Aluminum-alloy junction devices using silicon nitride as a mask

Abstract

Abstract THIS IS AN IMPROVED METHOD OF MANUFACTURING SEMICONDUCTOR DEVICES, IN PARTICULAR LOW VOLTAGE ZENER DIODES, HAVING ALUMINUM-ALLOY PN-JUNCTIONS. THE IMPROVEMENT IN MANUFACTURE RESULTS FROM USING SILICON NITRIDE INSTEAD OF SILICON DIOXIDE TO PASSIVATE AND MASK THE SURFACE OF A WAFER, SILICON NITRIDE BEING IMPERVIOUS TO ALUMINUM WHEREAS SILICON DIOXIDE TENDS TO INTERACT WITH ALUMINUM AT TEMPERATURES WHERE ALLOYING IS PERFORMED IN A MANNER WHICH IS DELETERIOUS TO THE DEVICE. AFTER SILICON NITRIDE IS DEPOSITED ON THE WAFER SURFACE, WINDOWS ARE ETCHED THEREIN AND ALUMINUM IS DEPOSITED OVER THE ENTIRE SURFACE. SINCE SILICON NITRIDE IS IMPERVIOUS TO ALUMINUM, THE ALUMINUM CAN BE ALLOYED INTO THE SUBSTRATE THROUGH THE WINDOW WITHOUT HAVING TO REMOVE THE ALUMINUM FROM THE SURFACE OF THE SILICON NITRIDE. D R A W I N G

Inventors

• 👤 Rajendra R Mehta
• 👤 Richard G Swann
• 👤 Thomas P Cauge

Bibliographic Details