Vertical power device based on gate field plate and drain field plate and its manufacturing method

Abstract

The invention discloses a vertical power device based on a gate field plate and a drain field plate. The vertical power device comprises a Schottky drain (11), a substrate (1), a drift layer (2), an aperture layer (3), two symmetrical current blocking layers (4), a channel layer (6), a barrier layer (7) and a grid (10) from bottom to top; source grooves (8) are carved at two sides of the channel layer and the barrier layer; sources (9) are deposited in the source grooves; a passivation layer (12) wraps all areas, except the bottom of the Schottky drain; an aperture (5) is between the current blocking layers; a two-stage step structure is adopted in the two current blocking layers; gate steps and drain steps are respectively carved at the upper part and the back at two sides of the passivation layer; metal is deposited on the steps; therefore, a step gate field plate (13) and a step drain filed plate (14) are formed; and the step gate field plate and the step drain filed plate are electrically connected with the grid and the Schottky drain separately. The vertical power device disclosed by the invention has high two-way breakdown voltage, low conduction resistance and high yield, and can be used for power electronic systems.

Description

technical field [0001] The invention belongs to the technical field of microelectronics and relates to a semiconductor device, especially a vertical power device based on a gate field plate and a 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 performance of traditional firs...

AI Technical Summary

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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