Contact isolation scheme for thin buried oxide substrate devices

US9105691B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Kangguo Cheng · Schenectady, US
• Bruce B. Doris · Brewster, US
• Laurent Grenouillet · Voiron, FR
• Ali Khakifirooz · Los Altos, US
• Yannick Le Tiec · Crolles, FR
• Qing Liu · Guilderland, US
• Maud Vinet · Voiron, FR

Key dates

• Filing date: Apr 9, 2013
• Grant date: Aug 11, 2015
• Expiry date: Apr 15, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76897
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of forming a semiconductor-on-insulator (SOI) device includes defining a shallow trench isolation (STI) structure in an SOI substrate, the SOI substrate including a bulk layer, a buried insulator (BOX) layer over the bulk layer, and an SOI layer over the BOX layer; forming a doped region in a portion of the bulk layer corresponding to a lower location of the STI structure, the doped region extending laterally into the bulk layer beneath the BOX layer; selectively etching the doped region of the bulk layer with respect to undoped regions of the bulk layer such that the lower location of the STI structure undercuts the BOX layer; and filling the STI structure with an insulator fill material.