Rapid Thermal Low-pressure Chemical Vapor Research Articles

Micro-scratch test study of TiN films grown on silicon by chemical vapor deposition

TiN thin films (0.095 μm) were deposited on silicon wafers at 800°C by rapid thermal low-pressure chemical vapor deposition from a TiCl 4+NH 3+H 2 gaseous mixture. Micro-scratches were performed using a system equipped with an optical microscope, an acoustic emission sensor and a friction force sensor. Critical loads were determined to evaluate the adhesion of TiN to the substrate. The influence of the indenter state on the critical load was studied. Scanning electron micrographs, electron probe microanalyses and chemical etching of the film were performed to identify and interpret the damage mechanisms. Experimental results were analyzed using the Weibull statistic. It was shown that small particles of TiN were chipped off and formed a third body, which modified the indenter–film contact and contributed to an increase in the range of the critical load. Models previously proposed in the literature, which allow calculation of the work of adhesion from a critical load, are discussed with respect to the damage mechanisms observed.

Optimization of Titanium Nitride Rapid Thermal CVD Process

Anomalous behavior during TiN growth through rapid thermal low-pressure chemical vapor deposition (RTLPCVD) from gas phase TiCl 4 -NH 3 -H 2 has been observed. Two deposition temperatures are used (500 °C and 800 °C) and two types of deposition process are defined (a long one-step process, and a multiple-step process). Resistivity, structure, composition, and growth behavior are examined and discussed in terms of oxygen contamination and classical nucleation theory. The long one-step process is better for mechanical applications, whereas the multiple-step process is more suitable for microelectronics.

Electrical and structural properties of poly-Si films grown by furnace and rapid thermal annealing of amorphous Si

In the present work, the effect of rapid thermal annealing (RTA) on the electrical and structural properties of poly-Si thin films, grown by the crystallization of a-Si films deposited by rapid thermal low-pressure chemical vapor deposition, has been studied. Structural and electrical results were obtained using atomic force microscopy, transmission electron microscopy, electron spin resonance, electrical resistivity, and Hall mobility techniques. The effects of the grain size, grain boundaries, and surface roughness on the electrical characteristics of poly-Si films have been investigated. Amorphous Si (a-Si) films crystallized by RTA at 850 °C for 45 s result in the formation of poly-Si with small grains, an electron spin density Ns=5.2×1016 cm−3, and a Hall mobility μH=30 cm2 V−1 s−1. A two-stage annealing, involving low-temperature annealing at 600 °C for 6 h, followed by RTA at 850 °C in five steps of 30 s each, results in the formation of poly-Si films with large grains free of in-grain defects, low surface roughness, and higher Hall mobility μH=43 cm2 V−1 s−1, characteristics rendering such poly-Si films suitable for the fabrication of good performance thin film transistors.

Geometric structure of thin SiO xN y films on Si(100)

Thin films of amorphous stoichometric SiO x N y are deposited on radiation-heated Si(100) by rapid thermal low-pressure chemical vapour deposition. We studied the whole range of possible compositions. In order to determine the geometric structure, we used EXAFS and photoelectron spectroscopy. Tetrahedrons constitute the short-range units with a central Si atom connected to N and O. The distribution of the possible tetrahedrons can be described by a mixture of the Random Bonding Model and the Random Mixture Model. For low oxygen contents x/( x+ y)≤0.3, the geometric structure of the film is almost the structure of a-Si 3N 4, with the oxygen preferably on top of Si–N 3 triangles. Higher oxygen contents induce changes in the bond lengths, bond angles and coordination numbers.

Low temperature rapid thermal low pressure chemical vapor deposition of 〈111〉 oriented TiN layers from the TiCl 4NH 3H 2 gaseous phase

Titanium nitride layers are deposited by Rapid Thermal Low-Pressure Chemical Vapor Deposition (RTLPCVD) from the TiCl 4NH 3H 2 gaseous phase. Growth rate, resistivity and crystallographic orientation are studied as a function of the deposition temperature and the NH 3/TiCl 4 partial pressures ratio called R. To fulfill the TiN barrier layer requirements, the deposition temperature and the R value have to be as low as possible. We show that with such conditions, the preferential orientation of the deposited TiN layer is always 〈200〉. This orientation enhances the 〈200〉 orientation of the aluminium overlayer which leads to poor electromigration resistance. In order to obtain 〈111〉 oriented TiN layer, a two step process is proposed. In this way, 〈111〉 oriented TiN layers are deposited at a deposition temperature and with an R ratio value as low as 500°C and 4, respectively. The resistivity of such as-deposited films is 200 μΩcm.

Rapid thermal low-pressure chemical vapour deposition of tungsten films onto InP using WF6 and H2

Tungsten (W) films were deposited onto InP in a cold wall, rapid thermal low-pressure chemical vapour deposition (RT-LPCVD) reactor, from a tungsten hexafluoride (WF6) gas reduced by hydrogen (H2). W films of thickness 50-450 nm were deposited in the temperature range 350-550 degrees C, pressure range 0.5-4.5 Torr at deposition rates up to 4 nm s-1 with an apparent activation energy of about 1.12 eV. The film stress varied depending upon the deposition pressure, from low compressive for deposition at 0.5 Torr to moderate tensile for deposition at about 4.5 Torr. The films were aged at temperatures as high as 300 degrees C for about 800 h and exhibited an excellent mechanical stability. Post-deposition sintering of the W films at temperatures up to 600 degrees C led to reduction of the resistivity with a minimum value of about 55 mu Omega cm as a result of heating at 500 degrees C. Conditions for both selective and blanket deposition were defined, and a dry etching process for further geometrical definitions of the films was developed, providing etch rates of 40-50 nm min-1. This report reflects the first attempt to deposit W films onto III-V semiconductor at a very high rate by means of RT-LPCVD.

Fast thermal kinetic growth of silicon dioxide films on InP by rapid thermal low-pressure chemical vapour deposition

Silicon dioxide films were deposited onto InP substrates in the ranges of 350-550 degrees C temperature, and 3-15 Torr pressure by means of the rapid thermal low-pressure chemical vapour deposition (RTLPCVD) technique. SiO2 films were deposited using a variety of Ox: SiH4 ratios in the range of 5:1-50:1, and deposition rates of 15-50 nm s-1. The high temperature and high rate deposition was obtained without creating any damage to the InP substrate surface, and resulted in highly densified SiO2 layers with good thickness control and low stress. The main parameters of the as-deposited and annealed films, such as deposition rate, density, refractive index, wet and dry etch rates, stresses, film microstructure, and the SiO2/InP interface quality are reported. These parameters were studied as a function of the process variables, which include deposition time, temperature, pressure, O2:SiH4 ratio, gas flow rates and chamber geometry.

W and Related Alloys Deposited onto InP by RT-LPCVD

ABSTRACTTungsten (W) films were deposited onto InP in a cold wall, rapid thermal low-pressure chemical vapor deposition (RT-LPCVD) reactor, from a tungsten hexafluoride (WF6) gas reduced by hydrogran (H2). W films of thickness 50 to 450 nm were deposited in the temperature range of 350° to 550°C, pressure range of 0.5 to 4.5 Torr and deposition rates up to 4 nm/sec with an apparent activation energy of about 1.12 eV. The film stress varied depending upon the deposition pressure, from low compressive for deposition at 0.5 Torr to moderate tensile for deposition at about 4.5 Torr. The films were aged at temperatures as high as 300°C for about 800 hr and exhibited an excellent mechanical stability. Post-deposition sintering of the W films at temperatures up to 600°C led to reduction of the resistivity with a minimum value of about 55μΩ-crn as a result of heating at 500°C. Conditions for both selective and blanket deposition were defined, and a dry etching process for further geometrical definitions of the films was developed, providing etch rates of 40 to 50 nm·sec-1. This report reflects the first attempt to deposit W films onto III-V semiconductor at a very high rate by means of RT-LPCVD.

Highly stable silicon dioxide films deposited by means of rapid thermal low-pressure chemical vapor deposition onto InP

An attempt was made to deposit a high thermally stable silicon dioxide (SiO2) film onto InP substrates. The films were grown by rapid thermal, low-pressure chemical vapor deposition (RT-LPCVD), using pure oxygen (O2) and 2% diluted silane (SiH4) in argon (Ar) gas sources, in the temperature range of 350–550 °C and pressure range of 3–10 Torr. The SiO2/InP structures were heated, post-deposition, up to 1000 °C for durations of up to 5 min, resulting in negligible changes in the properties of the SiO2 films and a limited SiO2/InP interfacial reaction of about 15 nm thick. The higher the initial deposition temperature of the SiO2 the larger was the film compressive stress and the less the degree of densification the film underwent through the post-deposition heating cycles.

Rapid thermal low-pressure chemical vapor deposition of SiOx films onto InP

High quality SiOx films have been deposited onto InP substrates by means of a rapid thermal low-pressure chemical vapor deposition technique, using oxygen (O2) and 2% diluted silane (SiH4) in argon (Ar) in the gas sources. Rapid deposition rates in the range of 15–40 nm s−1 with apparent activation energies of 0.12–0.15 eV were obtained at temperatures in the range of 350–550 °C, pressures between 5 and 15 Torr, and O2:SiH4 ratios in the range of 5:1–20:1. The SiOx films had refractive indexes between 1.44 and 1.50, densities of 2.25–2.37 g cm−3, internal compressive stresses of −0.5×109 to −3×109 dyn cm−2, and exhibited wet etch rates of 0.2–0.8 nm s−1 through the standard p-etch process. The influence of the various process parameters on all the SiOx film parameters such as morphology and microstructure was examined.