Browse Prior Art Database

Low Temperature Planarized Pre-Metal Passivation

IP.com Disclosure Number: IPCOM000103006D
Original Publication Date: 1990-May-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Pennington, SL: AUTHOR

Abstract

By the use of sputtering to help level a conformally deposited first insulator layer, deposition of a second layer of insulation under process conditions providing less than conformal coverage, and the addition of a temporary reflowed boron oxide (B2O3) layer prior to a planarizing process, good planarization and insulation is achieved while keeping process temperatures under 450 degrees Celsius. The entire process may be performed in a single, multistation tool.

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Low Temperature Planarized Pre-Metal Passivation

      By the use of sputtering to help level a conformally deposited
first insulator layer, deposition of a second layer of insulation
under process conditions providing less than conformal coverage, and
the addition of a temporary reflowed boron oxide (B2O3) layer prior
to a planarizing process, good planarization and insulation is
achieved while keeping process temperatures under 450 degrees
Celsius.  The entire process may be performed in a single,
multistation tool.

      Referring to the figure, on a topography such as that of
polysilicon lines 10 over silicon substrate 12, a first insulating
layer 14 is conformally deposited by chemical vapor deposition (CVD).
By argon ion bombardment, the conformal layer 14 is leveled somewhat,
i.e., steepness of edges in the topography is reduced and some
material is deposited in surface depressions.  A second silicon
dioxide (SiO2) insulating layer 16 is then deposited by CVD under
plasma conditions which results in a less than conformal coating.
Next, B2O3 layer 18 is deposited by CVD while the substrate is held
at approximately 450 degrees Celsius which reflows layer 18 and
results in a nearly planar surface. Finally, a reactive ion etching
process is used which removes B2O3 and SiO2 at nearly the same rate
until all of layer 18 and some of layer 16 is removed as indicated by
the dashed line.

      Disclosed anonymously.