Combinatorial screening of metallic diffusion barriers

US9297775B2 · kind B2 · utility

Assignee

• INTERMOLECULAR, INC. · US

Inventors

• Edwin Adhiprakasha · Mountain View, US
• Sean Barstow · San Jose, US
• Ashish Bodke · San Jose, US
• Zhendong Hong · San Jose, US
• Usha Raghuram · Saratoga, US
• Karthik Ramani · West Lafayette, US
• Vivian W. Ryan · Berne, US
• Jingang Su · Sunnyvale, US
• Xunyuan Zhang · Albany, US

Key dates

• Filing date: May 23, 2014
• Grant date: Mar 29, 2016
• Expiry date: May 23, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/041
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Barrier layers, barrier stacks, and seed layers for small-scale interconnects (e.g., copper) are combinatorially screened using test structures sputtered or co-sputtered through apertures of varying size. Various characteristics (e.g., resistivity, crystalline morphology, surface roughness) related to conductivity, diffusion blocking, and adhesion are measured before and/or after annealing and compared to arrive at materials and process parameters for low diffusion with high conductivity through the interconnect. Example results show that some formulations of tantalum-titanium barriers may replace thicker tantalum/tantalum-nitride stacks, in some cases with a Cu—Mn seed layer between the Ta—Ti and copper.