Patent ID: 9472456
Filing Date: 2016-10-18
CPC Classification: H01L

Claim Text:
1. A method for selectively removing titanium and titanium nitride from a workpiece, comprising: contacting said workpiece with a first solution comprising sulphuric acid and a peroxide to remove at least a portion of said titanium nitride; after removing at least a portion of said titanium nitride with said first solution, contacting said workpiece with a second solution to remove at least a portion of said titanium, the second solution comprising a corrosion inhibitor and products of a mixture of hydrofluoric acid (HF), a silicon containing precursor, and water; and contacting said workpiece with a third solution comprising sulphuric acid and a peroxide to remove at least a portion of residual titanium nitride on said workpiece, if any, remaining after contacting said workpiece with said first and second solutions; wherein said workpiece comprises: a non-planar transistor comprising at least a first gate having sides and a top surface; a gate barrier layer disposed on said sides; a gate capping material disposed on said top surface; a first gate contact barrier layer on said gate barrier layer and an upper surface of said gate capping material; and a second gate contact barrier layer on said first gate contact barrier layer, wherein said first gate contact barrier layer comprises said titanium, and said second gate contact barrier layer comprises said titanium nitride.