Browse Prior Art Database

End Point Detection of Oxide Polishing and Planarization of Semiconductor Devices

IP.com Disclosure Number: IPCOM000109463D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 1 page(s) / 78K

Publishing Venue

IBM

Related People

Hodgson, RT: AUTHOR [+4]

Abstract

Disclosed is a procedure for polishing and planarizing of an oxide film on the surface of a patterned or unpatterned wafer without complete removal of the insulating film. A laser fiberoptic reflectivity probe is used to determine the endpoint of the polish planarization process.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 54% of the total text.

End Point Detection of Oxide Polishing and Planarization of Semiconductor Devices

      Disclosed is a procedure for polishing and planarizing of an
oxide film on the surface of a patterned or unpatterned wafer without
complete removal of the insulating film.  A laser fiberoptic
reflectivity probe is used to determine the endpoint of the polish
planarization process.

      This disclosure involves use of an additional insulating film
deposited over the oxide.  The index of refraction of this film is
chosen so that it is sufficiently different from both that of the
oxide and the polishing medium (i.e. water).  For this condition, the
thickness of the insulator can be measured by monitoring the
intensity variation of the reflected beam caused by the interference
effects from the light reflected from the oxide-insulator interface
and from the insulator-liquid interface.  Once the sacrificial
insulator layer is removed, a second interference pattern would not
occur due to the low reflectivity of the oxide/water interface.

      In practice, sufficient blanket oxide is deposited to cover the
underlying topography.  Then a second sacrificial insulator film of
appropriate refractive index is deposited.  Materials which could be
used include boro phosphate silicate glass (BPSG), Al2O3 and
Polyimides, which all have index of refraction sufficiently different
from that of water.  For use with large size fiducials, endpoint of
the oxide polish process would be sig...