A semiconductor device and a method of fabricating the same are proposed. The semiconductor device includes a plurality of hole-channel Group III nitride devices and a plurality of electron-channel Group III nitride devices. In the above, the hole-channel Group III nitride devices and the electron-channel Group III nitride devices are arranged in correspondence with each other. The electron-channel Group III nitride device has a fin-shaped channel, and a two-dimensional hole gas and/or a two-dimensional electron gas can be simultaneously formed at an interface between a compound semiconductor layer and a nitride semiconductor layer.