Enhanced GaN-based power device and manufacturing method thereof

Abstract

The invention belongs to the field of a semiconductor and particularly relates to an enhanced GaN-based power device and a manufacturing method thereof. The method comprises steps that AlGaN / GaN on Siis selected as a substrate, source and drain patterns of ohmic contact are exposed on the substrate, a first metal is evaporated through an electron beam, and a source and a drain of the device are formed after stripping and annealing; a masking layer is then formed, a mesa pattern of the device is exposed, the masking layer and a AlGaN layer are subjected to dry etching, and a device region is formed through over-etching; through photolithography and etching, a gate opening is formed, polysilicon is deposited, p-type doping and annealing are performed, photolithography and etching are performed to form a P-type polysilicon gate; and lastly, patterns of metal leads are exposed, electron beam evaporation of the second metal is performed, through stripping, metal leads are obtained, and theenhanced GaN-based power device is obtained. The method is advantaged in that the p-type polysilicon gate is utilized to effectively suppress gate leakage, improve the threshold voltage stability ofthe device and have high compatibility with the silicon integrated circuit process.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, and in particular relates to an enhanced GaN-based power device and a preparation method thereof. Background technique [0002] GaN material is the third-generation semiconductor material after the first-generation Ge, Si semiconductor material, second-generation GaAs, and InP compound semiconductor materials. Due to its outstanding material properties, such as its unique polarization effect, large forbidden band Wide, high breakdown electric field, high-density two-dimensional electron gas, high-temperature operation, etc., are ideal materials for making high-temperature, high-voltage, high-frequency high-power microwave power devices. These advantages determine that AlGaN / GaN HEMTs will have a bright future in microwave power. The application prospects of depletion-type AlGaN / GaN HEMTs devices and their MMIC chips have been applied in batches in phased array radar T / R components, which also...

AI Technical Summary

Problems solved by technology

[0003] However, due to the polarization effect of traditional AlGaN / GaN HEMT devices, a natural electron channel is formed between the source and drain electrodes, so the two-dimensional electron gas in the channel under the gate needs to be depleted after a voltage is applied to the gate. , so that the channel is in the off-state

Therefore, the depletion-type GaN device is not conducive to the low power consumption of the chip, and it is necessary to add an auxiliary negative power supply to realize the shutdown function, which is difficult to be compatible with general electronic system standards

At present, researchers have respectively proposed the use of D-Mode GaN / N-MOS (Si) series cascode structure (Cascode), and growing a P-GaN capping layer on the AlGaN barrier layer to realize an enhancement-mode GaN device, but by The former circuit architecture introduces more off-chip parasitic components, which seriously affects device performance and reliability, while the P-GaN cap layer structure has gate current I g Larger threshold voltage drift, larger thermal power consumption in the gate, and the difficulty of monitoring the process of etching the capping layer, etc., and many other technical problems, and in the subsequent GaN power drive design and integration applications have added a larger Difficult to design, but also need to provide a buffer (Buffer) drive stage with ampere-level current drive capability

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