With metal alkoxide(Ti, Ta, Zr) and copolymer, hybrid insulator film between 10 nm and 100 nm was prepared by dip-coating method on Si substrate and showed better frequency performance in terms of dielectric characteristics than did the copolymer. Also, the dielectric constant of hybrid dielectrics became larger as the content of metal alkoxide increased. With very thin hybrid dielectrics, OTFT with pentacene as organic semi-conductor can be operated below 10 V. From the transfer characteristics, the mobility of OTFT performance and sub-threshold were 3.5 cm(2)/V, 0.09 V/dec, respectively, and on/off current ratio was similar to 2.9 x 10(7). Dipping process to make thin hybrid gate insulator has been confirmed to be easy and versatile. (C) 2011 Elsevier B. V. All rights reserved.