Silicon carbide heterojunction normally-off high-electron-mobility transistor and method for preparing the same

A method for preparing a silicon carbide (SiC) heterojunction normally-off high-electron-mobility transistor (HEMT), comprising steps of:

• S21:
• selecting an unintentionally doped n-type 4H-SiC chip as a substrate;
• S22:
• growing a 4H-SiC transition layer on an upper surface of the substrate through isomorphic epitaxial growth, and growing a C face on an upper surface of the 4H-SiC transition layer through epitaxial growth;
• S23:
• growing a first potential well layer of unintentionally doped 3C-SiC on the C face of the 4H-SiC transition layer;
• S24:
• growing a first barrier layer of n-type doped 4H-SiC on an upper surface of the 3C-SiC first potential well layer, and growing a C face on an upper surface of the 4H-SiC first barrier layer through epitaxial growth;
• S25:
• growing a second potential well layer of unintentionally doped 3C-SiC on the C face of the 4H-SiC first barrier layer;
• S26:
• growing a second barrier layer of n-type doped 4H-SiC on an upper surface of the 3C-SiC second potential well layer through epitaxial growth, and growing a Si face on an upper surface of the 4H-SiC second barrier layer through epitaxial growth;
• S27:
• growing an unintentionally doped 3C-SiC cap layer on the Si face of the 4H-SiC second barrier layer;
• and
• S28:
• producing electrodes and protective films, so as to obtain a 3C-SiC/4H-SiC heterojunction normally-off double-channel high-electron-mobility transistor.