In recent years, crystal growth processes have attracted great interest because of the importance in semiconductor devices as well as organic devices. In the present articles, experimental innovations to observe crystal growth processes using various microscopic methods are reviewed. Correspondingly, novel approaches in the theoretical investigation of crystal growth processes are also reviewed. Step dynamics including macrostep formation and step bunching, pattern formation, high-quality crystallization, chemical vapor deposition (CVD) process, and various crystal growth environments not only in vacuum but also in liquid and in space are focused.

Faceted macrostep formed at equilibrium is demonstrated based on numerical calculations using the tensor network method and the Monte Carlo method. The adopted model is a lattice model where the surface roughness excitations and the step-step attractive energy (ε_int) are taken into consideration. We calculated ε_int–T and p–T faceting diagrams for faceted macrosteps where T is the temperature, and p is the surface slope for an inclined surface. Applying the faceting diagrams to Si(113)＋(114) surfaces, the step-step attractive energy is approximately 123 meV. We also discuss elementary step attachment/detachment processes to/from the faceted macrostep near equilibrium.

High-quality crystalline organic thin films with large crystalline domain size were fabricated by vacuum deposition, followed by a post-annealing and cooling crystallization from their respective smectic A (SmA) liquid crystal precursor states. Crystallinity, surface smoothness and air exposure stability of ionic liquid crystalline thin films were much improved by this process, and the electric double layer action was for the first time observed at the SmA phase. Moreover, a seeded temperature gradient cooling process from the SmA phase was proposed and its capability was demonstrated in the fabrication of benzothienobenzothiophene derivative thin films, achieving their directional lateral crystal growth with high precision controllability.

We have investigated the propagation of threading screw dislocations (TSD) in the hybrid growth that combines solution growth and sublimation growth. The higher TSD conversion ratio in solution growth is attributed not only to the macrostep height but also to the lateral flow speed of macrosteps which increases the interaction between TSDs and macrosteps. In sublimation growth in the hybrid process, the basal plane defect can be eliminated efficiently by 15° off growth. The energetic stability and activation barrier in the conversion between TSD and basal plane defect have been discussed.

We review our recent study on step-bunching instability (SBI) of ice melt growth, one of the interfacial instabilities driven by self-organization of elementary step flow associated with crystal growth dynamics. With the aid of an advanced optical microscope and its combination with a two-beam interferometer, we realized quantitative in situ observations of the spatiotemporal dynamics of the SBI. This enables us to examine the origin of the SBI at the level of the step–step interaction. Our finding offers a significant clue to understanding the general mechanism of melt growth beyond ice-crystal growth, inseparably involving several broad research fields, including cryobiological, geophysical, and material branches.

Data-driven materials development using first-principles calculations (materials informatics, MI) is widely known. Process informatics (PI), which explores crystal growth processes, is expected to be pioneered as the next research target in materials development. However, simulation techniques for the chemical vapor deposition (CVD) process, which is the core of PI, have not been developed. This paper describes recent progress in simulation technology for CVD processes, with a particular focus on surface modeling.

Microgravity environments such as those on the International Space Station (ISS) are ideal experimental sites for crystal growth. I focused on an interesting phenomenon discovered in an ice crystal growth experiment on ISS, a spontaneous oscillatory growth, and theoretically investigated the mechanism that could reproduce this phenomenon. In this paper, in addition to the introduction of the research results, the importance of the crystal growth research in microgravity environments will be discussed.

Recent first-principles studies on step structures and adatom diffusion on SiC(0001) surfaces are reviewed. SiC is a promising material for next-generation power electronics, and SiC power devices are already on the market. The obtained formation energies of all the possible atomic steps provide a definite identification of the most relevant atomic step for two vicinal directions inclined toward either <1100> or <1120> direction on SiC(0001) surfaces. Relations between the energetics of surface steps and macroscopic step morphology are discussed. Diffusion mechanism for Si, C, and H adatoms which are three important chemical elements of gas sources of chemical vapor deposition (CVD) for SiC is revealed both on the surface terraces and near the surface steps.