Copper Contact for 22 nm and Beyond: Device Performance and Reliability Evaluation

• Published in: IEEE electron device letters Vol. 31; no. 12; pp. 1452 - 1454
• Main Authors: Soon-Cheon Seo, Chih-Chao Yang, Miaomiao Wang, Monsieur, Frederic, Adam, Lahir, Johnson, Jeffrey B, Horak, Dave, Fan, Susan, Kangguo Cheng, Stathis, James, Doris, Bruce
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circuit properties; CMOS; Contact; Contact reliability; Copper; copper contact; CVD Ru; Design. Technologies. Operation analysis. Testing; Devices; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; external resistance; Gates; Human computer interaction; Instability; Integrated circuits; Logic gates; Metallization; Microelectronic fabrication (materials and surfaces technology); Oscillators; Oscillators, resonators, synthetizers; Reliability; Resistance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Stability; Stress; Transistors; Thermal stress; Performance evaluation; CVD Ru; Electric breakdown; Barrier layer; Bias temperature instability; external resistance; n channel; Chemical vapor deposition; Ring oscillator; Field effect transistor; Microelectronic fabrication; copper contact; Complementary MOS technology; Hot carrier; High k dielectric; Delay time; Copper; Reliability; Contact reliability; Damaging; Charge carrier injection
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2010.2078483

We demonstrate the device performance benefit of Cu contact over W contact using high-κ/metal gate CMOS devices. The ring oscillator (RO) device of Cu contact showed reduction in external resistance, which resulted in an increase in drive current by 5% for both nFET and pFET devices. The delay on the gate-cap-loaded RO improved by 5%-7% with Cu contact. We evaluated device reliability tests for gate dielectric breakdown, positive-bias temperature instability, negative-bias temperature instability, and hot carrier injection on 32- and 22-nm-node devices with Cu contact. The reliability results for the Cu contacts with the reliable barrier layer and good gap fill are comparable to those of W contacts.