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Rms Roughness (rm + roughness)

Distribution by Scientific Domains

Physics and Astronomy	80%

Selected Abstracts

Synthesis and characterisation of NCD films on 10 × 10 mm2 and deposition on 2 inch wafer using rotating substrate-holder set-up

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 9 2008
S. Saada
Abstract In this study, we compare NCD films on 10 × 10 mm2 silicon substrates synthesised with high methane concentration and NCD films synthesised with prolongated bias during the growth step. Further, we performed in-situ sequential XPS analysis (carbon binding state) using an UHV surface analysis system connected to the MPCVD reactor. AFM and HRSEM were used to characterize films morphology. Using the same substrate holder, NCD films have been deposited on silicon 2 in wafers. To improve the homogeneity, a rotating substrate-holder set-up enabling biasing and heating of the stage has been developed and coupled with computer control of the process for a better reproducibility. UV-interferometry was performed to map the film thickness on 2 inches and quantify its thickness uniformity. Considering the symmetry of the system, AFM measurements were performed along the radius of the wafer to evaluate the surface homogeneity and its smoothness. The thickness uniformity of a NCD film of 1.6 µm deposited on 2 inch wafer is under 10% and the RMS roughness comprised between 13 and 14 nm. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

MOVPE of InN films on GaN templates grown on sapphire and silicon(111) substrates

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2008
Muhammad Jamil
Abstract This paper reports the study of MOVPE of InN on GaN templates grown on sapphire and silicon(111) substrates. Thermodynamic analysis of MOVPE of InN performed using NH3 as nitrogen source and the experimental findings support the droplet-free epitaxial growth of InN under high V/III ratios of input precursors. At a growth pressure of 500 Torr, the optimum growth temperature and V/III ratio of the InN film are 575,650 °C and >3 × 105, respectively. The surface RMS roughness of InN film grown GaN/sapphire template is ,0.3 nm on 2 ,m × 2 ,m area, while the RMS roughness of the InN film grown on GaN/Si (111) templates is found as ,0.7 nm. The X-ray diffraction (XRD) measurement reveals the (0002) texture of the InN film on GaN/sapphire template with a FWHM of 281 arcsec of the InN (0002) , rocking curve. For the film grown on GaN/Si template under identical growth conditions, the XRD measurements show the presence of metallic In, in addition to the (0002) orientation of InN layer. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Kinetics of the heteroepitaxial growth of Ge layer at low temperature on Si(001) in UHV-CVD

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2004
M. Halbwax
Abstract The Ge growth at 330 °C by ultrahigh vacuum chemical vapour deposition is investigated in real time by reflection high energy electron diffraction (RHEED) in combination with atomic force microscopy and Rutherford back scattering spectrometry (RBS). The Stranski-Krastanov-related 2D to 3D transition is avoided at low temperature and the major part of the relaxation process occurs during the deposition of the first two monolayers. The very low growth rate observed during this first step is related to the deposition of Ge on Si. Beyond 2 deposited MLs, the growth rate increases drastically due to a complete coverage of Si by Ge. Finally, the deposition of Ge at 330 °C results in an in-plane lattice parameter approaching 90% of that of Ge bulk and a flat surface with rms roughness of 0.6 nm for a film thickness lower than 30 nm. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Angle-resolved photoelectron spectroscopy study of the GaN(0001)-2×2 surface

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7-8 2010
P. Lorenz
Abstract GaN(0001)-2×2 surfaces were investigated by angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) as well as X-ray photoelectron spectroscopy (XPS). Contamination- and metal-free GaN thin films with a 2×2 reconstruction and a rms roughness below 1 nm were grown on 6H-SiC(0001) by plasma assisted molecular beam epitaxy (PAMBE). The valence band structure of the surface was investigated in-situ with ARUPS along the and directions of the surface Brillouin zone. Weak dispersive surface states related to the unreconstructed GaN surface or to the 2×2 superstructure as well as the dispersion of electron states of the bulk band structure are identified and compared to available results from density functional theory (DFT) calculations [Phys. Rev. B 77, 115120 (2008)] for GaN(0001). (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Pt Thin Film Collectors Prepared by Liquid-Delivery Metal,Organic CVD Using Pt(C2H5C5H4)(CH3)3 for LiCoO2 Thin Film Cathodes,

CHEMICAL VAPOR DEPOSITION, Issue 6 2003
W.-G. Choi
Abstract Platinum thin film collectors were deposited onto p-type Si(100) planar and trench substrates by liquid-delivery metal,organic (LD-MO) CVD using Pt(EtCp)Me3, Pt(C2H5C5H4)(CH3)3, for microbatteries. The resistivity and root-mean-square (rms) roughness of Pt thin films with (111) preferred orientation increased with the increase of both deposition temperature and system pressure. The deposition of Pt thin films was controlled by a gas-phase mass-transfer mechanism and Pt thin films deposited at 350,°C showed the lowest resistivity, rms roughness, and the highest step coverage, 57,%, in trench structure. The LiCoO2 cathode films (step coverage,=,51,%) deposited on the trench Pt collector showed an increase in discharge capacity of approximately two and half times that of the planar Pt collector. Platinum thin films deposited by LD-MOCVD have a possible application as collector materials for LiCoO2 thin film cathodes. [source]