrostatic chucks do not physically restrain objects, they are suitable for gripping very delicate workpieces such as metal foils and films. For this reason, they are used in semiconductor manufacturing equipment to transport wafers and as chucks during processing.

In other cases, electrostatic chucks are used in Critical Dimension Scanning Electron Microscope (CD-SEM) and Defect Review SEM (DR-SEM), which are used for inspection during semiconductor manufacturing. In these SEM electrostatic chucks, a retarding method is sometimes used in which a high voltage is applied to the electrostatic chuck to relatively decelerate (lower acceleration) the energy of the electron beam in order to reduce the effect of the electron beam on the wafer.

Matsusada Precision is a manufacturer of high voltage power supplies, and also produces specialized electrostatic chuck power supplies. We have a wide range of power supplies for electrostatic chucks that are compatible with both Coulomb force and Johnson-Rahbek force types. We also offer custom-designed and proprietary power supplies tailored to specific customer requirements. Please contact us for more information.