Ohmic Contact Structure and Fabrication Process Applicable to Practical SiC Devices

摘要

A contact structure and fabrication process capable of overcoming the drawbacks of conventional techniques and applicable to the manufacture of practical devices are proposed. One notable feature of the proposed approach is that the contact materials, very thin Ni for the n-type region and layered Ti/Al for p-type region, are defined precisely in the contact windows of the field oxide, leaving a constant and fine clearance, and are rapidly thermally annealed in a purified Ar ambient. Specific contact resistances in the range of 10~(-7) Ω cm~2 and 10~(-6) Ω cm~2 are demonstrated in the n-type and p-type regions, respectively, on (0001) 4H-SiC substrates.