Dynamic transition in etching with poisoning

Area of Science:

• Surface science
• Statistical physics
• Materials science

Background:

• Etching crystalline solids involves particle flux and surface reactions.
• Impurities can significantly alter etching dynamics and surface morphology.
• Understanding phase transitions in such systems is crucial for materials processing.

Purpose of the Study:

• To investigate a lattice model for crystalline solid etching with impurity deposition.
• To characterize the phase transition and universality class of the etching process.
• To analyze interface dynamics and roughening behavior.

Main Methods:

• Development of a lattice model incorporating normal and lateral erosion.
• Simulation of etching particle flux and impurity formation.
• Numerical analysis in d=1 and d=2 dimensions to confirm theoretical mappings.

Main Results:

• A continuous transition to a pinned phase was observed as impurity formation probability increased.
• The transition was identified as belonging to the directed percolation (DP) universality class.
• Interface width scaling exhibited crossover from DP to Kardar-Parisi-Zhang (KPZ) behavior near the critical point.
• Anomalous roughening at criticality was characterized by a roughness exponent related to DP exponents.

Conclusions:

• The etching process with impurities exhibits directed percolation criticality.
• Interface dynamics transition from critical DP behavior to KPZ scaling near the critical point.
• The findings suggest potential for anomalous roughening in real etching systems.