About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Surface Engineering IX
|
| Presentation Title |
Atomistic Mechanisms of Strain Relaxation During Lattice-Mismatched GaN Thin-Film Growth |
| Author(s) |
Yasir Mahmood, Justin Chen, Lucas Hale |
| On-Site Speaker (Planned) |
Yasir Mahmood |
| Abstract Scope |
AlGaN/GaN heterostructures enable high-electron-mobility transistors for next-generation power electronics. However, during deposition, lattice mismatch between the constituent layers can generate residual strain, leading to formation of defects, dislocations, and cracks that degrade film quality. In this work, molecular dynamics simulations were used to investigate strain relaxation mechanism during crystalline GaN growth on in-plane strained substrates. A preliminary parametric study identified the process window for crystalline growth, which was then used to examine the evolution of local strain, lattice distortion, and defect formation. The simulations reveal a progressive relaxation sequence beginning with localized lattice distortion and followed by the nucleation of defects. With increasing mismatch, these defects evolve into dislocations and crack precursors that disrupt film continuity. These findings provide an atomistic description of strain relaxation during lattice mismatched GaN growth and show how deposition process optimization can help preserve crystallinity while suppressing mechanically damaging relaxation pathways. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Electronic Materials, Thin Films and Interfaces, Computational Materials Science & Engineering |