Enhanced HEMT radio frequency device with gate-drain composite stepped field plate structure, and preparation method thereof

Abstract

The invention relates to an enhanced HEMT radio frequency device with a gate-drain composite step field plate structure, and a preparation method thereof. A p-GaN region is arranged on the surface of a barrier layer, a gate is arranged on the p-GaN region, a gate step field plate is arranged on the side wall, facing a drain, of the p-GaN region, and a drain step field plate is arranged on the side wall, facing the p-type GaN region, of the drain. The step field plate comprises at least two sub-field plates, and the width of each sub-field plate is gradually reduced from top to bottom. Through the arrangement of the gate-drain composite step field plate, the electric field distribution of the side, close to the drain, of the gate and the electric field distribution of the side, close to the gate, of the drain are changed, the average electric field intensity between the gate and the drain is improved, and the voltage withstanding performance and reliability of the device are improved; and the p-GaN region is arranged below the gate, and the enhanced HEMT radio frequency device has smaller gate-drain capacitance and shows higher cut-off frequency in combination with the gate-drain composite step field plate structure.

Description

technical field [0001] The invention relates to the field of enhanced HEMT radio frequency devices, in particular to an enhanced HEMT radio frequency device with a gate-drain compound stepped field plate structure and a preparation method thereof. Background technique [0002] GaN is a wide-bandgap semiconductor material. Due to its high saturation electron drift velocity and high breakdown electric field strength, GaN can also form a heterojunction with AlGaN, and form a two-dimensional electron gas with a high saturation rate at the interface of the structure. Therefore, devices made of GaN materials can be adapted to applications in extremely high frequency scenarios. [0003] However, at present, the recessed gate method is mostly used to manufacture enhanced HEMT devices. The AlGaN layer in the gate region is thinned or completely removed to reduce the two-dimensional electron gas concentration in this region, while retaining the two-dimensional electron gas in the acce...

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Problems solved by technology

Although this problem can be alleviated by thinning, due to the existence of a thin layer of AlGaN, there is a certain concentration of two-dimensional electron gas in the gate region, resulting in a small threshold voltage

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