Kwang-Man Lee

The deposition of SiOF film with low dielectric constant in a helicon plasma source

SiOF films deposited by a helicon wave plasma chemical vapor deposition method has been characterized using Fourier transform infrared spectroscopy and ellipsometry. High density plasma of ≳1012 cm−3 can be obtained on a substrate at low pressure (<10 mTorr) with rf power ≳400 W with a helicon plasma source. A gas mixture of SiF4, O2, and Ar was used to deposit SiOF films on 5 in. Si(100) wafers not intentionally heated. Optical emission spectroscopy was used to study the relation between the relative densities of the radicals and the deposition mechanism. It was found that the addition of Ar gas to the SiF4/O2 mixture greatly increased the F concentration in the SiOF film. Discharge conditions such as gas composition, sheath potential, and the relative densities of the radicals affect the properties of the film. The dielectric constant of the SiOF film deposited using the helicon plasma source was 3.1, a value lower than that of the oxide film by other methods.

A Study on Low Dielectric Material Deposition Using a Helicon Plasma Source

Characteristics of SiOF films deposited by a helicon plasma source have been investigated using Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and ellipsometry. High density Ar plasma of >10 12 cm -3 was obtained on a substrate at low pressure ( 400 W using a helicon plasma source. The effect of the RF power, the magnetic field strength, and the pressure on the helicon wave for high density plasma has been studied. A gas mixture of SiF 4 , O 2 , and Ar was used to deposit SiOF film on 5 in. (100) Si wafers not intentionally heated. Optical emission spectroscopy was used to study the relation between the relative densities of the radicals and the deposition mechanism. The effects of the RF power, the gas composition, and the Ar addition to the SiF 4 /O 2 mixture on the plasma-phase composition and on the properties of the film, have been studied. Discharge conditions such as gas composition, sheath potential, and relative densities of the radicals affect the properties of the film. The dielectric constant of the SiOF film deposited using the helicon plasma source was 3.1, a value lower than that of the oxide films obtained using other methods.

Formation and characterization of the fluorocarbonated-SiO2 films by O2/FTES-helicon plasma chemical vapor deposition

Abstract Fluorocarbonated-SiO 2 films were prepared on a p-type Si(100) substrate using FSi(OC 2 H 5 ) 3 (FTES) and O 2 mixture gases by a helicon plasma source. High density O 2 /FTES/Ar plasma of ∼10 12 cm −3 is obtained at low pressure ( 2 gases are greatly dissociated. The fluorocarbonated-SiO 2 film deposited in the helicon plasma chemical vapor deposition contains C–F bonds which are not found in the fluorocarbonated-SiO 2 film made by thermal chemical vapor deposition, where the FTES and O 2 react chemically on the substrate. Fourier transform infrared and X-ray photoelectron spectroscopy spectra show that the film has Si–F, Si–O, and C–F bonds. The Si–F and C–F bonds may lower the dielectric constant greatly. The relative dielectric constant, leakage current density, and dielectric breakdown voltage are about 2.8, 8×10 −9 A/cm 2 , and > 12 MV/cm, respectively. However the dielectric constant and leakage current density of the film annealed at 500°C are about 3.2 and 9×10 −11 A/cm 2 , respectively. The step-coverage of the deposited fluorocarbonated-SiO 2 film in 0.3 μm metal pattern is about 91%.

SiOF Film Deposition Using FSi ( OC 2 H 5 ) 3 Gas in a Helicon Plasma Source

SiOF film deposited using FSi(OC 2 H 5 ) 3 (known as FTES) and O 2 mixture in a helicon plasma source is characterized with various plasma conditions. High density O 2 /FTES/Ar plasma above 10 12 cm -3 is obtained at low pressure (<3 mTorr) with rf power above 900 W in the helicon plasma source. The plasma parameters such as electron density with the various rf power, the magnetic field strength, and the pressure are measured. A gas mixture of FTES and O 2 is used to deposit SiOF film on 5 in. Si(100) wafers without intentional heating or biasing the substrate. Optical emission spectroscopy (OES) is used to study the relation between the relative densities of the radicals and the film properties. The OES data imply that the FTES and O 2 gases are greatly dissociated at the helicon mode, which is launched above theshold plasma density. Thus, the SiOF film deposited in the helicon reactor contains C-F bonds which are not sound in the SiOF film made by thermal chemical vapor deposition, where the FTES and O 2 react chemically on the substrate. Fourier transform infrared and X-ray photoelectron spectroscopy spectra show that the film has Si-F, Si-O, and C-F bonds. The Si-F and C-F bonds may lower the dielectric constant greatly. As O 2 /FTES ratio decreases, the fluorine concentration increases and the dielectric constant decreases.

Porosity of organosilicate films in a range of organic properties

Organosilicate films divide into three properties, organic, hybrid and inorganic depending on the flow rate ratio between oxygen and bistrimethylsilylmethane precursor. The films with organic properties show decreased dielectric constant, because of pore incorporation in final materials. In this study, the porosity of organosilicate films with organic properties was investigated using the Maxwell–Garnett equation. The porosity of the films could be correlated with their IR properties, and increasing the porosity decreases the dielectric constant of the film.

Redshift and Blueshift Due to Interaction between C?H Bond of Methyl Radicals and Highly Electronegative Oxygen

Conventional chemical shifts in organic compounds usually consist of a redshift; however, hybrid-type SiOC films were found to exhibit a redshit and a blueshift. These chemical shifts originate from the interaction between the C–H bond and highly electronegative oxygen. The bonding structures of SiOC films can be divided into two types depending on the observed chemical shifts and consist of a Si–O–C cross-link structure and a Si–O–C cage-link structure. The blue shift in SiOC films is associated with the porosity due to an increase in the number of electron-rich groups, such as methyl radicals, resulting in the formation of a Si–O–C cage link structure. On the other hand, the Si–O–C cross-link structure associated with a redshift is generated from the adhesion due to C–H bond elongation.

Prevalence and Clinical Relevance of Exon 2 Deletion of COMMD1 in Bedlington Terriers in Korea

Background Deletion of exon 2 of copper metabolism domain containing 1 (COMMD1) results in copper toxicosis in Bedlington terriers (CT‐BT). Objectives This study was conducted to identify the prevalence and clinical relevance of the COMMD1 mutation in Bedlington terriers in Korea. Animals A total of 105 purebred Bedlington terriers (50 males, 55 females) from the kennels and pet dog clubs in Korea were examined during the period 2008–2013. Methods A multiplex PCR was carried out to detect exon 2 deletion of COMMD1. Clinical analysis was performed on each genetic group, and clinical status of the dogs was followed up to estimate survival probability. Results Of the 105 samples, 52 (49%) were wild‐type homozygote, 47 (45%) were heterozygote, and 6 (6%) were mutant‐type homozygote. Plasma alanine aminotransferase (ALT) activity was increased in the mutant‐type homozygous group >2 years of age (P < .0001). The survival probability of 6 mutant‐type homozygotes surviving 2.5 years was 0.67, and 4 years was 0.5. Conclusions and Clinical Importance Results show the prevalence and clinical relevance of exon 2 deletion of COMMD1 and could help establish a structured selective breeding program to prevent CT‐BT in Korea.