Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Selective SiO2/A12O3 Etching in High-Density Plasma

IP.com Disclosure Number: IPCOM000118639D
Original Publication Date: 1997-Apr-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Hsiao, R: AUTHOR [+3]

Abstract

Disclosed is a method of achieving highly selective etching of SiO2 over A12O3 in fluorine-containing high density plasma.

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

Selective SiO2/A12O3 Etching in High-Density Plasma

      Disclosed is a method of achieving highly selective etching of
SiO2 over A12O3 in fluorine-containing high density plasma.

      Highly selective SiO2/A12O3 etching can be achieved by using a
high density plasma etcher which has near independent control of ion
density and ion energy.  In such an etcher, the ion energy is
controlled by the bias RF power supplied to the electrode where the
sample to be etched is located and the ion density is controlled by
the RF power inductively coupled into the etcher.  The most effective
way to achieve higher SO2/A12O3 etch rate ratio is to use a lower
bias power.  The etch rate ratio can also be enhanced by using
relatively high process pressure and low inductive power.
Electronegative gas, such  as SF6, offers much higher etch rate ratio
than electronegative gas such as CF4.  The thin aluminum fluoride
formed on the A12O3 surface during etching can be removed by in-site
sputtering after reactive-ion-etching.  Using the method described,
highly selective SiO2/A12O3 etching process can be achieved without
producing etching residues such as fluorocarbon polymer.

      A12O3 and SiO2 are both well-known dielectric materials used
as the insulation layers in semiconductor devices and magnetic
recording heads.  Using the highly selective SiO2/A12O3 etching
process achieved  using the above method can result in great process
robustness.