Vertically-structured gallium nitride heterojunction HEMT (high electron mobility transistor)

Abstract

The present invention discloses a vertically-structured gallium nitride heterojunction HEMT (high electron mobility transistor). The vertically-structured gallium nitride heterojunction HEMT comprises a Si substrate layer, an N-type heavily doped GaN layer, an N-type doped N-GaN layer, a medium passivation layer and an ohmic metal electrode which are distributed sequentially from bottom to top; a GaN trench is formed in the N-type doped N-GaN layer through etching; a AlGaN layer is grown in the GaN trench; a AlGaN groove is formed in the AlGaN layer through etching; an undoped i-GaN layer, a P-type lightly-doped P-GaN layer and a heavily-doped polysilicon layer are sequentially grown in the AlGaN groove from bottom to top; and the ohmic metal electrode comprises a source, a drain and a gate, wherein the source and the gate are both arranged at the front surface of the device and are separated by the medium passivation layer, and the drain is arranged at the back surface of the device. According to the vertically-structured gallium nitride heterojunction HEMT of the invention, the AlGaN layer and the N-GaN layer form a two-dimensional electron gas, the two-dimensional electron gas is vertically transmitted through the source / drain, and the P-GaN layer and the N-GaN layer form a PN junction.

Description

technical field [0001] The invention relates to discrete device chip manufacturing technology, in particular to a gallium nitride heterojunction HEMT with a vertical structure. Background technique [0002] HEMT is a heterojunction field-effect transistor. According to the physical characteristics of semiconductors, due to the difference in the bandgap width of the two semiconductors in contact with the heterojunction, electrons will flow from the semiconductor with a wide bandgap to the semiconductor with a narrow bandgap, so that in the semiconductor Quantum wells are formed on the narrow bandgap semiconductor side of the cross-section. The free electrons confined in the quantum well move in the direction perpendicular to the contact surface of the heterojunction, so the quantum well is called a two-dimensional electron gas. Since the freely moving electrons in the channel are far away from Coulomb scattering of impurities in the wide-bandgap semiconductor, the carriers c...

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Problems solved by technology

[0004] The object of the present invention is to aim at the defects and deficiencies of the prior art, to provide a vertical gallium nitride heterojunction HEMT and its preparation method, which solves the problem that the planar gallium nitride heterojunction HEMT cannot The problem of integrating with other components, the source and gate of the HEMT are designed on the front of the device, and the drain is designed on the back of the device, thus effectively solving the problem of integrating GaN heterojunction HEMTs with other components question

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