High density carbon nanotube field emitter arrays (CNT-FEAs) with various multilayer cathode structures have been fabricated on Si utilizing conventional integrated circuit technology and microwave-heated chemical vapor deposition process. The CNT-FEAs were configured as triode emitters with 1-mu m thermal SiO2 as the insulator and 400-nm Cr as the gate, and compared per the resulting morphologies, Raman spectra, and field emission characteristics. It was found that the Ni/Cr/Si cathode structure is the best fit for selective growth of CNTs in gate holes. In particular, a CNT-FEA fabricated on Ni(60 nm)/Cr(80 nm)/Si cathode structure has yielded excellent emission characteristics, with low turn-on and threshold fields, being, respectively, at 0.45 and 3.7 V/mu m. This triode CNT device also exhibited a uniform image of high brightness (similar to 1800 cd/m(2)) on a green-phosphor coated idium-tin-oxide glass and a relatively stable emission current, being tested at a constant anode voltage of 1000 and 900 V, respectively. (c) 2005 American Vacuum Society.