Semiconductor device with metal fill by treatment of mobility layers including forming a refractory metal nitride using tmedt

Abstract

A recess having a height-to-width aspect ratio from about 6:1 to about 10:1 in a semiconductor structure is disclosed with a method of forming the same. In a first embodiment, a refractory metal layer is formed in the recess, which can be a trench, a contact hole, or a combination thereof. A refractory metal nitride layer is then formed on the refractory metal layer. A heat treatment is used to form a metal silicide contact at the bottom of the contact hole upon a semiconductor material. In a first alternative method, an ammonia high-temperature treatment is conducted to remove undesirable impurities within the refractory metal nitride layer lining the contact hole and to replace the impurities with more nitrogen. In a second alternative method, a second refractory metal nitride layer is formed by PVD upon the first refractory metal nitride layer. In either alternative, a metallization layer is deposited within the recess.