REASON | DESCRIPTION |
---|---|
Arcing at wafer or chamber wall | Arcing
is an electrical breakdown due to:
Particles are negatively charged and injected into the plasma bulk. Due to the balance of electrical force and gravity, they remain at the border of plasma sheath and plasma bulk. Likely, they will fall onto the wafer surface when the plasma is turned off. For more details, please refer to the Plasmetrex' "Plasma School for Semiconductor Manufacturing." |
Flaking at chamber wall |
The build-up of byproducts at the chamber
wall leads to flaking if the layers become
too thick. In
particular, a magnetic field can cause a large non-uniformity of the
polymer build-up and flaking. CF4 etch chemistry in a chamber with a ceramic dome can cause AlF3 particle generation. Particle generation is increased by:
|
Chemical reactions in plasma bulk | The
generation of particles is a result of unwanted chemical vapor
reactions in the
plasma bulk, at the chamber wall, and at the wafer. It depends on
chemistry (CF4, Cl, or HBr). Example:
|