AFM observation of nanosized SiC dots prepared by ion beam deposition

Abstract

Nanosized silicon carbide (SiC) dots are grown by low-energy mass-selected ion beam deposition (MSIBD) on 4• -off Si(111) substrates at temperatures of 800-950 • C and examined by atomic force microscopy (AFM).We find that the size distribution and the geometrical arrangement of SiC dots strongly depend on the substrate temperature, i.e. highly uniform SiC dots are formed at 800 • C and 850 • C; in particular, SiC dots are arranged in lines when the deposition temperature is as low as 800• C. These results indicate that self-assembled SiC dots can be prepared on misoriented substrates at low deposition temperatures.

Thermal effects in the size distribution of SiC nanodots on Si(111)

“…Most of these steps, which follow curved patterns, are pinned to the SiC n-dots and they are distributed over the surface with no particular orientation. We believe the pattern of the steps are influenced both, by the SiO desorption process together with the formation of the SiC n-dots [7]. Another interesting observation from this set of images is the temperature dependence of the dots distribution.…”

“…Frequently, the strength of the interaction inducing the self-ordering is limited and therefore methods for enhancing island ordering are being vigorously studied by several techniques, e.g. CVD [4,5], IBD [6,7], and MBE [8,9].…”

Thermally induced formation of SiC nanoparticles from Si/C/Si multilayers deposited by ultra-high-vacuum ion beam sputtering

“…The synthesis and characterization of nanoparticles have been extensively studied due to their unique nano-enabled properties, such as quantum confinement, and their many promising applications [1][2][3]. In particular, silicon carbide (SiC), a wide-bandgap semiconductor material, has attracted much attention due to its broad potential applications in radiation sensors, high-power electronics and optoelectronic devices [4][5][6][7][8][9]. Nanoscaled SiC in the form of nanoparticles or films has been fabricated in a variety of ways, such as the synthesis of nanopowder by CO 2 laser pyrolysis [1], physical vapour deposition (PVD) [4][5][6], and chemical vapour deposition (CVD) [7][8][9] in high vacuum.…”

“…In particular, silicon carbide (SiC), a wide-bandgap semiconductor material, has attracted much attention due to its broad potential applications in radiation sensors, high-power electronics and optoelectronic devices [4][5][6][7][8][9]. Nanoscaled SiC in the form of nanoparticles or films has been fabricated in a variety of ways, such as the synthesis of nanopowder by CO 2 laser pyrolysis [1], physical vapour deposition (PVD) [4][5][6], and chemical vapour deposition (CVD) [7][8][9] in high vacuum. CVD synthesis of nanopowder is in many senses more economical for mass production in the powder industry, whereas CO 2 laser pyrolysis is used for the synthesis of SiC nanopowder in small scale applications or where special nanoparticle properties and content are required [1].…”

“…Several groups have attempted to synthesize SiC nanoparticles on wafers [4,5,9,10]. Xu et al [4] used RF plasma sputtering and a compound SiC target (Si:C ∼ 1:1) to deposit SiC nanoparticles on Si(100) substrates with AlN buffer layers at a substrate temperature of 350 • C for 1.0 h. Xu et al [5] applied low-energy mass-selected ion beam deposition (MSIBD) to select C + ions at 100 eV to bombard a 4 •off Si(111) substrate in order to grow nanosized SiC dots at temperatures of 800-950 • C. Kametani [9] reported that the CVD ferrocene (Fe(C 5 H 5 ) 2 ) precursor was used to form SiC nanodots on Si(111) substrates by deposition at 600 • C followed by annealing at 600-800 • C. Flores et al [10] reported that Si(111) substrates with high C content were annealed at 660-810 • C to form SiC nanodots by segregation of carbon atoms from the bulk to the surface and reacted with Si to form SiC nanodots. In this paper, a novel approach to the synthesis of SiC nanoparticles on Si(100) wafers using an ultra-high-vacuum ion beam sputtering process followed by vacuum thermal annealing is reported.…”