Extending defect models for Si processing: The role of energy barriers for defect transformation, entropy and coalescence mechanism
- Resource Type
- Authors
- Iván Santos; Ana Caballo; María Aboy; Luis A. Marqués; Pedro López; Lourdes Pelaz
- Source
- UVaDOC. Repositorio Documental de la Universidad de Valladolid
instname
- Subject
- Nuclear and High Energy Physics
Ostwald ripening
Silicon processing
22 Física
Instrumentation
Si self-interstitial clusters
Atomistic simulations
- Language
Producción Científica
Emergent alternative Si processes and devices have promoted applications outside the usual processing temperature window and the failure of traditional defect kinetics models. These models are based on Ostwald ripening mechanisms, assume pre-established defect configurations and neglect entropic contributions. We performed molecular dynamics simulations of self-interstitial clustering in Si with no assumptions on preferential defect configurations. Relevant identified defects were characterized by their formation enthalpy and vibrational entropy calculated from their local vibrational modes. Our calculations show that entropic terms are key to understand defect kinetics at high temperature. We also show that for each cluster size, defect configurations may appear in different crystallographic orientations and transformations among these configurations are often hampered by energy barriers. This induces the presence of non-expected small-size defect cluster configurations that could be associated to optical signals in low temperature processes. At high temperatures, defect dynamics entails mobility and ripening through a coalescence mechanism.
Ministerio de Ciencia e Innovación (project PID2020-115118GB-I00)