Silicon carbide activation annealing method

Abstract

The invention discloses a silicon carbide activation annealing method. The method comprises the following steps: forming a first protection layer on the surface, subjected to ion implantation, of oneside of a silicon carbide wafer; forming a second protective layer on the surface of one side, at which the first protective layer is formed, of the silicon carbide wafer; carrying out annealing treatment of the silicon carbide wafer with the second protection layer, wherein the thermal stability of the second protection layer is superior to that of the first protection layer during annealing treatment. A first protection layer and a second protection layer are formed on the surface of silicon carbide. During the annealing treatment of the silicon carbide wafer, the second protection layer canprevent the first protection layer from melting at a high temperature and prevents the sublimation of silicon atoms, and the first protection layer can effectively prevent silicon atoms on the surface of the silicon carbide wafer from sublimating and depositing again, so the problems of sublimation and deposition of silicon atoms on the surface of silicon carbide in the annealing process can be solved through the two protection layers, and the reliability of activating annealing protection of silicon carbide is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor device preparation, in particular to a silicon carbide activation annealing method. Background technique [0002] Due to its excellent physical properties and device characteristics, silicon carbide devices have made remarkable achievements in the development of power electronic devices. In the silicon carbide device manufacturing process, ion implantation technology is a key process to achieve doping. In order to eliminate the damage to the crystal lattice caused by implantation and activate the implanted impurities, it is necessary to anneal silicon carbide at a high temperature above 1500°C. At such a high temperature, the silicon carbide on the surface of the wafer will decompose, the silicon atoms will sublimate, and form Si, Si 2 C. SiC 2 Forms such as re-deposited on the surface of silicon carbide wafers, resulting in rough surface of the wafer, affecting the characteristics of sil...

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Problems solved by technology

At such a high temperature, the silicon carbide on the surface of the wafer will decompose, the silicon atoms will sublimate, and form Si, Si 2 C. SiC 2 Forms such as re-deposition on the surface of silicon carbide wafers, resulting in rough surface of the wafer, affecting the characteristics of silicon carbide devices

[0003] In order to prevent the sublimation of silicon on the surface of silicon carbide wafers, in the traditional activation annealing process of silicon carbide, AIN is selected as the protective layer of silicon carbide wafers. Chip protection effect, low protection reliability

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