AVS 52nd International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP1
Vacuum Measurement by Carbon Nanotube Field Emission

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Vacuum Technology Poster Session
Presenter: I.M. Choi, KRISS (Korea Research Institute of Standards and Science)
Authors: I.M. Choi, KRISS (Korea Research Institute of Standards and Science)
S.Y. Woo, KRISS (Korea Research Institute of Standards and Science)
Correspondent: Click to Email
A new vacuum measurement technology using carbon nanotube(CNT) field emission effect has been designed and manufactured. The fabricated pressure sensor is a triode type similar with a conventional ionization gauge, but has planar structure similar with a Field Emission Display. Due to the excellent field emission characteristics of CNT, it is possible to make a cost effective cold cathode type ion gauge. The triode type CNT sensors have been manufactured by screen-printing method and by thermal CVD growth method. The glass grid with Cr deposited by E-Beam put on the cathode with the gap of 200 mm between two electrodes was manufactured. By the voltage applied to the grid, the electrons emitted from the carbon nanotubes ionize gas molecules in the chamber and the ionized molecules are gathered to the collector. On this occasion, two modes are available to detect the gas density in the chamber; one is electron emission mode, the other is ionization mode. In the electron emission mode, the collector voltage is controlled a little higher than the grid voltage. On the other hand, the collector voltages are controlled lower than the grid voltage to obtain a large ionization ratio in the ionization mode. The current ratio shows increase characteristic according to the pressure in each mode. The ionization characteristics are dependent on the gas and the voltage applied to the grid and the collector. In this paper, the various metrological characteristics of the home made pressure sensor utilizing carbon nanotubes will be shown.