RIE - ICP (helical)
Inductive Coupled Plasma

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  • typical process pressure: 1 - 100 mtorr
  • plasma density: ca 5 x 1011 / cm3
  • RF ("self") bias forms at the substrate electrode
  • Ion Energy (~ RF bias) dependent on the RF table power
  • Ion Current (Plasma Density) dependent on ICP power

Typical Applications:

  • low damage etching of 3-5's
  • high rate anisotropic etch of Si for MEMS applications with high mask selectivity
ICP RIE schematic/ 8 kB

effective electrostatic shielding to avoid the capacitive coupling
component (wall sputtering/ substrate bombardment)

graph: current density vs ICP power with/ without electrostatic screen

current density vs ICP power with/ without
electrostatic screen (at 7 mtorr)

  • lower (substrate) electrode RF driven
  • substrate electrode cooled
  • thermal contact by He backside cooling
  • automatic height adjustment of the substrate electrode
  • gas inlet through source and through distribution ring
  • high conductance pipework
  • parameter: gas flows, pressure, ICP power, table power

similar, older technology: ECR