Browse Prior Art Database

Reduced Si Recess for FIN Cut First Step

IP.com Disclosure Number: IPCOM000248437D
Publication Date: 2016-Nov-29
Document File: 1 page(s) / 160K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method to eliminate Silicon (Si) recess by protecting the Si while etching the Oxide and Nitride hardmask with a partial etch organic layer.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 01 of 1

Reduced Si Recess for FIN Cut First Step

FIN formation requires cutting/removing extra fin to define the final device. A FIN is created using a "SEA of FIN" by different techniques.

There are two ways to remove the extra fin:

• Cut first: before the FIN Silicon (Si) etch
• Etch last: after the FIN Si etch

For the FIN cut first approach, the goal is to achieve a minimal recess of the Si. The existing process for FIN first cut recesses the Si while removing the Oxide and Nitride hardmask, even with very good selectivity.

A method is needed to reduce or eliminate this recess while removing the extra FIN

with the usage of more selective chemistry while the silicon is still protected by the Optical Planarizing Layer (OPL).

The novel contribution is a method to eliminate the Si recess by protecting the Si while etching the Oxide and Nitride hardmask with a partial etch organic layer.

The method forms a fin structure of a semiconductor device by removing the hardmask using a partial organic etch to protect the Si subtract before etching the Si. This cut, first in hardmask, can be done multiple times before forming the final hardmask for a final Silicon Fin Etch. This method carries over a pre-existing Si recess from the mandrel etch definition and delivers a quasi-flat surface post Fin Etch.

Figure: Proposed process flow

As opposed to existing methods, this solution has no Si recess, provides a quasi-flat surface, and causes no Si damage.

1