Browse Prior Art Database

In-Situ Etch Rate/Endpoint Monitoring Process for Plasma Etching

IP.com Disclosure Number: IPCOM000101900D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 3 page(s) / 65K

Publishing Venue

IBM

Related People

Briska, M: AUTHOR [+5]

Abstract

This article describes a process for in-situ monitoring the etch rate and/or endpoint of films to be etched by means of a measuring strip. The measuring strip has a film thickness gradient and is produced by conventional silicon techniques.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 90% of the total text.

In-Situ Etch Rate/Endpoint Monitoring Process for Plasma Etching

       This article describes a process for in-situ monitoring
the etch rate and/or endpoint of films to be etched by means of a
measuring strip.  The measuring strip has a film thickness gradient
and is produced by conventional silicon techniques.

      Fig. 1A shows a film with an inhomogeneous thickness
distribution.  The material used preferably corresponds to that to be
etched later.  In the first step, the material is etched to the
desired extent across its entire surface at an inhomogeneous rate.

      Then, a suitable pattern is formed in a photolithographic step
which is applied to the substrate material by RIE methods (Figs. 1B
and 1C).  The resultant structure (Fig. 2A) serves as a measuring
strip.

      The measuring strip is processed along with the substrate to be
etched and controlled.  Connectors 1, 2, ...., n are coupled to
current generators (Fig. 2A).  The etching of webs N, having a
calibrated height profile in the unetched state (Fig. 2C), as well as
the etch rate, are controlled by observing the current I(total) as a
function of the etch time (Fig. 2B), with each discrete modification
of the current (shoulder) (Fig. 2B) indicating whether the web has
been etched in full.  Thus, the amount of material etched from the
substrate or removed from the time the shoulder occurs can be
accurately determined.

      This process allows determining the etch endpoint ev...