Papers by Keyword: Inductively Coupled Plasma

Abstract: This study focuses on the trench etching process for the fabrication of SiC Superjunction Schottky diodes, utilizing an ICP-RIE technique. Through a series of experiments, we optimized the etching parameters, including ICP power, RF power, and SF₆ gas flow rates, to achieve etching rates ranging from 157 nm/min to 372.1 nm/min. Additionally, the study identified the performance of the hard mask as a critical issue during the etching process, which was improved by reducing the RF power below 80 w. The deepest trench achieved reached a depth of 21 μm at 75 w RF power, 1000 w ICP power and 40 sccm SF₆, confirming the feasibility of this approach for fabricating high-performance SiC superjunction devices.

Abstract: Riceberry brown rice is regarded as a source of various nutrients; often richer than white rice. Non-thermal plasma has recently been gaining a role for improving properties of cereal grains, especially brown rice. A number of methods of plasma treatment has been proposed including discharges as capacitive coupled plasma (CCP) and inductive coupled plasma (ICP). ICP has two operation modes as capacitive (E-mode) and inductive (H-mode) discharge with rather distinct characters. In this study we have focused on using ICP Ar/O₂ plasma in both E-and H mode for plasma treatment on riceberry brown rice. The input power for plasma generation were set to 50 and 250 W for E-and H-mode, respectively. Plasma in H-mode was having higher plasma density than that in E-mode, as observed in the optical emission spectrum. The surface morphology of riceberry brown rice before and after Ar/O₂ plasma treatment was evaluated using a scanning electron microscope without or with an energy dispersive spectroscopy (SEM and SEM/EDS). It has been found that the bran layer was richer in elemental compositions than the endosperm. The surface of rice sample was found to be etched and more porous after plasma treatment. The Ar/O₂ plasma in H-mode was observed to offer higher effect. The surface contact angle was found to decrease from 120.1^o ± 0.9^o in untreated samples to 79.3^o ± 0.6^o and 99.2^o ± 0.8^o in plasma treated samples on E-and H-mode, respectively.

Abstract: Silicon carbide (SiC) is widely used in terrestrial and space applications because of its good mechanical, thermal and optical properties. Nevertheless, traditional grinding and polishing technologies cannot meet the machining requirements due to the high hardness and brittleness. In this paper, Inductively Coupled Plasma (ICP) is utilized to process the SiC optics. The effects of different processing recipes on the removal rate and temperature are investigated. The results show that the removal rate almost keeps stable with processing time and changes with the flow rate of plasma gas, reaction gas, the ratio of CF₄/O₂ and the power. The input power and processing time are the two main influence factors on the processing temperature.

Abstract: SiC molds have excellent performance for high-temperature molding optical lenses. The stable physical and chemical properties of SiC results in the difficulty of manufacture high precision SiC molds. Using etching method can manufacture SiC molds apace and accurately, which is used for Micro-embossing needs to study the suitable selectivity ratio of SiC and the anti-etch layer-epoxy resin. The etching gas is SF₆ and O₂. Under different ICP power, bias voltage, the gas mixing ratio and other parameters, it has studied the influence of various factors on the etching ratio, the etching rate and the etching quality. Experiments show that under the parameters of SF₆ flow of 80sccm, O₂ flow of 5sccm, ICP power of 1200w, bias power of 70w, temperature of 30 °C, and pressure of 30mTorr, the SiC etching rate is 246.44nm/min, and the epoxy etching rate is 616nm/min. The SiC/epoxy resin etching ratio is stable at 1:2.5. The roughness of SiC is 1.2nm (Sa= 1.2nm). The anisotropic of etching is good.

Abstract: The method for Lu determination in Yb preparations enriched in 176Yb by atomic and emission spectrometry with inductively coupled plasma (AES-ICP) is reported. The relative determination error from 0.0001 to 0.1% of Lu mass is less than 40%.

Abstract: Atmospheric Pressure Plasma Processing (APPP) of silicon-based optics and wafers is a form of chemical etching technology developed in recent years. The material removal rate is comparable to those of conventional mechanical processing methods in precision fabrication. Moreover, there is no mechanical contact or physical loading on the substrate surface, hence no surface or sub-surface damages are induced. Inductively coupled plasma is one realization of APPP. In this work, inductively coupled plasma torch is used to generate plasma and excite etchant particles at atmospheric pressure. These active particles then diffused to the workpiece surface, react with its atoms to form volatile products. The activity and number of particles in plasma are influenced by processing parameters such as input power, distance between nozzle and substrate surface, flow rate of plasma gas argon and precursor gas CF₄. These factors have various impacts on material removal rate. Processing experiments are conducted on fused silica to investigate the parameters’ influences on material removal rate. The basic interaction between substrate surface and plasma is illustrated, then the relationships between processing parameters and material removal rate are analyzed. From the experiments some trends are derived. Material removal rate rises with the increase of power and flow rate of CF₄, whereas decreases with the increase of processing distance, etc. The etching footprint is proved to be near Gaussian-shaped and believed to have high potential for deterministic surface processing.

Abstract: In order to enhance the treatment processing for powder of nanoparticle, we developed a modified setup using an inductively coupled radio frequency plasma with a pulsed explosion technique. Applying a negative pulsed bias voltage of -1 kV to the substrate stage in 15 seconds with a repetition frequency of 1 kHz and a duty ratio of 50 % in ammonia plasma, a significant increase of N 1s peak intensity in the X-ray photoelectron spectroscopy spectra was observed. The intensity of N 1s peak treated in the pulsed-biasing system raised both about four times higher than those of the particles treated without bias. After plasma treatment, the amino group was suggested to be covalently functionalized onto the nanoparticle surface and quantitatively examined by chemical derivatization. The amino group population attached onto treated nanoparticles was determined about 8.2 x 10⁴ molecules per nanoparticle, roughly four times higher than that of particle without biasing which was about 1.9 x 10⁴ molecules per nanoparticle. The surface structure analysis by a high resolution-transmission electron microscopy showed no significant damages were found on the nanoparticles, indicating that the present technique is suitable mainly for surface modification of powder materials without bringing any damages on their structural and morphological surface.

Abstract: Dry etching of Pt/Ti film was carried out using Cl₂/Ar plasmas in an inductively coupled plasma (ICP) reactor. The influence of the various process parameters, such as RIE power, ICP power and Cl₂/Ar gas mixing ratio, on the etch rate and selectivity of photoresist to Pt/Ti film were investigated systematically and optimized. It was revealed that the etch rate and the selectivity strongly depended on the key process parameters. The etch rate was found to increase dramatically with increasing of RIE power and ICP power. But by changing the ratio of Cl₂ to the total gas, the maximum etch rate could be obtained at the proper ratio of 20%. The results also indicated too low or too high RIE power and the Cl₂ ratio was detrimental to the selectivity. The optimized parameters of Pt/Ti dry etching for high etch rate and low selectivity of photoresist to Pt/Ti were obtained to be pressure: 10mT, RF power: 250W, ICP power: 0W, Cl₂: 8sccm (standard cubic centimeters per minute), Ar: 32sccm.

Abstract: A simple method capable of producing uniform, large-area cone arrays of carbon films was found in a planar inductively coupled RF plasma source. The technique employs a DC or RF bias to substrate holder. Si substrates were mechanically pretreated using diamond paste. Cone-shaped carbon crystals preferentially nucleate and grow on the scratches using relatively low bias. Variation of the depositing conditions enables control of the cone density, geometry, and height. The cone arrays are believed to can significantly improve the field emission properties and have a tempting perspective in the microelectromechanical system (MEMS).