Process to reduce substrate effects by forming channels under inductor devices and around analog blocks

US6869884B2 · kind B2 · utility

Assignee

• Chartered Semiconductor Manufacturing LTD · SG

Inventors

• Lap Chan · San Francisco, US
• Sanford Chu · Singapore, SG
• Chit Hwei Ng · Singapore, SG
• Purakh Raj Verma · Singapore, SG
• Jia Zhen Zheng · Singapore, SG
• Johnny Kok Wai Chew · Singapore, SG
• Choon-Beng Sia · Singapore, SG

Key dates

• Filing date: Aug 22, 2002
• Grant date: Mar 22, 2005
• Expiry date: Mar 1, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/764
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A first method of reducing semiconductor device substrate effects comprising the following steps. O+ or O2+ are selectively implanted into a silicon substrate to form a silicon-damaged silicon oxide region. One or more devices are formed over the silicon substrate proximate the silicon-damaged silicon oxide region within at least one upper dielectric layer. A passivation layer is formed over the at least one upper dielectric layer. The passivation layer and the at least one upper dielectric layer are patterned to form a trench exposing a portion of the silicon substrate over the silicon-damaged silicon oxide region. The silicon-damaged silicon oxide region is selectively etched to form a channel continuous and contiguous with the trench whereby the channel reduces the substrate effects of the one or more semiconductor devices. A second method of reducing substrate effects under analog devices includes forming an analog device on a SOI substrate and then selectively etching the silicon oxide layer of the SOI substrate to form a channel at least partially underlying the analog device.