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Mark J Kushner - One of the best experts on this subject based on the ideXlab platform.

  • contact edge roughness in the etching of high aspect ratio contacts in sio 2
    International Conference on Plasma Science, 2017
    Co-Authors: Shuo Huang, Mark J Kushner, Chad Huard, Seungbo Shim, Incheol Song, Siqing Lu
    Abstract:

    As the pattern density increases and critical dimensions decrease to the nanometer scale in Microelectronics Fabrication, contact edge roughness (CER) in high aspect ratio contacts (HARCs) becomes a major lithographic challenge. CER consists of striations or other roughness in the sidewalls of features etched in wafers. The origin of CER is the randomness of lithography that produces the photoresist (PR) mask as the feature size shrinks and mechanical stresses on the PR. CER appears as the PR is eroded and the roughness in the mask is transferred to the underlying material being etched. This results in pattern distortion such as scalloped and elliptic profiles which degrade the device performance.

  • modeling of dual frequency capacitively coupled plasma sources utilizing a full wave maxwell solver i scaling with high frequency
    Plasma Sources Science and Technology, 2010
    Co-Authors: Yang Yang, Mark J Kushner
    Abstract:

    Dual frequency capacitively coupled plasma (DF-CCP) tools for etching and deposition for Microelectronics Fabrication typically use a high frequency (HF, tens to hundreds of MHz) to sustain the plasma and a low frequency (LF, a few to 10MHz) for ion acceleration into the wafer. With an increase in both the HF and wafer size, electromagnetic wave effects (i.e. propagation, constructive and destructive interference) can affect the spatial distribution of power deposition and reactive fluxes to the wafer. In this paper, results from a two-dimensional computational investigation of a DF-CCP reactor, incorporating a full-wave solution of Maxwell’s equations, are discussed. As in single frequency CCPs, the electron density transitions from edge high to center high with increasing HF. This transition is analyzed by correlating the spatial variation of the phase, magnitude and wavelength of the HF electric field to the spatial variation of the electron energy distributions and ionization sources. This transition is sensitive to the gas mixture, particularly those containing electronegative gases due to the accompany change in conductivity. The consequences of these wave effects on the ion energy distributions incident onto the wafer are also discussed. (Some figures in this article are in colour only in the electronic version)

  • modeling of dual frequency capacitively coupled plasma sources utilizing a full wave maxwell solver ii scaling with pressure power and electronegativity
    Plasma Sources Science and Technology, 2010
    Co-Authors: Yang Yang, Mark J Kushner
    Abstract:

    The trend in dielectric etching in Microelectronics Fabrication with capacitively coupled plasmas is the use of multiple frequencies where a high frequency (HF, tens to hundreds of MHz) dominates ionization and a low frequency (LF, a few to tens MHz) is used to control ion energy distributions to the wafer. Process parameters, such as pressure, gas mixture and LF and HF power deposition, are important to determining the uniformity of the plasma and properties of ions incident on the wafer. In this paper, we report on a computational investigation of the consequences of these parameters on uniformity and ion energy distributions to the wafer in a dual frequency capacitively coupled plasma reactor sustained in Ar/CF4 gas mixtures. Due to the coupling of finite wavelength, electromagnetic skin, electrostatic edge and electronegative effects, there are no simple scaling laws for plasma uniformity. The plasma uniformity is ultimately a function of conductivity and energy relaxation distance of electrons accelerated by electric fields in and near the sheath. There is a strong second-order effect on uniformity due to feedback from the electron energy distributions (EEDs) to ionization sources. The trends from our parametric study are correlated with the spatial variation of the HF electric field, to the total power deposition and to the spatial variation of EEDs and ionization sources.

  • plasma atomic layer etching using conventional plasma equipment
    Journal of Vacuum Science and Technology, 2009
    Co-Authors: Ankur Agarwal, Mark J Kushner
    Abstract:

    The decrease in feature sizes in Microelectronics Fabrication will soon require plasma etching processes having atomic layer resolution. The basis of plasma atomic layer etching (PALE) is forming a layer of passivation that allows the underlying substrate material to be etched with lower activation energy than in the absence of the passivation. The subsequent removal of the passivation with carefully tailored activation energy then removes a single layer of the underlying material. If these goals are met, the process is self-limiting. A challenge of PALE is the high cost of specialized equipment and slow processing speed. In this work, results from a computational investigation of PALE will be discussed with the goal of demonstrating the potential of using conventional plasma etching equipment having acceptable processing speeds. Results will be discussed using inductively coupled and magnetically enhanced capacitively coupled plasmas in which nonsinusoidal waveforms are used to regulate ion energies to optimize the passivation and etch steps. This strategy may also enable the use of a single gas mixture, as opposed to changing gas mixtures between steps.

  • modeling of magnetically enhanced capacitively coupled plasma sources ar discharges
    Journal of Applied Physics, 2003
    Co-Authors: Mark J Kushner
    Abstract:

    Magnetically enhanced, capacitively coupled radio frequency plasma sources are finding continued use for etching of materials for Microelectronics Fabrication. MERIE (magnetically enhanced reactive ion etching) sources typically use magnetic fields of tens to hundreds of gauss parallel to the substrate to either increase the plasma density at a given pressure or to lower the operating pressure. The use of MERIEs for etching of dielectric materials, such as SiO2, often involves the use of complex gas mixtures, such as Ar/C4F8/O2/CO. In this paper results from a two-dimensional hybrid-fluid computational investigation of MERIE reactors operating in such mixtures are discussed. Fluxes and energy distributions for ions incident on the wafer are discussed for an industrially relevant geometry. The reduction in transverse electron mobility as the magnetic field increases produces a decrease in the sheath electric fields and a decrease in the dc bias (becoming more positive) at large magnetic fields thereby decr...

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

  • modeling of dual frequency capacitively coupled plasma sources utilizing a full wave maxwell solver i scaling with high frequency
    Plasma Sources Science and Technology, 2010
    Co-Authors: Yang Yang, Mark J Kushner
    Abstract:

    Dual frequency capacitively coupled plasma (DF-CCP) tools for etching and deposition for Microelectronics Fabrication typically use a high frequency (HF, tens to hundreds of MHz) to sustain the plasma and a low frequency (LF, a few to 10MHz) for ion acceleration into the wafer. With an increase in both the HF and wafer size, electromagnetic wave effects (i.e. propagation, constructive and destructive interference) can affect the spatial distribution of power deposition and reactive fluxes to the wafer. In this paper, results from a two-dimensional computational investigation of a DF-CCP reactor, incorporating a full-wave solution of Maxwell’s equations, are discussed. As in single frequency CCPs, the electron density transitions from edge high to center high with increasing HF. This transition is analyzed by correlating the spatial variation of the phase, magnitude and wavelength of the HF electric field to the spatial variation of the electron energy distributions and ionization sources. This transition is sensitive to the gas mixture, particularly those containing electronegative gases due to the accompany change in conductivity. The consequences of these wave effects on the ion energy distributions incident onto the wafer are also discussed. (Some figures in this article are in colour only in the electronic version)

  • modeling of dual frequency capacitively coupled plasma sources utilizing a full wave maxwell solver ii scaling with pressure power and electronegativity
    Plasma Sources Science and Technology, 2010
    Co-Authors: Yang Yang, Mark J Kushner
    Abstract:

    The trend in dielectric etching in Microelectronics Fabrication with capacitively coupled plasmas is the use of multiple frequencies where a high frequency (HF, tens to hundreds of MHz) dominates ionization and a low frequency (LF, a few to tens MHz) is used to control ion energy distributions to the wafer. Process parameters, such as pressure, gas mixture and LF and HF power deposition, are important to determining the uniformity of the plasma and properties of ions incident on the wafer. In this paper, we report on a computational investigation of the consequences of these parameters on uniformity and ion energy distributions to the wafer in a dual frequency capacitively coupled plasma reactor sustained in Ar/CF4 gas mixtures. Due to the coupling of finite wavelength, electromagnetic skin, electrostatic edge and electronegative effects, there are no simple scaling laws for plasma uniformity. The plasma uniformity is ultimately a function of conductivity and energy relaxation distance of electrons accelerated by electric fields in and near the sheath. There is a strong second-order effect on uniformity due to feedback from the electron energy distributions (EEDs) to ionization sources. The trends from our parametric study are correlated with the spatial variation of the HF electric field, to the total power deposition and to the spatial variation of EEDs and ionization sources.

Tarancón Rubio Albert - One of the best experts on this subject based on the ideXlab platform.

  • A Pd/Al2O3-based micro-reformer unit fully integrated in silicon technology for H-rich gas production
    'IOP Publishing', 2019
    Co-Authors: Bianchini Marco, Alayo Nerea, Soler Turu Lluís, Salleras M., Fonseca Chácharo Luis, Llorca Piqué Jordi, Tarancón Rubio Albert
    Abstract:

    This work reports the design, manufacturing and catalytic activity characterization of a micro-reformer for hydrogen-rich gas generation integrated in portable-solid oxide fuel cells (µ-SOFCs). The reformer has been designed as a silicon micro monolithic substrate compatible with the mainstream Microelectronics Fabrication technologies ensuring a cost-effective high reproducibility and reliability. Design and geometry of the system have been optimized comparing with the previous design, consisting in an array of more than 7x103 vertical through-silicon micro channels perfectly aligned (50 µm diameter) and a 5 W integrated serpentine heater consisting of three stacked metallic layers (TiW, W and Au) for perfect adhesion and passivation. Traditional fuels for SOFCs, such as ethanol or methanol, have been replaced by dimethyl ether (DME) and the chosen catalyst for DME conversion consists of Pd nanoparticles grafted on an alumina active support. The micro-channels have been coated by atomic layer deposition (ALD) with amorphous Al2O3 and the influence of rapid thermal processing (RTP) on such film has been studied. A customized ceramic 3D-printed holder has been designed to measure the specific hydrogen production rates, DME conversion and selectivity profiles of such catalyst at different temperatures.Postprint (published version

  • A Pd/Al2O3-based micro-reformer unit fully integrated in silicon technology for H-rich gas production
    'IOP Publishing', 2019
    Co-Authors: Bianchini Marco, Alayo Nerea, Soler Turu Lluís, Salleras M., Fonseca Chácharo Luis, Llorca Piqué Jordi, Tarancón Rubio Albert
    Abstract:

    This work reports the design, manufacturing and catalytic activity characterization of a micro-reformer for hydrogen-rich gas generation integrated in portable-solid oxide fuel cells (µ-SOFCs). The reformer has been designed as a silicon micro monolithic substrate compatible with the mainstream Microelectronics Fabrication technologies ensuring a cost-effective high reproducibility and reliability. Design and geometry of the system have been optimized comparing with the previous design, consisting in an array of more than 7x103 vertical through-silicon micro channels perfectly aligned (50 µm diameter) and a 5 W integrated serpentine heater consisting of three stacked metallic layers (TiW, W and Au) for perfect adhesion and passivation. Traditional fuels for SOFCs, such as ethanol or methanol, have been replaced by dimethyl ether (DME) and the chosen catalyst for DME conversion consists of Pd nanoparticles grafted on an alumina active support. The micro-channels have been coated by atomic layer deposition (ALD) with amorphous Al2O3 and the influence of rapid thermal processing (RTP) on such film has been studied. A customized ceramic 3D-printed holder has been designed to measure the specific hydrogen production rates, DME conversion and selectivity profiles of such catalyst at different temperatures

Seung Hwan Ko - One of the best experts on this subject based on the ideXlab platform.

  • Direct selective growth of ZnO nanowire arrays from inkjet-printed zinc acetate precursor on a heated substrate
    Nanoscale Research Letters, 2013
    Co-Authors: Jinhyeong Kwon, Junyeob Yeo, Seung Hwan Ko
    Abstract:

    Inkjet printing of functional materials has drawn tremendous interest as an alternative to the conventional photolithography-based Microelectronics Fabrication process development. We introduce direct selective nanowire array growth by inkjet printing of Zn acetate precursor ink patterning and subsequent hydrothermal ZnO local growth without nozzle clogging problem which frequently happens in nanoparticle inkjet printing. The proposed process can directly grow ZnO nanowires in any arbitrary patterned shape, and it is basically very fast, low cost, environmentally benign, and low temperature. Therefore, Zn acetate precursor inkjet printing-based direct nanowire local growth is expected to give extremely high flexibility in nanomaterial patterning for high-performance electronics Fabrication especially at the development stage. As a proof of concept of the proposed method, ZnO nanowire network-based field effect transistors and ultraviolet photo-detectors were demonstrated by direct patterned grown ZnO nanowires as active layer.

Bianchini Marco - One of the best experts on this subject based on the ideXlab platform.

  • A Pd/Al2O3-based micro-reformer unit fully integrated in silicon technology for H-rich gas production
    'IOP Publishing', 2019
    Co-Authors: Bianchini Marco, Alayo Nerea, Soler Turu Lluís, Salleras M., Fonseca Chácharo Luis, Llorca Piqué Jordi, Tarancón Rubio Albert
    Abstract:

    This work reports the design, manufacturing and catalytic activity characterization of a micro-reformer for hydrogen-rich gas generation integrated in portable-solid oxide fuel cells (µ-SOFCs). The reformer has been designed as a silicon micro monolithic substrate compatible with the mainstream Microelectronics Fabrication technologies ensuring a cost-effective high reproducibility and reliability. Design and geometry of the system have been optimized comparing with the previous design, consisting in an array of more than 7x103 vertical through-silicon micro channels perfectly aligned (50 µm diameter) and a 5 W integrated serpentine heater consisting of three stacked metallic layers (TiW, W and Au) for perfect adhesion and passivation. Traditional fuels for SOFCs, such as ethanol or methanol, have been replaced by dimethyl ether (DME) and the chosen catalyst for DME conversion consists of Pd nanoparticles grafted on an alumina active support. The micro-channels have been coated by atomic layer deposition (ALD) with amorphous Al2O3 and the influence of rapid thermal processing (RTP) on such film has been studied. A customized ceramic 3D-printed holder has been designed to measure the specific hydrogen production rates, DME conversion and selectivity profiles of such catalyst at different temperatures.Postprint (published version

  • A Pd/Al2O3-based micro-reformer unit fully integrated in silicon technology for H-rich gas production
    'IOP Publishing', 2019
    Co-Authors: Bianchini Marco, Alayo Nerea, Soler Turu Lluís, Salleras M., Fonseca Chácharo Luis, Llorca Piqué Jordi, Tarancón Rubio Albert
    Abstract:

    This work reports the design, manufacturing and catalytic activity characterization of a micro-reformer for hydrogen-rich gas generation integrated in portable-solid oxide fuel cells (µ-SOFCs). The reformer has been designed as a silicon micro monolithic substrate compatible with the mainstream Microelectronics Fabrication technologies ensuring a cost-effective high reproducibility and reliability. Design and geometry of the system have been optimized comparing with the previous design, consisting in an array of more than 7x103 vertical through-silicon micro channels perfectly aligned (50 µm diameter) and a 5 W integrated serpentine heater consisting of three stacked metallic layers (TiW, W and Au) for perfect adhesion and passivation. Traditional fuels for SOFCs, such as ethanol or methanol, have been replaced by dimethyl ether (DME) and the chosen catalyst for DME conversion consists of Pd nanoparticles grafted on an alumina active support. The micro-channels have been coated by atomic layer deposition (ALD) with amorphous Al2O3 and the influence of rapid thermal processing (RTP) on such film has been studied. A customized ceramic 3D-printed holder has been designed to measure the specific hydrogen production rates, DME conversion and selectivity profiles of such catalyst at different temperatures