Substrate Influence on the Formation of Titanium Silicide on Polycrystalline Silicon

1995 ◽  
Vol 402 ◽  
Author(s):  
Ana Neilde Rodrigues da Silva ◽  
Rogerio Furlan ◽  
J. J. Santiagoaviles
Keyword(s):  
Silicon Substrate ◽  
Polycrystalline Silicon ◽  
Chemical Reactivity ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Titanium Silicide ◽  
Maximum Temperature ◽  
Crystal Silicon ◽  
Kinetics Of Formation ◽  
Sputter Deposited

AbstractIn this work we investigated the influence of the polycrystalline silicon substrate on the titanium silicide formation process. The results are compared to those obtained when single crystal silicon wafers are used. We observed that the polycrystalline substrate affects both the kinetics of formation of the phase TiSi2-C49 and the temperature of transition from TiSi2-C49 to TiSi2-C54. The temperature of this phase transition is also influenced by the presence of phosphorous in the polycrystalline silicon substrate. In order to prevent degradation of the silicide film formed on polycrystalline silicon, the maximum temperature of RTP has to be lower than 900°C. Due to the high chemical reactivity between titanium and oxygen present in the ambient, we also investigated the use of a protective cap. For this purpose, a thin amorphous silicon layer was sputter-deposited sequentially on Ti films without breaking the vacuum.

Damaged Layer Analysis for AFM-Based Mechanical Modifications on (100) Si Surface

2009 ◽  
Vol 626-627 ◽  
pp. 29-34
Author(s):  
Jeong Woo Park ◽  
Nam Hun Kim
Keyword(s):  
Silicon Substrate ◽  
Potassium Hydroxide Solution ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Industrial Applications ◽  
Crystal Silicon ◽  
Atomic Force ◽  
Aqueous Potassium Hydroxide ◽  
Micro Cantilever ◽  
Micro Structures

Micro/Nanofabrication of silicon substrate based on the atomic force microscope (AFM) followed by wet chemical etching was demonstrated. A specially designed cantilever with a diamond tip, allowing the formation of damaged layer on silicon substrate by a simple scratching process, has been applied instead of conventional Si or Si3N4-based micro cantilever for scanning. A thin damaged layer forms in the substrate at the diamond tip-sample junction along scanning path of the tip, which was found to be a low crystallized amorphous silicon layer. Hence these sequential processes, called tribo nanolithography, TNL, can fabricate 2D or 3D micro structures in nanometer range. The developed TNL tools show outstanding machinability against single crystal silicon wafer. Hence, they are expected to have a possibility for industrial applications as a micro-to-nano machining tool. According to our results, it has been clearly known that the damaged layer withstands against aqueous potassium hydroxide solution, while it dissolves in diluted hydro fluoric (DHF) solution.

Analysis of Silicon-On-Insulator Structures Formed By Oxygen Ion Implantation

1985 ◽  
Vol 43 ◽  
pp. 300-301
Author(s):  
N. Lewis ◽  
E. L. Hall ◽  
A. Mogro-Campero ◽  
R. P. Love
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
High Dose ◽  
Crystal Silicon ◽  
Oxygen Ion ◽  
Oxygen Ion Implantation

The formation of buried oxide structures in single crystal silicon by high-dose oxygen ion implantation has received considerable attention recently for applications in advanced electronic device fabrication. This process is performed in a vacuum, and under the proper implantation conditions results in a silicon-on-insulator (SOI) structure with a top single crystal silicon layer on an amorphous silicon dioxide layer. The top Si layer has the same orientation as the silicon substrate. The quality of the outermost portion of the Si top layer is important in device fabrication since it either can be used directly to build devices, or epitaxial Si may be grown on this layer. Therefore, careful characterization of the results of the ion implantation process is essential.

scholarly journals A Flexible PI/Si/SiO2 Piezoresistive Microcantilever for Trace-Level Detection of Aflatoxin B1

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1118
Author(s):  
Yuan Tian ◽  
Yi Liu ◽  
Yang Wang ◽  
Jia Xu ◽  
Xiaomei Yu
Keyword(s):  
Single Crystal ◽  
Aflatoxin B1 ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Wheatstone Bridge ◽  
Silicon On Insulator ◽  
Passivation Layer ◽  
Spring Constant ◽  
Trace Level ◽  
Crystal Silicon

In this paper, a polyimide (PI)/Si/SiO2-based piezoresistive microcantilever biosensor was developed to achieve a trace level detection for aflatoxin B1. To take advantage of both the high piezoresistance coefficient of single-crystal silicon and the small spring constant of PI, the flexible piezoresistive microcantilever was designed using the buried oxide (BOX) layer of a silicon-on-insulator (SOI) wafer as a bottom passivation layer, the topmost single-crystal silicon layer as a piezoresistor layer, and a thin PI film as a top passivation layer. To obtain higher sensitivity and output voltage stability, four identical piezoresistors, two of which were located in the substrate and two integrated in the microcantilevers, were composed of a quarter-bridge configuration wheatstone bridge. The fabricated PI/Si/SiO2 microcantilever showed good mechanical properties with a spring constant of 21.31 nN/μm and a deflection sensitivity of 3.54 × 10−7 nm−1. The microcantilever biosensor also showed a stable voltage output in the Phosphate Buffered Saline (PBS) buffer with a fluctuation less than 1 μV @ 3 V. By functionalizing anti-aflatoxin B1 on the sensing piezoresistive microcantilever with a biotin avidin system (BAS), a linear aflatoxin B1 detection concentration resulting from 1 ng/mL to 100 ng/mL was obtained, and the toxic molecule detection also showed good specificity. The experimental results indicate that the PI/Si/SiO2 flexible piezoresistive microcantilever biosensor has excellent abilities in trace-level and specific detections of aflatoxin B1 and other biomolecules.

Thermal Conductivity of Ultra Thin Single Crystal Silicon Layers: Part II — Experimental Data and Modeling at High Temperatures

2004 ◽  
Author(s):  
Wenjun Liu ◽  
Mehdi Asheghi ◽  
K. E. Goodson
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Single Crystal ◽  
High Temperatures ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
Silicon On Insulator ◽  
Boltzmann Transport ◽  
Crystal Silicon ◽  
Strained Si

Simulations of the temperature field in Silicon-on-Insulator (SOI) and strained-Si transistors can benefit from experimental data and modeling of the thin silicon layer thermal conductivity at high temperatures. This work presents the first experimental data for 20 and 100 nm thick single crystal silicon layers at high temperatures and develops algebraic expressions to account for the reduction in thermal conductivity due to the phonon-boundary scattering for pure and doped silicon layers. The model applies to temperatures range 300–1000 K for silicon layer thicknesses from 10 nm to 1 μm (and even bulk) and agrees well with the experimental data. In addition, the model has an excellent agreement with the predictions of thin film thermal conductivity based on thermal conductivity integral and Boltzmann transport equation, although it is significantly more robust and convenient for integration into device simulators. The experimental data and predictions are required for accurate thermal simulation of the semiconductor devices, nanostructures and in particular the SOI and strained-Si transistors.

Non Destructive Determination of the Threading Dislocation Density of Smooth Simox Substrates using Atomic Force Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1088-1089
Author(s):  
A. Domenicucci ◽  
R. Murphy ◽  
D. Sadanna ◽  
S. Klepeis
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
High Dose ◽  
Threading Dislocation ◽  
Crystal Silicon ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Temperature Anneal

Atomic force microscopy (AFM) has been used extensively in recent years to study the topographic nature of surfaces in the nanometer range. Its high resolution and ability to be automated have made it an indispensable tool in semiconductor fabrication. Traditionally, AFM has been used to monitor the surface roughness of substrates fabricated by separation by implanted oxygen (SIMOX) processes. It was during such monitoring that a novel use of AFM was uncovered.A SIMOX process requires two basic steps - a high dose oxygen ion implantation (1017 to 1018 cm-3) followed by a high temperature anneal (>1200°C). The result of these processes is to form a buried oxide layer which isolates a top single crystal silicon layer from the underlying substrate. Pairs of threading dislocations can form in the top silicon layer during the high temperature anneal as a result of damage caused during the high dose oxygen implant.

Electrical Properties of Polycrystalline-Silicon Thin Films for VLSI

1986 ◽  
Vol 71 ◽  
Author(s):  
T I Kamins
Keyword(s):  
Electrical Properties ◽  
Integrated Circuits ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Crystalline Silicon ◽  
Single Crystal Silicon ◽  
Active Regions ◽  
Crystal Silicon ◽  
Polysilicon Film

AbstractThe electrical properties of polycrystalline silicon differ from those of single-crystal silicon because of the effect of grain boundaries. At low and moderate dopant concentrations, dopant segregation to and carrier trapping at grain boundaries reduces the conductivity of polysilicon markedly compared to that of similarly doped single-crystal silicon. Because the properties of moderately doped polysilicon are limited by grain boundaries, modifying the carrier traps at the grain boundaries by introducing hydrogen to saturate dangling bonds improves the conductivity of polysilicon and allows fabrication of moderate-quality transistors with their active regions in the polycrystalline films. Removing the grain boundaries by melting and recrystallization allows fabrication of high-quality transistors. When polysilicon is used as an interconnecting layer in integrated circuits, its limited conductivity can degrade circuit performance. At high dopant concentrations, the active carrier concentration is limited by the solid solubility of the dopant species in crystalline silicon. The current through oxide grown on polysilicon can be markedly higher than that on oxide of similar thickness grown on singlecrystal silicon because the rough surface of a polysilicon film enhances the local electric field in oxide thermally grown on it. Consequently, the structure must be controlled to obtain reproducible conduction through the oxide. The differences in the behavior of polysilicon and single-crystal silicon and the limited electrical conductivity in polysilicon are having a greater impact on integrated circuits as the feature size decreases and the number of devices on a chip increases in the VLSI era.

About the Electrical and Structural Properties of Erbium Thermally Diffused in Single Crystal Silicon

1996 ◽  
Vol 422 ◽  
Author(s):  
S. Binetti ◽  
M. Acciarri ◽  
I. Gelmi ◽  
S. Pizzini
Keyword(s):  
Electrical Properties ◽  
Chemical Analysis ◽  
Silicon Substrate ◽  
Silica Glass ◽  
Single Crystal Silicon ◽  
Auger Spectroscopy ◽  
Erbium Oxide ◽  
Erbium Doping ◽  
Crystal Silicon ◽  
Erbium Doped

AbstractHaving preliminary confirmed the possibility of erbium doping by thermal diffusion, we have used this process to introduce erbium into a silicon substrate from metallic erbium or erbium oxide sources. Diffusion experiments were carried out at 1050, 1200 and 1250°C. The Er:Si diffused samples were investigated using four probe resistivity and thermopower techniques for the measure of the concentration and type of carriers, SIMS and Auger spectroscopy for chemical analysis of the diffused layers and photoluminescence (PL) measurements at temperatures ranging from 2 to 298 K for the detection of optical activity. None of the samples prepared presented measurable PL at 2 K, except for one single sample on top of which was deposited an erbium doped silica glass. The electrical properties, instead, were deeply influenced by doping, indicating the formation of both donor and acceptors.

Heating Effects on The Young's Modulus of Films Sputtered onto Micromachined Resonators

1998 ◽  
Vol 518 ◽  
Author(s):  
H. Kahn ◽  
M.A. Huff ◽  
A.H. Heuer
Keyword(s):  
Temperature Dependence ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Resonant Structures ◽  
Young’S Moduli ◽  
Heating Effects ◽  
Sputter Deposited ◽  
Dc Current

AbstractSurface-micromachined polysilicon lateral resonant structures were fabricated and used to determine the temperature dependence of the Young's modulus of the polysilicon. This is done by passing a dc current through the beams during resonance testing, resulting in Joule-heating. The temperatures are calibrated by increasing the dc current until the melting point of silicon is attained. The calculated Young's moduli agree well with reported values for single crystal silicon.In addition, metal films were sputter-deposited onto the polysilicon resonators, and similar experiments performed on the composite devices to determine the temperature dependence of the modulus of the sputtered films. Ni films demonstrate a linear decrease in Young's modulus with temperature. TiNi films demonstrate two distinct modulus values with an intermediate transition region, due to the temperature-induced reversible phase transformation exhibited by TiNi.

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