Method of forming recessed container cells by wet etching conductive layer and dissimilar layer formed over conductive layer

US5963814A · kind A · utility

Assignee

• Micron Technology, Inc. · US

Inventors

• Michael A. Walker · Sumner, US
• Michael T. Andreas · Boise, US

Key dates

• Filing date: Oct 28, 1997
• Grant date: Oct 5, 1999
• Expiry date: Oct 28, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/047

Abstract

A container capacitor having a recessed conductive layer. The recessed conductive layer is typically made of polysilicon. The recessed structure reduces the chances of polysilicon "floaters," which are traces of polysilicon that remain on the surface of the substrate, coupling adjacent capacitors together to create short circuits. The disclosed method of creating such a recessed structure uses chemical mechanical planarization to remove the layer of polysilicon and an overlying layer of photoresist from the upper surface of the substrate in which a container is formed. A wet etch selectively isolates a rim of the polysilicon within the container to recess the a rim, while the remainder of the polysilicon in the container is protected by the layer of photoresist.