H. Fujiyama*, Y. Uchikawa, S. Sugimoto, K.Kuwahara and H. Kuwahara**

Faculty of Engineering, Nagasaki University, 1-14Bunkyo, Nagasaki 852-8521, Japan
hiroshi@ec.nagasaki-u.ac.jp

**Nissin Electric Co., 47 Umezu-Takase, Ukyo-ku, Kyoto 615, Japan

For the purpose of fine ceramics coating such as TiN on inner surface of narrow insulated tube by a reactive sputtering process, we have developed a coaxial magnetron pulsed plasma (CMPP)[1]. Pulsed discharge occurred between a cathode wire and a grounded short ring anode by applying a repetitive pulsed negative high voltage of 1% duty ratio to the cathode. Insulated glass tube was arrangedparallel to the cathode wire as a substrate. Axial magnetic field can make a breakdown easy in a narrow tube under low pressure conditions.

In the present paper, we report the experimental results regarding discharge characteristics, plasma generation and thin film deposition of Ti, Au and W on inner wall of narrow glass tubes of 8mm in inner diameter and 600mm in length. To examine the discharge characteristics and optimum condition for uniform and high-rate sputter-coating, gas pressure, pulsed voltage, repetitive frequency andmagnetic flux density were varied. High purity argon (Ar) was used as the sputtering gas in the present experiment.

It was found that the extended anode effect that a depositing thin film with electroconductivity acted on as an anode was effective to lengthen of inner coating. Typical deposition rate was 95nm/min (0.16nm/pulse) for P=30mTorr, B=1,050G, 1kHz repetitive frequency, 10ms pulse width and 2.5kV pulsed magnetron discharge.

In order to get uniform coating of a long substrate, two plasma sources were set in both ends of substrate and we named double-ended anode coaxial magnetron pulsed plasma (DCMPP). By using DCMPP, Ti film could be deposited on an inner surface of narrow glass tubes of 8mm in inner diameter and 1m in length.

[1] H.Fujiyama et al; Surface & Coatings Technology (1998, in press)