bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting and Comparing Electromigration Failure for Different Test Structures
Authors: Brown D.D. , Korhonen M.A. , Børgesen P. , Li C.-Y. 
Published: April 2011

ABSTRACTElectromigration and stress migration are important reliability concerns in the semiconductor industry. Relative and absolute assessments of lifetimes generally rely on the accelerated testing of ‘standard’ test structures. However, the sensitivity to various important electromigration phenomena is found to depend strongly on the type of test structure. Two common structures for electromigration testing are (i) a long line with large pads at either end and (ii) a more realistic interconnect line with W-studs at the line end. The effects of (a) different flux divergences at the line end, (b) interfacial diffusion, and (c) Cu-depletion generally result in different lifetimes for the two types of test structures under the same testing conditions. In this paper, we compare void growth rates and mean times to failure for both types of test structure taking these effects into account. Our results are used to explain differences in MTF values reported in the literature for different test structures.
Reliability Study of Plasma Etching Damage in ULSI Process
Authors: Li Xiao-Yu , Hsu Jen-Tai , Aum Paul , Bissessur Vivek , Chan David , Viswanathan C.R. 
Published: April 2011

ABSTRACTPlasma etching can cause damage in gate oxide during ULSI processing. The damage in the oxide is believed to arise through a high field induced stress current. However, there is another type of damage which is due to ion and photon bombardment on the edge of poly-Si gate during the plasma etching. These two damage mechanisms impose different reliability problems. One is hot-carrier(HC) stress and the other is Fowler-Nordheim(F-N) stress. MOS devices with special test structures to assess plasma process damage were fabricated using 0.35 μm CMOS technology. The devices with different poly gate antennas and etching through different poly-Si gate etching conditions were studied using SEM and various electrical techniques. It was found that oxide charging damaged device is more susceptible to F-N type of stress while ion and photon bombardment damaged device is more susceptible to HC type of stress.
The Formation Mechanism and Removal Methods of Metal Pillar by Plasma Etch
Authors: Kim Eungsoo , Yun Dong-Won , Jeong Chang-Bum , Han Sang-Kug , Lim Soon-Kwon , Choi Kyu-Hyun 
Published: April 2011

ABSTRACTDuring the plasma etching of Al-Si-Cu alloy used as a metal interconnection, it is generally reported that the metal pillar (or conical residue) affecting the degradation of device yield is formed by the micromasking effect of copper compound. However, it is stilldisputed with the formation mechanism and composition of the micromasking material. Moreover, the elimination method of the metal pillar is not well known.According to previous reports, it is argued that the micromasking material consists of Cu agglomerates, A12Cu, or CuC1, and the formation mechanism of the micromasking is due to byproduct during plasma etching or reaction product during metal depositionor etching. However, using scanning electron microscopy (SEM), energy dispersive of x-ray (EDX), and high resolution Auger spectroscopy (HRAES), it is newly found that the micromasking consists of three layered structure, that is copper aluminum oxide, A12Cu, and Cu agglomerates. These results are quite different from previous reports. In addition, the removal methods of the metal pillar are suggested, which are high power dry etch process and multilayered metal deposition.
Effect of Phosphorus-Doped Polysilicon Anneal on Thin Oxide Reliability as Probed with X-Ray Damage Characterization
Authors: Nachman R. , Cerrina F. 
Published: April 2011

ABSTRACTIn this paper we address the degradation of oxide reliability after annealing the phosphorusdoped polysilicon of MOS structures. The oxide reliability was studied in terms of X-ray radiation sensitivity as well as breakdown characteristics.We found that annealing the polysilicon increased the radiation sensitivity of the gate oxide. We believe that this increase is a result of the phosphorus out-diffusion from the polysilicon into the oxide and a result of the creation of phosphorus related traps in the oxide bulk. We also found that the oxide charge to breakdown (Qbd) degradation correlates well with the density of the phosphorus in the oxide.
A Review of Orientation-Microstructure-Property Relationships for PZT / Metal or Metal-Oxide Layered Heterostructures
Authors: Auciello Orlando , Shareef H. N. Al , Gifford K. D. , Lichtenwalner D. J. , Dat R. , Bellur K. R. , Kingon A. I. , Ramesh R. 
Published: April 2011

AbstractStudies performed by our group on orientation-microstructure-property relationships of Pb(ZrxTil1-x)O3 (PZT) / metal or metal-oxide layered heterostructure are reviewed. The work discussed is related to the synthesis and characterization of ferroelectric PZT and conductive Pt, RuO2, and Lao.5Sr0.5CoO3 layers and their integration into heterostructure capacitors suitable for non-volatile memories. The main objective of our research was to determine the influence of deposition techniques and their related parameters and layer processing on the orientation, microstructure, and properties of PZT-based capacitors, with the goal of controlling electrical properties such as polarization fatigue, retention, and imprint effects, in order to produce commercial non-volatile ferroelectric memories. The work discussed relates to the synthesis of films by ion beam sputter-deposition (IBSD), and pulsed laser ablation deposition (PLAD), where the heterostructures are grown in-situ without exposing the interfaces to uncontrollable atmospheric conditions. Comparisons are presented between orientation and microstructural characteristics and properties of PZT heterostructure capacitors produced by IBSD and PLAD and those synthesized by the sol-gel technique. The work reviewed indicates that substrate and template layers (at the ferroelectric/bottom electrode interface) and/or bottom electrode material type contribute to the control of orientation and/or microstructure, and properties of PZT-based capacitors.
Response Surface for CMOS Self-Aligned Titanium Silicide Process
Authors: Nanda A. K. , Meester S. , Wilkins C. W. 
Published: April 2011

ABSTRACTSputtered deposited titanium films on silicon substrates were used to study the effects of first rapid thermal anneal temperature, duration of anneal time and thickness of the titanium films for TiSi2 formation. A central composite, coupled with a cross design was used to analyze response surface. Empirical models were developed and contour plots were generated to describe the outcome of the first anneal. A window of operation to control the process of titanium silicide formation was recommended. Response surface analysis of data revealed an operating window of ±10° C for RTA1 for stable TiSi2 formation. Within this window of operation, the within wafer uniformity was found to be at its minimum. Anneal time was found to have minimum effect on the variability although sheet resistance decreases monotonically with increasing anneal time. Thickness of titanium films were found to be very critical in determining final TiSi2 thickness as determined by RBS and/or XRF techniques.
The Insertion of Single-Wafer Integrated Thermal/CVD Technology in Front-End and Back-End of the Line Processing; Lessons Learned
Authors: Kermani Ahmad , Omstead Tom , Moslehi Mehrdad , Spence Paul , Winters William 
Published: April 2011

ABSTRACTThe insertion of single-wafer thermal and CVD technologies into the front- and back-end of the line processing starts with study of the integrated circuits manufacturing and device performance requirements. Relying upon the lessons learned and using the concurrent engineering approach, next generation processing equipment design architecture is then defined. In order to meet the process performance, throughput, and cost of ownership requirements of semiconductor IC manufacturing as defined in the SIA road map, heavy emphasis must be put on sensor fusion and model-based process control. In the existing semiconductor IC manufacturing equipment, process control is usually accomplished by control of equipment settings, qualification wafer runs and ex-situ measurements of the various wafer properties, as well as design architecture for stable equipment performance. The conventional approach, however, suffers from slow drifts of various equipment state parameters such as infrared absorbing quartz media causing thermal memory effects, or deposition of films on the reactor walls causing variation in the optical characteristics of the reactor as well as chemical and particle memory effects. Using model-based real-time control in conjunction with implementation of various in-situ and ex-situ sensors, these effects can be well monitored and controlled. This paper is to discuss various production related issues with single-wafer thermal and CVD technologies.
Rapid Thermal Processing of Shallow Junctions Using Epitaxial CoSi2 as a Doping Source
Authors: Jones Erin C. , Ogawa Shinichi , Ameika Paul , Dass M. Lawrence A. , Fraser David B. , Chu Paul , Cheung Nathan W. 
Published: April 2011

ABSTRACTThe electrical properties of shallow P+/N junctions formed by boron outdiffusion from polycrystalline and epitaxial CoSi2 contacts are discussed. The CoSi2 contacts are grown on (100) Si from a sputtered metal layer by rapid thermal annealing (RTA) at 900°C in forming gas. The epitaxial CoSi2 (epi-CoSi2) is made from layers of 15 nm Co / 2 nm Ti, and the polycrystalline material (poly-CoSi2) is made from a 15 nm Co layer with no Ti. Dopant is introduced by ion implantation into the silicide and the P+/N junctions are formed by a second RTA step. Junctions are found to have total leakage current densities as low as 4 nA/cm2 for poly-CoSi2 and 12 nA/cm2 for epi-CoSi2 at -5V and metallurgical junction depths of 60 nm beyond silicide/Si interface after 700-800°C annealing.
The Growth and In-Situ Doping of SiGe/Si Strained Heterostructures by RTP/VLP-CVD
Authors: Gu Shulin , Zheng Youdou , Zhang Rong , Wang Ronghua , Han Ping , Huang Xiaodong , Zhong Peixing , Hu Liqun , Zhu Shunmin , Chen J.N. 
Published: April 2011

ABSTRACTSiH4 and GeH4 Deposition and In-Situ Doping of SiGe/Si Strained Heterostructures by Rapid Thermal Process Very Low Pressure Chemical Vapor Deposition method have been studied in this paper. Ge incorporation rate increases to a maximum value and then decreases as temperature increases, the growth rate of SiGe alloy reaches its maximum value and then decreases as Ge composition increases. Ge incorporation also enhances Si deposition rate in SiGe alloy. The Boron and Phosphorus doping would change thegrowth rate of SiGe layers and the sharp doping interfaces in SiGe/Si heterostructures have been obtained.
Waste Minimization In Semiconductor Processing
Authors: Hardwick Steven J. , Mailloux Joanne C. 
Published: April 2011

AbstractThe US semiconductor industry uses 5–7 thousand pounds of arsine annually. Fifty to eighty percent of the arsine used becomes a waste product, which requires abatement. Traditional methods of abatement are reviewed with an emphasis on dry chemical scrubbing. A variety of dry chemical scrubbing materials were evaluated for arsine capacity, using activated carbon as the baseline for comparison. A proprietary mixed oxide composition, employing copper oxide as the active ingredient was identified as having high capacity and efficiency. Disposal and possible reclamation options are discussed.
Structure/Reactivity Studies Of Nd2O3/MgO AND MgO/Nd2O3 Catalysts Used In Methane Coupling
Authors: Burrows A. , Kiely C. J. , Devenish R. W. , Hargreaves J. S. , Hutchings G. J. , Joyner R. W. , Sinev M. Y. 
Published: April 2011

AbstractUsing High Resolution Electron Microscopy, we have investigated the structure/function relationships of the Nd2O3/MgO and MgO/Nd2O3 catalyst systems which are active in the oxidative coupling of methane. In both cases catalytic performance was found to depend critically on the morphology of Nd2O3. We demonstrate that high selectivities are associated with a thin disordered film of neodymia on the MgO surface for the Nd2O3/MgO system whilst for the reverse catalyst, the dominant morphology is a highly disordered cubic form of Nd2O3.
Decomposition Of Co2 To Carbon By H2-Activated Ni(II)- And Co(II)-Bearing Ferrites At 300°C
Authors: Kodama Tatsuya , Sano Taizo , Chang Shig-Ger , Tsuji Masamichi , Tamaura Yutaka 
Published: April 2011

AbstractThe reactivity of the H2-activated Ni(II)- and Co(II)-bearing ferrites with different levels of metal substitution have been studied for CO2 → C decomposition in comparison with that of the H2-activated magnetite. Ni 2+ and Co2+ have been substituted for Fe2+ or Fe3+ in magnetite with the spinel-type structure up to 14 % and 26 % of the mole ratio of Ni2+ and Co2 + to the total Fe content respectively. The reactivity of the Ni(II)- and Co(II)-bearing ferrite increased with the level of metal substitution. Especially, the Ni(II) substitution significantly facilitated the CO2 → C decomposition in a batch system. The rates of H2-activation (reduction) and CO2-decomposition (oxidation) for N(II)-bearing ferrite were studied by a thermogravimeteric analysis. The rates of both H2-activation and CO2-decomposition were much improved in the Ni(II)-bearing ferrite with the Ni(II)/Fetoul mole ratio of 14%. It is considered that the reduced Ni(II) ions which were formed on the surface of the ferrite is very active to facilitate both dissociation reactions of 1) H2 → 2 Hads and 2) CO2→ Cads + 2Oads,. From the change in the lattice constant of the Ni(II)-bearing ferrite during the H2-activation and CO2-decomposition, the oxygens in CO2 were considered to be incorporated into the oxygen deficient spinel lattice of the oxygen deficient Ni(II)-bearing ferrite which had been formed by the H2-activation.
In-Situ Microstructure Characterization of Sintering of
Controlled Porosity Materials
Authors: Kerch Helen M. , Burdette Harold E. , Gerhardt Rosario , Krueger Susan , Allen Andrew J. , Long Gabrielle G. 
Published: April 2011

ABSTRACTThe isothermal sintering behavior of a colloidal gel with a
well-characterized pore structure was studied using a newly commissioned
in-situ small-angle neutron scattering furnace. The apparatus enables
small-angle scattering measurements to be performed on monolithic samples
during heat treatment in an oxidizing, reducing, or neutral environment at
temperatures up to 1700°C. In-situ, quantitative measurements of the pore
size evolution within a gel possessing a bimodal pore size distribution is
discussed. Also reported is the in-situ measurement of the gel's surface
area evolution which is an important microstructural parameter in
understanding the sintering behavior of highly porous materials.
Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of
YBa2Cu3O7-δ
Authors: Houk Carol S. , Burgoine Gary A. , Page Catherine J. 
Published: April 2011

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the
solution phase to the final product using transmission electron microscopy
(TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral
mapping techniques. The starting solutions contain stoichiometric amounts of
the metal 2‐(2‐methoxyethoxy)ethoxide components in
2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a
uniform distribution of particles having an average size of less than 40 â.
Through elemental mapping we see elemental segregation in the high
temperature (950 °C) products, which are orthorhombic by XRD. In elemental
maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also
see elemental inhomogeneity within particles and phase zoning in maps of
products from finely ground gels. A comparison of elemental maps and x‐ray
diffraction patterns of the products from gel processing and conventional
solid state processing is made.
Reorientational Motion and Phase Transitions of Cyclohexane in
Restricted Geometries
Authors: Zerda T. W. , Shao Yong 
Published: April 2011

ABSTRACTRotational motion of cyclohexane in the liquid and the solid plastic phase
is studied using Raman light scattering. The results are compared with
molecular dynamics simulations run for model pores of diameters similar to
those used in the experiment. The presence of the surface layer and its
effect on the relaxation times is discussed. The temperature of the
solid-solid phase transition is determined from the analysis of the
ν21 band shape. It is shown that the depression of the cubic
to monoclinic phase transition depends on the pore diameter and is different
for modified and unmodified surfaces. It is suggested that molecules near
the pore walls form the amorphous structure and only molecules near the
center of the pore form crystallographic structure.
Plasma Enhanced Chemical Vapor Deposition of Silicon Sulfide and
Phosphorus Sulfide thin Films
Authors: Shibao R.K. , Srdanov V.I. , Hay M. , Eckert H. 
Published: April 2011

ABSTRACTAmorphous SiSx:H (x ∼ 2) films have been synthesized from H2S and
SiH4 precursors using a remote plasma enhanced chemical vapor deposition
apparatus. Structural studies by solid state nuclear magnetic resonance
(NMR) and Raman scattering reveal that the atomic environments in these
materials are similar to those observed in melt-quenched silicon sulfide
glasses, and are characterized by corner- and edge-shared SiS4/2
tetrahedra. Compared to these glasses, however, the films show consistently
higher fractions of corner-sharing S1S4/2 tetrahedra. The ratio
of corner- to edge sharing tetrahedra and the Si:S ratio can be influenced
by the H2S/S1H4 flow rate ratio during deposition.
Thus, PECVD opens up wider opportunities for structural tailoring of
amorphous silicon sulfide materials than currently possible by means of the
melt-quenching method. Preliminary data for the PECVD synthesis of
phosphorus sulfide is also presented.
High Yield Polycarbosilane Precursors to Stoichiometric SiC.
Synthesis, Pyrolysis and Application
Authors: Interrante Leonard. V. , Whitmarsh C.W. , Sherwood W. , Wu H.-J. , Lewis R. , Maciel G. 
Published: April 2011

ABSTRACTThe synthesis and properties of two polycarbosilanes that have essentially a
“SiH2CH2” composition is described. One of these
polymers is a highly branched hydridopolycarbosilane (HPCS) derived from
Grignard coupling of CI3SiCH2CI followed by
LiAIH4 reduction. This synthesis is amenable to large scale
production and we are exploring applications of HPCS as a source of SiC
coatings and its allyl-derivative, AHPCS, as a matrix source for SiC- and
C-fiber-reinforced composites. These polymers thermoset on heating at
200-400 °C (or at 100 °C with a catalyst) and give near stoichiometric SiC
with low O content in ca. 80% yield on pyrolysis to 1000 °C. The second
method involves ring-opening polymerization of
1,1,3,3-tetrachlorodisilacyclobutane and yields a high molecular weight,
linear polymer that can be reduced to
[SiH2CH2]n (PSE), the monosilicon analog
of polyethylene. In contrast to high density polyethylene which melts at 135
°C, PSE is a liquid at room temperature which crystallizes at ca. 5 °C. On
pyrolysis to 1000 °C, PSE gives stoichiometric, nanocrystalline, SiC in
virtually quantitative yield. The polymer-to-ceramic conversion was examined
for PSE by using TGA, mass spec, solid state NMR, and IR methods yielding
information regarding the cross-linking and structural evolution processes.
The results of these studies of the polymer-to-ceramic conversion process
and our efforts to employ the AHPCS polymer as a source of SiC matrices are
described.
Polymeric Precursors for Yttria
Authors: Apblett Allen W. , Cannon Steven M. , Georgieva Galina D. , Long Jay C. , Raygoza-Maceda Isabel , Reinhardt Larry E. 
Published: April 2011

ABSTRACTPolymers that can be easily processed into fibers, films, or bodies are
excellent precursors for ceramics with useful morphologies. The ideal
preceramic polymer not only has proper physical properties (e.g. solubility
or fusibility) for processibility but also decomposes at low temperature
with high ceramic yield. One possibility for such precursors for yttria are
yttrium oxycarboxylates. The preparation of such polymers from YOC1 has been
investigated and several compounds with useful physical properties have been
discovered. These include a methanol-soluble yttrium oxycarboxylate,
(CH3OCH2CH2OCH2CO2YO)n
a liquid yttrium tricarboxylate,
(CH3OCH2CH2OCH2CO2)3Y,
and a method for preparing very concentrated yttrium mixed acetate and
formate sols.
Development of Acidity on Sol-Gel Prepared
TiO2-SiO2 Catalysts
Authors: Calvino J.J. , Cauqui M.A. , Gatica J.M. , Perez J.A. , Rodriguez-Izquierdo J.M. 
Published: April 2011

ABSTRACTThree different TiO2-SiO2 gels (Xerogel, Carbogel and
Aerogel) are more active acid catalysts than other reference samples used
here. As deduced from FTIR, XRD and XANES studies, the structural properties
of these gels are quite different to each other, thus revealing the strong
influence of the drying treatment. It is found that the degree of Si-O-Ti
linking and the surface acidity follows the same trend (X 〉 C 〉 A). We
conclude that supercritical drying at 600 K and 190 bars can induce Ti
leaching followed by redeposition in the narrower pores of the gel. These
effects modify both the textural and surface chemical properties of the
resulting material.
A New Route for The Synthesis of Reduced Transition Metal Oxides
Using Borohydrides
Authors: Manthiram A. , Zhu Y. T. , Dananjay A. 
Published: April 2011

ABSTRACTReduction of aqueous solutions of tungstates, molybdates or vanadates by
aqueous alkali metal borohydrides at ambient‐temperature results in a
formation of dark colored gel. The gel is amorphous to X‐ray diffraction and
crystallizes sharply at around 300‐500 °C to yield reduced transition metal
oxides such as the oxide bronzes, NaxMyOz,
or the binary oxides, MO2 (M = V, Mo or W). The nature and
composition of the products formed are strongly influenced by the reaction
conditions such as the reaction pH as well as the concentration and amount
of the reagents. Experimental procedures to obtain the different phases are
presented. This novel low‐temperature approach has a potential to access new
metastable phases.
A Molecular Orbital Model of Gel-Silica Ir
Spectra
Authors: Chia Taipau , West Jon K. , Hench Larry L. 
Published: April 2011

ABSTRACTThe infrared vibrational modes of sol-gel derived optical silica monoliths
depend upon thermal treatments and chemical environments, as shown by
Fourier transform infrared spectroscopy (FTIR). A semi-empirical quantum
mechanical theory (PM-3 in MOPAC 6.1) is used to analyze the structural
changes responsible for the spectral shifts. Optimized structures of
2-member, 3-, 4-, 5- and 6-member rings of SiO2 are calculated.
The force constants for the molecular bonds in the rings are obtained and
converted to the associated vibrational spectra for the rings. The peak
position of the asymmetric transverse optical (AS1TO) mode of the
rings shifts from 1070 cm−1 for 2-member rings to 1100
cm−1 for 3-member rings, 1150 cnr1 for 4-member
rings, 1140 cm−1 for 5-member and 1120 cm−1 for
6-member rings. The IR data show a 38 cm”1 shift of the
AS1TO mode as the gel-silica density changes from 1.1 g/cc to
2.2 g/cc. Thus, the intensification and shift of the AS1TO mode
in the gel-silica to higher wave-numbers corresponds to a change in the
distribution to larger silicate size rings.