The Growth of Silicon Oxide Films by Remote Plasma Enhanced CVD (original) (raw)
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MRS Proceedings, 1987
ABSTRACTWe have deposited a range of silicon oxides by the Remote Plasma Enhanced CVD method. By varying gas mixtures and/or substrate temperature, it is possible to deposit films that are essentially stoichiometric SiO_, Si-deficient oxides which have OH groups but no SiH and Si-rich oxides which have SiH groups and no OH. This paper addresses three issues : (1) the nature of the infrared vibrations associated with the SiH and SiOH groups; (2) the use of D for H substitutions to study the vibrations in (1); and (3) the chemical origin of the SiOH group in the Si-deficient films.
In this paper we report on synthesis of thin films of silicon dioxide (SiO2) using conventional plasma enhanced chemical vapor deposition (PE-CVD) from pure silane (SiH4) and oxygen (O2), gas mixture at low RF power (30 Watt) and at moderate substrate temperature (250 qC). We have systematically investigated the material properties of these films as a function of oxygen partial pressure in view of their use in MOS devices. The formation of SiO2 thin films is confirmed by Fourier transform infrared (FTIR) spectroscopy. The thickness and refractive indices of the films measured by ellipsometry. C-V measurement shows that the electrical properties are directly related to process parameters and Si/SiO2 interface. The MOS structures were also fabricated from optimized SiO2 layer to study C-V measurement and to estimate interface, oxide and effective border traps density.
MRS Proceedings, 1987
We have constructed an Ultra High Vacuum (UHV) multichamber system and have deposited ‘gate quality’ silicon dioxide by the remote plasma enhanced chemical vapor deposition (Remote PECVD) process at low substrate temperatures (Ts ≤400 °C). Native oxides and other surface contaminants are removed under ultra high vacuum (UHV) conditions and the character of the semiconductor surface is determined prior to film deposition using in-situ Reflection High Energy Electron Defraction (RHEED). Measurents made on MOS structures of capacitance-voltage, current-voltage, field break-down, hysteresis, and mobile ion drift indicate that these films are ‘comparable’ to thermally (Ts >1100 °C) grown oxides. The structural properties of the films arg studied by ir spectroscopy and ellipsometry.
High-density plasma silicon oxide thin films grown at room-temperature
Microelectronic Engineering, 2008
The fabrication at room-temperature of thin (<8 nm) silicon oxide films has been achieved, in a high-density helicon plasma source reactor using Ar/O 2 mixture, exhibiting relatively low concentration of fixed oxide and interface charges, after annealing. The developed plasma oxidation process was employed in order to fabricate SOI-MOSFETs at low thermal budget with competitive operating characteristics.
Current Applied Physics, 2009
Silicon oxide thin film Nitrogen-incorporated silicon oxide thin films Plasma enhanced chemical vapor deposition Tetramethoxysilane Optical emission spectroscopy a b s t r a c t Thin oxide films are deposited from tetramethoxysilane (TMOS) with some addition of O 2 (or N 2 O) gas in inductively coupled plasma (ICP) discharges supplied with radio frequency power. The effects of various deposition parameters such as O 2 (or N 2 O) partial pressure ratio, ICP power, and gas pressure on the growth characteristics and properties of the deposited films are investigated. The chemical bonding states of deposited films are analyzed by Fourier transform infrared spectroscopy, and the deposition rate and optical properties are determined from in-situ ellipsometry. For the TMOS=O 2 case, the deposition rate increases with increasing ICP power. Larger oxygen partial pressure ratio decreases the deposition rate. For the TMOS=N 2 O case, higher N 2 O fraction results in a decrease in nitrogen content in the gasphase and in the deposited films, thereby decreasing the refractive index. As the gas pressure increases, the deposition rate increases first and saturates later. Capacitance-voltage measurements are performed in MOS capacitors to obtain the electrical properties of the deposited films. The interface trap density is observed to decrease with increasing ICP power.
Journal of Applied Physics, 2000
The formation of nanosized Si crystals in dual-frequency plasma-enhanced chemical-vapor-deposited silicon oxides is identified in this study. As a higher SiH 4 N 2 O gas flow rate ratio is employed during the deposition process, the silicon-to-oxygen atomic ratio and the dangling bond density both increase. The resulting oxide films contain more Si-H bonds and less Si-O and Si-O-H bonds, as determined from the Fourier-transform infrared spectra. The main type of charge defects in these oxides change from "SiwO 3 bonds (EЈ centers͒ to "SiwSi 3 bonds, which eventually cluster together and precipitate out from the oxide network to form the Si nanocrystals. The size of these Si nanocrystals falls within the range of 30-50 nm, as observed by high-resolution transmission electron microscopy. The formation of these nanocrystals inside the silicon-rich oxides results in a lower film density, a tensile stress component, and a higher wet etching rate, even under the ion bombardment provided by the rf bias power during deposition. The underlying mechanisms for the formation of these Si nanocrystals from the silicon oxide will be proposed.
Thin Solid Films, 2007
Silicon oxides ranging from near stoichiometric to silicon rich silicon oxides can be obtained by plasma enhanced chemical vapour deposition from silane (SiH 4 ) and nitrous oxide (N 2 O) mixtures. During deposition, impurity bonds like Si-H and Si-OH incorporate into the oxide matrix depending on the deposition parameters and mainly on the precursor gas flow ratio, R = Q N2O / Q SiH4 . In this work, plasma deposition from SiH 4 and N 2 O has been modelled, in order to discuss the possible pathways that lead to the thin film composition variations with reactants flow ratio. It has been found that the SiH 2 /SiH 3 ratio determines whether the film deposition takes place through silanol precursors (SiH 3 O, SiH 2 O…), leading to the incorporation of Si-OH bonds into the oxide film, or it is done through SiO, Si and silane hydrides, with the result of oxygen vacancies formation in the films and the introduction of Si-H bonds.
Characterization of SiO2 films deposited at low temperature by means of remote ICPECVD
2007
Silicon dioxide films were deposited by means of remote inductively coupled plasma enhanced chemical vapor deposition (ICPECVD) in Ar-N 2 O-SiH 4 plasma at 150°C and pressures between 1 and 6 Pa. Chemical modeling of our plasma indicated an increased fraction of SiH 3 radicals at 6 Pa (compared to SiH 2 , SiH, and Si species), while at 1 Pa their relative contribution on film growth should be much smaller. Layer growth from SiH 3 radicals would result in better dielectric quality.