Lateral Silicide Growth

1983 ◽  
Vol 25 ◽  
Author(s):  
L. R. Zheng ◽  
E. Zingu ◽  
J. W. Mayer
Keyword(s):  
Activation Energy ◽  
Low Temperatures ◽  
Lateral Diffusion ◽  
Silicide Formation ◽  
Diffusion Couples ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Metal Silicides ◽  
Silicide Growth ◽  
Si Films

ABSTRACTSilicide formation and growth kinetics have been investigated with lateral diffusion couples formed by deposition of Ni and Cr layers on patterned Si substrates and by deposition of Ni patterns on Si films. For annealing temperatures between 520 and 650°C the growth of CrSi2follows a (time)½ dependence with an activation energy of 1.4± 0.1 eV. In Ni-silicide formation at temperatures below 600°C, Ni was the predominant moving species. As the temperature increased, the motion of Si became significant. The apparent activation energy for silicide formation varied from Ea ≅ 1.4 eV for Ni motion at relatively low temperatures to Ea≅ 2.3 eV for Si motion that occurs at high temperatures. Lateral diffusion in device geometry structures resulted in degradation of contact planarity due to the penetration of metal silicides in Ni-Si structures or the erosion of silicon in Cr-Si structures.

Silicon Transport in Lateral Silicide Growth of CrSi2

1986 ◽  
Vol 71 ◽  
Author(s):  
L. R. Zheng ◽  
L. R. Doolittle ◽  
J. W. Mayer
Keyword(s):  
Growth Kinetics ◽  
Lateral Diffusion ◽  
Diffusion Couples ◽  
Si Substrates ◽  
Impurity Segregation ◽  
Silicide Growth ◽  
Device Geometry ◽  
Metal Layers ◽  
Kinetics Of ◽  
Influence Of Impurities

AbstractSilicide formation and growth are studied in three geometries: conventional planar thin films, lateral diffusion couples formed by depositing metal layers on Si islands, and device geometry couples formed by depositing metal on oxide-patterned Si substrates. The influence of impurities is studied by implanting arsenic and krypton into conventional and device geometry structures.Here we present growth kinetics of CrSi2 where the presence of impurities has a strong influence. Si transport dominates in disilicide formation and leads to erosion of contacts around the periphery of oxide windows. Implantation of arsenic suppresses CrSi 2 formation; with krypton implantation, the growth kinetics shifts from linear to square-root in character. We attribute these results to impurity segregation at interfaces or grain boundaries.

Ni Silicide Formation on Polycrystalline SiGe and SiGeC Layers

2002 ◽  
Vol 745 ◽  
Author(s):  
Erik Haralson ◽  
Tobias Jarmar ◽  
Johan Seger ◽  
Henry H. Radamson ◽  
Shi-Li Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Lateral Diffusion ◽  
Lateral Growth ◽  
Silicide Formation ◽  
Diffusion Couples ◽  
Planar Configuration ◽  
20 Nm

ABSTRACTThe reactions of Ni with polycrystalline Si, Si0.82Ge0.18 and Si0.818Ge0.18C0.002 films in two different configurations during rapid thermal processing were studied. For the usually studied planar configuration with 20 nm thick Ni on 130–290 nm thick Si1-x-yGexCy, NiSi1-xGex(C) forms at 450°C on either Si0.82Ge0.18 or Si0.818Ge0.18C0.002, comparable to NiSi formed on Si. However, the agglomeration of NiSi1-xGex(C) on Si0.818Ge0.18C0.002 occurs at 625°C, about 50°C higher than that of NiSi1-xGex on Si0.82Ge0.18. For thin-film lateral diffusion couples, a 200-nm thick Ni film was in contact with 80–130 nm thick Si1-x-yGexCy through 1–10 μm sized contact openings in a 170 nm thick SiO2 isolation. While the Ni3Si phase was formed for both the Si0.82Ge0.18 and Si0.818Ge0.18C0.002 samples, the presence of 0.2 at.% C caused a slightly slower lateral growth.

Silicide formation in lateral diffusion couples

1983 ◽  
Vol 1 (2) ◽  
pp. 758-761 ◽  
Author(s):  
L. R. Zheng ◽  
L. S. Hung ◽  
J. W. Mayer
Keyword(s):  
Lateral Diffusion ◽  
Silicide Formation ◽  
Diffusion Couples

Lateral Diffusion of Platinum Through Pt2Si in Pt/Si Couples

1982 ◽  
Vol 18 ◽  
Author(s):  
L. R. Zheng ◽  
L. S. Hung ◽  
J. W. Mayer
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Electron Microprobe ◽  
Lateral Diffusion ◽  
Square Root ◽  
Diffusion Couples ◽  
X Ray ◽  
Temperature Range ◽  
Scanning Electron

Lateral diffusion couples formed by depositing platinum islands on silicon layers on Al2O3 were used in conjunction with scanning electron microprobe measurements to investigate the growth of platinum silicides in the temperature range 400–700 °C. The phase Pt2Si grows over a length of 4–30 μm with a rate proportional to the square root of time and an activation energy of approximately 1.3 eV. With samples containing 7 at.% Rh in the platinum, the growth rate of Pt2Si is reduced and the activation energy is increased to about 2.0 eV. In these Pt–7at.% Rh samples, electron-induced X-ray measurements indicate that rhodium remains in the original deposited region while both platinum and silicon diffuse in the formed Pt2Si region.

Comparison of Kinetics of TiSi2 Formation on Si(100) and Si(111)

1986 ◽  
Vol 71 ◽  
Author(s):  
C. A. Pico ◽  
N. C. Tran ◽  
J. R. Jacobs ◽  
M. G. Lagally
Keyword(s):  
Refractory Metal ◽  
Eutectic Temperature ◽  
Vacuum System ◽  
Silicide Formation ◽  
Substrate Orientation ◽  
Si Substrates ◽  
Metal Silicides ◽  
Kinetics Of Formation ◽  
P Type ◽  
Kinetics Of

AbstractRefractory-metal silicides are currently receiving widespread attention because of their usefulness as interconnects in VLSI devices. Potentially the most important of these silicides is TiSi2. TiSi2 offers a sharp stable interface, a high process-compatible eutectic temperature, and the lowest resistivity of all refractory-metal silicides. Much of the previous work on TiSi2 [1-8] has been directed towards the understanding of the kinetics of silicide formation in order to optimize these electrical and interfacial properties. One parameter that may affect the silicide formation is substrate orientation [9]. We have compared the kinetics of formation of TiSi2 for Ti deposited onto p-type 10Ω-cm Si(100) and Si(111). All process parameters except substrate orientation were identical. 2800Å of Ti was electron-beam evaporated at a rate of 20Å/s and a background pressure of 9×10−8 torr onto chemically cleaned (HNO3, HF, rinse) Si substrates and subsequently annealed at temperatures between 470°C and 700°C in evacuated sealed quartz tubes. A turbopumped vacuum system was used to evacuate the quartz tube before sealing. A Ti getter was independently heated to remove remaining background contaminants prior to annealing.

Titanium Disilicide Formation on Cmos Structures with Phosphorous Doped Gates

1993 ◽  
Vol 303 ◽  
Author(s):  
S. Chtttipeddi ◽  
A. K. Nanda ◽  
V. C. Kannan ◽  
W. T. Cochran
Keyword(s):  
Grain Size ◽  
Refractory Metal ◽  
Silicide Formation ◽  
Titanium Disilicide ◽  
Si Substrates ◽  
Metal Silicides ◽  
The Difference ◽  
Single Implant

ABSTRACTSelf aligned refractory metal silicides such as titanium disilicide have been used extensively in VLSI and ULSI structures. Unlike earlier work which has relied on undoped substrates and a single implant species, in the present study TiSi2 formation on phosphorous doped poly-Si in the presence of multiple dopants has been investigated. TEM micrographs are discussed which show the difference in silicide formation for the case of the BF2 and arsenic implanted samples. We have found that the presence of fluorine in the BF2 implant retards the silicide formation for phosphorous doped poly-Si substrates. Additionally, the effect of substrate grain size on TiSi2 formation has been investigated using undoped α-Si and poly-Si substrates.

Diffusional Phase Transformation under Induced Thermal Stress

1991 ◽  
Vol 230 ◽  
Author(s):  
E C Zingu ◽  
B T Mofokeng
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Elevated Temperatures ◽  
Film Structure ◽  
Intrinsic Stress ◽  
Silicide Formation ◽  
Si Substrates ◽  
Silicide Growth ◽  
Expansion Coefficients ◽  
Large Tensile Stress

AbstractWhen thin films are deposited on substrates or when compound films are formed through interdiffusion of multi-film structures, intrinsic stress develops in the various films. Thermal mismatch between the expansion coefficients of the substrate and films in multi-film structures gives rise to extrinsic stress at elevated temperaturesBy using Si<100> and rolled Al foil substrates supporting the same multi-film structure SiO2/Si/Co, the effect of extrinsic stress on interdiffusion of thin films is isolated.Silicide growth is found to be inhibited (delayed) when formed on Al substrates compared to that formed on Si substrates. The delay in silicide growth is ascribed to delamination caused by large tensile stress prior to silicide formation. The growth rate of Co2Si is found to be similar on both Al and Si substrates

Metal Silicides Formed by Direct Ion Beam Deposition

1988 ◽  
Vol 128 ◽  
Author(s):  
R. A. Zuhr ◽  
S. J. Pennycook ◽  
T. E. Haynes ◽  
O. W. Holland
Keyword(s):  
Low Temperatures ◽  
Metal Ion ◽  
Ion Beam ◽  
Good Control ◽  
Metallic Ions ◽  
Silicide Formation ◽  
Electrical Measurements ◽  
Ion Beam Deposition ◽  
Metal Silicides ◽  
Beam Deposition

ABSTRACTThin films of transition metal silicides have been produced at low temperatures on Si substrates by direct ion beam deposition (IBD) of the metal ion. Using a mass-analyzed beam of metallic ions rastered over the target at energies on the order of 100 eV and at substrate temperatures near 500°C, stoichiometric silicide films of varying thicknesses up to 300 nm have been formed on both n- and p-type Si. The advantages of this technique over other methods for silicide formation include good control of thickness by current integration, high purity due to the mass analysis, and control of incident ion energy which permits formation of the disilicide phase at low temperatures, thereby minimizing the thermal budget and the associated dopant diffusion in the underlying substrate. Films were characterized by Rutherford backscattering, transmission electron microscopy, and electrical measurements. Co, Fe, Ni, Ti, and W silicides have been formed by this direct deposition process. The effectiveness of the technique has been found to be dependent upon the diffusion characteristics of the particular metal/Si couple involved, with systems in which Si is the dominant diffuser, such as Ti/Si, giving the best results. Stoichiometric TiSi2 films produced at 550°C by this process show low bulk-like resistivity (15 μΩ-cm) without subsequent high-temperature annealing. All of these characteristics make silicide formation by IBD attractive for integrated circuit fabrication and shallow junction technology.

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.

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.

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