Plasma etching is a form of plasma processing used to fabricate integrated circuits. It involves a high-speed stream of glow discharge (plasma) of an appropriate gas mixture being shot (in pulses) at a sample. The plasma source, known as etch species, can be either charged (ions) or neutral (atoms and radicals). During the process, the plasma will generate volatile etch products at room temperature from the chemical reactions between the elements of the material etched and the reactive species generated by the plasma. Eventually the atoms of the shot element embed themselves at or just below the surface of the target, thus modifying the physical properties of the target.
MATERIAL | GAS USED |
---|---|
Aluminum (Al) – anisotropic | Cl2 + BCl3 |
Aluminum (Al) – isotropic | Cl2 + BCl3 |
Aluminum Gallium Arsenide (AlGaAs) | SiCl4 + BCl3 + Ar |
Aluminum Nitride (AlN) | Cl2 + BCl3 |
Black Diamond | CF4 |
BPSG | CHF3/ (02 or Ar) |
Carbon (C) | O2 + Argon |
Chrome (Cr) | Cl2 + O2 |
Copper (Cu) | BCl3 + Cl2 (heat) |
Epoxy | O2 + %5 CF4 |
Gallium Antimonide (GaSb) | Ar + Cl2 (5:1) |
Gallium Arsenide (GaAs) – thinning | Cl2 + BCl3 (isotropic) |
Gallium Arsenide (GaAs) – profile | Cl2+BCl3 (anisotropic) |
Gallium Arsenide (GaAs) | Cl2 + BCl3 |
GaAs/AlGaAs – selective etch | SF6 + BCl3 |
Gallium Nitride (GaN) | Cl2 |
Gold | HBr + BCI3 |
Graphite (C) | O2 + Argon |
Indium & Aluminum – containing III-V’s | HBr + BCI3 |
Indium Phosphide (InP) | CH4 + H2 |
Indium Phosphide (InP) | HBr + BCI3 |
Iridium (Ir) | SF6 |
Molybdenum (Mo) | SF6 |
Oxynitride | CF4 + 5% O2 |
Photoresist | O2 |
Platinum | Cl2, Ar (90oC) |
Polyimide | O2 + Ar |
Polysilicon – isotropic | Cl2 |
Polysilicon – anisotropic | Cl2 |
PSG | CF4 / (O2 or Ar) |
Quartz | CHF3 + CF4 |
Sapphire (Al2O3) | BCl3 |
Silicon (Si) | CF4 + 2% O2 |
Silicon Carbide (SiC) | NF3 + O2 |
Silicon Dioxide (SiO2) | CF4 + CHF3 |
SiLK (Pr) | CF4 |
SU8 (Pr) | O2 + CF4 |
SU8 (Pr) | O2 + Ar + CF4 |
Silicon Nitride (Si3N4) | SF6/O2 or CF4/O2 |
Tantalum – anisotropic | CF4 + O2 |
Tantalum – isotropic | CF4 + O2 |
Tantalum Nitride (TaN) | CF4 + O2 |
Titanium (Ti) | Cl2 + BCl3 |
Tinitride (TiN) | CF4 + O2 |
Titanium Tungsten (TiW) – isotropic | SF6 |
Titanium Tungsten (TiW) – anisotropic | SF6 |
Tungsten (W) – isotropic | SF6 |
Tungsten (W) – anisotropic | SF6 |
Amorphous Silicon | SiH4 |