SiC MOS capacitor of Al2O3/HfxLa1-xO/SiO2 stacking gate dielectric layer and manufacturing method

Abstract

The invention relates to a SiC MOS capacitor of an Al2O3 / HfxLa1-xO / SiO2 stacking gate dielectric layer and a manufacturing method. A SiC epitaxial layer is arranged on a SiC substrate, the stacking gate dielectric layer comprises a lower-layer SiO2 transition layer, an HfxLa1-xO layer and an Al2O3 covering layer, the lower-layer SiO2 transition layer is arranged on the SiC epitaxial layer, the HfxLa1-xO layer is arranged on the lower-layer SiO2 transition layer, and the Al2O3 covering layer is arranged on the HfxLa1-xO layer. A positive electrode and a negative electrode are respectively connected with the surface of the Al2O3 covering layer and the back face of the SiC substrate. The interface state density and boundary trap density are reduced, MOS channel mobility is increased, gate leakage current is decreased, the voltage endurance capability of the dielectric layer is improved, and the quality and reliability of the SiC MOS capacitor are improved.

Description

technical field [0001] The invention relates to a SiC MOS capacitor and a manufacturing method thereof, in particular to an Al 2 o 3 / Hf x La 1-x O / SiO 2 A SiC MOS capacitor with stacked gate dielectric layers and a manufacturing method thereof. Background technique [0002] With the continuous development of microelectronics technology and power electronics technology, practical applications have higher and higher performance requirements for devices working under conditions such as high temperature, high power, and high frequency. The first generation of semiconductor materials represented by Si and represented by GaAs The application of the second-generation semiconductor materials in these areas has become a bottleneck. Silicon carbide (SiC) material, as one of the typical representatives of the third-generation wide bandgap semiconductor materials, has a large bandgap, high critical breakdown electric field, high thermal conductivity, high electron saturation rate ...

AI Technical Summary

Problems solved by technology

However, SiO 2 / SiC MOS devices currently have the following disadvantages: First, compared with Si materials, the surface of SiC forms SiO through dry oxygen oxidation 2 The speed is quite slow, which increases the process cost, while SiO 2 The thickness of the can not grow too thick

Al currently 2 o 3 , HfO 2 , AlN and ZrO 2 There has been some research on high-k materials in SiC MOS, but high-k dielectrics directly replace SiO 2 The interface state density between the dielectric and the SiC substrate is larger, and the trap density and leakage current of the oxide layer are also larger

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