ELECTRODE FORMATION OF SILICON CARBIDE SEMICONDUCTOR ELEMENT

• Main Authors: NAKADA TOSHITAKE, OTA KIYOSHI, FUJIKAWA YOSHIHARU
• Format: Patent
• Language: English
• Published: 24.04.1990
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To form an electrode in n-type SiC capable of firm wire-bonding process by a method wherein an Au/Ni electrode film is laminated on an n-type silicon carbide to be heat-treated at high temperature and then an Au/Cr electrode film is laminated on the Au/Ni electrode to be heat-treated at low temperature. CONSTITUTION:In order to form an ohmic electrode on an n-type silicon carbide 1, an Au/Ni electrode 4 is laminated on the n-type silicon carbide 1 to be heat- treated at high temperature. Next, an Au/Cr electrode film 6 is laminated on the said heat treated Au/Ni electrode film 4 to be heat-treated at low temperature. For example, 5000Angstrom thick Ni and 5000Angstrom thick Au are deposited on the n-type SiC substrate 1 by vacuum evaporation to form the Au/Ni electrode film 4, which is then heat-treated at 1000 deg.C for around 5 minutes. Next, after surface-processing in HF, an Au/Si electrode film 5 is formed on p-type SiC layer 3 to be heat-treated at 950 deg.C. Finally, 500Angstrom thick Cr and 5000Angstrom thick Au are deposited on the Au/Ni electrode film 4 by vacuum evaporation to form the Au/Cr electrode film 6, which is then heat-treated at 500 deg.C for around 20 minutes.