SiOC Films Research Articles

Ohmic Contact Effect and Electrical Characteristics of ITO Thin Film Depending on SiOC Insulator

To research the characteristics of ITO film depending on a polarity of SiOC, specimens of ITO/SiOC/glass with metal-insulator-substrates (MIS) were prepared using a sputtering system. SiOC film with 17 sccm of oxygen flow rate became a non-polarity with low surface energy. The PL spectra of the ITO films deposited with various argon flow rates on SiOC film as non-polarity were found to lead to similar formations. However, the PL spectra of ITO deposited with various argon flow rates on SiOC with polarity were seen to have various features owing to the chemical reaction between ITO and the polar sites of SiOC. Most ITO/SiOC films non-linearly showed the Schottky contacts and current increased. But the ITO/SiOC film with a low current demonstrated an Ohmic contact.

Synthesis of SiOC(–H) Films by the Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition Method

Synthesis of SiOC(–H) Films by the Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition Method

반도체 절연박막의 두께변화와 결정성에 대한 누설전류의 의존성

디스플레이를 위한 반도체 절연막으로 적합한 SiOC 박막의 특성을 살펴보기 위해서 스퍼터를 이용한 SiOC 박막을 증착하고 전기적인 특성을 조사하였다. SiOC 박막의 절연성은 열처리 온도에 따라서도 달라졌으며, 100도에서 열처리한 박막의 두께는 증가하고 굴절률은 감소하였으며, XRD의 비정질 특성이 높아지고, 커패시턴스의 감소와 누설전류가 감소하는 특성이 관찰되었다. SiOC 박막의 누설전류 감소의 특성은 절연막으로서의 특성이 개선되고 있다는 것을 의미하며, 두께의 증가현상 또한 누설전류가 감소할 수 있는 조건을 잘 만들고 있었다. 분극의 감소에 의한 비정질의 특성은 SiOC박막을 구성하고 있는 원자 간의 배열이 불규칙적으로 변하고 원자 사이의 결합길이가 최대한 길어지면서 이루어졌기 때문이며, 따라서 두께가 증가하였다. 100도에서 열처리 한 박막에서 두께가 증가하였으며, 누설전류가 감소하였다. 스퍼터에 의한 SiOC 박막의 100도 온도에 의한 극적인 누설전류의 감소는 저온공정이 필수적인 디스플레이용 반도체소자에서 적합한 절연막 임을 확인할 수 있었다. SiOC films were prepared as insulators for displays by sputtering at low temperatures, and the relationship with the electrical properties waaas examined. The electrical properties of SiOC films were affected by the annealing process, and SiOC films annealed at 100oC showed a significant increase in thickness and a decrease in the reflective index. XRD revealed an increase in the degree of the amorphous structure. Moreover, the capacitance and leakage current of the SiOC films annealed at 100oC decreased. These characteristics of SiOC films highlight their potential as ideal insulators. Amorphous SiOC films by the reduction of polarization are dependent on the elongation effect of the bonding lengths in the structure and the thickness. The properties of these SiOC films are suitable for low temperature displays.

Correlation Between Arrhenius Equation and Binding Energy by X-ray Photoelectron Spectroscopy

SiOC films were prepared by capacitively coupled plasma chemical vapor deposition, and the correlation between the binding energy by X-ray photoelectron spectroscopy and Arrhenius equation for ionization energy was studied. The ionization energy decreased with increase of the potential barrier, and then the dielectric constant also decreased. The binding energy decreased with increase of the potential barrier. The dielectric constant and electrical characteristic of SiOC film was obtained by Arrhenius equation. The dielectric constant of SiOC film was decreased by lowering the polarization, which was made from the recombination between opposite polar sites, and the dissociation energy during the deposition. The SiOC film with the lowest dielectric constant had a flat surface, which depended on how carbocations recombined with other broken bonds of precursor molecules, and it became a fine cross-linked structure with low ionization energy, which contributed to decreasing the binding energy by Si 2p, C 1s electron orbital spectra and O 1s electron orbital spectra. The dielectric constant after annealing decreased, owing to the extraction of the <TEX>$H_2O$</TEX> group, and lowering of the polarity.

White light emission from Eu-doped SiOC films

Bilayers consisting of two SiOC films doped with Eu at different concentrations have been synthesized by magnetron cosputtering. The proper choice of annealing temperature allows us to avoid Eu diffusion and clustering, so that each layer maintains its optical properties. Under these conditions, the bilayer allows us to take advantage of the dependence of the photoluminescence peak position on the Eu concentration, so that an intense white emission is obtained at room temperature. This finding constitutes relevant progress towards the realization of efficient Si-based white light sources, which can be of great interest for applications in photonics or solid-state lighting.

Chemical Shift and Surface Characteristics of Al-Doped ZnO Thin Film on SiOC Dielectrics

Aluminum doped zinc oxide (AZO) films were fabricated on SiOC/p-Si wafer and SiOC film was prepared on a p-type Si substrate with the SiC target at oxygen ambient with the gas flow rate of 5-30 sccm by a RF magnetron sputter. C-V curve of SiOC/Si wafer was measured to observe the relationship between the polarity of SiOC dielectrics and the change of capacitance depending on oxygen gas flow rate. The SiOC film could be controlled to be polar or nonpolar, and their surface energy was changed depending on the polarity. Smooth surface is essential to improve the TFT performance. AZO-TFTs used smooth SiOC film with low polarity as a gate insulator was observed to show low leakage current (IL) and low subthreshold voltage swing. It is proposed that SiOC film with high degree amorphous structure as a gate insulator between AZO and Si wafer could solve problems of the mismatched interfaces, which was originated from the electron scattering due to the grain boundary.

Deep Level Emission of ZnO and Amorphous SiOC Films by Photoluminescence

Effect of polarity in substrate for ZnO growth was researched. The zinc oxide films were deposited on SiOC/Si wafer by a RF magnetron sputtering system. SiOC film was also deposited by RF magnetron sputtering to obtain a low temperature process. Polarity in SiOC film changed with increasing the oxygen gas flow rates, and the chemical shift in the PL spectra was observed because of lowering the polarity of SiOC film caused by chemical reactions between CH group and OH group as the polar sites by high plasma energy. The chemical shift after ZnO deposition on SiOC film made was attributed to defects owing to the Vo and Zni and the valence band in ZnO at interfaces between ZnO and SiOC films. ZnO grown on SiOC film including polar sites changed the roughness owing to the induction of the trap charge resulted from the defects. The roughness of ZnO increased at SiOC with low polarity. SiOC with polar sites enhanced the level of blue emission deeply, and showed the blue shift in PL spectra.

Hard Coat Layers by PE-CVD Process for the Top Surface of Touch Panel

In order to protect surface from damages, the high pencil hardness and the high abrasion resistance are required for the hard coat layers on polyethylene telephthalate (PET) films for the application of touch panel surface. We have already found that the UV-curing-hard-coat-polymer (UHP) coated PET films show the poor abrasion resistance, while they have the high pencil hardness. It reveals that the abrasion resistance of hard coat layers of the UHP is not simply dependent on the pencil hardness. In this work, we have studied to improve the abrasion resistance of SiOC films as hard coat layers, which were formed by PE-CVD process on UHP coated PET. The abrasion resistance was evaluated by Taber abrasion test. PE-CVD hard coat layers which formed on UHP coater PET films have showed the better abrasion resistance and have the possibility of substitution to the thin glass sheets for touch panel application.

New strategies to improve the luminescence efficiency of Eu ions embedded in Si-based matrices

The comparison of the performances of SiO2 and SiOC layers as host matrices for optically active Eu ions is presented. A SiO2 matrix allows to observe light emission from both Eu2+ and Eu3+ ions, owing to a proper tuning of the thermal annealing process used for the optical activation of the rare earth. However, the photoluminescence efficiency of both ions remains relatively low and quite far from the requirements for technological applications, mainly due to the extensive formation of Eu-containing precipitates. A detailed study by transmission electron microscopy allowed us to analyze and elucidate the clustering process and to find suitable strategies for minimizing it. We found that the substitution of SiO2 matrix with a SiOC film allows to obtain a very bright light emission centered at about 440 nm from Eu2+ ions. In fact, SiOC is able to efficiently promote the Eu3+ → Eu2+ reduction; furthermore, Eu ions are characterized by an enhanced mobility and solubility in this matrix, and as a consequence, Eu precipitation is strongly reduced. Since SiOC is a material fully compatible with standard Si technology, Eu-doped SiOC layers can be considered a highly interesting candidate for photonic applications.

The effects of UV radiation on SiC(O)N/SiOC(− H) thin films grown on Si substrates using plasma-enhanced atomic layer deposition

Multilayer Cu/SiC(O)N/dense SiOC(−H)/porous SiOC(−H)/p-Si(100) thin-film stacks were fabricated. A 200-nm-thick porous SiOC(−H) film was deposited on an Si substrate using plasma-enhanced chemical vapor deposition. Subsequently, a 60-nm-thick dense SiOC(−H) film followed by a 20-nm-thick SiC(O)N film was deposited using plasma-enhanced atomic layer deposition. These multilayer films were then irradiated with ultraviolet (UV) light at 400°C for various times in the range 5 to 20min to improve their structural, mechanical, and electrical properties. The effects of the UV radiation on the interfacial bonding configurations and the mechanical properties of the interface between the SiC(O)N etch stop layer and the porous low-k SiOC(−H) film were investigated. The elemental concentrations of Si, C, N, and O were determined at the SiC(O)N/SiOC(−H) interfaces using Auger electron spectroscopy depth-profile analysis, and the electrical properties of the Cu/SiC(O)N/SiOC(−H)/Si metal-insulator-semiconductor structures were investigated using capacitance–voltage and current–voltage profiling. Based on our experimental results, UV exposure for 5 to 10min is optimal for improving the characteristics of Cu/SiC(O)N/SiOC(−H)/Si multilayered films.

Method of sealing pores in porous low-k SiOC(-H) films fabricated using plasma-assisted atomic layer deposition

The influence of substrate temperature during plasma-assisted atomic layer deposition (PAALD) of porous low-k SiOC(-H) thin films on p-type Si(100) substrates is reported. Dimethoxydimethylsilane and porogen were used as precursors, and the deposited films were then annealed at 425 °C for 1 hour in ambient N2 to remove the porogen. The optical, chemical, and electrical characteristics of the porous low-k SiOC(-H) film were investigated using ellipsometry, Fourier-transform infrared spectroscopy, and capacitance-voltage measurements, respectively. The refractive indices and the dielectric constants of porous low-k SiOC(-H) films showed remarkable decreases and increases with increasing substrate temperature up to 100 °C and greater than 150 °C, respectively. We also show that for substrate temperatures the open pores can be sealed by using a layer-by-layer deposition method. Furthermore, using PAALD, we developed a novel technique to deposit high-quality, porous low-k SiOC(-H) films and to seal open pores at relatively low substrate temperatures.

SiOC 박막에서 열처리에 의한 분극의 감쇄현상에 관한 연구

탄소를 포함한 SiOC 박막은 BTMSM과 산소의 혼합 프리커서를 이용하여 CVD방법으로 증착하였다. 전통적으로 유전상수를 측정하기 위해서 MIS(금속/절연막/반도체)방법을 이용하는데 박막의 균일성을 보장할 수 없기 때문에 나타나는 오차의 한계를 보상하기 위해서 광학적인 분석방법과 경도측정 등을 통하여 SiOC 박막이 분극이 낮아지는 영역을 추적하였다. 분극이 낮고 비정질성이 높은 박막에서 유전상수가 낮아지는 특성을 이용하여 유전상수를 도출하였다. 열처리 후 SiOC 박막의 유전상수는 분극의 감소에 의해 감소하였으며, FTIR 분석에 의한 결합신호는 높은 파수 영역으로 이동하였다. 950~1200 cm-1 영역의 주 결합은 Si-C와 Si-O 결합으로 이루어졌으며, Si-O 결합의 강도가 증가한 것은 결합력이 증착한 샘플에서 보다 증가하였다는 것을 의미하며, 열처리 후 더 안정된 박막이 되었다. 열처리 후 SiOC 박막은 유전상수가 2.06으로 낮게 나타났다. The SiOC film of carbon centered system was prepared using bistrimethylsilylmethane (BTMSM) and oxygen mixed precursor by the chemical vapor deposition. The dielectric constant is measured by MIS(metal/insulator/Si) structure, but it could decrease the reliability because the uniformity is not assured. To research the dielectric constant of SiOC film, the range of low polarization was researched in SiOC film using the optical analysis and hardness, and then calculated the dielectric constant of SiOC film with amorphous structure of high degree. After annealing, the dielectric constant of SiOC film was decreased owing to the lowering of polarization, and FTIR spectra of the main bond was shifted to higher wave number. The main bond of 950~1200 cm-1 was composed of the Si-C and Si-O bonds. The intensity increases in Si-O bond infers the bonding strength became stronger than that of deposited film. Annealed SiOC film showed 2.06 in dielectric constant.

스퍼터링에 의한 Low-k 박막의 특성

저온공정을 위해 스퍼터 방법에 의해 SiOC 박막을 증착하였으며, SiOC 박막 위에 투명전극을 제작하기 위해서 AZO박막과 ZnO 박막을 증착하였다. 박막의 광학적 특성은 PL 분석기와 스펙트라포토미터를 이용하였다. SiOC 박막은 n-type Si 위에 증착하였을 때 증착조건에 따라서 방사 효과가 다양하게 나타났으며, 두꺼운 박막에서 blue shit 현상이 나타났다. SiOC/Si 박막 위에 AZO 박막을 증착할 경우 빛의 흡수영역이 넓어졌다. 이러한 특성은 태양전지의 투명전극을 만들 경우 효율을 높일 수 있게 된다. To obtain available process at low temperature, SiOC thin film was prepared with various flow rates by using the rf magnetron sputtering, and AZO thin film was also deposited on SiOC film by rf magnetron sputtering system. The optical electrical properties of the SiOC film and SiOC/AZO were analyzed by the uv visible spectrometer and PL spectra. SiOC film on n type Si showed various type emission according to the deposition condition. The SiOC film showed the blue shift with increasing the thickness in PL spectra. AZO/SiOC/Si film had a broad emission characteristic, which is enhanced the efficiency in solar cell.

AZO 투명전극의 결정성과 광학적 특성

The optical properties of AZO thin films prepared by the RF mangnetron sputtering system was studied to research the dependance of chemical properties of substrate. The substrate was the SiOC film deposited by Inductively coupled plasma chemical vapor deposition with various gas flow rate of and Ar (DMDMOS). In accordance with the increase of Ar gas flow rates, the Si-O bond in the SiOC film increased and then progressed the amorphism. The roughness of AZO grown on SiOC film with high degree of amorphism decreased and then improved the flatness of surfaces. Moreover, the ultra violet emission with high intensity was spontaneously induced in the AZO film growed on SiOC film with high degree of amorphism.

Optical properties of SiOC film by PL spectrometer and reflectance

SiOC films made by the inductive coupled plasma chemical vapor deposition were analyzed by the photo luminance spectra and reflectance. Chemical shift obtained by PL spectra was observed and the reflectance was decreased at sample with low refractive index. The refractive index was in inverse proportion to the thickness of SiOC film. Lowering the reflectance caused to decrease the energy band gap and polarization, so increased an absorbance of the light. Low polarization of SiOC film was induced from the recombination and dissociation of alkyl sites by neighboring high electro negative oxygen. The electron affinity related to the energy band gap at surfaces increased at sample with low polarization, and finally, the reflectance decreased according to the reduction of polarity.

Characterization of Ultra Low-k SiOC(H) Film Deposited by Plasma-Enhanced Chemical Vapor Deposition (PECVD)

In this study, deposition of low-dielectric constant SiOC(H) films by conventional plasma-enhanced chemical vapor deposition (PECVD) were investigated through various characterization techniques. The results show that, with an increase in the plasma power density, the relative dielectric constant (k) of the deposited films decreases whereas the refractive index increases. This is mainly due to the incorporation of organic molecules with CH 3 group into the Si-O- Si cage structure. It is as confirmed by FT-IR measurements in which the absorption peak at 1,129 cm -1 corresponding to Si-O-Si cage structure increases with power plasma density. Electrical characterization reveals that even after fast thermal annealing process, the leakage current density of the deposited films is in the order of 10 -11 A/cm at 1.5 MV/ cm. The reliability of the SiOC(H) film is also further characterized by using BTS test.

Study on the Characteristics of Amorphous Low-&lt;I&gt;k&lt;/I&gt; Thin Film for Solar Cells

The most practical solar cells are silicon based crystal silicon solar cells. Phosphorus oxychloride for n+ type doping was diffused on a p+ Si, SiC and poly Si using N2 carrier gas by low pressure chemical vapor deposition. The series resistances on various p type silicon substrates were researched. An n(+)-p+ junction was fabricated by thermal diffusion of phosphorus oxychloride into a p+ Si wafer. For the rear metallization, Al was deposited using screen printing and SiOC film was used instead of SiO2 film as a passivation material for the metal layer. SiOC film was made by the capacitive coupled plasma chemical vapor deposition. When the Fourier transform infrared spectra of SiOC film shows organic properties including a strong peak of the Si-CH3 bond, the efficiency was increased, because of the reduction of the recombination at the back surface.

탄소주입 실리콘 산화막 박막의 광학적 특성과 화학적 이동의 상관성

SiOC films made by the inductive coupled CVD with dimethyldimethoxysilane were analyzed to find out the correlation between the chemical and optical properties by using the Foruier transform infrared spectroscopy, spectrophotometer and ellipsometer. The bonding structure of SiOC film was formed during the depositeion and the adhesion was increased after annealing process. SiOC film decreased the polarization by the chemical reaction between alkyl group and hydroxyl group, and increased the degree of amorphism. For the range of 950 cm-1 in FTIR spectra, the spectra were divided into two types depending on polar sites. The refractive index of SiOC film with the lowest polarization increased and the thickness of that decreased.

Effects of ultraviolet irradiation treatment on low-k SiOC(−H) ultra-thin films deposited by using TMS/O2 PEALD

We report on the electrical characteristics for the metal-insulator-semiconductor (MIS) structure of low-dielectric-constant SiOC(−H) films. The SiOC(−H) thin films were deposited on p-Si(100) substrates by using a plasma-enhanced atomic layer deposition (PEALD) system. To improve the structural and the electrical characteristics, we post-treated the SiOC(−H) films deposited using PEALD with ultraviolet (UV) irradiation for various time intervals. The radical intensities in the bulk plasma were observed to be influenced strongly by the radio-frequency (rf) power. A complete dissociation of the trimethylsilane (TMS) precursor took place for rf powers greater than 300 W. As the UV treatment time was increased, the bonding structure of the SiOC(−H) film clearly separated to Si-O-Si and Si-O-C bonds. Also, the fixed charge density and the interface state density on the SiOC(−H)/p-Si(100) interface decreased as the UV treatment time was increased to 6 min. Therefore, we were able to minimize the defects and to reduce the interface charge by adjusting the UV dose.

High-rate HMDSO-based coatings in open air using atmospheric-pressure plasma jet

This work deals with the high-rate and dust-free formation of carbon-containing silicon oxide (SiOC) coatings in open air without substrate heating using an atmospheric-pressure (AP) plasma jet. The AP plasma was excited by a 13.56-MHz radio frequency (RF) power. Hexamethyldisiloxane and oxygen (O2) were used as the source gases. By optimizing the O2 flow rate and RF power, SiOC films were readily fabricated at deposition rates higher than 100nm/s without suffering from particulate contaminations of the film surface. Additionally, an inorganic SiO2-like film exhibiting O/Si atomic ratio of approximately 2 was obtained at a deposition rate of ~13 nm/s, the value of which is still greater than those obtained in other AP plasma sources. Further systematic studies are needed to see if good-quality inorganic SiO2-like films can be obtained with higher rates.