bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure of Thermally Grown SiO2 on Crystalline 6H‐SíC
Authors: Tsuchida H. , Kamata I. , Izumi K. 
Published: April 2011

AbstractThe structure of a thermally grown SiO2 film on a crystalline 6H‐SiC substrate was investigated using X‐ray reflectivity and fourier‐transformed infrared attenuated total reflection (FTIR‐ATR). The density, surface roughness and interface roughness of thermal oxide on 6H‐SiC were obtained by X‐ray reflectivity. The TO mode and the LO mode of Si‐O‐Si stretching vibration from the thermal oxide film on 6H‐SiC were obtained from polarized ATR spectra. The local structure of SiO2 film near the SiO2 /SiC interface was discussed from the measurements, and the thermally grown SiO2 film on a 6H‐SiC substrate was found to have a structural transition layer with thickness below 10 nm near the SiO2/SiC interface.
Preparation And Characterization Of Pzt Thin Films On Ruox/Pt Multilayered Electrode By Mocvd
Authors: Kim Tae‐Young , Km Daesig , Chung Chee Won , Lee June Key , Song Inyong 
Published: April 2011

AbstractFerroelectric lead zirconate titanate (PZT) thin films have been successfully prepared on a RuOx/Pt multilayered electrode by Metal Organic Chemical Vapor Deposition (MOCVD). The multilayered electrode was introduced to enhance device reliability for FRAM and DRAM applications. The variations in the microstructure and ferroelectric properties of the PZT thin films were investigated as a function of substrate thickness. The microstructure of the PZT thin films was found to have a strong dependence on the surface morphology of the substrate. The control of microstructure resulted in improved ferroelectric properties. The endurance of the Pt/RuOx/PZT/RuOx/Pt capacitor was also maintained up to 1010 cycles without any serious degradation. The ferroelectric capacitors on 4” wafer were integrated by using Inductively Coupled Plasma Reactive Ion Etching (ICP RIE) system and the fully processed MOCVD PZT capacitors showed good ferroelectric properties (Vc=0.57V, ργ=22μC/cm2 respectively).
Structural characterization of different insulating films by spectroscopic ellipsometry and grazing x‐ray reflectance
Authors: Boher P. , Stehle J.L. , Hennet L. 
Published: April 2011

AbstractSpectroscopic Ellipsometry (SE) and Grazing X‐ray Reflectance (GXR) techniques are applied for different insulating films to determine precisely the thickness and optical indices of the layers. Antireflective coatings for microlithography in the DUV range are first analyzed. In the infrared range the layers are transparent and one can take into account the optical index of the layers by a simple dispersion law. Thicknesses obtained by this method are checked by the GXR technique. Extraction of the optical indices from UV to IR is made very accurately taking into account different SE measurements at various incident angles simultaneously. Amorphous carbon thin films are also analyzed in the same way. The main difference is that the layer is absorbant in the entire wavelength range. In this case, a first characterization by the GXR technique is essential to extract the thickness of the layer. Then the optical indices of the layer can be extracted very accurately by SE.
Nitrided Silicon Oxide Gate Dielectrics for Submicron Device Technology
Authors: Lucovsky G. 
Published: April 2011

AbstractThe research in this paper is based on an approach to low‐temperature/low‐thermal budget device fabrication that combines plasma and rapid thermal processing, and which has been customized to control separately: (i) the N‐atom bonding chemistry and composition profiles, and (ii) the structural and chemical relaxations necessary for device‐quality performance and reliability for stacked gate structures. Control of N‐atom incorporation at the monolayer level at the crystalline‐Si and polycrystalline‐Si interfaces of field effect transistors, and at alloy levels within the bulk dielectrics has been achieved by combining low‐temperature (∼300°C) plasma‐assisted processes to generate the N‐atom concentration profiles, with low‐thermal‐budget rapid thermal annealing (RTA) to promote chemical and structural relaxations that minimize defects and defect precursors.
Improved Reliability With a New Plasma Nh3 Process for 0.35μιη P+ Poly-Gate Nitrided Oxide P-Mosfet's
Authors: Bravaix A. , Vuillaume D. , Goguenheim D. , Lasserre V. , Straboni A. , Haond M. 
Published: April 2011

AbstractThe electrical properties and the hot-carrier reliability of P+ poly-gate P-MOSFET's are investigated for advanced 0.35 μπι LDD CMOS technologies. It is shown that surface-channel p-devices with an optimized plasma NH3 nitrided gate-oxide have good barrier properties and electrical performances which lead to a higher hot-carrier immunity in 8nm thick nitrided gate-oxides than in pure oxides using DC and AC experiments. The AC stressing shows that reducing the gate-oxide thickness leads to a larger influence of electron detrapping inducing a stronger influence of donor type interface traps than the usual build-up of negative charges. These distinct degradation mechanisms are less significant in nitrided oxide p-MOSFET's due to the lower lateral electric field leading to a lower amount of trapped charges which are quickly suppressed during subsequent detrapping phases leaving the main influence of the interface traps.
A Plasma Reactor for Solid Waste Treatment on Pecvd Production Systems
Authors: Raoux S. , Fodor M. A. , Taylor W. N. , Cheung D. , Fairbairn K. 
Published: April 2011

AbstractThe growth of particulates within a PECVD (Plasma Enhanced Chemical Vapor Deposition) reactor has been extensively studied in recent years. As one of the early concerns was wafer particle contamination, the attention of industry also shifted to environmental issues. In the particular case of Si3N4 film deposition, the amount of dust particles created within the plasma is great and a significant amount of dust is dragged out of the RF interelectrode region along with the exhausted process gases. On a production system, this results in solid residues accumulation in the exhaust line (or foreline), frequent maintenance and poor vacuum pump lifetime. We developed a DPA (Downstream Plasma Apparatus) placed downstream of the deposition chamber to solve the issue of solid waste treatment for thin films applications such as SiO2, Si3N4, SiC, SiOxNy,…, α‐Si,…). The DPA is designed to capture all the residue during deposition, using both a passive and an active mode. It consists of two labyrinth‐shaped electrodes that can trap particles by gravitation (passive) and electrostatically (active) by application of a DC electric field. The second function of the device is to vaporize the previously trapped residues using a periodic plasma assisted clean. The vaporization process is performed by re‐ionizing the effluent PFCs gas (PerFluoro‐Coumpounds) from the processing chamber. All byproducts of the reaction are gaseous and water soluble. This results in the elimination of solid waste as well as improving vacuum pump lifetime. There is also better clean gas utilization and the emission of PFCs in the atmosphere is reduced. In this paper, we review the particulate formation, their size and composition. We describe the DPA reactor designed to trap charged particulates with closed to 100% efficiency. We examine the plasma‐assisted cleaning process and the implications of the device in terms of solid waste treatment and environmental impact.
Point-of-Use Silicon Sources for Cvd
Authors: Saulys D.A. , Safvi S.A. , Pauly N. , Dopke J.A. , Preston B.R. , Gaines D.F. , Kuech T.F. 
Published: April 2011

AbstractThe reliance of the semiconductor industry on pyrophoric silane gas as the primary source of silicon entails high risk and attendant cost. In order to enhance safety and improve control we are engaged in a systematic study of the decomposition characteristics of alkyl silanes with a focus on chemical species and conditions that exhibit silane type behavior or that actually produce silane. We have prepared a series of air stable innocuous liquid alkyl silanes, RSiH3, that generate silane and stable organic (R-H) byproducts upon flow tube pyrolysis. T-buty1, t-hexy1, and t-decyl silane as well as the corresponding R-H products exhibit a range of physical properties : room temperature vapor pressures, for example, range from several Torr to over an atmosphere. Relevant physical properties as well as kinetics and mechanisms of the hydride transfer process will be described and correlated with structural characteristics of the RSiH3 precursors.
PFC Emission Control Options for Plasma Processing Tools: A Current Assessment
Authors: Mocella M. T. 
Published: April 2011

AbstractPerfluorocompounds (PFCs) are critical processing gases for a number of plasma-based IC processing steps, especially dry etching and in situ CVD chamber cleaning. The long atmospheric lifetimes and large infrared absorption cross sections for such gases (which include CF4, C2F6, C3F8, NF3, SF6, and CHF3) have raised concerns about the contributions of PFC emissions to possible global warming. Global regulatory policies on greenhouse gases are expected to include the PFCs, and the specific attention given to these gases in negotiations between the U.S. government and the semiconductor industry may expand internationally as well.Several options exist for PFC emission control, including process optimization, chemical substitution, capture/recovery/recycle, and destructive abatement (including combustion, reactive adsorption, and plasma decomposition). An assessment of each option will be made in terms of both technical effectiveness (i.e., PFC reduction achievable) as well as implementation issues (e.g., commercialization timing, cost of ownership). PFC users can expect to have several commercial options to choose from to meet future PFC emission control requirements.
Environmental Issues of Perfluorocompounds in the Semiconductor Industry
Authors: Williams Jeffrey D. 
Published: April 2011

AbstractA critical class of semiconductor manufacturing compounds is the family of perfluorocompounds, or PFCs. Originally thought to be environmentally benign compounds, they are likely long-lived atmospheric compounds with high global warming potentials. This paper reviews the options available to industry to reduce PFC emissions. Process optimization, chemical substitution, abatement, and recovery will be discussed as they relate to specific processes. Each will be reviewed with respect to the particular gas affected and the potential impact realized. Collateral environmental impacts will also be discussed. Finally, the voluntary EPA program, the PFC Emission Reduction Partnership for the Semiconductor Industry, will be presented.
High Power InAsSb/InAsSbP Laser Diodes Emitting at 3 ∼ 5 μm Range
Authors: Razeghi M. , Diaz J. , Yi H. J. , Wu D. , Lane B. , Rybaltowski A. , Xiao Y. , Jeon H. 
Published: April 2011

ABSTRACTWe report metalorganic chemical vapor deposition-grown double heterostructure and multiple quantum well InAsSb/InAsSbP laser diodes emitting at 3 to 4 μm and light emitting diodes up to 5 μm. Maximum output power up to 1 W (from two facets) with differential efficiency above 70 % up to 150 K was obtained from a MQW laser with stripe width of 100 μm and cavity length of 700 μm for emitting wavelength of 3.6 μm at 90 K. Maximum operating temperature up to 220 K with threshold current density of 40 A/cm2 at 78 K were achieved from the double-heterostructure lasers emitting at 3.2 μm. The far-field beam divergence as narrow as 24° was achieved with the use of higher energy gap barrier layers, i.e., lower effective refractive index, in MQW active region. We also discuss the effect of composition-fluctuation in the InAsSb active region on the gain and threshold current of the lasers.
Single Mode Operation of Impurity-Induced Disordering Large Area Vertical Cavity Surface Emitting Lasers
Authors: Lo C. W. , Yu S. F. 
Published: April 2011

ABSTRACTVertical-cavity surface-emitting lasers (VCSELs) with suitable interdiffusion quantum wells profile by the use of selective impurity-induced disordering is proposed for high power single mode operation in large area devices. It is shown that the transverse optical confinement in the quantum well active region formed by the diffusion profile counteracts the influence of carrier spatial hole burning for VCSELs biased at high injection current Results indicate that a single mode operation can be maintained in VCSELs with the diameter of core region equal to 50μm.
1.5 μm In0.53Al0.14Ga0.33As/In0.52Al0.48As Distributed Bragg Reflector and Single Cavity Active Layer Grown with In-Situ Double Beam Laser Reflectometry
Authors: Baek Jong-Hyeob , Lee Bun , Lee Jin Hong , Han Won Seok , Lee El-Hang 
Published: April 2011

ABSTRACTWe report the highly reflecting (>99.9%) In0.53Al0.14Ga0.33As/In0.52Al0.48As 30.5 pairs distributed Bragg reflector (DBR) and the In0.53Ga0.47As/ In0.52Al0.48As active cavity layer grown at high temperature by low pressure metal organic chemical vapor deposition with in-situ double beam laser reflectometry. One of the laser wavelengths selected for in-situ measurement was same as the DBR wavelength. The growth temperature was 750 °C. Good surface morphology of the multi-layer stacks was achieved by the temperature ramping of the InP buffer layer at the beginning of a multi-layer stacks. The width of stop band edge of the DBR reflectivity spectrum was found to be 1000Å.
Intersubband Transitions, Infrared Detectors, and Optical Nonlinearities in SiGe Multiquantum Wells
Authors: Helm M. , Kruck P. , Fromherz T. , Seto M. , Bauer G. , Nützel J. F. , Abstreiter G. 
Published: April 2011

ABSTRACTA survey is given about the potential use of Si/SiGe heterostructures for applications in the mid-infrared spectral range. We discuss theoretical foundations and experiments of intersubband absorption in p-type Si/SiGe quantum wells and show that due to the complex valence-band structure, normal-incidence absorption can be observed. On the basis of these quantum wells, mid-infrared detectors were fabricated and characterized in terms of responsivity, dark current and detectivity. In asymmetric, compositionally stepped quantum wells second harmonic generation of CO2 laser radiation has been demonstrated.
P-Type Doping with Arsenic in MBE-HgCdTe Using Planar Doping Approach
Authors: Aqariden F. , Wijew Arnasuriya P. S. , Rujirawat S. , Sivananthan S. 
Published: April 2011

ABSTRACTThe results of arsenic incorporation in HgCdTe (MCT) layers grown by molecular beam epitaxy (MBE) are reported. The incorporation into MBE-MCT was carried out by a technique called planar doping. Arsenic was successfully incorporated during the MBE growth or after a low temperature anneal as acceptors. These results are very promising for in-situ fabrication of advanced optoelectronic devices using HgCdTe material.
Self-Trapping of Optical Beams and Light-Induced Waveguiding in Photorefractive InP at Telecommunication Wavelengths
Authors: Chauvet M. E. , Hawkins S. A. , Salamo G. J. , Segev M. , Bliss D. F. , Bryant G. 
Published: April 2011

ABSTRACTWe demonstrate self-trapping of a two-dimensional beam at 1.3 microns wavelength in resonantly-enhanced InP. The self-trapped beam also induces a two-dimensional optical waveguide in bulk InP, which guides a second beam at 1.55 micron wavelength.
Diffused Quantum Well Structures: Advances in Materials and Device Realizations
Authors: Herbert Li E. 
Published: April 2011

ABSTRACTThe Diffused Quantum Well (DFQW) structures created by both impurity induced and impurity free or vacancy promoted processes have recently been advanced to a higher level. The interdiffusion mechanism is no longer confined to two constituent atoms, but consists of two or multiple phase interdiffusion as well as multiple species, such as three cations interdiffusion and two pairs of cation-anion interdiffusion. Results show that the outcome of these interdiffusions is quite different. For instance, both compressive or tensile strain materials and both blue or red shifts in the bandgap can be achieved dependent on the type of interdiffusion. The advantage of being able to tune the material properties allows the realizations of higher performance lasers and modulators. Two lasing wavelengths (60 nm apart) are produced at λ ∼ 1.55μm, on the same substrate, with threshold currents of 290mA, and an extremely large relative reflectance change (over 10000) is predicted with power consumption reduced by 67%. A six fold enhancement of the third order susceptibility over that of the bulk materials can be achieved by using the inter-subband transitions in the DFQW at λ ∼ μm. Broadband (1000nm) detectors have also been realized due to the wide DFQW spectral bandwidth. Several state-of-the-art results of the DFQW will be summarized with an emphasis on the future developments and directions of the DFQW.
Interdiffusion in Quantum Wells: Mixing Mechanisms and Energy Levels
Authors: Gass Richard G , Jackson Howard E , Hughes P J , Weiss Bernard L 
Published: April 2011

AbstractCompositional interdiffusion in Al0.3Ga0.7As/GaAs superlattice structures with equal 3.5 nm barrier and well widths induced by Si focused ion beam implantation and subsequent rapid thermal annealing has been modeled. A strong depth dependence of the mixing process is observed at a Si++ energy of 100 keV and at a dose of 1×1014 cm−2; this depth dependence is modeled by considering the second derivative of the vacancy profile. That is the maximum in the vacancy injection generated by the transient vacancy concentration gradient. We have included the dynamics of the spatial vacancy profile in the model and find good agreement with experimental results.Interdiffusion across the well/barrier interfaces modifies the subband structure in AlGaAs/GaAs single quantum well (QW) structures. We have investigated the interrelated changes in both confinement energy of the subband states and the composition dependence of the bandgap energy in the QW, both of which are a strong function of the initial well width. Higher order transitions are found to be more sensitive than the ground state transitions to interdiffusion especially during the early stages of interdiffusion. These calculations model the experimental measurements (photoluminescence and photoreflectance) which are used to characterize interdiffused QW structures.
Polarization Insensitivity in Interdiffused, Strained InGaAs/InP Quantum Wells
Authors: Micallef Joseph , Borg James L. , Shiu Wai-Chee 
Published: April 2011

ABSTRACTTheoretical results are presented showing how quantum well disordering affects the TE and TM absorption coefficient spectra of In0.53Ga0.47As/InP single quantum wells. An error function distribution is used to model the constituent atom composition after interdiffusion. Different interdiffusion rates on the group V and group III sublattices are considered resulting in a strained structure. With a suitable interdiffusion process the heavy hole and light hole ground state, excitonic transition energies merge and the absorption coefficient spectra near the fundamental absorption edge become polarization insensitive. The results also show that this polarization insensitivity can persist with the application of an electric field, which is of considerable interest in waveguide modulators.
The Confinement Profile of As-Grown Movpe AlGaAs/GaAs Quantum Well Structures
Authors: Choy W. C. H. , Hughes P. J. , Weiss B. L. 
Published: April 2011

ABSTRACTInterband transitions of a series of as-grown AlGaAs/GaAs quantum well structures grown by MOVPE have been studied using photoreflectance to determine their well shape. The transition energies calculated using three different quantum well profiles are compared to those obtained using photoreflectance. The results show that the shape of these structures is best represented by an exponential potential profile.
Preparation of AlAsSb and Mid-Infrared (3–5μm) Lasers By Metal-Organic Chemical Vapor Deposition
Authors: Allerman A. A. , Biefeld R. M. , Kurtz S. R. 
Published: April 2011

ABSTRACTMid-infrared (3–5 μm) infrared lasers and LEDs are being developed for use in chemical sensor systems. As-rich, InAsSb heterostructures display unique electronic properties that are beneficial to the performance of these midwave infrared emitters. We have grown AlAs1−xSbx epitaxial layers by metal-organic chemical vapor deposition using trimethylamine (TMAA) or ethyldimethylamine alane (EDMAA), triethylantimony (TESb) and arsine. We examined the growth of AlAsl−xSbx using temperatures of 500 to 600 °C, pressures of 70 to 630 torr, V/III ratios of 1–27, and growth rates of 0.3 to 2.7 μm/hour in a horizontal quartz reactor. The semi-metal properties of a p-GaAsSb/n-InAs heterojunction are utilized as a source for injection of electrons into the active region of lasers. A regrowth technique has been used to fabricate gain-guided lasers using AlAs1−xSbx for optical confinement with either a strained InAsSb/InAs multi-quantum well (MQW) or an InAsSb/InAsP strained layer superlattice (SLS) as the active region. Under pulsed injection, the InAsSb/InAs MQW laser operated up to 210K with an emission wavelength of 3.8–3.9 μm. Under pulsed optical pumping, the InAsSb/InAsP SLS operated to 240K with an emission wavelength of 3.5–3.7 μm. LED emission has been observed with both active regions in both p-n junction and semi-metal injection structures.
The Profile Design of Strained Sige-Channel P-Type Modulation Doped Fet
Authors: Hsu Klaus Y.J. , Huang S. M. 
Published: April 2011

ABSTRACTTo improve the performance of p-type SiGe-channel FEPs is important for Si-based high-speed/high-frequency applications. This work discusses the design of germamium profiles in the strained Si1−xGex channel region of p-type SiGe modulation doped FET's and studies its effect on device performance. Two-dimensional device simulator is used to simulate the large-signal device performance for various Ge distributions including triangular, trapezoidal, and flat profiles. In particular, the thickness of the strained SiGe channel layer is 15 nm and a 5 ran thick Si cap layer is on top of the channel. It is found that with the same integrated Ge content in the strained channel, graded Ge profiles lead to higher transconductances and larger threshold voltage windows than those of flat profiles, due to deeper potential wells and better carrier confinement ability. For triangularly graded profiles, the peak position must be located in the upper half portion of the channel layer to result in superior performance. By adding more Ge to extend the peak region, triangular profiles become trapezoidal ones. However, more Ge content does not necessarily produce better performance. If the well depth of trapezoidal profile is the same as that of triangular profile and if the trapezoid plateau begins at the same position as that of triangle peak, the device performance is almost the same for both profiles.
Examples of Hydrothermal Titration and Real Time X-Ray Diffraction in the Synthesis of Open Frameworks
Authors: Parise J. B. , Tan K. , Norby P. , Ko Y. , Cahill C. 
Published: April 2011

AbstractHydrothermal titration (HTT) techniques represent a new synthetic strategy for the production of open frameworks. As an example, initial digestion of amorphous GeS2 in the presence of tetraethyl ammonium hydroxide (TEAOH) at 100°C is followed by injection of Ag+ into this mixture to condense the [Ge4S10]4− clusters and form a framework consisting of 8-ring channels bounded by alternating GeS-clusters and Ag+. The rational use of this apparatus depends upon determining the timing of injection. Insight into the changes occurring during reactant digestion is provided by real time synchrotron X-ray powder diffraction. Changes in the the system dimethylamine-Sb-S have been followed in real time at different temperatures. The transformation from mixtures of DMA, Sb and S to the known open phase DMA-SbS-SB8 was followed by observing monochromatic X-ray scattering detected on an imaging plates over a 8 hr period with one continuous exposure.