Ceramic ESCs (spray coating)

Electrostatic chucks for wafer clamping (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.

CE-MAT provides ceramic ESCs for several process chambers. The manufacturing of the CESCs is done according Semi-standard.

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 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 micro arcing. 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).

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