Effects of Ion Metal Plasma (IMP) Titanium Deposition on Ti Silicide Formation

1999 ◽  
Vol 564 ◽  
Author(s):  
A. Sabbadini ◽  
F. Cazzaniga ◽  
M. Brambilla ◽  
C. Bresolin ◽  
V. Cusi ◽  
...  
Keyword(s):  
Sheet Resistance ◽  
Layer Structure ◽  
Direct Interaction ◽  
Phase Evolution ◽  
Titanium Silicide ◽  
Silicide Formation ◽  
Si Substrates ◽  
Metal Plasma ◽  
The One ◽  
Substrate Nature

AbstractTitanium disilicide obtained by direct interaction between Si and a deposited Ti layer is a choice for low- resistance gate interconnections and source and drain areas. The properties of the TiSi2 film can be influenced by many factors; such as substrate nature and doping, the depositing Ti layer, structure dimensions [1][2][3][4]. This work is addressed to study the properties of TiSi2 film as obtained from titanium deposited by Ion Metal Plasma (IMP), which has recently been introduced in high aspect ratio contact and via applications.Its suitability for titanium silicide formation is investigated here in comparison to standard PVD deposition. The study was carried out on flat and patterned samples. Titanium silicide formed on mono- Si substrates were characterized as a function of RTP temperature in terms of sheet resistance, tilm morphology, crystallography and phase evolution. It was found that the TiSi2 film obtained from IMP- Ti is very similar to the one obtained from PVD standard deposition. However, for annealing below 700°C, an increase in the sheet resistance of the TiSi2 C49 phase from IMP- Ti compared to the one from PVD- Ti was found, and is explained by different silicide grain size. Analyses performed on patterned samples with doped silicon and poly- Si lines show similar electrical results for TiSi2 from IMP and PVD deposition; however, fbr p+ poly-Si lines, the IMP samples displayed correct TiSi2 formation down to 0.18µm line width, while the PVD wafers showed discontinuous results at these minimum feature sizes.

A parametric study of titanium silicide formation by rapid thermal processing

1996 ◽  
Vol 11 (2) ◽  
pp. 412-421 ◽  
Author(s):  
A. V. Amorsolo ◽  
P. D. Funkenbusch ◽  
A. M. Kadin
Keyword(s):  
Sheet Resistance ◽  
Parametric Study ◽  
Thermal Processing ◽  
Annealing Temperature ◽  
Rapid Thermal Processing ◽  
Titanium Silicide ◽  
Wet Etching ◽  
Silicide Formation ◽  
Temperature Variations ◽  
Sputter Etching

A parametric study of titanium silicide formation by rapid thermal processing was conducted to determine the effects of annealing temperature (650 °C, 750 °C), annealing time (30 s, 60 s), wet etching (no HF dip, with HF dip), sputter etching (no sputter etch, with sputter etch), and annealing ambient (Ar, N2) on the completeness of conversion of 60 nm Ti on (111)-Si to C54–TiSi2 based on sheet resistance and the uniformity of the sheet resistance measurements across the entire wafer. Statistical analysis of the results showed that temperature, annealing ambient, and sputter etching had the greatest influence. Increasing the temperature and using argon gas instead of nitrogen promoted conversion of the film to C54–TiSi2. On the other hand, sputter etching retarded it. The results also indicated significant interactions among these factors. The best uniformity in sheet resistance was obtained by annealing at 750 °C without sputter etching. The different sheet resistance profiles showed gradients that were consistent with expected profile behaviors, arising from temperature variations across the wafer due to the effect of a flowing cold gas and the effects of the wafer edge and flats.

In Situ Rapid Thermal Hydrogenation Pretreatment of Ti for Salicide RTA

1996 ◽  
Vol 429 ◽  
Author(s):  
K. Ando ◽  
T. Ishigami ◽  
Y. Matsubara ◽  
T. Horiuchi ◽  
S. Nishimoto
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Diffraction Analysis ◽  
Sheet Resistance ◽  
Rapid Thermal Annealing ◽  
Titanium Silicide ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray

AbstractAn in situ rapid thermal hydrogenation (RTH) pretreatment of titanium prior to rapid thermal annealing (RTA), or RTH/RTA, is proposed as a silicide formation annealing in a CMOS self-aligned silicide (salicide) process. The in situ RTH is found to enhance silicidation, to reduce nitridation, and even to lower the resultant sheet resistance of titanium silicide.During in situ RTH (e.g., at 550°C), amorphous Ti silicide (e.g., 15-nm thick) grows selectively on Si. Furthermore, Ti nitridation during subsequent RTA (690°C, N2, 10 Torr, 30 s) is reduced depending on RTH (H2, 10 Torr, 30 s) temperature. Accordingly, for 550°C RTH and an initial Ti thickness of 15 nm, the sheet resistance obtained at the 0.27-μm-wide n+ poly-Si gate after a phase transition annealing (800°C, Ar, 10 s) was lower (11.7 Ω /□, st. dev. = 6%) than that of conventional Ti silicide (15.8 Ω/□, st. dev. = 10%). The silicidation enhancement and nitridation reduction are related to crystal structure metamorphosis or to hydrogen interstitial incorporation in the Ti layer during RTH as observed by x-ray diffraction analysis. It is concluded that in situ RTH pretreatment before RTA is very promising as a sub-quarter-micron CMOS salicide process.

Ultra-Shallow Raised P+N Junctions with Self-Aligned Titanium Silicide Contacts formed by Boron Outdiffusion from Selectively Deposited Silicon Epitaxial Layers

1995 ◽  
Vol 387 ◽  
Author(s):  
H. T. Shih ◽  
K. E. Violette ◽  
M. C. Öztürk
Keyword(s):  
Ion Implantation ◽  
Sheet Resistance ◽  
Total Pressure ◽  
Titanium Silicide ◽  
Background Concentration ◽  
Epitaxial Layers ◽  
Silicide Formation ◽  
Implantation Damage ◽  
Selective Etch ◽  
Current Densities

AbstractIn this study, we have fabricated ultra-shallow p+n junctions by boron outdiffusion from selectively deposited Si epitaxial layers. The undoped layers (900 – 1000 Å) were selectively deposited on active areas in a UHV-RTCVD reactor using Si2H6 and Cl2 at 800°C and at a total pressure less than 30 mTorr. Junctions were formed by BF2 ion-implantation into epitaxial layers with and without Ge preamorphization followed by RTA at 1000°C and 1050°C for 10 s in Ar. Junction depths ranging from 400 Å to 700 Å were formed at a background concentration of l×1016 cm−3. Abrupt boron profiles with epitaxy/substrate interface concentrations on the order of 1020 cm-3 were formed. Self-aligned TiSi2 was formed at four different thicknesses by evaporating 100, 200, 300 or 400 Å thick Ti followed by a two-step RTA cycle with a selective etch between to remove the unreacted Ti on Si02. Our results show that raised junctions with a Ti thickness of 400 Å (corresponding to a TiSi2 thickness over 900 Å and consumption of the entire epitaxial layer) exhibit a reverse leakage of less than 10 pA for a device area of 800×800 μm2. This corresponds to areal and peripheral leakage current densities of 67 pA/cm2 and 4 pA/cm. Therefore, thick silicide layers can be used on raised junctions reducing the junction sheet resistance and eliminating the possibility of silicide agglomeration. Furthermore, implantation damage in substrate is eliminated by confining the implant into the raised region which is later consumed during silicide formation.

Effect of a Ti-capped and Ti-mediated Layer on Co Silicide Formation

2002 ◽  
Vol 716 ◽  
Author(s):  
G.Z. Pan ◽  
E.W. Chang ◽  
Y. Rahmat-Samii
Keyword(s):  
Electron Diffraction ◽  
Sheet Resistance ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Diffusion Barrier ◽  
Silicide Formation ◽  
Plan View ◽  
Processing Window

AbstractWe comparatively studied the formation of ultra thin Co silicides, Co2Si, CoSi and CoSi2, with/without a Ti-capped and Ti-mediated layer by using rapid thermal annealing in a N2 ambient. Four-point-probe sheet resistance measurements and plan-view electron diffraction were used to characterize the silicides as well as the epitaxial characteristics of CoSi2 with Si. We found that the formation of the Co silicides and their existing duration are strongly influenced by the presence of a Ti-capped and Ti-mediated layer. A Ti-capped layer promotes significantly CoSi formation but suppresses Co2Si, and delays CoSi2, which advantageously increases the silicidation-processing window. A Ti-mediated layer acting as a diffusion barrier to the supply of Co suppresses the formation of both Co2Si and CoSi but energetically favors directly forming CoSi2. Plan-view electron diffraction studies indicated that both a Ti-capped and Ti-mediated layer could be used to form ultra thin epitaxial CoSi2 silicide.

Amorphous Phase Formation of Titanium Silicide on The 4° off-Axis and on-Axis Si(100) Substrates

1996 ◽  
Vol 427 ◽  
Author(s):  
Hyeongtag Jeon ◽  
Sukjae Lee ◽  
Hwackjoo Lee ◽  
Hyun Ruh
Keyword(s):  
Layer Thickness ◽  
Amorphous Layer ◽  
Film Deposition ◽  
Titanium Silicide ◽  
Atomic Scale ◽  
Phase Identification ◽  
Atomic Steps ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Scale Roughness

AbstractTwo different Si(100) substrates, the 4°off-axis and the on-axis Si(100), were prepared. Ti thin films were deposited in an e-beam evaporation system and the amorphous layers of Ti-silicide were formed at different annealing temperatures. The Si(100) substrates before Ti film deposition were examined with AFM to verify the atomic scale roughness of the initial Si substrates. The amorphous layer was observed by HRTEM and TEM. And the chemical analysis and phase identification were examined by AES and XRD. The Si(100) substrate after HF clean shows the atomic scale microroughness such as atomic steps and pits on the Si surface. The on-axis Si(100) substrate exhibits much rougher surface morphologies than those of the off-axis Si(100). These differences of atomic scale roughnesses of Si substrates result in the difference of the thicknesses of amorphous Ti-silicide layers. The amorphous layer thicknesses on the on-axis exhibit thicker than those of the off-axis Si(100) and these differences inamorphous layer thicknesses became decreased as annealing temperatures increased. These indicate that the role of the atomic scale roughness on the amorphous layer thickness is much significant at low temperatures. In this study, the correlation between the atomic scale roughness and the amorphous layer thickness is discussed in terms of the atomic steps and pits based on the observation with using analysis tools such as AFM, TEM and HRTEM.

MBE Growth of Low Dislocation and High Mobility GaAs-on-Si

1986 ◽  
Vol 67 ◽  
Author(s):  
Jhang Woo Lee
Keyword(s):  
Layer Structure ◽  
High Mobility ◽  
Gaas Layer ◽  
Buffer Layers ◽  
Misfit Dislocations ◽  
Si Substrates ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Low Dislocation Density ◽  
Molecular Beam Epitaxial Growth

ABSTRACTData is presented on the optimization of several molecular beam epitaxial growth processes to provide low dislocation density and high mobility GaAs single crystals on (100) Si wafers. The substrate tilt angle, the growth temperature, and the first buffer layer structure, were investigated Tor this purpose. Using Hall measurements the GaAs layers grown on 2 or 3-degree tilt (100) Si showed consistently high mobilities which are equivalent to the homoepitaxial GaAs mobility. Transmission electron microscopy (TEM) revealed that on tilted (100) Si substrates most of the misfit dislocations were confined within the first 50 Å GaAs layer by forming a type of edge dislocation at the Si surface step edges. Also low temperature grown buffer layers always gave better morphologies and lower etch pit densities while keeping the high mobilities on overgrown GaAs layers.

scholarly journals Measurements from mobile surface vehicles during LAPSE-RATE

2020 ◽  
Author(s):  
Gijs de Boer ◽  
Sean Waugh ◽  
Alexander Erwin ◽  
Steven Borenstein ◽  
Cory Dixon ◽  
...  
Keyword(s):  
Layer Structure ◽  
Unmanned Aircraft ◽  
Lapse Rate ◽  
Data Sets ◽  
San Luis Valley ◽  
San Luis ◽  
Remotely Piloted Aircraft ◽  
In Situ Sensors ◽  
Set Up ◽  
The One

Abstract. Between 14 and 20 July 2018, small unmanned aircraft systems (sUAS) were deployed to the San Luis Valley of Colorado (USA) alongside surface-based remote, in-situ sensors, and radiosonde systems as part of the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE). The measurements collected as part of LAPSE-RATE targeted quantities related to enhancing our understanding of boundary layer structure, cloud and aerosol properties and surface-atmosphere exchange, and provide detailed information to support model evaluation and improvement work. Additionally, intensive intercomparison between the different unmanned aircraft platforms was completed. The current manuscript describes the observations obtained using three different types of surface-based mobile observing vehicles. These included the University of Colorado Mobile UAS Research Collaboratory (MURC), the National Oceanic and Atmospheric Administration National Severe Storms Laboratory Mobile Mesonet, and two University of Nebraska Combined Mesonet and Tracker (CoMeT) vehicles. Over the one-week campaign, a total of 143 hours of data were collected using this combination of vehicles. The data from these coordinated activities provide detailed perspectives on the spatial variability of atmospheric state parameters (air temperature, humidity, pressure, and wind) throughout the northern half of the San Luis Valley. These data sets have been checked for quality and published to the Zenodo data archive under a specific community set up for LAPSE-RATE (https://zenodo.org/communities/lapse-rate/) and are accessible at no cost by all registered users. The primary dataset DOIs are https://doi.org/10.5281/zenodo.3814765 (CU MURC measurements; de Boer et al., 2020d), https://doi.org/10.5281/zenodo.3738175 (NSSL MM measurements; Waugh, 2020) and https://doi.org/10.5281/zenodo.3838724 (UNL CoMeT measurements; Houston and Erwin., 2020).

Direct Deposition Reactions Between Nickel and Silicon Substrates

1993 ◽  
Vol 311 ◽  
Author(s):  
Lin Zhang ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Deposition Rates ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

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