Gallium oxide transistor and its preparation method

Abstract

The invention provides a gallium oxide transistor and a preparation method thereof, wherein the transistor comprises: a gallium oxide single crystal material, one side of which is provided with a channel; an upper electrode is arranged on the top of the channel of the gallium oxide single crystal material; The impurity layer is arranged on the channel bottom of the gallium oxide single crystal material; the gate dielectric layer is arranged on the P-type doped layer; the gate electrode is arranged on the gate dielectric layer; and the lower electrode is arranged on the oxide layer On the other side of the gallium single crystal material. The gallium oxide transistor of the present invention makes full use of the extremely wide band gap and high theoretical breakdown field strength of the gallium oxide material itself to achieve the purpose of further improving the high voltage bearing capability of the MOSFET.

Description

technical field [0001] The invention relates to the field of semiconductors, further relates to a gallium oxide transistor, and further relates to a preparation method of the gallium oxide transistor. Background technique [0002] Gallium oxide is a new type of ultra-wide bandgap semiconductor material. Its bandgap exceeds traditional wide-gap semiconductor materials such as SiC and GaN, and it has a higher theoretical breakdown field strength (E c =8MV / cm), which means that it can carry a higher voltage without being damaged by breakdown, through the power quality factor (μm 0 E. c 2 , μ is the carrier mobility, m 0 is the carrier effective mass), which exceeds SiC and GaN, so gallium oxide-based power devices are expected to carry higher voltage than SiC and GaN, thus occupying a place in the field of ultra-high voltage. In addition, large-scale, high-quality gallium oxide single crystals can be prepared on a large scale through an improved fusion method, known as the ...

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Problems solved by technology

However, because gallium oxide is difficult to invert, and P-type impurities are difficult to activate effectively, it is impossible to use the channel layer and the source-drain active region to form a reverse PN junction to achieve effective turn-off. Therefore, the realization of normally-off MOSFET based on gallium oxide material more difficult

[0005] The preparation MOSFET problem of prior art is: the small bandgap width of Si itself, low theoretical breakdown field intensity have limited the performance of HVFET greatly; Complicated Si base HVFET structure (as Super-Junction , Reduce Surface Field, etc.) increase the production cost of the device and reduce the stability of the device, so that the cost advantage of the Si material itself is weakened due to the introduction of complex processes

Although the high interface state charge depletes the channel and realizes the normally-off operation, it also brings about the problem of device stability.

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