GaN (Gallium Nitride) HEMT (High Electron Mobility Transistor) device and preparation method thereof

Abstract

The invention discloses a GaN (Gallium Nitride) HEMT (High Electron Mobility Transistor) device and a preparation method thereof. The GaN HEMT device comprises an N-type cap layer, a first passivationlayer and a first dielectric layer, wherein a gate metal region is penetrated in the middle parts of the N-type cap layer, the first passivation layer and the first dielectric layer; a second passivation layer is formed in the gate metal region and covers the lateral surfaces of the N-type cap layer, the first passivation layer and the first dielectric layer exposed in the gate metal region and apart of the upper surface of a barrier layer; a second dielectric layer is formed in the gate metal region and is superposed on the second passivation layer; a gate metal layer covers the residual upper surface of the barrier layer exposed in the gate metal region, the second passivation layer and the second dielectric layer; and the second passivation layer and the second dielectric layer are superposed at two sides of the gate metal layer. The N-type cap layer is adopted to reduce the parasitic resistance of a source and a drain, and a lateral wall process is adopted to manufacture the second passivation layer and the second dielectric layer which are superposed at two sides of the gate metal layer to reduce the gate length size and reduce the parasitic capacitance, thereby obtaining the GaN HEMT device with excellent radio frequency characteristics.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, and in particular relates to a GaN HEMT device and a preparation method thereof. Background technique [0002] The research and application of GaN materials and devices is the frontier and hotspot of global semiconductor research. Together with SiC and diamond materials, GaN materials are known as the third-generation semiconductor materials. GaN material has the advantages of wide band gap, high critical breakdown electric field, high electron saturation velocity, high thermal conductivity, and high concentration of two-dimensional electron gas at the heterojunction interface. It is an ideal substitute for next-generation power and radio frequency devices. [0003] Traditional GaN HEMT devices adopt a non-doped barrier layer structure, resulting in relatively large source-drain parasitic resistance, which severely limits the high-frequency characteristics of GaN HEMT devices. In order to im...

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Problems solved by technology

[0003] Traditional GaN HEMT devices adopt a non-doped barrier layer structure, resulting in relatively large source-drain parasitic resistance, which severely limits the high-frequency characteristics of GaN HEMT devices. In order to improve the RF performance of the device, one way is to use source-drain regrowth The epitaxial technology forms an N-type heavily doped epitaxial layer. The combination of device and epitaxial technology will undoubtedly increase the complexity of the device preparation process, which is not conducive to mass production

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