Vertical power device based on arc-shaped source field plate and arc-shaped drain field plate and its manufacturing method

Abstract

The invention discloses a vertical power device based on arc-shaped source field plates and arc-shaped drain field plates, which comprises a Schottky drain electrode (11), a substrate (1), a drift layer (2), an aperture layer (3), two current blocking layers (4) with a two-level step structure, an aperture (5), a channel layer (6), a barrier layer (7) and a grid electrode (10) from the bottom up, and is characterized in that two source electrodes (9) are respectively deposited at two sides of the barrier layer, two injection regions (8) are injected below the source electrodes respectively, all regions except for the bottom of the Schottky drain electrode are packaged by a passivation layer (12), the upper and lower parts at the left and the right of the passivation layer are engraved with arc-shaped steps respectively, metal is deposited on the arc-shaped steps so as to form arc-shaped source field plates (13) and arc-shaped drain field plates (14), and the arc-shaped source field plates, the arc-shaped drain field plates, the Schottky drain electrode and the passivation layer are covered by a protection layer (15). The vertical power device is high in bidirectional breakdown voltage, low in on resistance, high in finished product ratio and capable of being applied to 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 a vertical power device based on an arc-shaped source field plate and an arc-shaped drain field plate, 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...

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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

[0009] In addition, the existing GaN-based current aperture heterojunction field effect devices all use ohmic drains. When a very low reverse voltage is applied to the device drain, the current blocking layer in the device will fail, forming a large drain-source Leakage current, and as the drain reverse voltage increases, the device gate will also open forward, and a large gate current will pass, eventually leading to device failure

Therefore, none of the existing GaN-based current aperture heterojunction field effect devices can realize the reverse blocking function. break feature has no effect

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