Surface Studies Relevant to the Initial Stages of Diamond Nucleation

1994 ◽  
Vol 339 ◽  
Author(s):  
J. M. Lannon ◽  
J. S. Gold ◽  
C. D. Stinespring

ABSTRACTStudies of diamond heteroepitaxy on silicon indicate that C-C surface species act as nucleation precursors. We have investigated the conversion of the Si(100) 2×1 surface to SiC using C2H4 to obtain an understanding of how C-C species may be formed and to determine the effect of an O-adlayer on enhancing or selecting the reaction channel which leads to these species. Under appropriate conditions, the interaction between C2H4 and the clean silicon surface yields both SiC and C-C species. The presence of an O-adlayer significantly reduces the activity of silicon and enhances the formation of sp2 and sp3 C-C species. These results provide key insights into diamond nucleation conditions in conventional growth processes.

1981 ◽  
Vol 5 ◽  
Author(s):  
S. C. Perino ◽  
C. R. Helms

ABSTRACTThe molecular character of arsenic adsorbed on the Si (100) surface has been investigated using thermal desorption spectroscopy (TDS) and Auger electron spectroscopy (AES). A variety of arsenic surface species were deposited on the silicon surface by employing different evaporation sources, including metallic arsenic, arsine gas, and chips of GaAs crystals. We present coverage dependent spectra showing the desorption of As4 tetramers at 350°C and As2 dimers at 900°C. The loosely bound arsenic is adsorbed from the solid evaporation sources only and resides on the surface as tetramers. The tightly bound arsenic does not form multiple layers and the high desorption temperatures suggests the adsorbed arsenic exists as monomers.


1998 ◽  
Vol 529 ◽  
Author(s):  
R.Q. Zhang ◽  
W.J. Zhang ◽  
C. Sun ◽  
X. Jiang ◽  
S.-T. Lee

AbstractThe origin of mis-oriented diamond grains frequently observed in heteroepitaxial diamond films on (001) silicon surfaces was studied. By statistically analyzing the in-plane rotation angles of diamond grains in scanning electron microscopy observations, it was found that the distribution of the grain orientation is not random and two satellite distribution peaks at about 20° and 30° accompany the main distribution peak at zero degree referenced to the <110> direction of substrate. The interface structure corresponding to the main distribution peak at zero degree of oriented diamond growth has been proposed in our previous studies. In this study, our molecular orbital PM3 simulation of a step-by-step diamond nucleation further reveals two other metastable diamond/silicon interfacial structures. The orientations of the corresponding diamond grains are parallel to the (001) silicon surface but with in-plane rotations of 20° and 30° respectively with respect to the <110> direction. We relate these two mis-oriented growths to the two satellite peaks of grain orientation distribution. Based on this study, the possibility in experiment to reduce the formation of mis-oriented configurations and to obtain a perfectly oriented diamond growth is discussed.


1986 ◽  
Vol 75 ◽  
Author(s):  
T. W. Sigmon

AbstractThe use of a pulsed UV excimer laser based process for the incorporation of dopant impurities into Si is described. The process can result in high concentration shallow box like profiles suitable for submicron VLSI device fabrication. The process consists of exposure of the clean silicon surface to a doping gas (B2H6, AsH3, PH3) then driving the adsorbed monolayers of dopant into the Si by a melt-regrowth process initiated by a pulsed XeCl excimer laser. Modeling of the process allows prediction of the resulting doping profiles and electrical properties of the doped layers. Excellent crystal quality of the doped layers is found even without a postdoping anneal. Also, recent results indicate that post doping annealing may not be needed for improvement of the electrical characteristics of the doped layers provided certain conditions are met. Detailed descriptions of the process, results, modeling and device fabrication are presented.


1999 ◽  
Vol 569 ◽  
Author(s):  
V.S. Smentkowskiv ◽  
A. R. Krauss ◽  
O. Auciello ◽  
J. Im ◽  
D.M. Gruen ◽  
...  

ABSTRACTTime-of-flight ion scattering and recoil spectroscopy (TOF-ISARS) enables the characterization of the composition and structure of surfaces with 1–2 monolayer specificity. It will be shown that surface analysis is possible at ambient pressures greater than 3 mTorr using TOF-ISARS techniques; allowing for real-time, in situ studies of film growth processes. TOF-ISARS comprises three analytical techniques: ion scattering spectroscopy (ISS), which detects the backscattered primary ion beam; direct recoil spectroscopy (DRS), which detects the surface species recoiled into the forward scattering direction; and mass spectroscopy of recoiled ions (MSRI), which is a variant of DRS capable of isotopic resolution for all surface species - including H and He. The advantages and limitations of each of these techniques will be discussed.The use of the three TOF-ISARS methods for real-time, in situ film growth studies at high ambient pressures will be illustrated. It will be shown that MSRI analysis is possible during sputter deposition. It will be also be demonstrated that the analyzer used for MSRI can also be used for time of flight secondary ion mass spectroscopy (TOF-SIMS) under high vacuum conditions. The use of a single analyzer to perform the complimentary surface analytical techniques of MSRI and SIMS is unique. The dual functionality of the MSRI analyzer provides surface information not obtained when either MSRI or SIMS is used independently.


1990 ◽  
Vol 204 ◽  
Author(s):  
A.C. Dillon ◽  
P. Gupta ◽  
M.B. Robinson ◽  
A.S. Bracker ◽  
S.M. George

ABSTRACTFourier transform infrared (FTIR) transmission spectroscopy. was used to monitor the decomposition of H2O (D2O) and NH3(ND3) on silicon surfaces. Experiments were performed in-situ in an ultra-high vacuum (UHV) chamber using high surface area poroussilicon samples. The FTIR spectra revealed that H2O dissociates upon adsorption at 300K to form SiH and SiNH2 surface species. NH3 also issociates upon adsorption at 300 K to form SiH and SiOH2 species. Silicon samples with saturation exposures of H2O and NH3 were progressively annealed from 300 K to 860 K. The FTIR spectra of an H2O-saturated silicon surface revealed that the SiOH species decomposed to form a silicon oxide species and additional surface hydrogen between 460 K and 580 K. Likewise, the SiNH2 species decomposed between 540 K and 660 K to produce silicon nitride and additional surface hydrogen. In both cases, the Sill surface species decreased as H2 desorption from the silicon surface was observed above 700 K.


2009 ◽  
Vol 79 (4) ◽  
Author(s):  
A. L. Pinardi ◽  
S. J. Leake ◽  
R. Felici ◽  
I. K. Robinson

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