When the Particle release specification is Specify current, the Etch subnode is available from the context menu (right-click the Wall parent node) or from the Physics toolbar, Attributes menu, which computes the etch rate due to the impact of particles.

Select an Angular dependence model: Argon on polysilicon (the default) or Expression. Argon on polysilicon defines the dependence of the etch rate on the angle of incidence by using an empirical model for the impact of argon ions on polysilicon. For Expression enter an Angular dependence function Y (dimensionless). The default is 1.

Enter a Threshold energy Eth (SI unit: J). The default is 50 eV.

Enter a Slope of etch yield curve Y (SI unit: J). The default is 625 eV.

Enter a Plasma type: Collisionless (default) or Collisional. For Collisional enter a value or expression for the Normal ion current density n · Ji (SI unit: A/m2). The default is 0. If the normal ion current density is computed by another physics interface then it can be selected from the list.

The following settings are required if the Angular dependence model is set to Expression.