GaN heterojunction HEMT (High Electron Mobility Transistor) device

Abstract

The invention discloses a GaN heterojunction HEMT (High Electron Mobility Transistor) device, belonging to the technical field of semiconductor devices. The GaN heterojunction HEMT device comprises a substrate and an InAIN / GaN heterojunction, wherein the InAIN / GaN heterojunction is positioned on the surface of the substrate; the surface of an InAIN layer is provided with a grid electrode, a source electrode and a drain electrode; and the drain electrode and the surface of the InAIN layer form ohmic contact, while the source electrode and the surface of the InAIN layer form Schottky contact. The GaN heterojunction HEMT device disclosed by the invention has the advantages that the Schottky contact is adopted at the source electrode, the electric field in GaN under the source electrode is uniformly distributed due to a good appearance characteristic, the electron injection of the source electrode is effectively restrained, and the current leakage of GaN and collision ionization and current leakage of the grid electrode caused by the current leakage are reduced, so that the off-state puncture voltage of the device is improved; the drain electrode adopts ohmic contact still, so that the positive on resistance of the device is reduced as low as possible, and better positive current driving capability of the device is ensured; in addition, the GaN heterojunction HEMT device is compatible to the traditional process, simultaneously the distance between the grid electrode and the source electrode can be very short, and the wafer occupying area is smaller, so that lower cost of the device is ensured.

Description

technical field [0001] The invention belongs to the technical field of semiconductor devices and relates to a GaN heterojunction electron mobility transistor (HEMT). Background technique [0002] Gallium nitride (GaN) is one of the representatives of the third-generation wide-bandgap semiconductor materials, with excellent characteristics: high critical breakdown electric field (~3.3×10 6 V / cm), high electron mobility (~2000cm 2 / V·s), high two-dimensional electron gas (2DEG) concentration (~10 13 cm -2 ), good high temperature working ability. High electron mobility transistors (HEMTs) based on GaN materials have been applied in the semiconductor field, especially in the radio frequency / microwave field, and have been used in wireless communication, satellite communication, etc. In addition, for power electronics applications, this type of device has the characteristics of high reverse blocking voltage, low forward conduction resistance, and high operating frequency, so ...

AI Technical Summary

Problems solved by technology

This solution is at the cost of sacrificing the on-resistance of the device, and it also increases the wafer area required for a single device, which eventually leads to an increase in the cost of the device, which does not conform to the theory of seeking the optimal value of the on-resistance and breakdown voltage of the device.

On the other hand, the field plate structure can effectively increase the off-state breakdown voltage of the device, but the process steps are more complicated than devices without field plates, and the effect of the field plate structure is closely related to the quality of the dielectric layer material

Therefore, it is a more complicated problem to improve the off-state breakdown voltage of the device through the field plate structure.

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