▎ 摘　　要

NOVELTY - Device comprises a substrate (1), a transition layer (2) and a barrier layer (3). The upper part of barrier layer (3) is provided with a P-GaN gate (4). A gate metal is deposited on upper part of P-GaN gate. The upper left and right edges of barrier layer is provided with a source electrode (6) and a drain electrode (7). A composite electrode (5) is provided on barrier layer between P-GaN gate and drain electrode. The composite electrode is composed of a lower modulation block (51) and an upper modulation metal (52). The substrate is sapphire, silicon carbide, silicon, graphene and/or other materials. USE - The device is useful as normal-off channel modulation device and as basic device in power electronic system, national economy and military field and high electron mobility device. ADVANTAGE - The device: ensures two-dimensional electron gas in channel formed between lower potential barrier layer and transition layer; can suppress current collapse of normally-off device, which can apply for basic device of power electronic system. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing normal-off channel modulation device.. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of structure of normal-off channel modulation device. Substrate (1) Transition layer (2) Barrier layer (3) P-GaN gate (4) Source electrode (6) Drain electrode (7) Lower modulation block (51) Lower modulation block (52)