Tunneling enhancement type HEMT device

Abstract

The invention relates to the semiconductor technical field and specifically relates to a tunneling enhancement type HEMT device. A reverse polarization layer grows on the upper surface of a barrier layer between a source electrode and a drain electrode. The reverse polarization layer, the barrier layer and a buffer layer between the source electrode and the drain electrode form a double heterojunction. Two-dimensional hole gas (2DHG) and two-dimensional electron gas (2DEG) are respectively generated on the interface of the double heterojunction. A polarization super junction is thus formed. In a blocking state, the polarization super junction assists in exhausting a drift region to optimize the transverse field distribution of the device and improve the voltage withstanding of the device. Furthermore, source electrode metal contacts the barrier layer to form a Schottky barrier. Meanwhile, the source electrode and the reverse polarization layer contact to form ohm contact. The Schottky barrier between the source metal and the barrier layer blocks electrons from the source electrode to a 2DEG vertical conductive channel. When a voltage is added to a grid electrode, the Schottky barrier between the source electrode and the barrier layer is modulated. An electronic tunneling current is formed. The aim of enhancement is thus achieved.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to an enhanced 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 concentration of electrons in the two-dimensional electron gas (2DEG) channel, and high critical breakdown electric field, make them operate at high current and low power consumption. , The application field of high-voltage switching devices has a huge application prospect. [0003] The key to power switching devices is to achieve high breakdown voltage, low on-resistance and high reliability. The breakdown of HEMT devices is mainly caused by the leakage current of the gate Schottky junction and the leakage current through the buffer layer. In order to make full use of the excellent characteristics of GaN materials such as ...

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Problems solved by technology

However, all fluorine ions are implanted into the lower barrier layer of the gate, on the one hand, the concentration and mobility of 2DEG are greatly reduced, and the forward current capability is reduced; on the other hand, the process of implanting fluorine ions into the thinner semiconductor barrier layer It is easy to cause damage to the barrier layer material, thus affecting the mobility of carriers in the channel and the reliability of the device

Literature (LiYuan, HongweiChen, and KevinJ.Chen, "NormallyOffAlGaN / GaNMetal–2DEGTunnel-JunctionField-EffectTransistors" IEEE ElectronDeviceLetters, Vol.32, No.3, pp.303-305, 2011) reported the use of Schottky sources to achieve enhanced , the height and thickness of the barrier between the Schottky source and the barrier layer are controlled by the field pressure on the gate, and the tunneling current is generated, such as Figure 4 As shown, but this method requires the grid electrode to be very close to the source electrode to realize the enhanced mode, and the ability of the planar grid to regulate the energy band of the Schottky barrier is relatively weak, and when the threshold voltage is high, when the gate voltage is high, the grid Xiao The base junction may also be turned on, affecting the reliability of the device

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