Manufacturing method of n-type low-resistivity 4H-SiC ohmic contact

Abstract

The invention discloses a manufacturing method of an n-type low-resistivity 4H-SiC ohmic contact. The manufacturing method comprises the following steps: step 1, cleaning an n-type 4H heavily doped SiC substrate; step 2, depositing a metal nickel layer on the back surface of the n-type 4H heavily doped SiC substrate; and step 3, heating the metal nickel layer by using LPCVD equipment, so that the metal nickel layer permeates into the n-type 4H heavily-doped SiC substrate, and carrying out combination reaction on nickel metal in the metal nickel layer and SiC to form NixSiy and a carbon cluster layer, thereby completing ohmic contact. The ohmic contact of the SiC material is formed by using LPCVD equipment, the Ar gas flow and the vacuum pressure value in the chamber are stable and controllable in the annealing process, the nickel silicide / SiC system can be stably transited to the ohmic contact from Schottky contact in the progressive heating process, the structure defects induced in the complex silicification process are reduced, and under the lower high doping concentration, stable, effective and uniform NixSiy and carbon cluster layer silicide are formed, and the preparation process of ohmic contact is completed.

Description

technical field [0001] The invention belongs to the field of microelectronic manufacturing technology, in particular to an n-type low-resistivity 4H-SiC ohmic contact manufacturing method. Background technique [0002] As a representative of the third generation of new wide-bandgap semiconductor materials, SiC has an important position and Broad prospects. [0003] However, one major process technology limiting SiC electronics is the ohmic contact. At present, the development of the SiC chip industry is still in its infancy, the uniformity and stability of product parameters are poor, and the chip yield rate is low. The main reason for the low yield rate is the ohmic contact problem. Due to the large band gap of SiC, the height of the Schottky barrier formed by all metals fabricated on 4H-SiC is about 1eV, which is a serious challenge for forming low-resistivity ohmic contacts on SiC. [0004] Achieving low-resistance ohmic contact technology is a major pain point in the ...

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Problems solved by technology

[0004] Realizing low-resistance ohmic contact technology is a major pain point in the development of SiC chips. It is difficult to achieve high product stability and uniformity while achieving low-resistivity ohmic contact. The process requirements of good performance and high yield

At present, the n-type 4H-SiC ohmic contact manufacturing process is still in the stage of laboratory research and exploration, and the academic controversy is relatively large. There has not been a unified standard for the selection of metals for making ohmic contacts to the control of the metallization annealing process, and there is a lack of industrialization. Batch production, n-type 4H-SiC ohmic contact process manufacturing method with effective process specification, easy implementation, high parameter stability, good parameter uniformity, and high yield

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