title: Crystal Orientation Dynamics of Collective Zn dots before Preferential Nucleation.
abstract: The island nucleation in the context of heterogeneous thin film growth is often complicated by the growth kinetics involved in the subsequent thermodynamics. We show how the evolution of sputtered Zn island nucleation on Si(111) by magnetron sputtering in a large area can be completely understood as a model system by combining reflective second harmonic generation (RSHG), a 2D pole figure with synchrotron X-ray diffraction. Zn dots are then oxidized on the surfaces when exposed to the atmosphere as Zn/ZnO dots. Derived from the RSHG patterns of Zn dots at different growth times, the Zn dots grow following a unique transition from kinetic to thermodynamic control. Under kinetic-favoring growth, tiny Zn dots prefer arranging themselves with a tilted c-axis to the Si(111) substrate toward any of the sixfold in-plane Si<110> directions. Upon growth, the Zn dots subsequently evolve themselves to a metastable state with a smaller tilting angle toward selective <110> directions. As the Zn dots grow over a critical size, they become most thermodynamically stable with the c-axis vertical to the Si(111) substrate. For a system with large lattice mismatch, small volume dots take kinetic pathways with insignificant deviations in energy barriers.
authors.affiliation: Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Chun-Chu
authors.initials: CC
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Jun-Han
authors.initials: JH
authors.lastname: Huang
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan.
authors.forename: Ching-Shun
authors.initials: CS
authors.lastname: Ku
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan.
authors.forename: Shang-Jui
authors.initials: SJ
authors.lastname: Chiu
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Jay
authors.initials: J
authors.lastname: Ghatak
authors.affiliation: Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Sanjaya
authors.initials: S
authors.lastname: Brahma
authors.affiliation: Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Chung-Wei
authors.initials: CW
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Chuan-Pu
authors.initials: CP
authors.lastname: Liu
authors.affiliation: Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Kuang-Yao
authors.initials: KY
authors.lastname: Lo