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Shigetoshi Sugawa - One of the best experts on this subject based on the ideXlab platform.

  • Plasma resistance of sintered and ion-plated yttrium oxyfluorides with various Y, O, and F composition ratios for use in plasma Process Chamber
    Journal of Vacuum Science & Technology A, 2020
    Co-Authors: Tetsuya Goto, Yoshinobu Shiba, Akinobu Teramoto, Yukio Kishi, Shigetoshi Sugawa
    Abstract:

    Yttrium oxyfluoride was developed for use in the plasma Process Chamber using various corrosive gases. In this paper, sintered yttrium oxyfluorides with various Y, O, and F composition ratios (YxOyFz) and ion-plated YOF and Y5O4F7 films were prepared, and the physical etching behavior due to Ar ion bombardment and NF3/Ar plasma resistance was investigated. It was found that the etching rate of the sintered yttrium oxyfluoride due to the bombardment of Ar ions with an energy of 500 eV decreased as the oxygen composition ratio in the samples decreased, i.e., F-rich yttrium oxyfluoride had better resistance against energetic-ion bombardment. It was also found that the surface roughness of sintered YOF and Y5O4F7, both of which had the stable phases, was much smoother after Ar ion bombardment than that of yttrium oxyfluorides without the stable phase. NF3/Ar plasma resistance was also investigated. For the sintered yttrium oxyfluoride, both YOF and Y5O4F7 showed good resistance against the NF3/Ar plasma, where the ideal stoichiometric atomic composition ratio could be kept even after plasma irradiation. For both as-deposited ion-plated YOF and Y5O4F7 films, the F composition ratio was slightly smaller than the ideal stoichiometric ratios, suggesting that some amount of fluorine was escaped from the starting materials of YOF and/or Y5O4F7 during the ion-plated film deposition Processes. After NF3/Ar plasma irradiation, F composition ratios were increased for both ion-plated YOF and Y5O4F7 films, and the atomic composition ratio becomes closer to the ideal stoichiometric ratios for both films.

  • Stable yttrium oxyfluoride used in plasma Process Chamber
    Journal of Vacuum Science & Technology A: Vacuum Surfaces and Films, 2017
    Co-Authors: Yoshinobu Shiba, Tetsuya Goto, Yasuyuki Shirai, Akinobu Teramoto, Yukio Kishi, Shigetoshi Sugawa
    Abstract:

    An yttrium oxyfluoride (YOF) protective material was developed for the inner wall of plasma Process equipment. Using microwave-excited surface-wave high-density plasma equipment, the chemical stability of the obtained YOF films was evaluated by exposure to H2/Ar, N2/Ar, NH3/Ar, O2/Ar, and NF3/Ar plasmas. The YOF film surface was stable against these plasmas containing hydrogen, nitrogen, oxygen, and fluorine. Especially, the stability of YOF against fluoridation was better than that of Y2O3, which is currently widely used as the protective material in plasma Process Chambers.

Ilgu Yun - One of the best experts on this subject based on the ideXlab platform.

  • Real-Time Plasma Uniformity Monitoring via Selective Plasma Light Intensity Measurement Using Transparent-LCD-Module-Adapted Optical Emission Spectroscopy
    IEEE Sensors Journal, 2021
    Co-Authors: In Joong Kim, Chuntaek Park, Dongseok Shin, Ilgu Yun
    Abstract:

    A real-time selective plasma light intensity measurement technique involving optical emission spectroscopy (OES) is proposed for Process uniformity monitoring and detection in various plasma regions during semiconductor Processing. Among plasma diagnostic techniques, OES is a noncontact plasma measurement technique for Process end point and plasma abnormality detection that does not cause any Process damage. Therefore, it is mostly used in all plasma-based tools. However, conventional OES systems are incapable of real-time plasma uniformity detection at specific OES sampling times, and therefore, there is a need for improving them. In this study, we show that selective plasma light intensity, including those on the left and right sides of a Process Chamber, can be measured with transparent-LCD-module-adapted conventional OES for determining Process uniformity. The proposed technique can be used to measure the selective plasma light intensity in specific regions of the Process Chamber, such as the center and edge regions of a wafer, and to thereby analyze the plasma Process uniformity.

  • Real-Time Plasma Uniformity Measurement Technique Using Optical Emission Spectroscopy With Revolving Module
    IEEE Sensors Journal, 2019
    Co-Authors: In Joong Kim, Ilgu Yun
    Abstract:

    A measurement technique for analyzing real-time plasma abnormality using optical emission spectroscopy (OES) is proposed to detect Process uniformity during semiconductor Processing. Among many measurement techniques, OES is a non-contact plasma measurement system for detecting Process end points and plasma abnormality without influencing the Process. Thus, this system can be widely used and utilized essentially in almost all tools for plasma Processing. Despite easy installation and high utilization in plasma manufacturing tools, most OES systems are not able to detect real-time plasma uniformity. Therefore, the improved OES systems are required to overcome the limitations. In this paper, the measurement technique of the plasma light intensity in the left and right sides of a Process Chamber by a revolving module adapted to conventional OES in real time is investigated. This technique can be used to measure the plasma light in specific regions in the Process Chamber and detect real-time plasma Process abnormalities by comparing light intensities from different regions.

  • Plasma Process Uniformity Diagnosis Technique Using Optical Emission Spectroscopy With Spatially Resolved Ring Lens
    IEEE Transactions on Industrial Electronics, 2016
    Co-Authors: In Joong Kim, Ilgu Yun
    Abstract:

    A novel method to measure the positional plasma intensity, which indicates the uniformity of plasma Processes, using optical emission spectroscopy (OES) with a spatially resolved ring lens (SRRL) is proposed. OES offers a noncontact and nondestructive plasma diagnostic tool and is easily implemented. Despite these advantages, the light intensities in local regions are difficult to measure by the principle of superposition of light. In this study, by blocking the light passage through the center of the SRRL, the intensity of the plasma light as a function of the distance in the Process Chamber is measured precisely. This methodology improves the distortion of the near light source and measures the local light intensities. Thus, it can be used to obtain the plasma distribution in a Process Chamber and thereby assess the uniformity of the plasma Process.

R.s. Amano - One of the best experts on this subject based on the ideXlab platform.

  • Solid Powder Heating Process With Vaporization Modeling in the Warm-Up Stage of Process Chamber
    Volume 3: 26th Computers and Information in Engineering Conference, 2006
    Co-Authors: Yunhan Zheng, R.s. Amano
    Abstract:

    Part accuracy and quality in rapid prototyping Process using solid powder in the part cake are typically dependent upon thermal system and powder properties. The part cake is a rectangular mild steel cylinder with movable part plate piston. For maximum thermal stress reduction in the part-building Process, about 1.27 cm or 2.54 cm initial solid powder was uniformly laid in the part cake. The powder was then warmed to a certain temperature before sintering. The amount of moisture present in the solid powder will have significant impact on the required warm-up time. In the moisture vaporization Process, solid powder temperature in the computational cell will remain at 100°C until the moisture mass fraction reaches zero. The warm-up time of the cell will increase as the moisture content of the powder increases. Reference data has yet to be published on warm-up times, therefore machine operators will find variances in warm-up times. To better predict the warm-up time for the solid powder heating Process with moisture vaporization in the warm-up stage of the part cake, a vaporization code model was developed that can also simulate the heating Process with vaporization for any solid particle mixed with any liquid agent.Copyright © 2006 by ASME

  • Thermal Design and Characteristics of Thermal Distribution in Process Chamber
    Volume 3: 25th Computers and Information in Engineering Conference Parts A and B, 2005
    Co-Authors: Y.h. Zheng, R.s. Amano
    Abstract:

    Thermal distribution has a critical effect on prototyping accuracy in rapid prototyping and rapid manufacturing. Any uneven thermal distribution in the work bed of the prototyping machine Process Chamber will result in product distortion. In order to optimize the thermal distribution enhance product accuracy of product and guide future design efforts, a full understanding is necessary, of the characteristics of thermal distribution in the Process Chamber. This study focuses on how to design and control thermal distribution in the Process Chamber due to natural convection with experimental and numerical thermal model. For optimal thermal design, the computational fluid mechanics (CFD) approach is one of the most powerful tools. Both experimental and numerical studies of six design configurations for different source heater locations and baffle configurations are presented in this paper.Copyright © 2005 by ASME

  • Investigation Of Thermal Distribution In TheProcess Chamber With The Effects Of Shape AndWall Insulation
    WIT transactions on engineering sciences, 2004
    Co-Authors: Y.h. Zheng, R.s. Amano
    Abstract:

    Uniform thermal distribution has a critical effect on prototyping accuracy in rapid prototyping and rapid manufacturing. Any uneven thermal distribution in the work bed of the prototyping machine Process Chamber will result in product distortion. In order to get the best thermal distribution on the work bed, what kind of machine Process Chamber (PC) shape do we need to design? Do we need to insulate the Process Chamber wall? What are the effects of Process Chamber shape and wall insulation for a free convection flow pattern inside the Process Chamber? What’s the relationship between the thermal distribution and convection flow? In this study we have utilized CFD to develop fundamental understanding of thermal distribution and characteristic in the Process Chamber with the effects of different PC shape and different PC wall insulation. Numerical study in four configurations of PC shape and six configurations of PC wall insulation with different radiant heater duty cycles are presented in this paper.

  • Experimental and Numerical Study in Thermal Design and Characteristics of Thermal Distribution in the Process Chamber
    Volume 1: 23rd Computers and Information in Engineering Conference Parts A and B, 2003
    Co-Authors: Y.h. Zheng, R.s. Amano
    Abstract:

    Thermal distribution has a critical effect on prototyping accuracy in rapid prototyping and rapid manufacturing. Any uneven thermal distribution in the work bed of the prototyping machine Process Chamber will result in product distortion. In order to optimize the thermal distribution enhance product accuracy of product and guide future design efforts, a full understanding is necessary, of the characteristics of thermal distribution in the Process Chamber. This study will focus on how to design and control thermal distribution in the Process Chamber due to natural convection with experimental and numerical thermal model. For optimal thermal design, the computational fluid mechanics (CFD) approach is one of the most powerful tools. Both experimental and numerical studies of six design configurations for different source heater locations and baffle configurations are presented in this paper.Copyright © 2003 by ASME

Markus Krumme - One of the best experts on this subject based on the ideXlab platform.

  • Runtime Maximization of Continuous Precipitation in an Ultrasonic Process Chamber
    Organic Process Research & Development, 2020
    Co-Authors: Manuel Zettl, Manuel Kreimer, Isabella Aigner, Thomas Mannschott, Peter Van Der Wel, Johannes Khinast, Markus Krumme
    Abstract:

    The goal of this investigation was to develop a continuous Process in order to produce as much material on dry basis as possible, at stable conditions, in a harsh, precipitating environment. Therefore a novel approach, the direct application of ultrasound (US) in the Process Chamber, was used to prolong the Process time. The main focus was to avoid fouling and build-up, which is an undesired effect in continuous manufacturing. Fouling can occur for many reasons and has several mechanisms (precipitation fouling, particulate fouling, biofouling, corrosion fouling, chemical reaction fouling etc.). In the worst case, fouling can lead to a complete shutdown due to equipment blocking. In this work, two model substance combinations were used (lactose/water/isopropanol and ibuprofen/ethanol/water). A feed suspension was mixed with an anti-solvent in an ultrasonic Process Chamber, which transduces the power directly into the mixture. The feed suspension is composed of solids distributed in a saturated liquid, which was saturated with the respective solid. The solids are precipitated during mixing, and blockage of the system can take place due to introduced fouling and accumulation in the system. Critical Process parameters (the product temperature, the US input and the solid loading) were analyzed in terms of their influence on the Process stability and duration. Since this Process could also be applied to produce or purify particles, the particle size distribution (PSD) of the two substances was evaluated with regard to agglomeration and attrition.

  • Runtime Maximization of Continuous Precipitation in an Ultrasonic Process Chamber
    Organic Process Research & Development, 2020
    Co-Authors: Manuel Zettl, Manuel Kreimer, Isabella Aigner, Thomas Mannschott, Peter Van Der Wel, Johannes Khinast, Markus Krumme
    Abstract:

    The goal of this investigation was to develop a continuous Process for producing as much dry material as possible under stable operating conditions in an intentionally or unintentionally precipitat...

Tetsuya Goto - One of the best experts on this subject based on the ideXlab platform.

  • Plasma resistance of sintered and ion-plated yttrium oxyfluorides with various Y, O, and F composition ratios for use in plasma Process Chamber
    Journal of Vacuum Science & Technology A, 2020
    Co-Authors: Tetsuya Goto, Yoshinobu Shiba, Akinobu Teramoto, Yukio Kishi, Shigetoshi Sugawa
    Abstract:

    Yttrium oxyfluoride was developed for use in the plasma Process Chamber using various corrosive gases. In this paper, sintered yttrium oxyfluorides with various Y, O, and F composition ratios (YxOyFz) and ion-plated YOF and Y5O4F7 films were prepared, and the physical etching behavior due to Ar ion bombardment and NF3/Ar plasma resistance was investigated. It was found that the etching rate of the sintered yttrium oxyfluoride due to the bombardment of Ar ions with an energy of 500 eV decreased as the oxygen composition ratio in the samples decreased, i.e., F-rich yttrium oxyfluoride had better resistance against energetic-ion bombardment. It was also found that the surface roughness of sintered YOF and Y5O4F7, both of which had the stable phases, was much smoother after Ar ion bombardment than that of yttrium oxyfluorides without the stable phase. NF3/Ar plasma resistance was also investigated. For the sintered yttrium oxyfluoride, both YOF and Y5O4F7 showed good resistance against the NF3/Ar plasma, where the ideal stoichiometric atomic composition ratio could be kept even after plasma irradiation. For both as-deposited ion-plated YOF and Y5O4F7 films, the F composition ratio was slightly smaller than the ideal stoichiometric ratios, suggesting that some amount of fluorine was escaped from the starting materials of YOF and/or Y5O4F7 during the ion-plated film deposition Processes. After NF3/Ar plasma irradiation, F composition ratios were increased for both ion-plated YOF and Y5O4F7 films, and the atomic composition ratio becomes closer to the ideal stoichiometric ratios for both films.

  • Stable yttrium oxyfluoride used in plasma Process Chamber
    Journal of Vacuum Science & Technology A: Vacuum Surfaces and Films, 2017
    Co-Authors: Yoshinobu Shiba, Tetsuya Goto, Yasuyuki Shirai, Akinobu Teramoto, Yukio Kishi, Shigetoshi Sugawa
    Abstract:

    An yttrium oxyfluoride (YOF) protective material was developed for the inner wall of plasma Process equipment. Using microwave-excited surface-wave high-density plasma equipment, the chemical stability of the obtained YOF films was evaluated by exposure to H2/Ar, N2/Ar, NH3/Ar, O2/Ar, and NF3/Ar plasmas. The YOF film surface was stable against these plasmas containing hydrogen, nitrogen, oxygen, and fluorine. Especially, the stability of YOF against fluoridation was better than that of Y2O3, which is currently widely used as the protective material in plasma Process Chambers.

  • gas flow characteristics in a plasma Process Chamber and proposal of new pulse controlled gas injection method using interference matrix operation for rapid stabilization of gas pressure
    Japanese Journal of Applied Physics, 2012
    Co-Authors: Sadaharu Morishita, Tetsuya Goto, Yasuyuki Shirai, Tadahiro Ohmi
    Abstract:

    To realize precise and high-throughput multiProcesses in a single plasma Process Chamber with a rapid alternative of multiple gases, gas flow characteristics in a plasma Process Chamber are investigated and a pulse-controlled gas injection method is developed. It is found that gas replacement characteristics greatly depend on the gas supply method used. An upper shower plate has a great advantage in realizing a rapid gas replacement over the case without using the upper shower plate, resulting from the realization of the down flow pattern of feed gas in the Chamber. The pulse-controlled gas injection method employs the intentional overshoot pulse at the beginning of gas supply to rapidly stabilize gas pressure. Interference matrix operation is newly introduced to determine the pulse size for the arbitrary gas flow pattern in the Chamber. The optimum pulse size can be successfully obtained in the case of HBr addition to a pure Ar plasma.

  • Establishment of very uniform gas-flow pattern in the Process Chamber for microwave-excited high-density plasma by ceramic shower plate
    Journal of Vacuum Science and Technology, 2009
    Co-Authors: Tetsuya Goto, Atsutoshi Inokuchi, Seij Yasuda, Masayuki Kohno, Masahiro Okesaku, Toshio Nakanishi, Masaru Sasaki, Toshihisa Nozawa, Kiyotaka Ishibashi, Masaki Hirayama
    Abstract:

    The authors developed a ceramic upper shower plate used in the microwave-excited high-density plasma Process equipment incorporating a dual shower-plate structure to establish a very uniform gas-flow pattern in the Process Chamber. Thousands of very fine gas-injection holes are implemented on this Al2O3 upper shower plate with optimized allocation to establish a uniform gas-flow pattern of plasma-excitation gases and radical-generation gases for generating intended radicals in the plasma-excitation region. The size of these fine holes must be 50μm or less in diameter and 8mm or more in length because these holes perform an essential role: They completely avoid the plasma excitation in these fine holes and upper gas-supply regions resulting from the plasma penetration into these regions from excited high-density plasma, even if very high-density plasma greater than 1×1012cm−3 is excited just under the ceramic upper shower plate by microwaves supplied from the radial line slot antenna. On the other hand, va...

  • Fast Gas Replacement in Plasma Process Chamber by Improving Gas Flow Pattern
    Japanese Journal of Applied Physics, 2009
    Co-Authors: Sadaharu Morishita, Tetsuya Goto, Isao Akutsu, Kenji Ohyama, Takashi Ito, Tadahiro Ohmi
    Abstract:

    The precise and high-speed alteration of various gas species is important for realizing precise and well-controlled multiProcesses in a single plasma Process Chamber with high throughput. The gas replacement times in the replacement of N2 by Ar and that of H2 by Ar are measured in a microwave excited high-density and low electron-temperature plasma Process Chamber at various working pressures and gas flow rates, incorporating a new gas flow control system, which can avoid overshoot of the gas pressure in the Chamber immediately after the valve operation, and a gradational lead screw booster pump, which can maintain excellent pumping capability for various gas species including lightweight gases such as H2 in a wide pressure region from 10-1 to 104 Pa. Furthermore, to control the gas flow pattern in the Chamber, upper ceramic shower plates, which have thousands of very fine gas injection holes (numbers of 1200 and 2400) formed with optimized allocation on the plates, are adopted, while the conventional gas supply method in the microwave-excited plasma Chamber uses many holes only opened at the sidewall of the Chamber (gas ring). It has been confirmed that, in the replacement of N2 by Ar, a short replacement time of approximately 1 s in the cases of 133 and 13.3 Pa and approximately 3 s in the case of 4 Pa can be achieved when the upper shower plate has 2400 holes, while a replacement time longer than approximately 10 s is required for all pressure cases where the gas ring is used. In addition, thanks to the excellent pumping capability of the gradational lead screw booster pump for lightweight gases, it has also been confirmed that the replacement time of H2 by Ar is almost the same as that of N2 by Ar.