Coefficient of Thermal Expansion & Wafer Matching in ESCs
October 9, 2026
Why electrostatic chuck CTE and wafer matching matter: alumina, AlN and silicon expansion, differential stress, particles and thermal uniformity.
ESCT and TEMNEST offer the latest ESC technology to our customers. We are focused on ESC’s, and have full R&D capability with design, fabrication and test under one roof.
Why electrostatic chuck CTE and wafer matching matter: alumina, AlN and silicon expansion, differential stress, particles and thermal uniformity.
We repair all of our own ESC’s.
We repair 300mm OEM ESC’s.
Our own ESC’s can be repaired >3 times, returned to as-new condition. This process is guaranteed and an important part of our sustainability goals to reduce waste. Repairs reduce cost of ownership:
Cost of ownership = Purchase Cost / (extended lifetime * repair cycles)
Lifetime tracking of each ESC is done by serial number, to help customers improve process and ESC cleaning. A record of the ESC test results at Final Test is kept.
ESC’s are Coulomb type using a high impedance non conducting dielectric material Alumina (Al2O3). This has excellent dielectric properties and is durable.
A chucking force P forms between the dielectric layer and the top surface of the wafer when a voltage is applied to the electrode. A chucking voltage V is applied resulting in force P which depends on dielectric constant and thickness of the top Al2O3 layer.
ESC’s can be monopolar or bipolar or inter-digitated, the electrodes are made of a conductive material like Tungsten. Advanced materials used are critical to improved performance and longer ESC lifetime, as well as wafer processing.
All ESC’s are made new to customer order, completely redesigned and tested. 2 basic fabrication techniques are used, both with Al2O3 as the dielectric.
Manufacturing and design are fully ISO certified, also our environmental systems for ISO compliance.
The processes and materials are OEM qualified (major equipment OEM’s), as a fully certified supplier.
ESC lifetime is tracked in our systems each time an ESC goes through final test (manufacture plus repairs), and all processes are reviewed regularly for Continuous Improvement.
To keep up with process developments in the wafer fab, it is necessary to continually develop the ESC materials used. Important considerations are:
New advanced processes, new wafers and materials all demand new ESC solutions.
Our R&D roadmap for materials and fabrication is at the leading edge of ESC technology. We are open to collaboration and joint developments with our partners and customers.
If you are interested to look at future potential solutions for your ESC, please contact us or TEMNEST local representative to discuss.
