Field effect transistor of radio frequency lateral double-diffusion and preparation method thereof

The invention discloses a field effect transistor of a radio frequency lateral double-diffusion which comprises a P-type substrate. A P-type epitaxial layer is formed on the P-type substrate in an epitaxial growth mode, and a veneer of monox layer is deposited on the upper portion of the P-type epitaxial layer. A veneer of metal layer is deposited on the monox layer and formed a faraday layer in an etching form. A veneer of silicon nitride layer is arranged between the monox layer and the faraday layer. The field effect transistor of the radio frequency lateral double-diffusion has the advantages of reducing one metal deposition process, meanwhile achieving higher breakdown voltage (BV), reducing the electric field intensity of the lower portion of gate-oxide edge, and helping to restrain domino effect of (HCI) hot carrier injection.