摘要 |
1,267,828. Semi-conductor devices. GENERAL ELECTRIC CO. 28 Oct., 1969 [31 Oct., 1968], No. 52833/69. Heading H1K. A method of producing metallic contacts in apertures 10 in an insulating surface layer 3 on a semi-conductor body wherein this surface layer 3 is clad with a heat removable mask 2 comprises depositing by vacuum deposition at least one metallic layer 20 all over the surface while maintaining the semi-conductor body 1 and the mask thereon at a temperature below that at which the mask begins to clear, that is in the range 150-210‹ C., then heating the mask to a temperature in the range 400-570‹ C., when it chars to loosen and remove it together with the metallic layer or layers thereon, and continuing this heating to sinter the metallic layer or layers to the semi-conductor body to form ohmic contacts therewith. The heat removable mask is an organic photoresist and the metallic layers comprise a lower layer 7 of an active metal such as titanium, vanadium, chromium, niobium, zirconium, palladium, tantalum or compounds thereof covered by an upper layer 8 of metal with good bonding properties such as aluminium, silver, gold, platinum or compounds thereof. As a final step to remove remaining portions of the heat removable mask the body is placed in an ultrasonically agitated bath. |