Ceramic ESCs (spray coating)
Electrostatic chucks for waferclamping (ESCs) are used in many dry etch processes and in many deposition applications as well, e. g. PVD and HDP-CVD. ESCs are critical parts from the material side and from their functional side, as they have an very important influence to the process performance in the case of etch rate and uniformity.
Many ESCs of the OEMs have technical or material specific „bottle necks“. Polyimide ESCs can easily fail by electrical mal functions (electrical breakdown). In addition there is a high risk for corrosive attacks by the process atmosphere and mechanical damages.
This also effects the ceramic ESCs from the OEMs, in a which a “ceramic puck” as the functional surface is fixed to the body with an organic adhesive that could be attacked by the process plasma. Some of these ESCs are multipart assemblies with resulting vulnerabilities.
CE-MAT supplies ceramic ESCs as a one-piece components with functional surfaces of high-purity Al2O3 with very high plasma resistance and high electrical breakdown strengths. The ceramic surface of these CESCs reduces the risk of electrical malfunctions and microarcing. The number of particles and the defects on the back of the wafer is reduced dramatically. The lifetime of the components increases by the use of the CESCs. In addition improved uniformity in terms of temperature distribution and etch rate lead into higher yields. As a big advantage of the CESCs waferless-clean processes (insitu-clean) are possible, which would be unthinkable for polyimide ESCs. Regarding the components’ geometries in terms of dimensions, voltage and gas supply, the CESCs fit perfectly to the OEM cathodes and base structures (plug and play).
Due to numerous successful qualifications of the Ceramic ESCs at well-known customers CE-MAT has sufficient references.
In numerous process chambers Lam Research and TEL also work with ESCs, which have a glued-on ceramic puck with an integrated electrode as functional surface. The resulting bond gaps between the ceramic puck and the ESC body may be undercut by the agressive processes plasma. Particle and uniformity problems could occur as consequence of this weak point.
CE-MAT offers Ceramic ESCs for Lam Research and TEL chambers with a technical improvement, as the adhesive gap of the OEM ESCs is constructively covered. Chemical undercut is prevented, the problem of backside particles and uniformity problems is eliminated. The ESCs for Lam Research and TEL chambers are equipped with OEM-like cooling systems, electrical connections and gas supplies, that are also designed according to the „plug and play“ principle. CE-MAT CESCs can be installed without adapters or other changes into the systems of the OEMs.
This also effects the ESCs from SPTS with glued-on „ceramic sandwiches“ as functional surface. CE-MAT provides an optimized technical solution for this type of ESCs as well.
Ceramic ESC advantages
- Longer lifetime
- “Plug and Play”
- no assembling at customer
- less maintanance
- waferless cleaning possible
- no delamination
- no etch in gap under puck / plate
- less particles
- less arcing
- less wafer sticking
- better quality
- lower cost of ownership
|OEM||Chamber||Process||Material of wafer layer (OEM)||He cooling system|
|Centura 5200||Tungsten back etch||Polyimide||Single|
|DPS||Poly etch / Metal etch||Polyimide and ceramic||Single and Dual|
|DPN||Nitride etch||Polyimide and ceramic||Single and Dual|
|DPS+||Poly etch / Metal etch||ceramic AlN||Dual|
|Super-E||Poly etch||ceramic AlN||Dual|
|Ultima||HDP CVD||ceramic Al2O3||Dual|
|Lam Research||TCP||Poly etch||Donut and Base||Single|
|Alliance||Metal etch||Donut and Base||Single|
|Rainbow 4420||Poly etch / metal etch||Donut and Base||Single|
|Rainbow 4520||Oxide etch||Plate / Cap electrode||Single and Dual|
|TEL||Unity||Oxide etch||Polyimide and Ceramic||Single and Dual|
|DRM||Poly etch||Polyimide and Ceramic||Single and Dual|
|SCCM||Polyimide and Ceramic||Single and Dual|