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A Hybrid Planarization Process

IP.com Disclosure Number: IPCOM000110476D
Original Publication Date: 1992-Nov-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 48K

Publishing Venue

IBM

Related People

Chen, MM: AUTHOR [+3]

Abstract

Disclosed is a planarization process for metal features on substrate surfaces. A dielectric material is used as an overcoat layer. The process employs mechanical lapping to planarize the dielectric layer over the metal features and uses ion beam milling to precisely control the final thickness of the dielectric material above the metal features. In applications where the dielectric material is completely removed above the metal features a planar metal-dielectric surface is achieved.

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A Hybrid Planarization Process

      Disclosed is a planarization process for metal features on
substrate surfaces.  A dielectric material is used as an overcoat
layer.  The process employs mechanical lapping to planarize the
dielectric layer over the metal features and uses ion beam milling to
precisely control the final thickness of the dielectric material
above the metal features.  In applications where the dielectric
material is completely removed above the metal features a planar
metal-dielectric surface is achieved.

      The process is illustrated in Figure 1.  Dielectric material is
deposited over the metal features.  The dielectric layer thickness is
greater than the height of the metal features.  Mechanical lapping is
used to remove the features which have been replicated into the
dielectric layer.  Initially the lapping force is applied only to the
featured areas and rapid material removal results.  When
planarization is achieved the lapping force is distributed over the
entire substrate surface and the material removal rate decreases.
After the decrease in removal rate of overcoat material is observed,
the planarized surface is ion beam milled to precisely reduce the
overcoat material thickness to a desired final value.

      Mechanical lapping has the advantage of large material rates
but the disadvantage of precise endpoint control.  Ion beam milling
has the advantage of controlled material removal but at slow rates.
The combination of b...