Longitudinal super-junction enhanced MIS HEMT device

Abstract

The invention belongs to the semiconductor technology field and relates to a longitudinal super-junction enhanced MIS HEMT device. In the invention, a super-junction buffer layer, an N-type semiconductor buffer layer and a P-type semiconductor buffer layer are mutually compensated and exhausted so as to reach charge balance and increase dosage concentration. During positive conducting, because the dosage concentration of the super-junction buffer layer is high, a conduction resistance of the device is obviously reduced. Under a reverse blocking state, longitudinal electric fields in the buffer layer are uniformly distributed so as to realize a high off-state breakdown voltage. Simultaneously, a p-type doped barrier layer which is contacted with a groove grid sidewall is used to pinch off a vertical conductive channel of 2DEG and the buffer layer; and a voltage on an insulated grid electrode is used to control the conductive channel so as to realize an enhanced type. A device manufacturing technology in the invention is compatible with a traditional technology.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a vertical superjunction enhanced MIS HEMT (High Electron Mobility Transistor, high electron mobility transistor) device. Background technique [0002] High electron mobility transistors (HEMTs) based on GaN materials, due to high electron saturation velocity, high density two-dimensional electron gas (2DEG) and high critical breakdown electric field, make it in high current, low power consumption, high frequency and high voltage The switch application field has a huge application prospect. [0003] Lateral GaN HEMTs are favored in high-frequency and low-power applications due to their high-density two-dimensional electron gas (2DEG). The basic structure of the device is as follows: figure 1 shown. However, lateral GaN HEMTs have the following disadvantages: 1. In the off state, it is easy to form a peak electric field on the side of the gate close to the dra...

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Problems solved by technology

However, lateral GaN HEMTs have the following disadvantages: 1. In the off state, it is easy to form a peak electric field on the side of the gate close to the drain terminal, which leads to early breakdown of the device and limits the improvement of the withstand voltage; 2. There is a buffer layer leakage current in the off state, and excessive A large buffer layer leakage current will lead to early breakdown of the device, which limits the application of GaN HEMTs in high voltage; 3. The lateral GaN HEMT device mainly withstands the withstand voltage through the active region between the gate and the drain, so the high-voltage GaN HEMT Larger gate-to-drain spacing is required, causing the device to occupy an excessively large chip area, which is not conducive to the development trend of miniaturization

[0005] For conventional vertical GaN HEMTs, vertical devices cannot fully use 2DEG to achieve conduction, and the conduction current needs to flow through the buffer layer, which makes the on-resistance much higher than that of lateral devices; and with the increase of breakdown voltage, it needs to be reduced The doping concentration of the buffer layer increases its thickness, which makes the on-resistance increase sharply and restricts the forward current capability of the device. Therefore, conventional vertical GaN HEMT devices have a contradictory relationship between breakdown voltage and on-resistance

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