Agglomeration-Free Nanoscale Cobalt Silicide Film Formation Via Substrate Preamorphization

1993 ◽  
Vol 309 ◽  
Author(s):  
S. Pramanick ◽  
B.K. Patnaik ◽  
G. A. Rozgonyi
Keyword(s):  
Grain Size ◽  
Film Formation ◽  
Single Crystal Silicon ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Concurrent Processing ◽  
Process Modification ◽  
Boron Doped ◽  
Heavily Doped ◽  
Stability Issues

AbstractWe have used preamorphization of silicon substrates as a process modification to suppress agglomeration during cobalt disilicide film formation. Planar, continuous and low resistivity (<21 μΩ-cm) silicide films less than 35 nm thick have been produced both on single crystal silicon and polysilicon. Nanoscale(<35 nm) silicide films are more susceptible to islanding phenomena since agglomeration is dependent onthe ratio of grain size to film thickness. Preamorphization prior to silicidation favorsa large increase in silicide nucleation rate, as well as reduction in critical nuclei size, both of which aid the formation of silicide with small grains. The resulting small grain silicides enable nanoscale films to remain below the critical grain size to thickness ratio for which thin films become morphologically unstable. An interphase void band which occurs between CoSi and CoSi2 layers, acts as a convenient diffusion marker and aids interpretation of the complex stability issues. Preamorphization prior to silicidation was also extended to heavily doped substrates to study the applicability of this approach for junctions and gate contacts. Silicidation of amorphized heavily boron doped substrates produces non uniform layers due to the collision of the advancing silicidation and SPE interfaces. A comparision of concurrent processing, i.e. simulatneous dopant activation and silicide formation, with conventional silicidation of Si+ preamorphized heavily doped(B) substrates is also presented.

Effect of Boron Doping on the C49 TO C54 Phase Transformation in Ti/Si (100) Bilayers

1996 ◽  
Vol 441 ◽  
Author(s):  
M. Libera ◽  
A. Quintero
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Single Crystal Silicon ◽  
Interface Roughness ◽  
Ex Situ ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Boron Doped ◽  
Transmission Electron

AbstractWe have demonstrated that the formation of C54 TiSi2 on Boron-doped single crystal silicon substrates, under RTA annealing conditions in a Nitrogen ambient, leads to a thicker TiN capping surface layer, thinner silicide layer, higher C49 to C54 transformation temperature and greater interface roughness compared to C54 TiSi 2 formation on undoped single crystal silicon substrates. Titanium films 32 nm thick were deposited on undoped and boron-doped single crystal silicon substrates. The films were annealed at 3 /C/isn nitrogen to final quenching temperatures between 500 °C and 900 TC. Ex-situ four point probe sheet resistance, cross sectional transmission electron microscopy (XTEM), high resolution transmission electron microscopy (HRTEM) and x-ray diffraction (XRD) were used to analyze the resulting TiN on TiSi2 bilayer. The C49 to C54 transformation occurs circa 760 TC and 810 TC for the undoped and boron-doped cases respectively. HRTEM observations reveal a thick 20 nm TIN layer on the C54 TiSi2 film in the boron-doped case but only fine dispersed TiN particles embedded on the top of the silicide in the undoped case. It was observed that the resultant silicide in the boron-doped case was thinner and the TiSi2 /Si(100) interface is rougher. XRD and TEM analysis show that in the boron doped case, there is a preferred C54 (040) orientation compared to a random orientation for the undoped case.

Electron Microscope Observations of Mechanisms of thin Film Delamination from Substrates

1988 ◽  
Vol 119 ◽  
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Film Formation ◽  
Single Crystal Silicon ◽  
Metal Films ◽  
Model Systems ◽  
Silicon Substrates ◽  
Formation Model ◽  
Crystal Silicon ◽  
Transmission Electron

AbstractTransmission electron microscope techniques have been applied to the problem of thin film delamination from substrates during film formation. Model systems involving metal films on single crystal silicon substrates have been used and it is found that delamination of the films is initiated by the formation of damage in the substrate. This understanding removes some of the fundamental problems regarding delamination.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

A Current Conduction Mechanism in Laser Recrystallized Silicon Metal-Oxide-Semiconductor Transistors

1983 ◽  
Vol 23 ◽  
Author(s):  
Han-Sheng Lee
Keyword(s):  
Conduction Mechanism ◽  
Single Crystal Silicon ◽  
Silicon Films ◽  
Oxide Semiconductor ◽  
Silicon Substrates ◽  
Mos Transistors ◽  
Crystal Silicon ◽  
Ion Laser ◽  
Argon Ion ◽  
A Current

ABSTRACTN-channel MOS transistors were fabricated on silicon films that had been recrystallized by an argon ion laser at different power levels. These transistors showed electrical characteristics similar, but somewhat inferior to those devices fabricated on single crystal silicon substrates. These differences are attributed to the presence of trapping states at the grain boundaries of the crystallites in the recrystallized silicon. A coulombic scattering model is presented to explain these differences. In the case of films annealed at low laser power, an additional factor of nonuniform trap state distribution is invoked to explain device characteristics. This model provides an adequate explanation for the observed transport properties of transistors fabricated from recrystallized silicon films.

Laser Writing of High Purity Gold Lines

1989 ◽  
Vol 158 ◽  
Author(s):  
M. Jubber ◽  
J.I.B. Wilson ◽  
J.L. Davidson ◽  
P. John ◽  
P.G. Roberts
Keyword(s):  
Rectangular Cross Section ◽  
Single Crystal Silicon ◽  
Gold Surface ◽  
Decomposition Temperature ◽  
Silicon Substrates ◽  
Beam Diameter ◽  
Scanning Calorimetry ◽  
Crystal Silicon ◽  
Ion Laser ◽  
Stage Process

ABSTRACTGold tracks have been deposited on thermally oxidised and single crystal silicon, gold and nichrome coated silicon wafers by pyrolytic decomposition of gaseous alkyl (triethyl phosphine) gold(I) complexes using focussed 514 nm radiation from an argon ion laser. The precursors, RAu(I)Et3P, R = CH3, C2H5 are low melting point crystalline solids with relatively high vapour pressures (∼5 mtorr). They are representative of a class of compounds being evaluated for laser deposition of gold. Differential scanning calorimetry, DSC, shows that the thermal decomposition of MeAu(I)Et3P in the solid state is a two-stage process. The decomposition temperature is 63 ± 1°C. Tracks were deposited at laser scan speeds up to 35 μm s−1 with a beam diameter (1/e2) at the focus of ∼12 μm. SIMS, EDX and laser ionisation microprobe analysis, LIMA, were used to determine the chemical composition of the tracks. The purity of >98% is consistent with the measured resistivities (4.2 μΩ cm) at room temperature compared to bulk gold (∼2 μΩ cm). These resistivities were achieved without post deposition annealing. Stylus profilimetry and SEM data showed the lines produced from MeAu(I)Et3P have a virtually rectangular cross-section. Together with the absence of the ubiquitous λ-ripples, this feature suggests that deposition is more rapid on the gold surface than on the SiO2 substrate. Laser power thresholds are lower for silicon substrates coated with thin (5 - 10°A) films of gold or nichrome.

Microheater Made of Heavily Boron Doped Single Crystal Silicon Beam

1992 ◽  
Vol 276 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Kazuhiro Komatsuzaki
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Bridge Structure ◽  
Quick Response ◽  
Crystal Silicon ◽  
Etching Technique ◽  
Small Power ◽  
Boron Doped ◽  
Type Layer ◽  
P Type

ABSTRACTMicroheater made of heavily Boron doped single crystal Si beam covered with SiO2 film, 1000×300×3 μm, is fabricated on the n type Si substrate by the anisotropic etching technique. As this microheater has an air bridge structure of low resistivity semiconductor material with positive but small temperature coefficient of resistance, a broad heating area up to 800 °C is easily obtained and it has quick response with the thermal time constant t of about 4 ms and has small power consumption. Since this heating area is made of p type layer in the n type substrate,this area can be electrically isolated from the substrate because of the formation of p-n junction.

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