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

Alkaline Formulations for Chemical Mechanical Polishing of Copper Utilizing Azole Passivation

IP.com Disclosure Number: IPCOM000113829D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Brusic, VA: AUTHOR [+3]

Abstract

Disclosed is a specific chemical mechanical slurry formulation for removal of Copper films under weakly alkaline conditions with low removal rates of underlying semiconductor films so as to facilitate achieving endpoint. The approach is to modify a previously disclosed Copper polish slurry, such that azole passivating films, rather than copper oxides, are formed furing the polishing process. This formulation allows removal rates of the Copper during CMP, while the protective layers are continuously being reformed, to be maximized but with removal rates of the underlying insulating films slow, thus resulting in high etch rate ratios. The process is specific to alkaline pH's in the range of 8-10.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 63% of the total text.

Alkaline Formulations for Chemical Mechanical Polishing of Copper
Utilizing Azole Passivation

      Disclosed is a specific chemical mechanical slurry formulation
for removal of Copper films under weakly alkaline conditions with low
removal rates of underlying semiconductor films so as to facilitate
achieving endpoint.  The approach is to modify a previously disclosed
Copper polish slurry, such that azole passivating films, rather than
copper oxides, are formed furing the polishing process.  This
formulation allows removal rates of the Copper during CMP, while the
protective layers are continuously being reformed, to be maximized
but with removal rates of the underlying insulating films slow, thus
resulting in high etch rate ratios.  The process is specific to
alkaline pH's in the range of 8-10.

      Prior art references include a chem mech polish process for
Nickel in which the continuous formation of a passivating oxide
surface layer (1) on the metal is thought to be the process
mechanism.  In addition, Benzotriazole is disclosed in (2) as an
additive for mechanical polishing of Copper to prevent the surface
from oxidizing.  Finally, Benzotriazole, in the presence of an acid
aqueous solution of peroxide, is disclosed in (3) as a chemical
surface treatment for Cu yielding superior surface quality.  In non
of the prior art was there disclosed a method similar to that of the
present invention.

      The ammonium persulfate/KOH pH 10 slurry for Cu CMP (1)...