Enhanced grid field plate gan-based current aperture heterojunction field effect device and fabrication method thereof

Abstract

The invention discloses an enhanced grid field plate GaN-based current aperture heterojunction field-effect device and a fabrication method thereof. The enhanced grid field plate GaN-based current aperture heterojunction field-effect device comprises an n<+> type GaN substrate (1), an n<-> type GaN drift layer (2), an n type GaN aperture layer (3), current blocking layers (4), a GaN channel layer (6) and a barrier layer (7), wherein sources (11) are deposited at two sides of the barrier layer, a p<+> type GaN cap layer (8) is arranged on the barrier layer between the sources, steps (9) are etched at two sides of the p<+> type GaN cap layer, a grid (12) is deposited on the p<+> type GaN cap layer, a drain (13) is deposited under the n<+> type GaN substrate, a passivation layer (14) wraps other regions except a bottom part of the drain, stepped field plates (15) are arranged at two sides of the passivation layer and are electrically connected with the grid, and a protection layer (16) is arranged on the passivation layer and the stepped field plates. The enhanced grid field plate GaN-based current aperture heterojunction field-effect device has the advantages of high breakdown voltage, simple process and small conduction resistance, and can be used for a power electronic system.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and relates to a semiconductor device, in particular to an enhanced grid field plate GaN-based current aperture heterojunction field effect device, which can be used in a power electronic system. [0002] technical background [0003] Power semiconductor devices are the core components of power electronics technology. As energy and environmental issues become increasingly prominent, research and development of new high-performance, low-loss power devices has become one of the effective ways to improve power utilization, save energy, and alleviate energy crises. In the research of power devices, there is a serious restrictive relationship between high speed, high voltage and low on-resistance. Reasonable and effective improvement of this restrictive relationship is the key to improving the overall performance of the device. With the development of microelectronics technology, the performan...

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Problems solved by technology

However, up to now, there is still no precedent of the field plate structure being successfully applied to GaN-based current aperture heterojunction field effect devices at home and abroad. This is mainly due to the inherent defects in the structure of GaN-based current aperture heterojunction field effect devices. As a result, the strongest electric field peak in the device drift layer is located near the interface between the current blocking layer and the aperture layer, and the electric field peak is far away from the surfaces on both sides of the drift layer, so the field plate structure can hardly play the role of effectively modulating the electric field distribution in the device, even in GaN The field plate structure is used in the base current aperture heterojunction field effect device, and there is almost no improvement in device performance

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