Characterization of Etching Processes on CU Surfaces

1996 ◽  
Vol 451 ◽  
Author(s):  
C. Y. Nakakura ◽  
V. M. Phanse ◽  
G. Zheng ◽  
E. I. Altman

ABSTRACTThe etching of single crystal and polycrystalline Cu surfaces by halogens was studied using temperature programmed desorption (TPD), low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). For Br2 and Cl2 on Cu(100) and polycrystalline Cu, the etching mechanism could be characterized as a two step process: 1) formation of a bulk Cu(I) halide, and 2) removal of the halide by sublimation. In all cases the first step was found to be adsorption rate limited. Halide formation was observed to consume Cu atoms from the step edge and thus etching can be considered the reverse of step flow growth. While STM showed that Cl2 reacts isotropically with steps on Cu(100), the rate of CuBr formation was observed to be sensitive to the local adsorbate structure at the step edge. For Cl2, it was found that halide removal could be characterized as a simple bulk sublimation process independent of the structure of the underlying Cu. In contrast, a CuBr desorption peak at temperatures lower than anticipated from bulk vapor pressure data was observed. The presence of narrowly spaced steps on the Cu surface was observed to stabilize this low-temperature desorption peak.

2002 ◽  
Vol 749 ◽  
Author(s):  
J. Mysliveček ◽  
C. Schelling ◽  
F. Schäffler ◽  
G. Springholz ◽  
P. Šmilauer ◽  
...  

ABSTRACTScanning tunneling microscopy experiments show that the unstable growth morphology observed during molecular beam homoepitaxy on slightly vicinal Si(001) surfaces consists of straight step bunches. The instability occurs under step-flow growth conditions and vanishes both during low-temperature island growth and at high temperatures. An instability with the same characteristics is observed in a 2D Kinetic Monte Carlo model of growth with incorporated Si(001)-like diffusion anisotropy. This provides strong evidence that the diffusion anisotropy destabilizes growth on Si(001) and similar surfaces towards step bunching. This new instability mechanism is operational without any additional step edge barriers.


2007 ◽  
Vol 996 ◽  
Author(s):  
Kenta Arima ◽  
Hideyuki Hara ◽  
Yasuhisa Sano ◽  
Keita Yagi ◽  
Ryota Okamoto ◽  
...  

AbstractScanning tunneling microscopy (STM) observations are performed on 4H-SiC(0001) surfaces after wet-chemical preparation steps including HF treatments.1×1 structures are formed on a terrace together with other local structures. Their atomic images are investigated in conjunction with low-energy electron diffraction and electron spectroscopy for chemical analysis. It is suggested that each bright dot forming the 1×1 phase corresponds to an OH-terminated Si atom.


2011 ◽  
Vol 115 (16) ◽  
pp. 8034-8041 ◽  
Author(s):  
Aimeric Ouvrard ◽  
Johannes Niebauer ◽  
Ahmed Ghalgaoui ◽  
Clemens Barth ◽  
Claude R. Henry ◽  
...  

2008 ◽  
Vol 92 (2) ◽  
pp. 022904 ◽  
Author(s):  
Y. C. Ong ◽  
D. S. Ang ◽  
K. L. Pey ◽  
Z. R. Wang ◽  
S. J. O’Shea ◽  
...  

1992 ◽  
Vol 295 ◽  
Author(s):  
P. Molinàs-Mata ◽  
J. Zegenhagen ◽  
M. Böhringer ◽  
N. Takeuchi ◽  
A. Selloni

AbstractWe report on new experimental studies of the Ge(111)-c(2×8) reconstruction performed with low-energy electron diffraction. (LEED) and scanning tunneling microscopy (STM). Weak quarter-order reflections are present in the c(2 × 8) LEED pattern in agreement with previous observations and results of ab initio calculations. In order to gain insight into the predicted splitting of dangling bond states, we compare constant current topographs (CCT's) performed at high-tunneling currents (40.nA) with first-principles calculations of the local density of states (LDOS) 1Å above the surface adatoms and obtain good qualitative agreement. We finally discuss to what extent the STM CCT's at high tunneling currents (small sample-tip distances (STD)) are sensitive to surface states outside the Г point.


2016 ◽  
Vol 42 ◽  
pp. 14-46 ◽  
Author(s):  
Oleg G. Lysenko ◽  
Vladimir I. Grushko ◽  
Sergey N. Dub ◽  
Eugene I. Mitskevich ◽  
Nikolay V. Novikov ◽  
...  

Nanoscale experiments with diamond tip that include processing, visualization and tunneling spectroscopy of the surface are presented. Single crystal diamond synthesized by the temperature gradient method under high pressure–high temperature (HPHT) conditions is proposed as a multifunctional tip for scanning tunneling microscopy (STM). Sequence of the procedures covering growing crystals with predetermined physical properties, selection of the synthesized crystals with the desired habit and their precise shaping have been developed. The original STM’s peculiarity is the electromagnetic probe-to-surface load measuring system. The results of fabrication and characterization of nanostructures for nanoelectronics, data storages and biology are demonstrated and discussed.


1998 ◽  
Vol 05 (01) ◽  
pp. 69-76
Author(s):  
F. P. Netzer ◽  
L. Vitali ◽  
J. Kraft ◽  
M. G. Ramesy

The interaction of vapor phase P2 with the [Formula: see text] monolayer surface at room temperature and elevated temperature has been monitored by scanning tunneling microscopy (STM) and spectroscopy (STS) in conjunction with Auger electron spectroscopy and low-energy electron diffraction (LEED). The surface rection can be readily followed by STM because of the very different contrast of the reacted areas in the STM images. The reaction develops around overlayer defects at room temperature and appears to be diffusion-limited, whereas at 300°C the reaction is initiated at the step edges, from which the reaction front progresses onto the lower terrace areas. At elevated temperature several ordered surface reconstructions, showing different STS fingerprints, are detected on the P–In/Si(111) surfaces, which are associated tentatively with P- and Si-terminated structures and an ordered InP phase.


1997 ◽  
Vol 04 (06) ◽  
pp. 1167-1171 ◽  
Author(s):  
CH. AMMER ◽  
K. MEINEL ◽  
H. WOLTER ◽  
A. BECKMANN ◽  
H. NEDDERMEYER

Recent scanning tunneling microscopy (STM) observations revealed different layer structures in the heteroepitaxial Cu/Ru(0001) system with increasing film thickness attributed to various stages of strain relaxation. High-resolution low-energy electron diffraction (HRLEED) analysis permits one to derive more exactly both lattice periodicities and lattice rotations. Furthermore, the representative character of local STM results can be proved. However, STM measurements are needed to identify and to assign the satellite spots to coexistent different superstructures which are superposed incoherently in the diffraction pattern. Generally, the integral LEED results confirm the crystallographic data obtained by STM in a local scale.


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