Ceramic Electrostatic Chuck (ESC) —— Precision Substrate Clamping for High-Vacuum & Plasma Environments

Ceramic Electrostatic Chuck (ESC) —— Precision Substrate Clamping for High-Vacuum & Plasma Environments

In advanced semiconductor fabrication and thin-film deposition, conventional mechanical or vacuum clamping methods fail to meet the ultra-clean, high-vacuum, and temperature-controlled requirements of sub-nanometer processing. Our Ceramic Electrostatic Chucks (ESC) utilize Coulombic or Johnsen-Rahbek (J-R) electrostatic forces to securely clamp wafers and substrates without mechanical edge contact, delivering exceptional temperature uniformity, wafer flatness, and particle reduction.

Technical Mechanisms & Types

We engineer both primary electrostatic chuck configurations tailored to specific processing environments:

• Johnsen-Rahbek (J-R) Type Ceramic ESC: Manufactured using semi-conductive ceramic formulations (such as doped Alumina or Silicon Carbide). Utilizing micro-leakage currents at the wafer-chuck interface, J-R chucks generate immense electrostatic clamping forces at lower operating voltages, making them ideal for high-density plasma etching and PVD/CVD processes.

• Coulombic Type Ceramic ESC: Constructed with high-purity insulating ceramics. Clamping relies entirely on pure electrostatic charge accumulation, providing stable clamping across broad temperature ranges and ultra-fast de-chucking capabilities for sensitive dielectric materials.

Key Advantages

1. Exceptional Thermal Control & Uniformity

Integrated with multi-zone resistive heating elements and embedded helium cooling channels, our ceramic ESCs ensure precise wafer temperature distribution ($le pm 1^circtext{C}$ across $300 text{mm}$ wafers), critical for critical dimension (CD) control in etching and deposition.

2. High Corrosion & Plasma Resistance

Engineered from advanced technical ceramics such as High-Purity Alumina ($Al_2O_3$) and Aluminum Nitride ($AlN$), the chuck surface resists aggressive halogen plasmas ($F_2$, $Cl_2$) and reactive gases, minimizing chamber particle generation and extending operational lifespan.

3. Ultra-Flat Surface & Particle Suppression

Micro-machined mesa (pin) patterns on the ceramic surface drastically reduce the contact area between the wafer backside and the chuck, preventing backside particle contamination and maintaining superior wafer flatness ($le 1 mutext{m}$).

4. Fast Response & Reliable De-Chucking

Optimized dielectric layers and advanced power control allow for rapid chucking and de-chucking cycles, eliminating residual electrostatic charge and maximizing wafer throughput.

Typical Applications