Chi Kyu Choi

A study on the formation and characteristics of the SiOCH composite thin films with low dielectric constant for advanced semiconductor devices

The SiOCH composite thin films were deposited on a p-type Si(100) substrate using bis-trimethylsilane (BTMSM) and O2 mixture gases by an inductively coupled plasma chemical vapor deposition (ICPCVD). High density plasma of approximately ∼1012 cm−3 is obtained at low pressure (<320 mtorr) with an RF power of approximately 300 W in the inductively coupled plasma source where the BTMSM and oxygen gases are greatly dissociated. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra show that the film has SiCH3 and OH related bonds. The CH3 groups formed the void in the film and the Si atoms in the annealed sample have different chemical states from those in the deposited sample. It means that the void is formed due to the removing of OH related bonds during the annealing process. The relative dielectric constant of the annealed sample with the flow rate ratio O2/BTMSM as 0.3 at 500°C for 30 min is approximately 2.5.

The influence of carbon content in carbon-doped silicon oxide film by thermal treatment

Abstract Carbon-doped silicon oxide (SiOC) low- k dielectric film was deposited on a p-type Si(100) substrate with mixture of bis-trimethylsilylmethane (BTMSM) and oxygen by inductively coupled plasma chemical vapor deposition (ICPCVD). Electron density and electron temperature of ∼10 12 cm −3 and 1.6 eV, respectively, were obtained at low pressure (

Synchrotron X-ray scattering and reflectivity studies of the structure of low dielectric constant SiOCH thin films prepared from bistrimethylsilylmethane by chemical vapor deposition

Quantitative, non-destructive grazing-incidence X-ray scattering and specular X-ray reflectivity analysis with synchrotron radiation sources, along with spectroscopic ellipsometry analysis, were successfully used to characterize a series of low dielectric constant, nanoporous SiOCH dielectric thin films with nanometre-scale thicknesses prepared by radio-frequency inductively coupled plasma chemical vapor deposition of bistrimethylsilylmethane precursor and oxygen gas at various flow rate ratios followed by annealing at 298, 473, 573 or 673 K. These analyses provided important information on the structures and properties of the nanoporous films. The average size of the nanopores generated in each film was 3.07 nm in radius or less, depending on the process conditions. The film electron densities ranged from 414 to 569 nm−3, the refractive indices ranged from 1.434 to 1.512 at 633 nm wavelength, and the porosities ranged from 16.1 to 38.9%. Collectively, the present findings show that SiOCH thin films of the type reported here are suitable for use as low dielectric constant interdielectric layer materials in the fabrication of advanced integrated circuits.

Electrical Properties of Low-Dielectric-Constant SiOC(–H) Films Prepared by Plasma-Enhanced Chemical Vapor Deposition from Methyltriethoxysilane and O2

SiOC(–H) films were deposited on a p-type Si(100) substrate by plasma-enhanced chemical vapor deposition (PECVD) from methyltriethoxysilane (MTES) and oxygen precursors. The MTES/O2 flow rate ratio was varied from 40 to 100% to investigate its effect on the properties of the films. Film thickness and refractive index were measured by field-emission scanning electron microscopy (FESEM) and ellipsometry, respectively. The chemical structures of the SiOC(–H) films were characterized by Fourier transform infrared spectroscopy (FTIR) in the absorbance mode. The bonding configurations of the SiOC(–H) films remained the unchanged upon annealing, showing their good thermal stability. The electrical properties of the films were measured using a metal–insulator–semiconductor (MIS) Al/SiOC(–H)/ p-Si structure. The experimental lowest dielectric constant of the SiOC(–H) film was found to be 2.38 at an annealing temperature 500 °C and the film has excellent thermal stability up to 500 °C. The SiOC(–H) films deposited by MTES and O2 precursors are a promising material for next-generation Cu-interconnect technology.

The electronic structures of epitaxial CrSi2 film prepared on Si(111) substrate

Abstract The valence band (VB) electronic structures of CrSi 2 were studied by synchrotron radiation photoemission. Overall features of the VB photoemission spectra measured at room temperature (RT) and 20 K by using synchrotron radiation (photon energy, hν =20–120 eV) were similar. Two characteristic emissions were observed corresponding to the bonding and the nonbonding Cr- d partial density of states (PDOS) in the CrSi 2 . The onset of the VB photoemission measured at 20 K was located at about 0.32 eV below Fermi level, due to the energy band gap of CrSi 2 more than 0.32 eV.

HOMO-LUMO Interaction between Diene and Dienophile with an Electron-Withdrawing Group

Recently, the carbon-centered organic system with C-H hydrogen bonds is being examined and reported with particular focus on its chemical shifts. These properties are traditionally associated with the red shifted hydrogen bond due to the weak interaction of C-H hydrogen bonds. In a few cases, however, the strengthening of the C-H bond is characterized by the blue shift. In this study, organic-inorganic hybrid silica and fluorinated amorphous carbon films have been deposited on a p-type Si (100) substrate by inductively coupled plasma chemical vapor deposition. The reason for the chemical shift in the low dielectric constant materials with C-H hydrogen bonds was researched on, and the effect of the meso-structure of the films by the inverse electron demand Diels-Alder reaction of the C=C and C=O double bond was also studied.

Effect of UV Illumination on Deposition of Low-k Si-O-C(-H) Films by PECVD

The characteristics of plasma are important for the deposition of SiOC(-H) low dielectric thin film. The effect of UV light illumination on the plasma parameter in the capacitive coupled plasma chemical vapor deposition (CCP-CVD) system is investigated. The electron density is almost not changed, but the electron temperature decreases by UV light illumination. The deposition rate increases and the dielectric constant of the film is lowered with UV light.

Structural and Mechanical Properties of Low Dielectric Constant SiOC(-H) Films Using MTES/O2 Deposited by PECVD

Low dielectric constant SiOC(-H) films were deposited on p-type Si (100) substrates by plasma enhanced chemical vapor deposition (PECVD) using methyltriethoxysilane (MTES; C7H18O3Si) and oxygen gas as precursors. The SiOC(-H) films were deposited at room temperature and then annealed. Nanoindentation studies were carried out in order to determine the mechanical properties of the SiOC(-H) films. The elastic modulus and hardness of SiOC(-H) films were measured to be in the range of 2.14 – 5.02 and 0.12 – 0.74 GPa, respectively. It was observed that the values of elastic modulus and hardness decreases with increase of flow rate ratio of the precursors. In the SiOC(-H) film, -CH3 group as an end group was introduced into -O-Si-O- chain network, thereby reducing the film density to decrease the values of the mechanical properties.

Fractional Diversion of Discharge Current into Conductive Bodies in Contact with Plasmas

The phenomenon of discharge current diversion by conductive parts (electrodes, design elements or substrates) in contact with plasmas is considered for both DC and AC discharges. For the first time, atmospheric plasmatrons are analysed together with the glow discharge devices. A special experiment has been carried out that proved directly the correctness of the proposed approach. The negative sides of the phenomenon are discussed. In some practical cases, non-evident problems are formulated and their solutions are proposed

Plasma-Chemical Processing of Silicon Substrates Using a Novel Arc Plasmatron

A novel arc plasma source is proposed, which has low anode erosion rate allowing it to generate nearly spectrally clean plasma flow at the lifetime of 103~104 hours. The temperature of plasma near the nozzle exit is below 100 degC at arc power up to 2 kW. The design and characteristics of the plasmatron are discussed. Vacuum experiments with heterogeneous plasma-chemical processes showed that this device can serve as an effective tool for plasma-chemical treatment at pressures P~100 mbar. As an example, plasma-chemical etching processes for mono-crystal silicon in CF4 plasma and photo-resist on a silicon wafer in air, O2 and CF4 plasmas have been demonstrated