Threshold value adjusting type GaN device and preparation method thereof

The invention provides a threshold value adjusting type GaN device and a preparation method thereof. Through surface treatment on a GaN cap layer, an adjusting film layer containing a Ga-O bond is formed on the surface of the GaN cap layer, 2DEG of a gate region is changed, the 2DEG is reduced, the surface potential of a GaN channel layer is increased, and the threshold value of the GaN device is changed. The preparation process is high in implementation, ion damage of etching to the barrier layer can be avoided, further, the threshold value can be conveniently changed through control over the surface treatment process, and preparation of the multi-threshold GaN device is achieved. 本发明提供一种阈值调整式GaN器件及其制备方法，通过对所述GaN帽层的表面处理，在所述GaN帽层的表面形成含Ga-O键的所述调节膜层，改变栅极区的2DEG，使2DEG减少，所述GaN沟道层的表面势升高，改变GaN器件的阈值。本发明制备工艺可实施性较强，且可避免刻蚀对势垒层的离子损伤，进一步的，通过对表面处理工艺的控制，可便捷的改变阈值大小，实现多阈值GaN器件的制备。