Deposition and sputter etch approach to extend the gap fill capability of HDP CVD process to ≦0.10 microns

US6872633B2 · kind B2 · utility

Assignee

• Chartered Semiconductor Manufacturing LTD · SG

Inventors

• Liu Huang · Singapore, SG
• John Sudijono · Singapore, SG

Key dates

• Filing date: May 31, 2002
• Grant date: Mar 29, 2005
• Expiry date: May 31, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76224
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of filling an STI feature with a dielectric material using a HDP CVD technique is described. By omitting an inert carrier gas like argon in the first CVD step, a small keyhole in a SiO2 layer is formed near the top of the trench. A sputter etch step in the same CVD chamber then removes dielectric material above the keyhole. A second CVD step completely fills the STI trench which is free of voids and forms a layer above the adjacent nitride layer. The nitride layer serves as an etch stop during a CMP step to lower the level of dielectric material until it is coplanar with the nitride layer. The method is low cost since all deposition and sputter etch steps are performed in an existing CVD tool and the same tool is useful in forming trenches of various sizes ranging from below 0.13 micron to above 0.25 micron.