The present application relates to the technical field of
transistor, and relates to a P-type
field effect transistor based on tunneling effect, which comprises a substrate, a buffer layer, a channel layer, a
barrier layer and a first P-type material layer arranged in sequence; a second P-type material layer, a
dielectric layer and a third P-type material layer are arranged above the first P-type material layer; a source
electrode is arranged above the second P-type material layer; a drain
electrode is arranged above the third P-type material layer; the
dielectric layer covers the source
electrode, the second P-type material layer, the third P-type material layer and the drain electrode; a gate electrode is arranged on the
dielectric layer; the drain electrode and the third P-type material layer form an
ohmic contact, and the source electrode and the second P-type material layer form a Schottky contact. The present application further provides a preparation method, which comprises the following steps: S1, providing an epitaxial structure; S2, depositing a drain electrode; S3, depositing a source electrode; S4, selectively
etching a P-type material layer; S5, depositing a
dielectric layer; S6, selectively removing the
dielectric layer; and S7, depositing a gate electrode. The present application can guarantee the always-off characteristic and reduce the on-resistance.