Non Destructive Determination of the Threading Dislocation Density of Smooth Simox Substrates using Atomic Force Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1088-1089
Author(s):  
A. Domenicucci ◽  
R. Murphy ◽  
D. Sadanna ◽  
S. Klepeis

Atomic force microscopy (AFM) has been used extensively in recent years to study the topographic nature of surfaces in the nanometer range. Its high resolution and ability to be automated have made it an indispensable tool in semiconductor fabrication. Traditionally, AFM has been used to monitor the surface roughness of substrates fabricated by separation by implanted oxygen (SIMOX) processes. It was during such monitoring that a novel use of AFM was uncovered.A SIMOX process requires two basic steps - a high dose oxygen ion implantation (1017 to 1018 cm-3) followed by a high temperature anneal (>1200°C). The result of these processes is to form a buried oxide layer which isolates a top single crystal silicon layer from the underlying substrate. Pairs of threading dislocations can form in the top silicon layer during the high temperature anneal as a result of damage caused during the high dose oxygen implant.

2006 ◽  
Vol 527-529 ◽  
pp. 1265-1268 ◽  
Author(s):  
Jeffery B. Fedison ◽  
Chris S. Cowen ◽  
Jerome L. Garrett ◽  
E.T. Downey ◽  
James W. Kretchmer ◽  
...  

Results of a 1200V 4H-SiC vertical DMOSFET based on ion implanted n+ source and pwell regions are reported. The implanted regions are activated by way of a high temperature anneal (1675°C for 30 min) during which the SiC surface is protected by a layer of graphite. Atomic force microscopy shows the graphite to effectively prevent surface roughening that otherwise occurs when no capping layer is used. MOSFETs are demonstrated using the graphite capped anneal process with a gate oxide grown in N2O and show specific on-resistance of 64 mW×cm2, blocking voltage of up to 1600V and leakage current of 0.5–3 ´10-6 A/cm2 at 1200V. The effective nchannel mobility was found to be 1.5 cm2/V×s at room temperature and increases as temperature increases (2.8 cm2/V×s at 200°C).


1997 ◽  
Vol 12 (12) ◽  
pp. 3219-3224 ◽  
Author(s):  
Vilas N. Koinkar ◽  
Bharat Bhushan

Atomic force microscopy (AFM) is commonly used for microwear/machining studies of materials at very light loads. To understand material removal mechanism on the microscale, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies were conducted on the microworn/machined single-crystal silicon. SEM studies of micromachined single-crystal silicon indicate that at light loads material is removed by ploughing. Fine particulate debris is observed at light loads. At higher loads, cutting type and ribbon-like debris were observed. This debris is loose and can be easily removed by scanning with an AFM tip. TEM images of a wear mark generated at 40 μN show bend contours in and around the wear mark, suggesting that there are residual stresses. Dislocations, cracks, or any special features were not observed inside or outside wear marks using plan-view TEM. Therefore, material is mostly removed in a brittle manner or by chipping without major dislocation activity, crack formation, and phase transformation at the surface. However, presence of ribbon-like debris suggests some plastic deformation as well.


Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.


1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.


2004 ◽  
Vol 815 ◽  
Author(s):  
S. Rao ◽  
S.E. Saddow ◽  
F. Bergamini ◽  
R. Nipoti ◽  
Y. Emirov ◽  
...  

AbstractHigh-dose Al implants in n-type epitaxial layers have been successfully annealed at 1600°C without any evidence of step bunching. Anneals were conducted in a silane ambient and at a process pressure of 150 Torr. Silane, 3% premixed in 97% UHP Ar, was further diluted in a 6 slm Ar carrier gas and introduced into a CVD reactor where the sample was heated via RF induction. A 30 minute anneal was performed followed by a purge in Ar at which time the RF power was switched off. The samples were then studied via plan-view secondary electron microscopy (SEM) and atomic force microscopy (AFM). The resulting surface morphology was step- free and flat.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yong-Jin Cho ◽  
Alex Summerfield ◽  
Andrew Davies ◽  
Tin S. Cheng ◽  
Emily F. Smith ◽  
...  

Abstract We demonstrate direct epitaxial growth of high-quality hexagonal boron nitride (hBN) layers on graphite using high-temperature plasma-assisted molecular beam epitaxy. Atomic force microscopy reveals mono- and few-layer island growth, while conducting atomic force microscopy shows that the grown hBN has a resistance which increases exponentially with the number of layers, and has electrical properties comparable to exfoliated hBN. X-ray photoelectron spectroscopy, Raman microscopy and spectroscopic ellipsometry measurements on hBN confirm the formation of sp2-bonded hBN and a band gap of 5.9 ± 0.1 eV with no chemical intermixing with graphite. We also observe hexagonal moiré patterns with a period of 15 nm, consistent with the alignment of the hBN lattice and the graphite substrate.


2008 ◽  
Vol 92 (4) ◽  
pp. 043102 ◽  
Author(s):  
Joska Broekmaat ◽  
Alexander Brinkman ◽  
Dave H. A. Blank ◽  
Guus Rijnders

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