Method of fabricating improved Schottky barrier contacts

Abstract

Abstract An aluminum-transition metal Schottky barrier contact, and methods of fabrication thereof are disclosed. In one preferred embodiment, the junction is comprised of an aluminum-tantalum intermetallic layer abutting a silicon substrate. Alternate embodiments utilize an intermetallic compound of a metal selected from the group of tantalum, zirconium, hafnium, niobium, titanium and nickel in combination with aluminum. The preferred embodiments can be fabricated by evaporation of a layer of a metal selected from the above mentioned group followed by evaporation of a layer of aluminum on a silicon substrate, after which an annealing step is utilized which creates the desired intermetallic compound in a layer abutting the silicon surface. Alternatively, the junction can be created by hot or cold sputtering of a preselected intermetallic compound of one of the metals with aluminum directly upon the silicon substrate, followed by deposition of a conductive layer such as aluminum. In the case of cold sputtering an annealing step is required to perfect the desired intermetallic compound structure; and in the case of hot sputtering an annealing step may be useful in perfecting the desired intermetallic structure, although it is not essential. The resulting devices are highly thermally stable with predictable barrier heights; and exhibit excellent electrical properties while they are capable of fabrication with good planarity.

Inventors

• 👤 James K. Howard
• 👤 William D. Rosenberg
• 👤 James F. White

Bibliographic Details