Changes in Surface Condition during Fabrication Process of Bioactive Apatite Nuclei Incorporated PEEK

We aimed to clarify the effect of sulfuric acid treatment and oxygen plasma treatment on changes in surface condition of PEEK substrates during fabrication process of bioactive apatite nuclei (AN) precipitated PEEK. We treated PEEK substrate by sulfuric acid treatment. This treatment contributed to provide micropores and sulfo groups on the surface of the PEEK. Next, we treated the PEEK with oxygen plasma at 200 W for 4 minutes. By this treatment, both generation of carboxyl groups and increase of sulfo groups were occurred and significant improvement of hydrophilicity of the surface of the PEEK was occurred. Finally, we precipitated AN on the surface of the PEEK. By this treatment, high apatite-forming ability was achieved.

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Influence of Oxygen–Plasma Treatment on In-Situ SiN/AlGaN/GaN MOSHEMT with PECVD SiO2 Gate Insulator

Materials ◽

10.3390/ma12233968 ◽

2019 ◽

Vol 12 (23) ◽

pp. 3968

Author(s):

Cho ◽

Cha ◽

Kim

Keyword(s):

Plasma Treatment ◽

Oxygen Plasma ◽

Surface Condition ◽

Chemical Vapor ◽

High Electron Mobility Transistor ◽

Gate Insulator ◽

Oxygen Plasma Treatment ◽

High Electron ◽

Threshold Voltage Shift

The influence of oxygen–plasma treatment on in situ SiN/AlGaN/GaN MOS high electron mobility transistor with SiO2 gate insulator was investigated. Oxygen–plasma treatment was performed on in situ SiN, before SiO2 gate insulator was deposited by plasma-enhanced chemical vapor deposition (PECVD). DC I-V characteristics were not changed by oxygen plasma treatment. However, pulsed I-V characteristics were improved, showing less dispersion compared to non-treated devices. During short-term gate bias stress, the threshold voltage shift was also smaller in a treated device than in an untreated one. X-ray photoemission spectroscopy also revealed that SiO2 on in situ SiN with oxygen–plasma treatment has an O/Si ratio close to the theoretical value. This suggests that the oxygen plasma treatment-modified surface condition of the SiN layer is favorable to SiO2 formation by PECVD.

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Apatite Formation Ability of Bioactive Bearing Grade Polyetheretherketone Fabricated by Incorporation of Apatite Nuclei

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.758.69 ◽

2017 ◽

Vol 758 ◽

pp. 69-74

Author(s):

Tomoko Hiruta ◽

Takeshi Yabutsuka ◽

Shin Watanabe ◽

Keito Fukushima ◽

Shigeomi Takai ◽

...

Keyword(s):

Sulfuric Acid ◽

Glow Discharge ◽

Acid Treatment ◽

Fabrication Process ◽

Apatite Formation ◽

Sulfuric Acid Treatment ◽

Final Treatment

The fabrication process of bioactive bearing grade PEEK was consisted of three steps. First, micropores were formed on the bearing grade PEEK plates by sulfuric acid treatment. Second, plates were exposed to O2 plasma by glow discharge. Finally, the plates were immediately immersed in SBF controlled at pH 8.4 at 25.0 °C and held at 70 °C for 24 hours. By this final treatment, Apatite Nuclei were precipitated inside of the pores. In order to investigate which step has the most influence on enriching bioactivity, four types of samples were obtained by changing the combinations of each process and evaluated the bioactivity by using SBF.

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A simple fabrication process for stepwise gradient wrinkle pattern with spatially-controlled wavelength based on sequential oxygen plasma treatment

Microelectronic Engineering ◽

10.1016/j.mee.2017.02.022 ◽

2017 ◽

Vol 176 ◽

pp. 101-105 ◽

Cited By ~ 8

Author(s):

Jeong Su Lee ◽

Hyeonjun Hong ◽

Sung Jea Park ◽

Seong Jin Lee ◽

Dong Sung Kim

Keyword(s):

Plasma Treatment ◽

Oxygen Plasma ◽

Fabrication Process ◽

Oxygen Plasma Treatment ◽

Stepwise Gradient

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High Breakdown Voltage GaN HEMT Device Fabricated on Self-Standing GaN Substrate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.347-350.1535 ◽

2013 ◽

Vol 347-350 ◽

pp. 1535-1539

Author(s):

Jian Jun Zhou ◽

Liang Li ◽

Hai Yan Lu ◽

Ceng Kong ◽

Yue Chan Kong ◽

...

Keyword(s):

Plasma Treatment ◽

Breakdown Voltage ◽

Oxygen Plasma ◽

Cutoff Frequency ◽

Chemical Vapor ◽

Current Gain ◽

Organic Chemical ◽

Oxygen Plasma Treatment ◽

Gan Hemt ◽

High Breakdown Voltage

In this letter, a high breakdown voltage GaN HEMT device fabricated on semi-insulating self-standing GaN substrate is presented. High quality AlGaN/GaN epilayer was grown on self-standing GaN substrate by metal organic chemical vapor deposition. A 0.8μm gate length GaN HEMT device was fabricated with oxygen plasma treatment. By using oxygen plasma treatment, gate forward working voltage is increased, and a breakdown voltage of more than 170V is demonstrated. The measured maximum drain current of the device is larger than 700 mA/mm at 4V gate bias voltage. The maximum transconductance of the device is 162 mS/mm. In addition, high frequency performance of the GaN HEMT device is also obtained. The current gain cutoff frequency and power gain cutoff frequency are 19.7 GHz and 32.8 GHz, respectively. A high fT-LG product of 15.76 GHzμm indicating that homoepitaxy technology is helpful to improve the frequency performance of the device.

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