Self-Assembled Epitaxial Growth of High Density β-FeSi₂ Nanodots on Si (001) and Their Spatially Resolved Optical Absorption Properties

Abstract

A self-assembly technique for high density (∼1 × 10 11 cm -2 ) β-FeSi 2 nanodots epitaxially grown on Si (001) substrates was developed using a codeposition method of Fe and Si on ultrathin SiO 2 films with Si nuclei. Photoabsorption spectra of individual nanodots and their photoabsorption maps at the direct-transition photoabsorption edge were obtained using electric field modulation spectroscopy combined with scanning tunneling microscopy with a nanometer spatial resolution.

Epitaxial Growth of Iron-Silicide Nanodots on Si Substrates Using Ultrathin SiO2 Film Technique and Their Physical Properties

“…RHEED patterns proved the epitaxial growth of NDs on Si substrates (not shown). In the case of Si(001) substrates, we could also form E-FeSi 2 NDs epitaxially grown on Si (001) substrates using modified ultrathin SiO 2 film technique, that is codeposition of Fe and Si at room temperature followed by annealing [11]. Figure 1 (c) is a cross sectional scanning TEM image of Fe 3 Si NDs epitaxially grown on Si(111) substrates, which corresponds with the sample indicated by Fig.…”

“…In this paper, we present the formation method of high density iron silicides NDs epitaxially grown on Si substrates by modifying ultrathin SiO 2 film technique [5][6][7][8][9][10]. Additionally, we clarify the optical properties of E-FeSi 2 NDs [11] and magnetic properties of Fe 3 Si NDs. [12] Experiment Samples cut from an n-type Si wafer were introduced into an ultrahigh-vacuum chamber with a base pressure of about 1×10 -8 Pa.…”

Optimization of substrate pretreatment and deposition conditions for epitaxial growth of β‐FeSi2 film on Si(100)

“…3(b). The importance of Fe/Si ratio in silicide nanodot formation has been pointed out by Nakamura et al [14]. They showed that β-FeSi 2 nanodots were obtained on ultrathin SiO 2 films with Si nuclei via solid phase epitaxy (SPE), where the local Fe/Si ratio was kept at 0.5.…”

“…In addition, the formation of α-FeSi 2 nanodots was observed by Fe deposition on Si nanodots on Si (111) surface at around 873 K, in which the Si surface was covered with ultrathin Si oxide film [12,13]. The α-FeSi 2 nanodots were also seen to epitaxially grown on Si (001) surface by codeposition of Fe and Si (Fe/Si = 0.5) at 773 K, indicating that α-FeSi 2 nanodots grow more easily on Si (001) than on Si (111) [14]. Since the growth of nanostructure can be considered as the nucleation stage in thin film fabrication process, it is reasonable to assume that the formation of α-FeSi 2 phase observed at 973 K in the present study is related to formation and growth of such nanocrystals.…”

Insight into the electronic and thermodynamic properties of NbSi2 from first-principles calculations

“…[1][2][3][4][5] These properties can be exploited in a variety of applications in the microelectronics industry, such as ohmic contacts, interface diffusion barriers and interconnections. [6][7][8] In addition to these applications, TMSi 2 also exhibits great advantages in the eld of lithium-ion batteries. For example, a number of transition metal disilicides, such as MoSi 2 , CrSi 2 , TiSi 2 , NiSi 2 , TaSi 2 and VSi 2 , are used as anode materials or anode coating materials for lithium-ion batteries.…”