Sub-lithographic dimensioned air gap formation and related structure

US7943480B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Daniel C. Edelstein · White Plains, US
• Nicholas C. M. Fuller · Elmsford, US
• David V. Horak · South Burlington, US
• Elbert E. Huang · Carmel, US
• Wai-Kin Li · Hopewell Junction, US
• Anthony D. Lisi · Poughkeepsie, US
• Satyanarayana V. Nitta · Poughquag, US
• Shom Ponoth · Irvine, US

Key dates

• Filing date: Feb 12, 2008
• Grant date: May 17, 2011
• Expiry date: Oct 30, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31144
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Sub-lithographic dimensioned air gap formation and related structure are disclosed. In one embodiment, a method includes forming a dielectric layer including interconnects on a substrate; depositing a cap layer on the dielectric layer; depositing a photoresist over the cap layer; patterning the photoresist to include a first trench pattern at most partially overlying the interconnects; forming a spacer within the first trench pattern to form a second trench pattern having a sub-lithographic dimension; transferring the second trench pattern into the cap layer and into the dielectric layer between the interconnects; and depositing another dielectric layer to form an air gap by pinching off the trench in the dielectric layer.