Defect and Dopant Control During Silicon Epitaxy Using B and Ge

1987 ◽  
Vol 104 ◽  
Author(s):  
R. R. Kola ◽  
J. B. Posthill ◽  
A. S. M. Salih ◽  
G. A. Rozgonyi ◽  
K. E. Bean ◽  
...  
Keyword(s):  
High Speed ◽  
Maximum Yield ◽  
Dark Field ◽  
Electrical Performance ◽  
Epitaxial Layers ◽  
Threading Dislocation ◽  
Epitaxial Silicon ◽  
Cross Sectional ◽  
Plan View ◽  
Co Doped

ABSTRACTThe control of dopants, impurities and defects for VLSI of silicon integrated circuits requires a complex set of crystal and processing conditions to be satisfied simultaneously. In order to achieve the maximum yield and highest level of electrical performance for a given device design, we have manipulated the lattice constant and boron doping levels in CVD epitaxial silicon layers co-doped with germanium. By adjusting the ratios of germane and diborane in a dichlorosilane/hydrogen CVD reactor we have obtained buried high conducting layers which are strain-free and lattice matched to the Si substrate. Degenerate boron and boron and germanium codoped epitaxial layers on (100) p-type silicon substrates were investigated. Solubility, electrical activity limits and defect structure of boron in strained and strain-free silicon epitaxial layers were investigated by spreading resistance, SIMS profiling, X-ray and transmission electron microscopy techniques. Bright field and weak-beam dark field imaging of cross-sectional and plan-view specimens were used to confirm the presence or absence of precipitates and threading dislocations. A model has been proposed to describe the mechanism of threading dislocation formation in heavily boron-doped layers. We are now in a position to strategically locate co-doped Si(B, Ge) p++ layers as recombination zones or buried field plates to suit the needs of MOS latchup control, high speed and radiation hard devices, as well as the needs of defect free p++ etch stops for thin membranes and three-dimensional silicon structures.

Crystal Defects In Gan On (0001) Sapphire

1997 ◽  
Vol 482 ◽  
Author(s):  
Matthew T. Johnson ◽  
Zhigang Mao ◽  
C. Barry Carter
Keyword(s):  
Dark Field ◽  
Crystal Defects ◽  
Growth Surface ◽  
Threading Dislocation ◽  
Defect Structures ◽  
Plan View ◽  
Planar Defects ◽  
Dark Field Imaging ◽  
Inversion Domain ◽  
Different Types

AbstractDefect structures in GaN thin films grown on (0001) sapphire have been studied using a combination of different transmission electron microscopy (TEM) techniques. Two fundamentally different types of defects are found in these films. Planar defects which lie on planes perpendicular to the growth surface are common. In some regions of the films, other planar defects are present which run parallel to the surface of the substrate. The terminology used to describe these different defects varies quite widely in the literature and includes combinations of antiphase (inversion) domain boundaries and stacking faults. The second type of defect is generally referred to as a threading dislocation since many thread through the whole thickness of the film. Dislocations with different Burgers vectors have been identified in this work and in previous studies; these dislocations usually have a component of their Burgers vector lying normal to the (0001) plane. The overall defect structures in these films have been characterized using conventional bright-field and dark-field imaging. The detailed structure of the individual defects have been examined using weak-beam microscopy both in plan view and in cross section. This paper illustrates the different types of defects, both planar and linear, compares them to defects which have been characterized more thoroughly in related materials, and discuss the nomenclature of the different defect configurations.

High Quality in.Ga1−xas Heterostructures Grown on GaAs With Movpe

1998 ◽  
Vol 510 ◽  
Author(s):  
M.T. Bulsara ◽  
E.A. Fitzgerald
Keyword(s):  
Surface Roughness ◽  
Phase Separation ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Cross Sectional ◽  
Plan View ◽  
Force Microscopy ◽  
Optimum Growth Temperature ◽  
Transmission Electron ◽  
Metal Organic

AbstractInxGa1−xAs structures with compositionally graded buffers were grown by metal-organic vapor phase epitaxy (MOVPE) on GaAs substrates and characterized with plan-view and cross-sectional transmission electron microscopy (PV-TEM and X-TEM), atomic force microscopy (AFM), and x-ray diffraction (XRD). The results show that surface roughness experiences a maximum at growth temperatures where phase separation occurs in InxGa1−xAs. The strain energy due misfit dislocations in the graded buffer indirectly influences phase separation. At growth temperatures above and below this temperature, the surface roughness is decreased significantly; however, only growth temperatures above this regime ensure nearly complete relaxed graded buffers with the most uniform composition caps. With the optimum growth temperature for grading InxGa1−xAs determined to be 700°C, it was possible to produce In0.33Ga0.67As diode structures on GaAs with threading dislocation densities < 8.5 × 106/cm2

Tem Investigation of Al0.5Ga0.5As1-y Sby Buffer Layer Systems

1997 ◽  
Vol 484 ◽  
Author(s):  
E. Chen ◽  
J. S. Ahearn ◽  
K. Nichols ◽  
P. Uppal ◽  
D. C. Paine
Keyword(s):  
Buffer Layer ◽  
Active Regions ◽  
Dark Field ◽  
Layer Growth ◽  
Buffer Layers ◽  
Growth Surface ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Plan View ◽  
Dark Field Imaging

AbstractWe report on a TEM study of Sb-adjusted quaternary Al0.5Ga0.5As1-y Sby buffer-layers grown on <001> GaAs substrates. A series of structures were grown by MBE at 470°C that utilize a multilayer grading scheme in which the Sb content of Al0.5Ga0.5As1-ySby is successively increased in a series of eight 125 nm thick layers. Post growth analysis using conventional bright field and weak beam dark field imaging of these buffer layers in cross-section reveals that the interface misfit dislocations are primarily of the 60° type and are distributed through out the interfaces of the buffer layer. Plan view studies show that the threading dislocation density in the active regions of the structure (approximately 2 μm from the GaAs substrate) is 105–6/cm2 which is comparable to equivalent InxGa1−x As buffers. Weak Sb-As compositional modulations with a period of 1.8 nm were observed that provide a marker for establishing the planarity of the growth process. These features reveal that the growth surface remains planar through out the buffer layer growth sequence.

Formation of Ge Nanocrystals in Lu2O3 High-k Dielectric and its Application in Non-Volatile Memory Device

2007 ◽  
Vol 997 ◽  
Author(s):  
Mei Yin Chan ◽  
Pooi See Lee ◽  
Vincent Ho
Keyword(s):  
Photoelectron Spectroscopy ◽  
Annealing Treatment ◽  
Electrical Performance ◽  
Cross Sectional ◽  
Plan View ◽  
High K ◽  
Non Volatile Memory ◽  
Volatile Memory ◽  
High K Dielectric ◽  
Ge Nanocrystals

AbstractA simple technique for the formation of Ge nanocrystals embedded in amorphous Lu2O3 high-k dielectric was demonstrated by pulsed laser ablation followed by rapid thermal annealing in N2 ambient. The structure and composition of the Ge nanocrystals in the oxide matrix have been studied by transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) analysis. A significant change in the structure and chemical composition of the film was obtained upon annealing. Cross-sectional and plan-view TEM images confirmed the formation of small Ge nanocrystals in amorphous Lu2O3 matrix with a mean size of about 6nm in diameter and a high areal density of 7 × 1011cm−2. The nanocrystals are well-isolated by the amorphous Lu2O3 in between, with almost spherical shape which are favorable for non-volatile memory (NVM) application due to an effective charge confinement. XPS measurements on the as-deposited sample indicate the existence of Ge in its oxidized state, consisting of GeO2 and Ge suboxides. A spontaneous reduction of GeO2 and GeOx was obtained after the annealing treatment, which provides Ge nuclei for nanocrystal formation. It is found that a low annealing temperature of 400oC is sufficient to dissociate the GeO2 and GeOx leading to the formation of Ge nanocrystals. The application of the nanocrystals in NVM devices was demonstrated by C-V characterization of the memory capacitor devices fabricated with Al2O3 control oxide layer. C-V results show a significant effect of the structure and composition of the film on the electrical performance of the device. The annealed device exhibits good memory behavior with a large memory window of 1.2V achieved with a low operation voltage.

Transmission electron microscopy study of (103)-oriented epitaxial SrBi2Nb2O9 films grown on (111) SrTiO3 and (111) SrRuO3/(111) SrTiO3

2001 ◽  
Vol 16 (2) ◽  
pp. 489-502 ◽  
Author(s):  
M. A. Zurbuchen ◽  
J. Lettieri ◽  
Y. Jia ◽  
D. G. Schlom ◽  
S. K. Streiffer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Substrate Surface ◽  
Microscopy Study ◽  
Dark Field ◽  
Electron Microscopy Study ◽  
Cross Sectional ◽  
Plan View ◽  
Transmission Electron ◽  
Second Phases

Portions of the same epitaxial (103)-oriented SrBi2Nb2O9 film grown on (111) SrTiO3 for which we recently reported the highest remanent polarization (Pr) ever achieved in SrBi2Nb2O9 (or SrBi2Ta2O9) films, i.e., Pr = 15.7 μC/cm2, have been characterized microstructurally by plan-view and cross-sectional transmission electron microscopy (TEM) along three orthogonal viewing directions. SrBi2Nb2O9 grows with its c axis tilted 57° from the substrate surface normal in a three-fold twin structure about the substrate [111], with the growth twins' c axes nominally aligned with the three 〈100〉 SrTiO3 directions. (103) SrBi2Nb2O9 films with and without an underlying epitaxial SrRuO3 bottom electrode have been studied. Dark-field TEM imaging over a 12 μm2 area shows no evidence of second phases (crystalline or amorphous). A high density of out-of-phase boundaries exists in the films.

Origin of the defect structures in oxygen-implanted silicon-on-insulator material

1993 ◽  
Vol 51 ◽  
pp. 1108-1109
Author(s):  
D. Venables ◽  
S.J. Krause ◽  
J.D. Lee ◽  
J.C. Park ◽  
P. Roitman
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Silicon Layer ◽  
Dark Field ◽  
Silicon On Insulator ◽  
High Dose ◽  
Defect Structures ◽  
Plan View ◽  
High Temperature Anneal ◽  
Single Oxygen

Silicon-on-insulator material fabricated by high-dose oxygen implantation (known as SIMOX) has been used for high speed and radiation hard devices and is under consideration for use in low power applications. However, a continuing problem has been crystalline defects in the top silicon layer. SIMOX is fabricated by two distinct methods: a single oxygen implant to a dose of 1.8×l018 cm-2 followed by a high-temperature anneal (≥1300°C, 4-6 hr) or by multiple lower dose implants (∼6×l017 cm-2) with high-temperature anneals after each implant. To date, there has been no systematic comparison of the defect structures produced by these two fabrication methods. Therefore, we have compared the defect structure and densities in multiple vs. single implant wafers. In this paper we describe the origin and characteristics of the defect structures in SIMOX and show how their densities are controlled by the processing method and conditions.Silicon (100) wafers were implanted in a high current implanter at ∼620°C to doses of 1.8×l018 or 0.6/0.6/0.6×l018 cm-2 and annealed at 1325°C, 4 hr in 0.5% or 5% O2 in Ar. Cross-section (XTEM) and plan-view (PTEM) samples were studied with bright field and weak beam dark field techniques in a transmission electron microscope operating at 200 keV.

Relaxed Inx.Ga1−xas Graded Buffers Grown With Organometallic Vapor Phase Epitaxy on GaAs

1997 ◽  
Vol 484 ◽  
Author(s):  
M. T. Bulsara ◽  
C. Leitz ◽  
E. A. Fitzgerald
Keyword(s):  
Surface Roughness ◽  
Phase Separation ◽  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Organometallic Vapor Phase Epitaxy ◽  
Cross Sectional ◽  
Plan View ◽  
Optimum Growth Temperature

AbstractInxGa1−xAs structures with compositionally graded buffers were grown with organometallic vapor phase epitaxy (OMVPE) on GaAs substrates and characterized with plan-view and cross-sectional transmission electron microscopy (PV-TEM and X-TEM), atomic force microscopy (AFM), and x-ray diffraction (XRD). The results show that surface roughness experiences a maximum at growth temperatures where phase separation occurs in In.Gal.,As. The strain fields from misfit dislocations induce this phase separation in the <110> directions. At growth temperatures above and below this temperature, the surface roughness decreases significantly; however, only growth temperatures above this regime ensure nearly complete relaxed graded buffers with the most uniform composition caps. With the optimum growth temperature for grading InxGa1−x,As determined to be 700 °C, it was possible to produce In0.33Ga0.67As diodes on GaAs with threading dislocation densities < 8.5 × 106/cm2.

Low-Temperature (< 100°C) Growth of Ain by Ion Beam Assisted Deposition+

1995 ◽  
Vol 396 ◽  
Author(s):  
H. Karimy ◽  
E. Tobin ◽  
R. Bricault ◽  
A. Cremins-Costa ◽  
P. Colter ◽  
...  
Keyword(s):  
High Temperature ◽  
Crystal Size ◽  
Ion Beam ◽  
Physical And Mechanical Properties ◽  
Dark Field ◽  
Cross Sectional ◽  
Plan View ◽  
The Past ◽  
Ion Beam Assisted Deposition ◽  
Transmission Electron

AbstractDuring the past few years, there has been growing interest in aluminum nitride (A1N) thin films because of their excellent optical, electrical, chemical, mechanical and high-temperature properties. Ion beam assisted deposition (IBAD) was used to deposit A1N films on flat and curved substrates, including Si, SIMOX, sapphire, quartz, aluminum, stainless steel, and carbon, at temperatures substantially below 100°C. The objective was to enhance the physical and mechanical properties of A1N film by controlling the crystal size and structures.Experimental results, as obtained by Rutherford backscattering spectroscopy (RBS) show the formation of stoichiometric A1N. Plan-view/cross-sectional transmission electron microscopy (TEM), clearly demonstrated the formation of a smooth, uniform A1N film. Electron diffraction and dark field TEM studies clearly show the growth of A1N crystallites with cubic and/or hexagonal structures and dimensions of 30 to 100A. The films are transparent and have good adhesion to all substrates. In addition to excellent high temperature (up to 1050°C measured) and chemical stability (shown through a variety of acid tests), these films have demonstrated extreme hardness, greater than two times that of bulk AIN.

Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

1996 ◽  
Vol 54 ◽  
pp. 1000-1001
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Dark Field ◽  
Nickel Layer ◽  
Multilayer Thin Films ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

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