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Browse Prior Art Database

High Aspect Ratio Fill by Multiple Depositions And Reflows

IP.com Disclosure Number: IPCOM000101011D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Chen, TC: AUTHOR [+2]

Abstract

The filling of high aspect ratio structures is becoming increasingly important in the fabrication of advanced integrated circuit structures. Disclosed is a process for filling these structures with a re-flowable glass and which incorporates multiple depositions and reflow cycles.

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This is the abbreviated version, containing approximately 90% of the total text.

High Aspect Ratio Fill by Multiple Depositions And Reflows

       The filling of high aspect ratio structures is becoming
increasingly important in the fabrication of advanced integrated
circuit structures.  Disclosed is a process for filling these
structures with a re-flowable glass and which incorporates multiple
depositions and reflow cycles.

      Low temperature, chemical vapor deposition processes are
generally of limited use in the filling of structures with an aspect
ratio of greater than approximately one. This results from the
limited capture angle inside of a high aspect ratio structure coupled
with the limited surface mobility of the deposited species [*].  The
combination of these factors yields a deposited profile shown
schematically in Fig. 1.  As the deposition proceeds, the capture
angle near the bottom of these structures worsens (the aspect ratio
increases), and less material is deposited there. These factors lead
to void formation inside of the structure if the deposition is
continued until the surface is sealed.

      A solution to this problem is to fill the structure partially
(as in Fig. 1) with a re-flowable glass and then anneal the structure
at a sufficiently high temperature to allow the glass to flow.  Flow
in the glass proceeds until the surface energy of the structure is
minimized yielding the structure shown in Fig. 2.  A combination of
multiple depositions and reflow cycles allows high aspect ratio
structures to be filled...