Electrostatic chuck (E-Chuck) | Application

Release: 2020-04-22, Modified: 2025-11-07, N.T.

An electrostatic chuck (E-Chuck or ESC) is a device that holds and secures a workpiece using electrostatic force. When a voltage is applied to electrodes embedded within the chuck, it induces charge separation in the workpiece. This creates a strong attractive Coulomb force between the workpiece and the chuck surface, holding it firmly in place.

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 (JR) type, which uses a slightly conductive dielectric material. A small leakage current flows across the interface between the workpiece and the chuck, generating a powerful attractive force through electrostatic polarization. The Coulomb-force typeis the more prevalent of the two, accounting for approximately 60% of ESC applications.

Since electrostatic chucks do not require mechanical clamps, they are suitable for gripping very delicate workpieces such as silicon wafers, metal foils, and films. For this reason, they are used in semiconductor manufacturing equipment to transport wafers and to hold them securely in place during processing.

Additionally, 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 SEMs, a retarding field method is sometimes employed. This technique involves applying a high negative voltage to the E-Chuck to decelerate the primary electron beam just before it impacts the wafer. This reduces beam-induced damage and charging effects, enabling high-resolution imaging at low landing energies.

Matsusada Precision manufactures a wide range of high-voltage power supplies, including specialized models for electrostatic chucks. We have a wide range of power supplies for electrostatic chucks that are compatible with both Coulomb force and Johnsen-Rahbek (JR) types. We also offer custom-designed power supplies tailored to specific customer requirements. Please contact us for more information.