However, so far, no large-area (>1 × 1 μm2), well-regular parallel CeSi MLN0128 concentration x NW arrays with uniform distribution and identical dimension can be formed on flat and vicinal Si(100) surfaces. Recently, we have demonstrated that RE metals (e.g., Gd, Ce, and Er) can be self-organized to form a mesoscopically ordered parallel RES NW array on single-domain Si(110)-16 × 2 surfaces [23–25]. These parallel-aligned and unidirectional RES NWs exhibit identical sizes, periodic positions, large aspect ratios (length >1 μm, width ≤5 nm) exceeding 300, and ultra-high integration density up to 104 NWs/μm2.

Such large-area self-ordered growths of massively parallel RES NW arrays on Si(110) surfaces can open the possibility for wafer-scale integration into nanoelectronic devices combining the well-established Si(110)-based integrated-circuit technology [26–28] with the exotic 1D physical properties of RES NWs. To date, there is little knowledge of this template-directed 1D self-organization process that leads to the formation of well-ordered parallel DAPT RES NW arrays on single-domain Si(110)-16 × 2 surfaces. In this article, we have investigated the growth evolutions of CeSi x NWs on Si(110) surfaces over a wide range (1 to 9 monolayers (ML)) of Ce coverage by scanning tunneling microscopy (STM).

Our comprehensive study provides a detailed understanding of the 1D self-organization mechanism of perfectly ordered parallel arrays consisting of periodic and atomically identical CeSi x NWs on single-domain Si(110)-16 × 2 surfaces. Methods Our experiments were performed in an ultra-high vacuum, variable-temperature STM system (Omicron Nanotechnology GmbH, Taunusstein, Germany) with a base pressure of less than 3.0 × 10-11 mbar. An n-type P-doped Si(110) surface with a resistivity of about 10 Ω cm was cleaned by well-established annealing procedures [25, 29, 30]. An atomically

Lepirudin clean single-domain Si(110)-16 × 2 surface was confirmed by STM observation (Figure 1). Different parallel CeSi x NW arrays were produced by depositing high-purity (99.95%) Ce metals with coverages ranging from 1 to 9 ML (1 ML = 9.59 × 1014 atoms/cm2) onto a single-domain Si(110)-16 × 2 surface at 675 K with a deposition rate of 0.15 ML/min and subsequently annealed at 875 K for 20 min. The growth temperature cannot be higher than 675 K; otherwise, a large amount of Ce clusters will be formed [20, 21]. Ce metals were evaporated from an electron-beam evaporator with an internal flux meter; their deposition coverage was determined in situ by a quartz crystal thickness monitor with an accuracy of 20%. The sample temperature was measured using an infrared pyrometer with an uncertainty of ± 30 K. The chamber pressure remained below 1.0 × 10-9 mbar during evaporation. The STM measurements were acquired at 300 K using electrochemically etched nickel tips. Figure 1 STM images and topography profile of the atomically clean Si(110)-16 × 2 surface.