Depth Profile Of Point Defects In Ion Implanted n+p and p+n Junctions Formed By 450°C Post-Implantation Annealing And Impact Of Defects On Junction Characteristics

1996 ◽  
Vol 442 ◽  
Author(s):  
Mauricio Massazumi Oka ◽  
Akira Nakada ◽  
Yukio Tamai ◽  
Kei Kanemoto ◽  
Tadashi Shibata ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Point Defects ◽  
Substrate Type ◽  
Leakage Currents ◽  
Defect Clusters ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Point Defect Clusters ◽  
Ion Species ◽  
Post Implantation

AbstractIt is shown that defects generated by ion implantation, remaining after annealing at low temperature, are deep-distributed in the bulk silicon and their amount is demonstrated to be function of the substrate type and the implanted ion species. The confirmation that defects penetrate deeply into the silicon is made by a new method that consists in damaging by ion implantation a previously formed pn junction that shows very low leakage current and has a deep junction. It is proposed that the dopants in the substrate act as nucleation centers for the formation of point defect clusters and that these clusters actually degrade the junction. It was found that point defects penetrate much more deeply in p+n junctions than in n+p junctions. It was also found that BF2+ introduces much more defects into the silicon than As+, owing to the presence of fluorine. The leakage currents at 5 V of n+p and p+n diodes made by implantation of P+ and B+, respectively, could be lowered by one to two orders of magnitude with respect to values obtained by implantation of As+ and BF2+ because the former ones produce less defects than the latter.

X-Ray Diffuse Scattering Investigation of Defects in Ion Implanted and Annealed Silicon

1998 ◽  
Vol 524 ◽  
Author(s):  
C. H. Chang ◽  
U. Beck ◽  
T. H. Metzger ◽  
J. R. Patel
Keyword(s):  
Ion Implantation ◽  
Point Defect ◽  
Point Defects ◽  
Diffuse Scattering ◽  
Grazing Incidence ◽  
X Rays ◽  
Scattered Intensity ◽  
X Ray ◽  
Defect Clusters ◽  
Point Defect Clusters

ABSTRACTTo characterize the point defects and point defect clusters introduced by ion implantation and annealing, we have used grazing incidence x-rays to measure the diffuse scattering in the tails of Bragg peaks (Huang Scattering). An analysis of the diffuse scattered intensity will allow us to characterize the nature of point defects or defect clusters introduced by ion implantation. We have also observed unexpected satellite peaks in the diffuse scattered tails. Possible causes for the occurrence of the peaks will be discussed.

scholarly journals The Formation of Amorphous Silicon by Light Ion Damage

1985 ◽  
Vol 45 ◽  
Author(s):  
Y. Shih ◽  
J. Washburn ◽  
E.R. Weber ◽  
R. Gronsky
Keyword(s):  
Ion Implantation ◽  
Amorphous Silicon ◽  
Point Defect ◽  
Point Defects ◽  
Liquid Nitrogen Temperature ◽  
Paramagnetic Resonance ◽  
High Resolution Tem ◽  
Different Temperatures ◽  
Boron Ions ◽  
Point Defect Clusters

ABSTRACTA model for formation of amorphous silicon by light ion implantation is proposed. It is suggested that accumulation of point defects and/or complexes is required at the initial stage of the amorphization process. Amorphous zones can only form at the end of incoming light ion tracks when the pre-accumulated concentration of point defects reaches a critical value. Depending on the uniformity of the point defect distribution, two possibilities for the second stage of amorphization are suggested when ion implantation is performed at different temperatures.Silicon wafers implanted with boron ions below and above the critical amorphization dose at various temperatures have been investigated using cross section specimens in high resolution TEM. Complementary analyses of these specimens by Electron Paramagnetic Resonance have revealed the presence of dangling bonds in amorphous zones and point defect clusters. Extrinsic stacking faults with 1/3 <111> displacements and other smaller distortions with 1/x<111> displacements were also found to result from the amorphization process. Liquid nitrogen temperature was found to be necessary to cause complete amorphization of silicon by boron ion implantation.

Disorder in TiO 2─ x

1982 ◽  
Vol 384 (1786) ◽  
pp. 157-173 ◽  
Keyword(s):  
Dielectric Constant ◽  
Point Defects ◽  
Simulation Methods ◽  
Extended Defects ◽  
Stable Point ◽  
Defect Clusters ◽  
The Stability ◽  
Point Defect Clusters ◽  
Formation Energies ◽  
Shear Planes

We present a theoretical survey, based on reliable computer simulation methods, of defect energetics in TiO 2─ x . A lattice potential for TiO 2 is developed and used in calculations of the formation energies of point and extended defects. We predict vacancies to be the most stable point defects. We show that they will exist in equilibrium with the shear planes that microscopy studies have detected in reduced rutile. We suggest that the stability of the extended defects is due predominantly to the occurrence of large stabilizing relaxations of the cations neighbouring the shear planes. The absence of appreciable binding for point defect clusters may also, however, be important. We show how both factors may be related to the exceptionally high static dielectric constant for the material.

Temperature and Doping Dependency of Piezoresistivity in p-type Silicon

2000 ◽  
Vol 657 ◽  
Author(s):  
Eivind Lund ◽  
Terje G. Finstad
Keyword(s):  
Leakage Current ◽  
Negative Temperature ◽  
Leakage Currents ◽  
Micro Electro Mechanical Systems ◽  
Type Silicon ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Wafer Thickness ◽  
P Type ◽  
Doping Profiles

ABSTRACTWe have performed new measurements of the temperature and doping dependency of the piezoresistive effect in p-type silicon. Piezoresistivity is one of the most common sensing principles of micro-electro-mechanical-systems (MEMS). Our measurements are performed in a specially designed setup based on the well-known 4 point bending technique. The samples are beams of full wafer thickness. To minimize leakage currents and to obtain uniform doping profiles, we have used SIMOX (Separation by IMplantation of OXygen) substrates with resistors defined in an epitaxial layer. Spreading resistance measurements show that the doping profiles are uniform with depth, while measurements of leakage current versus temperature indicate low leakage current. In this paper we present results for the doping concentration range from 1×1017 – 1×1020 cm−3 and the temperature range from –30 to 150 degrees Celsius. The results show a doping dependency of piezoresistivity well described by the current models. The measurements of the temperature dependency of the coefficients of piezoresistivity are compared to a linear model with a negative temperature coefficient whose absolute value decreases with increasing doping.

Formation of Defect Clusters in SrTiO3 Crystals Implanted with Xenon Ions

2007 ◽  
Vol 561-565 ◽  
pp. 1757-1760 ◽  
Author(s):  
Ming Hui Song ◽  
Xing Jian Guo ◽  
Nobuhiro Ishikawa ◽  
Masaki Takeguchi ◽  
Kazutaka Mitsuishi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Point Defects ◽  
Crystalline State ◽  
Implantation Dose ◽  
Defect Clusters ◽  
Other Point Defects ◽  
Transmission Electron ◽  
Post Implantation

SrTiO3 crystals were implanted with 100 keV xenon (Xe+) ions at 673 or 1073 K up to 2.0 × 1020 ions m−2. Defect clusters formed in the ion-implanted samples were investigated with conventional and high-resolution transmission electron microscopy. Nanometer-sized clusters were formed in the samples. The clusters grew large in size after post-implantation annealing and with increasing the implantation dose. The clusters were faceted with {100}, or {110} of SrTiO3. Though the nano-sized clusters were expected to contain Xe atoms, they were not in crystalline state. The results suggest that even if the clusters contain Xe atoms, they also contain other point defects such as vacancies.

Study of point defects in as-grown and annealed bismuth germanate single crystals

2005 ◽  
Vol 38 (3) ◽  
pp. 448-454 ◽  
Author(s):  
G. Bhagavannarayana ◽  
A. Choubey ◽  
Yu. V. Shubin ◽  
Krishan Lal
Keyword(s):  
Point Defect ◽  
Single Crystals ◽  
Point Defects ◽  
Bismuth Germanate ◽  
Cluster Radius ◽  
X Ray ◽  
Defect Clusters ◽  
X Ray Scattering ◽  
Point Defect Clusters ◽  
Ray Scattering

Point defects and their clusters in bismuth germanate single crystals free from grain boundaries and having low density of dislocations were studied by high-resolution diffuse X-ray scattering measurements. Differences in defects in the colourless crystals (type A) and the crystals having yellow tinge (type B), which were grown with different raw materials, were investigated. In addition, interesting differences in defect structures in specimens from different regions of the same boule were investigated. Specimens with diffracting surfaces along (111), (112) and (100) planes were studied. A multicrystal X-ray diffractometer employing a well collimated and highly monochromated Mo Kα1 beam and set in (+,−,−,+) configuration was employed. The diffraction curves of all the samples were quite narrow with half-widths in the range 7–11 arcsec, which are close to the theoretically expected values, if instrumental broadenings are taken into account. The observed distribution of diffuse X-ray scattering (DXS) intensity showed that not all the point defects are isolated but a significant fraction are agglomerated into clusters. Experimental data of DXS intensity were analysed by using a phenomenological model for a small concentration of dislocation loops wherein the point defects are loosely clustered with weak interactions among them. From this analysis, the cluster radius R cl, cluster volume A cl, the number of point defects within a cluster N cl and the relative concentration of the point-defect clusters among the samples were estimated. It was observed that cluster sizes do not vary from sample to sample. However, it was found that the concentration of clusters is approximately twice in the coloured sample compared with that of the colourless sample from the same boule. Annealing of the crystals at 1273 K produced an increase in point-defect clusters by a factor of ∼200. It was accompanied by a reduction in volume of clusters by a factor of ∼0.14.

Creation and Annealing out Mechanism of Defects in Ion-Implanted Si Crystals Investigated by Positron Annihilation

1997 ◽  
Vol 470 ◽  
Author(s):  
S. Tanigawa
Keyword(s):  
Ion Implantation ◽  
Positron Annihilation ◽  
Point Defects ◽  
General Feature ◽  
Positron Beam ◽  
Point Of View ◽  
Ion Energy ◽  
Energy Variable ◽  
Ion Species ◽  
Ion Implanted

ABATRACTVacancy-type defects in Si crystals introduced by ion implantation have been investigated by an energy-variable positron beam The present paper describes the general feature of point defects induced by ion implantation from the point of view of their dependence on implanted ion species, ion dose, ion energy, implanted targets, thermal after implantation, the presence of oxide overlayers and so on.

ZnO-Pr6O11-Co3O4-TiO2-Based Ceramic Varistor Materials

2010 ◽  
Vol 434-435 ◽  
pp. 389-392
Author(s):  
Hai Feng ◽  
Zhi Jian Peng ◽  
Cheng Biao Wang ◽  
Zhi Qiang Fu ◽  
He Zhuo Miao
Keyword(s):  
Grain Growth ◽  
Leakage Current ◽  
Nonlinear Property ◽  
Leakage Currents ◽  
Nonlinear Properties ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Ceramic Varistor

The preparation and characterization of ZnO-Pr6O11-Co3O4-TiO2 (ZPCT) based varistor materials with different doping levels of TiO2 and Pr6O11 were investigated. The results reveal that: (1) TiO2 is an important additive, acting as an inhibitor of ZnO grain growth. The doping of appropriate amount of TiO2 can significantly improve the nonlinear properties and decreases the leakage current of the varistors, achieving a relatively high nonlinear exponent and low leakage current with 1.0 mol% TiO2 doped. (2) The oxide of Pr6O11 microstructurally plays the role of inhibition in grain growth. The doping of appropriate amount of Pr6O11 can improve the nonlinear property, and decrease the leakage currents of the varistors, acquiring the optimum results with 1.5 mol% Pr6O11 doped.

Leakage currents of large area InP/InGaAs heterostructures

2014 ◽  
Vol 1635 ◽  
pp. 75-81
Author(s):  
Anders Olsson ◽  
Abuduwayiti Aierken ◽  
Jani Oksanen ◽  
Harri Lipsanen ◽  
Jukka Tulkki
Keyword(s):  
Cooling Capacity ◽  
Large Area ◽  
Leakage Currents ◽  
Light Emitting ◽  
Low Leakage ◽  
Optical Cooling ◽  
Low Leakage Current ◽  
Current Voltage ◽  
Current Densities ◽  
Electroluminescent Cooling

ABSTRACTLight-emitting diodes (LEDs) based on the conventional III-V compound semiconductors are known to exhibit internal quantum efficiencies (IQE) that are very close to unity. Ideally, the high IQE is expected to enable electroluminescent cooling with a cooling capacity of several Watts per cm2 of emitter area. One key requirement in enabling such cooling is the ability to fabricate high quality large area LEDs. However, detailed information on the performance of relevant large area devices and their yield is extremely scarce. In this report we present data on the yield and related large area scaling of InP/InGaAs LEDs by using current-voltage measurements performed on LED wafers fabricated at five different facilities. The samples were processed to contain square shaped mesas of sizes 0.25 mm2 and 16 mm2 operating as LEDs. While most of the smaller mesas showed relatively good electrical characteristics and low leakage current densities, some of them also exhibited very large leakage currents. In addition, in some cases the large area devices exhibited large, and even almost linearly behaving leakage currents. Such information on the scaling and unidealities of diodes fabricated using established fabrication technologies is crucial for the development of the optical cooling technologies relying on large area devices.

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