Low temperature-high vacuum contact formation process

Abstract

Abstract THIS INVENTION RELATES TO AN IMPROVED A METHOD OF FORMING A METALLIC ELECTRICAL CONTACT ON A SEMICONDUCTOR BODY HAVING AN INSULATING COVER PROVIDED WITH AT LEAST ONE CONTACT LOCATING APERTURE EXPOSING A PORTION OF THE TOP SURFACE OF THE BODY, AND WHEREIN THE INSULATING COVER IS ITSELF COVERED OR COATED WITH A SELECTIVELY-PATTERNED MASK OF HEAT-REMOVABLE MATAERIAL SUCH AS A LAYER OF ORGANIC PHOTOERESIST. A LAYER OF METAL IS DEPOSITED BY CONDENSATION FROM THE VAPOR STATE, IN A VACUUM OF ABOUT 1.0X10**-6 TORR OVER THE SURFACE OF THE PHOTORESIST LAYER AND THE SURFACE OF THE BODY EXPOSED THROUGH THE APERTURE, WHILE MAINTAINING THE SEMICONDUCTOR MATERIAL AND PHOTOESIST AT A TEMPERTURE SLIGHTLY BELOW THAT AT WHICH THE PHOTORESIST BEGINS TO CHAR. AFTER THE DEPOSITION OF THE METAL, REMOVAL OF THE PHOTOERESIST MATERIAL TOGETHER WITH THE PORTION OF THE METAL LAYER OVERLYING THE PHOTORESIST IS ACCOMPLISHED BY A ONE-SHOT HEATING STEP, BY WHICH THE PHOTORESIST AND SEMICONDUCTOR MATERIAL ARE HEATED TO A TEMPERATURE IN THE RANGE OF 400 TO 570*C. THIS HEATING ALSO SINTERS THE UN-REMOVED PORTION OF THE METAL LAYER TO THE SEMICONDUCTOR BODY TO PROVIDE A NON-RECTIFYING ELECTRICAL CONNECTION OF INCREASED MECHANICAL STRENGTH.

Inventors

• 👤 Theodore R Cox
• 👤 Clair E Logan

Bibliographic Details