Ultralow-K dielectric-gap wrapped contacts and method

US11978661B2 · kind B2 · utility

Assignee

• GLOBALFOUNDRIES U.S. Inc. · US

Inventors

• Fuad H. Al-Amoody · Rexford, US
• Felix P. Anderson · Colchester, US
• Spencer H. Porter · Colchester, US
• Mark D. Levy · Williston, US
• Siva P. Adusumilli · South Burlington, US

Key dates

• Filing date: Dec 11, 2020
• Grant date: May 7, 2024
• Expiry date: Jul 20, 2041

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/60
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Disclosed is a structure with ultralow-K (ULK) dielectric-gap wrapped contact(s). The structure includes an opening, which extends through a dielectric layer and is aligned above a device. A contact is within the opening and electrically connected to the device. Instead of the contact completely filling the opening, a ULK dielectric-gap (e.g., an air or gas-filled gap or a void) at least partially separates the contact from the sidewall(s) of the contact opening and further wraps laterally around the contact. Also disclosed is a method for forming the structure and, particularly, for forming a ULK dielectric-gap by etching back an exposed top end of an adhesive layer initially lining a contact opening to form a gap between the sidewall(s) of the opening and the contact and then capping the gap with an additional dielectric layer such that the gap is filled with air or gas or is under vacuum.