PREPARATION OF FIELD-EFFECT TRANSISTOR USING NANO-CRYSTALLINE GAN

Bottom gate type thin film transistors using nano-crystalline GaN (nc- GaN) films were studied. The nc-GaN films were deposited by a reactive sputtering method and were annealed at 800 degrees C after deposition s. The grain sizes were 10 to 20 nm by using Scherrer's formula. The t hreshold voltage (V-th), the field effect mobility (mu) and the ratio of on-current and off-current (R-on/off) were -0.4 V, 6 x 10(-2) cm(2) /V s and 3000, respectively. The fabricated nc-GaN TFT was a depletion type. The possibility for applying the nc-GaN film to high temperatur e operation is shown. (C) 1998 Elsevier Science B.V. All rights reserv ed.