In situ real-time monitoring of profile evolution during plasma etching of mesoporous low-dielectric-constant SiO 2Patterning of fluorine-, hydrogen-, and carbon-containing SiO 2 -like low dielectric constant materials in highdensity fluorocarbon plasmas: Comparison with SiO 2 O 2 plasma ashing is commonly used to remove photoresist. The effect of O 2 plasma ashing on the porous organosilicate glass (CH 3 SiO 1.5 ) n , one of the spin-on materials, is investigated. O 2 plasma can oxidize the methyl groups in porous organosilicate glass ͑POSG͒, which leads to the formation of Si-OH groups. The hydrophilic Si-OH groups will induce moisture uptake so that electrical degradation will occur in POSG film. Pure hexamethyldisilazane ͑HMDS͒ vapor ͑100% HMDS͒ can react with the Si-OH groups in POSG film. It converts hydrophilic Si-OH groups into hydrophobic Si-O-Si(CH 3 ) 3 groups against moisture uptake. The leakage current density decreases by a factor of 2-3 and the dielectric constant decreases from 3.62 to 2.4 when O 2 plasma-damaged POSG undergoes HMDS treatment at 80°C for 15 min. Therefore, HMDS treatment is the effective technique to repair the electrical degradation to POSG film during photoresist stripping processing.
The growth kinetics of amorphous interlayer (a interlayerbb) in polycrystalline Ti films on single-crystal-silicon has been studied by cross-sectional transmission electron microscopy. The growth was found to follow a linear growth law initially in samples annealed at 350–425 °C. The activation energy of the linear growth was measured to be 1.6±0.3 eV. Maximum thicknesses of the a interlayers were measured to be of the order of 10 nm. The formation of an a interlayer was observed in samples annealed at a temperature as high as 600 °C. The formation and growth kinetics of a interlayers in Ti/Si and Ni/Zr systems are compared. Essential factors for the formation and growth of an a interlayer are discussed. The results represent the first report on the growth kinetics of an a interlayer in metal thin films on single-crystal silicon.
To develop a low-stress dielectric thin film, a novel liquid-phase deposition (LPD) technique utilizing silica-saturated hydrofluosilicic (H2SiF6) solution with only H20 added is proposed. Due to fluorine incorporation, the stress in asdeposited LPD oxide can he as low as 83.3 MPa (tensile). Addition of 1120 greatly affects the stresses in as-deposited LPD oxide: the less 1120 added, the lower the stress will be. The stress variations accompanying thermal cycling have also been clarified. Films deposited with a larger quantity of H20 added exhibited larger stress variations (hysteresis). After ex situ annealing at around 600°C, the total stress decreased to near 0 MPa. To meet future high-density and high-performance requirements for ultralarge scale integration (ULSI) devices, multilevel interconnection has become more important than ever. For multilevel interconnection, low
The dielectric properties of organic-porous silica films deteriorate after photoresist removal processing. O 2 plasma ashing has been commonly used to remove photoresist. Nevertheless, the O 2 plasma will destroy the functional groups and induce moisture uptake in porous silica films. In this study, trimethylchlorosilane ͑TMCS͒ is used to repair the damage to porous silica caused by the O 2 plasma ashing process. The leakage current and dielectric constant will decrease significantly after the TMCS treatment is applied to damaged porous silica. These experimental results show that the TMCS treatment is a promising technique to repair the damage to porous silica during photoresist removal processing.
Fluorine can be naturally incorporated into the silicon oxide (SiO2−xFx) prepared by the liquid phase deposition (LPD) method at 35 °C. Fourier transform infrared and x-ray photoelectron spectroscopy spectra show that an annealing treatment can change its bond-structure. Changes in properties accompanying the restructuring are also observed. The annealing also densifies the LPD oxide and reduces its thickness because Si–F intensity decreases and the Si–O–Si intensity increases as annealing temperature increases.
Interfacial reactions of cobalt thin films on BF+2 -implanted (001)Si have been studied by both cross-sectional and plan-view transmission electron microscopy as well as by sheet resistance measurements. The implantation-amorphous samples were found to favor the formation of CoSi2 at 400 °C and laterally uniform growth of the phase at higher temperatures. Two discrete layers of fluorine bubbles were observed in cobalt silicides in all BF+2 -implanted samples annealed at 400–800 °C. In 800–900 °C annealed samples, large bubbles were often observed to distribute near the CoSi2 grain boundaries. The results indicated that (1) fluorine atoms diffuse rapidly at a temperature as low as 400 °C, and (2) appreciable amounts of fluorine atoms are present with low solubility in cobalt silicides after annealing at 400–900 °C. The residual interstitial defects in BF+2 -implanted samples were completely annihilated by CoSi2 formation at 800–900 °C. The elimination of all interstitial defects in these samples is attributed to the injection of a high density of vacancies which were generated during silicide formation. The electrical resistivity of CoSi on blank silicon was measured to be about 350 μΩ cm. The presently measured electrical resistivity value is believed to be one of the most accurate values obtained for CoSi to date. Factors influencing the formation of cobalt silicides and defect structure are discussed.
Interfacial reactions of titanium thin films on BF+2 -implanted (001)Si have been studied by both cross-sectional and planview transmission electron microscopy as well as by sheet resistivity measurement. Amorphous Ti-Si interlayers were observed in Ti films on blank and implanted samples following 400 °C annealing. The presence of the doping impurities was found to promote the early growth of the C54-TiSi2 phase. 100% surface coverage of TiSi2 on silicon was found in implantation amorphous samples annealed at 1000 °C for 1 h. The C54-TiSi2/Si interface energy and/or the silicide surface energy are thought to be lowered by the presence of the doping impurities to improve the surface morphology at high temperatures. The distribution of fluorine bubbles in doped samples with Ti overlayers annealed at 500–1000 °C indicated that (1) the solubilities of F in Ti silicides are very low, (2) the diffusivities of F in both C49- and C54-TiSi2 are rather high, and (3) most of fluorine atoms in TiSi2 layer escaped into ambient during 900–1000 °C annealing. The end-of-range defects were found to be not significantly affected by the TiSi2 formation. In samples annealed at 700–800 °C, the sheet resistance values were found to be the same in spite of the difference in distribution of doping impurities and defect structure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.