BIC Formation and Boron Diffusion in Relaxed Si0.8Ge0.2

2004 ◽  
Vol 810 ◽  
Author(s):  
R. T. Crosby ◽  
L. Radic ◽  
K. S. Jones ◽  
M. E. Law ◽  
P.E. Thompson ◽  
...  

ABSTRACTThe relationships between Boron Interstitial Cluster (BIC) evolution and boron diffusion in relaxed Si0.8Ge0.2 have been investigated. Structures were grown by Molecular Beam Epitaxy (MBE) with surface boron wells of variant composition extending 0.25 [.proportional]m into the substrate, as well as boron marker layers positioned 0.50 [.proportional]m below the surface. The boron well concentrations are as follows: 0, 7.5×1018, 1.5×1019, and 5.0×1019 atoms/cm3. The boron marker layers are approximately 3 nm wide and have a peak concentration of 5×1018 atoms/cm3. Samples were ion implanted with 60 keV Si+ at a dose of 1×1014 atoms/cm2 and subsequently annealed at 675°C and 750°C for various times. Plan-view Transmission Electron Microscopy (PTEM) was used to monitor the agglomeration of injected silicon interstitials and the evolution of extended defects in the near surface region. Secondary Ion Mass Spectroscopy (SIMS) concentration profiles facilitated the characterization of boron diffusion behaviors during annealing. Interstitial supersaturation conditions and the resultant defect structures of ion implanted relaxed Si0.8Ge0.2 in both the presence and absence of boron have been characterized.

MRS Advances ◽  
2018 ◽  
Vol 3 (31) ◽  
pp. 1799-1805 ◽  
Author(s):  
Ítalo M. Oyarzabal ◽  
Mariana de M. Timm ◽  
Willian M. Pasini ◽  
Franciele S. M. de Oliveira ◽  
Francine Tatsch ◽  
...  

ABSTRACT200 μm thick solution annealed AISI 316L stainless steel foils were implanted with Ar ions to produce a 0.25 at. % concentration-depth plateau extending from the near surface to a depth of ≈ 250 nm, and then annealed at 550°C for 2 hours to form small Ar bubbles and Ar-vacancy clusters. Distinct sets of samples (including control ones without Ar) were irradiated at the temperature of 550 °C with Au ions accelerated at 5 MeV to produce an average damage content about ≈36 dpa at the region containing the Ar plateau. These samples were investigated by transmission electron microscopy using plan-view specimens prepared by ion milling. In contrast with the control samples where the irradiation causes the formation of a high concentration of extended defects and large cavities, carbonite precipitation of 1:1 metal-carbon (MC) content with a cubic structure occurs only in the samples containing the Ar bubbles. This precipitation phenomenon is not commonly observed in the literature. The results are interpreted considering that the precipitate growth process requires the emission of vacancies which are synergistically absorbed by the growth of the Ar bubbles.


1996 ◽  
Vol 439 ◽  
Author(s):  
R. A. Brown ◽  
O. Kononchuk ◽  
Z. Radzimski ◽  
G. A. Rozgonyi ◽  
F. Gonzalez

AbstractSecondary defect and impurity distributions in MeV self-implanted Czochralski (Cz) and float-zone (FZ) silicon have been investigated by transmission electron microscopy, optical microscopy with preferential chemical etching, and secondary ion mass spectroscopy. We found that the ion fluence and the oxygen content of the implanted wafers affect the number and depth distribution of extended defects remaining after annealing. Intrinsic oxygen also redistributes during annealing of Cz wafers, producing two regions of relatively high oxygen concentration: one at extended defects near the ion projected range, and another, shallower region, which correlates with the distribution of vacancy-type defects. Both of these regions are also able to getter metallic impurities, depending on the implantation and annealing conditions. These defect issues may adversely affect the quality of the near surface device region, and must be controlled for successful gettering by ion implantation.


1995 ◽  
Vol 396 ◽  
Author(s):  
I. A. Buyanova ◽  
A. Henry ◽  
B. Monemar ◽  
J. L. Lindström ◽  
A. Lamprecht ◽  
...  

AbstractDefect characterization in n-type silicon after the reactive ion etching (RIE) in low-pressure plasmas containing fluorine and oxygen is performed by using photoluminescence (PL) and deep level transient spectroscopies (DLTS). It is shown that RIE treatment results in the formation of (i) luminescence centers giving rise to the C- and G- excitonic lines and broad emission bands related to radiation-induced defect complexes and extended defects and (ii) several electron traps located at 0.16 eV, 0.26 eV, 0.43 eV and 0.58 eV below the conduction band. The addition of oxygen to the SF6 and CF4 plasma is shown to cause nonuniform stress in the near surface region. This stress is responsible for the experimentally observed splitting of the C- and G-excitonic lines, a low energy shift of the phosphorous bound exciton lines, as well as the splitting of the DLTS spectra. It is shown that the stress field is highly inhomogeneous across the wafer, and is rather related to the RIE-induced extended defects than caused by the reaction layer formed on the Si surface.


1988 ◽  
Vol 144 ◽  
Author(s):  
Samuel Chen ◽  
S.-Tong Lee ◽  
G. Braunstein ◽  
G. Rajeswaran

ABSTRACTLayer intermixing in MeV Si-implanted quantum well superlattices (SLs) has been studied by transmission electron microscopy, secondary ion mass spectrometry and Rutherford backscattering spectroscopy. Molecular beam epitaxially grown GaAs(200Å) - Al0. 5Ga0.5As(200Å) SLs were implanted with 1 MeV Si+ at doses between 3 × 1014 and 1 × 1016/cm2. The implanted SLs were either furnace annealed at 850°C for 3 hr or rapid thermally annealed at 1050°C for 10 sec, both under GaAs proximity capping conditions. Totally mixed regions were observed only for the SLs implanted with 1 × 1016 Si/cm2 and then furnace annealed at 850°C for 3 hr. For the same dose, the RTA annealed SLs only showed slight layer intermixing. At lower doses, no appreciable intermixing was detected in either furnace or RTA annealed samples. By contrast, under either annealing condition extensive intermixing has been demonstrated for lower energy (220 keV) implantation, but at doses almost two orders of magnitude lowerl XTEM showed that in all the annealed samples, a defect-free zone existed in the near-surface region, followed by a band of secondary defects, with the maximum density located at about 1 μm below the surface. In the disordered samples, the position of the intermixed layers correlated with the defect band maximum. Under both annealing conditions, Si concentration profiles only showed slight broadening, and they correlated with the distribution of secondary defects as well as with the depth of the intermixed layers. The effects of dynamic annealing and surface on the implantation energy dependence, i.e., MeV vs. keV, of layer intermixing are discussed.


1994 ◽  
Vol 373 ◽  
Author(s):  
Shelly X. Ren ◽  
Carl J. Mchargue ◽  
L. F. Allard ◽  
Y. Chen ◽  
J. D. Hunn ◽  
...  

AbstractNanocomposites of iron in sapphire (α-A12 O3) prepared by ion implantation have been studied as a model to investigate the potential of such materials for applications in high technology areas. The implantation was performed with 160 keV ions at several doses; the nanocomposites were then annealed at selected temperatures between 700 and 1400°C in an Ar-4&H2 atmosphere for 1 hour. Rutherford backscattering spectroscopy and high resolution transmission electron microscopy (TEM) were used to characterize the structure of these nanocomposites. Measurements showed that damage depth extended to about 300 nm and the embedded iron extended to about 200 nm. This region became amorphous when the fluence reaches 2x1017 Fe/cm2 at this energy. At this dose, oriented precipitates with diameters of 2 to 3 nm were identified by TEM techniques as α-Fe which had the following orientation relationship with the sapphire matrix: <111>Fe||<310>Sapphire and (011)Fe||{006}sapphire. Thermal annealing could be used to restore the crystallinity to the damaged near-surface region, to form the metallic colloids, and also to coarsen the precipitates. The optical density and luminescence spectra were also measured. The predominant defects were oxygen vacancies with two electrons (F center) at the known absorption peak of 200 nm.


1996 ◽  
Vol 438 ◽  
Author(s):  
R. A. Brown ◽  
O. Kononchuk ◽  
Z. Radzimski ◽  
G. A. Rozgonyi ◽  
F. Gonzalez

AbstractSecondary defect and impurity distributions in MeV self-implanted Czochralski (Cz) and float-zone (FZ) silicon have been investigated by transmission electron microscopy, optical microscopy with preferential chemical etching, and secondary ion mass spectroscopy. We found that the ion fluence and the oxygen content of the implanted wafers affect the number and depth distribution of extended defects remaining after annealing. Intrinsic oxygen also redistributes during annealing of Cz wafers, producing two regions of relatively high oxygen concentration: one at extended defects near the ion projected range, and another, shallower region, which correlates with the distribution of vacancy-type defects. Both of these regions are also able to getter metallic impurities, depending on the implantation and annealing conditions. These defect issues may adversely affect the quality of the near surface device region, and must be controlled for successful gettering by ion implantation.


Author(s):  
Julia T. Luck ◽  
C. W. Boggs ◽  
S. J. Pennycook

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.


2007 ◽  
Vol 7 (12) ◽  
pp. 4378-4390 ◽  
Author(s):  
Anuradha Somayaji ◽  
Ramoun Mourhatch ◽  
Pranesh B. Aswath

Tribofilms with thickness ranging from 100–200 nm were developed in-situ during wear tests using a zinc dialkyl dithiophosphates (ZDDP) and fluorinated ZDDP (F-ZDDP). The influence of the antioxidant alkylated diphenyl amine on the formation and properties of these tribofilm is examined. Results indicate that the thickness of the tribofilms formed when F-ZDDP is used is always thicker than the tribofilm formed with ZDDP. In addition, in the presence of antioxidants the tribofilm thickness is increased. The hardness of these tribofilms in the absence of the antioxidants is significantly higher at the near surface region (0–30 nm) when compared to the films formed in the presence of antioxidant. Nanoscratch tests conducted to examine the abrasion resistance of the tribofilms also indicate that the tribofilms formed by F-ZDDP are more resistant to scratch compared to films formed by ZDDP. In the presence of antioxidant, tribofilms formed by F-ZDDP are significantly thicker while both films behave in a similar fashion in nanoscratch tests. Transmission electron microscopy of the wear debris formed during the tests were examined and results indicate the nucleation and growth of nanoparticles of Fe3O4 with an approximate size of 5–10 nm embedded within an otherwise amorphous tribofilm.


1994 ◽  
Vol 339 ◽  
Author(s):  
V. Heera ◽  
R. Kögler ◽  
W. Skorupa ◽  
J. Stoemenos

ABSTRACTThe evolution of the damage in the near surface region of single crystalline 6H-SiC generated by 200 keV Ge+ ion implantation at room temperature (RT) was investigated by Rutherford backscattering spectroscopy/chanelling (RBS/C). The threshold dose for amorphization was found to be about 3 · 1014 cm-2, Amorphous surface layers produced with Ge+ ion doses above the threshold were partly annealed by 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) at a relatively low temperature of 480°C For comparison, temperatures of at least 1450°C are necessary to recrystallize amorphous SiC layers without assisting ion irradiation. The structure and quality of both the amorphous and recrystallized layers were characterized by cross-section transmission electron microscopy (XTEM). Density changes of SiC due to amorphization were measured by step height measurements.


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