A New, Nearly Single-Domain Surface Structure of Homoepitaxial Diamondr (001) Films

1996 ◽  
Vol 423 ◽  
Author(s):  
Yalei Kuang ◽  
Naesung Lee ◽  
Andrzej Badzian ◽  
Teresa Badzian ◽  
Tien T. Tsong

AbstractBoron-doped homoepitaxial diamond films were grown on natural diamond (001) substrates using microwave-assisted plasma chemical vapor deposition techniques. The surface structures were investigated using scanning tunneling microscopy (STM). This showed a dimertype 2×1 reconstruction structure with single-layer steps where dimer rows on the upper terrace are normal to or parallel to the step edges. We found that dimer rows parallel to the step edges are much longer than those normal to the step edges. The nearly single-domain surface structure observed by STM is in agreement with the low-energy electron diffraction (LEED) patterns from these surfaces. The high atomic resolution STM image showed that the local 1×1 configurations exist.

1992 ◽  
Vol 242 ◽  
Author(s):  
Takashi Tsuno ◽  
Takahiro Imai ◽  
Yoshiki Nishibayashi ◽  
Naoji Fujimori

ABSTRACTUndoped and boron-doped diamond epitaxial films were deposited on diamond(001) substrate by micro-wave plasma assisted chemical vapor deposition and their surfaces were studied by scanning tunneling microscopy in air. An atomic order resolution was confirmed for the observation.For the undoped epitaxial films, which showed 2×1 and 1×2 RHEED patterns, dimer type reconstruction was observed and it was considered that the growth occurs through the dimer row extension. In the case of B-doped films, the dimer reconstruction was also observed. However, 2×2 structure due to the absence of dimer was partially observed.The effect of boron concentration and methane concentration during epitaxial growth on the surface morphology were also studied. The morphology observed by STM became flatter, as the concentration of B-doping and methane concentration, during growth, increased.


1998 ◽  
Vol 509 ◽  
Author(s):  
R.E. Stallcup ◽  
J.M. Perez

AbstractThe effects of Cs on oxygenated epitaxial diamond (100) films are studied using ultrahigh vacuum (UHV) scanning tunneling microscopy (STM). The epitaxial diamond (100) films are grown on synthetic diamond substrates using chemical vapor deposition and are boron doped. Before Cs deposition and oxygenation, UHV STM imaging of the epitaxial (100) films reveals a (2×l) dimer reconstruction. After Cs deposition and oxygenation, steps with relatively smooth surfaces are observed using positive tip voltages. Using negative tip voltages, many round bright structures approximately 20 Å in diameter are observed on the surface. We propose that these bright structures are Cs atoms or clusters of Cs atoms. Since these structures are only observed for negative tip voltages, they have a large number of empty states. Our observations are compared with recent theoretical predictions for Cs adsorbed on oxygenated diamond (100).


2010 ◽  
Vol 25 (3) ◽  
pp. 444-457 ◽  
Author(s):  
Sanju Gupta ◽  
John Farmer ◽  
Dario Daghero ◽  
Renato Gonnelli

We report temperature-dependent electrical resistivity (or dc conductivity, σdc) down to 4 K for pristine and gamma-irradiated microwave plasma-assisted chemical vapor-deposited boron-doped diamond films with [B]/[C]gas = 4000 ppm to gain insights into the nature of conduction mechanism, distribution, and kinetics of point defects generated due to gamma irradiation prompted by the article [Gupta et al., J. Mater. Res.24, 1498 (2009)]. The pristine samples exhibit typical metallic conduction up to 50 K and with reduction in temperature to 25 K, the σdc decreases monotonically followed by saturation at 4 K, suggesting “disordered” metal or “localized” behavior. For irradiated films, continuous increasing resistivity with decreasing temperature demonstrates semiconducting behavior with thermal activation/hopping conduction phenomena. It is intriguing to propose that irradiation leads to substantial hydrogen redistribution leading to unexpected low-temperature resistivity behavior. Scanning tunneling microscopy/spectroscopy helped to illustrate local grain and grain boundary effects.


Author(s):  
M. G. Lagally

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.


RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98001-98009 ◽  
Author(s):  
Thais Chagas ◽  
Thiago H. R. Cunha ◽  
Matheus J. S. Matos ◽  
Diogo D. dos Reis ◽  
Karolline A. S. Araujo ◽  
...  

We have used atomically-resolved scanning tunneling microscopy and spectroscopy to study the interplay between the atomic and electronic structure of graphene formed on copper via chemical vapor deposition.


2017 ◽  
Vol 53 (6) ◽  
pp. 1104-1107 ◽  
Author(s):  
Abdolreza Jahanbekam ◽  
Colin Harthcock ◽  
David Y. Lee

A new method to directly modify the surface structure and energy levels of a porphyrin monolayer was examined with molecular-scale resolution using scanning tunneling microscopy and spectroscopy (STM and STS) and presented in this communication.


2000 ◽  
Vol 87 (2) ◽  
pp. 711-716
Author(s):  
Tsutomu Kawamura ◽  
Tomohide Kanzawa ◽  
Shiro Kojima ◽  
George A. Rozgonyi

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