Effect of Mo Doping on Formation of Ti-Silicide Phases Studied by HRTEM

1998 ◽  
Vol 523 ◽  
Author(s):  
M. A. Gribelyuk ◽  
S. B. Samavedam ◽  
J. A. Kittl
Keyword(s):  
Reaction Path ◽  
Si Substrates ◽  
Mo Doping ◽  
Phase Sequence ◽  
Accelerated Growth ◽  
Induced Reaction

AbstractThe phase sequence of the RTP induced reaction at T=650°C has been studied. We found that pre-amorphization of poly-Si substrates does not change the reaction path. i.e. Ti5Si4, and C-49 TiSi2 phases were formed_ with the latter growing upon further anneal. In the Mo doped poly-Si/Ti system the C-54 TiSi2 phase has formed along with Ti5Si4 and two Mo silicide phases, MoSi2 and Mo5Si3; no C-49 TiSi2 was observed. We show that the reaction in the Mo doped system follows the template mechanism with MoSi2 and Mo5Si3 based phase acting as template phases for accelerated growth of C-54 TiSi2.

Low Temperature Formation of C54 TiSi2 Bypassing the C49 Phase: Effect of Si Crystallinity, Metallic Impurities and Applications TO 0.10 μm CMOS

1998 ◽  
Vol 514 ◽  
Author(s):  
J. A. Kittl ◽  
M. A Gribelyuk ◽  
S. B. Samavedam ◽  
Q. Z. Hong ◽  
N. Yu ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Cmos Technology ◽  
High Resistivity ◽  
Si Substrates ◽  
Early Stages ◽  
Mo Doping ◽  
Large Structures ◽  
Diffusion Limited ◽  
Transmission Electron ◽  
Phase Sequence

ABSTRACTThe mechanism and evolution from the early stages of the Ti/Si reaction by rapid thermal processing (RTP) at 650°C in the presence of Mo doping was studied and compared to the case without Mo doping; for amorphous, polycrystalline and single crystal (100) Si substrates. It was found that for Mo doped polycrystalline Si or Mo doped amorphous Si, the low resitivity C54 TiSi2 phase nucleates at the Ti/Si interface and grows following diffusion limited kinetics, bypassing the nucleation of the high resistivity C49 TiSi2 phase. The conventional phase sequence, with C49 TiSi 2 nucleation and growth, was observed on Mo doped (100) Si and all samples without Mo. The mechanism of early C54 nucleation was identified by high resolution transmission electron microscopy (HRTEM): at early stages of the reaction, precursor silicide phases lattice matched to C54 TiSi2 nucleate at the Ti/Mo doped Si interface, and act as templates for epitaxial nucleation of C54 TiSi2. Two such phases were observed, MoSi2 and a phase with spacings of 2.26 Å and 4.2 Å. Image simulations suggest that the structure of the second template phase is based on Mo5Si3. Similar kinetics were observed on large structures and narrow lines for Mo doped Si (except for the case of (100) Si), indicating that this growth mechanism eliminates the linewidth dependence. Implementation on a 0.10 μm CMOS technology of a process combining Mo doping with pre-amorphization (PAI) achieves low source/drain (S/D) sheet resistance, and the first Ti salicide process with low gate sheet resistance down to 0.06 μm.

Effect of Mo doping on accelerated growth of C-54 TiSi2: Evidence for template mechanism

1999 ◽  
Vol 86 (5) ◽  
pp. 2571-2575 ◽  
Author(s):  
M. A. Gribelyuk ◽  
J. A. Kittl ◽  
S. B. Samavedam
Keyword(s):  
Mo Doping ◽  
Accelerated Growth

Proton formation and diffusion in amorphous SiNx:H

2011 ◽  
Vol 1330 ◽  
Author(s):  
H.F.W. Dekkers ◽  
V. Prajapati ◽  
S. Van Elshocht ◽  
E. Vancoille
Keyword(s):  
Thermal Treatment ◽  
Tensile Stress ◽  
Ab Initio ◽  
Atomic Hydrogen ◽  
Reaction Path ◽  
Charge Trapping ◽  
Si Substrates ◽  
Uv Illumination ◽  
And Diffusion ◽  
Diffusion Of Hydrogen

ABSTRACTIn this work the release of atomic hydrogen from SiNx:H films is investigated. Thermal treatment as well as UV-illumination induces the formation of H2, increasing the tensile stress in the film. N-rich SiNx:H films release hydrogen only by UV-illumination, indicating involvement of charge trapping. Ab initio calculations show a possible reaction path for the release and diffusion of protons that also explain the diffusion of hydrogen into Si substrates.

Carbonylvanadium, -mangan- und -molybdänkomplexe mit den Liganden o-C6H4EPh2(E'Ph2) (E,E' = P, As, Sb, Bi) und cis-Ph2PCH=CHPPh2 / Carbonylvanadium, -manganese and -molybdenum Complexes of the Ligandso-C6H4EPh2(E'Ph2) (E,E' = P, As, Sb, Bi) und cis-Ph2PCH=CHPPh2

1981 ◽  
Vol 36 (4) ◽  
pp. 451-462 ◽  
Author(s):  
Ridvan Talay ◽  
Dieter Rehder
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Reaction Path ◽  
Crystal And Molecular Structure ◽  
Flexible Structures ◽  
Ring Structure ◽  
Molybdenum Complexes ◽  
Tetragonal Pyramidal ◽  
Derivatives Of ◽  
Induced Reaction

Abstract The photo-induced reaction between the complexes [Et4N][V(CO)6] (1), η5-C5H5V(CO)4 (2), η5-C5H5Mn(CO)3 (3) or η5-C5H5Mo(CO)3CH3 (4) and the ligands o-C6H4EPh2(E'Ph2) (E = E' = P: a; E = P, E'=As: b; E = E ' = As: C; E = P, E ' = S b : d; E = P, E ' = Bi: e; E = As, E' = Sb: f) and cis-Ph2PCH = CHPPh2 (g), L, yields - depending on the steric requirement of L - the compounds (M}L ({M} = cis-V(CO)4-, cis-CpV(CO)2, CpMn(CO), CpMo(CO)CH3; L = a, b, c, g), {M'}L ({M'} = V(CO)5-, L - d; {M'} - CpV(CO)3, L - d, e; {M'} = CpMn(CO)2, L = e) or mixtures of {M}L and (M'}L ({M}, {M'} = V(CO)4,5, L = e,f; {M}, {M'} = CpV(CO)2,3, L = f). In the mono-substituted species {M'}L coordination (as indicated by the 51V NMR spectra) occurs through EPh2 and E'Ph2, which is explained by a reaction path via a labile chelate 5-ring structure. Shielding of the 51V nucleus decreases in the order g > SbPh2 > PPh2 > AsPh2 > BiPh2 (derivatives of 1) and g > SbPh2 > PPh2 > BiPh2 >AsPh2 (derivatives of 2), and is smaller in the rigid chelates incorporating the o-phenylene ligands than in the more flexible structures of phospha- and arsabutane complexes. This fact is discussed in terms of hindered σ-overlap due to distortion of the EVE angle, which also results in an increase of CO valence force constants in rigid chelates. 31P coordination shifts increase according to dppe < a < g and arphos < b (dppe = Ph2P(CH2)2PPh2, arphos = Ph2As(CH2)2PPh2). 31P NMR spectra of the molybdenum complexes suggest that the basic geometry for 4a and 4b likely is tetragonal pyramidal, while the preferred structure for 4g appears to be the trigonal bipyramid with the ligand in equatorial positions. The crystal and molecular structure of 1a is reported. The complex crystallizes in the space group C2/c (a = 2196.0, b= 1080.1, c = 2022.7 pm, β= 124.6°). The most striking result is the small PVP angle of 80.8 (0.2)°. Optimized methods for the synthesis of the ligands a-f are described; the ligands are characterized by their mass spectra.

Interactions Between Al and Cr Thin Films

1976 ◽  
Vol 34 ◽  
pp. 638-639
Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Vacuum System ◽  
Processing Temperature ◽  
Diffusion Couples ◽  
Electronic Circuits ◽  
Intermetallic Formation ◽  
Si Substrates ◽  
Aluminum Silicon

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.

Use of 2½ D imaging in analysis of NiTi martensite

1978 ◽  
Vol 36 (1) ◽  
pp. 610-611
Author(s):  
G. M. Michal
Keyword(s):  
Memory Effect ◽  
Monoclinic Phase ◽  
Reaction Path ◽  
Structural Characteristics ◽  
Salient Feature ◽  
Martensite Phase ◽  
Orientation Relationships ◽  
Low Symmetry ◽  
Hydride Phases ◽  
Unusual Shape

Several TEM investigations have attempted to correlate the structural characteristics to the unusual shape memory effect in NiTi, the consensus being the essence of the memory effect is ostensible manifest in the structure of NiTi transforming martensitic- ally from a B2 ordered lattice to a low temperature monoclinic phase. Commensurate with the low symmetry of the martensite phase, many variants may form from the B2 lattice explaining the very complex transformed microstructure. The microstructure may also be complicated by the enhanced formation of oxide or hydride phases and precipitation of intermetallic compounds by electron beam exposure. Variants are typically found in selfaccommodation groups with members of a group internally twinned and the twins themselves are often observed to be internally twinned. Often the most salient feature of a group of variants is their close clustering around a given orientation. Analysis of such orientation relationships may be a key to determining the nature of the reaction path that gives the transformation its apparently perfect reversibility.

Electron Energy Analysis of Germanium and Silica Layers on Silicon Substrates

1975 ◽  
Vol 33 ◽  
pp. 96-97
Author(s):  
R. W. Ditchfield ◽  
A. G. Cullis
Keyword(s):  
Epitaxial Growth ◽  
Electron Energy ◽  
Silicon Substrates ◽  
Secondary Phases ◽  
Si Substrates ◽  
Transmission Electron ◽  
Layer Structures ◽  
Si Films ◽  
Electron Energy Loss ◽  
Growth Centres

An energy analyzing transmission electron microscope of the Möllenstedt type was used to measure the electron energy loss spectra given by various layer structures to a spatial resolution of 100Å. The technique is an important, method of microanalysis and has been used to identify secondary phases in alloys and impurity particles incorporated into epitaxial Si films.Layers Formed by the Epitaxial Growth of Ge on Si Substrates Following studies of the epitaxial growth of Ge on (111) Si substrates by vacuum evaporation, it was important to investigate the possible mixing of these two elements in the grown layers. These layers consisted of separate growth centres which were often triangular and oriented in the same sense, as shown in Fig. 1.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

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