A method of depositing metal contact regions on a silicon substrate

Abstract

Abstract Metal, such as tungsten, contact regions for an integrated circuit are deposited on exposed portions of a silicon substrate having an apertured silicon dioxide layer thereon by the steps of: (1) disposing the substrate in a deposition chamber; (2) introducing a gaseous compound of a metal into the cham­ber, which compound reacts with silicon so that metal from the compound substitutes for silicon in the surface of the subst­rate to form a deposited metal layer in the apertures in the silicon dioxide layer; and (3) introducing hydrogen into the chamber in addition to the gaseous compound whereby the hydrogen reacts with the gaseous compound to form a further deposition of the metal, the metal being deposited during said further deposition on the surface of both the previously deposited metal layer and the silicon dioxide layer. During step (3) an etching gas (e.g nitrogen trifluoride) which etches the metal when activated, is introduced into the chamber and a plasma struck to activate the etching gas. By controlling the amount of the etching gas introduced into the chamber and the elec­trical power coupled into the plasma, the silicon surface portions of the substrate are kept substantially free of the metal and a further deposit of the metal is produced on the previously deposited metal layer.

Inventors

• 👤 Subramanian Srikanteswara Iyer
• 👤 Rajiv Vasant Joshi

Bibliographic Details