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Browse Prior Art Database

Improved Stud Formation using a Sacrificial BN Film

IP.com Disclosure Number: IPCOM000104043D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 4 page(s) / 102K

Publishing Venue

IBM

Related People

Ng, H: AUTHOR [+4]

Abstract

The authors have developed a novel process which eliminates excessive W recess and other problems associated with current blanket RIE etchback and CMP methods used to form W studs.

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Improved Stud Formation using a Sacrificial BN Film

      The  authors have developed a novel process which eliminates
excessive  W  recess  and  other  problems  associated  with current
blanket RIE etchback and CMP methods used to form W studs.

      The  disclosed  process,  in  the  case  of  non-planar
substrates  using recess etch stud formation, is as follows:  Deposit
oxide or suitable dielectric as shown  in  step  1A.  Deposit
1000-2000A  of  Boron Nitride (BN) as shown in step 1B.  Do the via
level lithography, RIE etch the BN and  oxide and  strip  the
resist.  The structure to this point in the process is shown in step
1C.  Deposit Ti/TiN  adhesion  layer and  W  metalization  layer, as
shown in step D. Blanket RIE etchback the W/TiN/Ti as shown in step
E.  Note that  the  W stud  is  etched back below the level of the BN
which allows sufficient overetch to remove W stringers.  The
presence  of the  BN will also offset micro-loading effects.  RIE
etch the BN selectively to the W stud, Ti, TiN and oxide  dielectric.
Hot  phosphoric  may also be used to strip the BN.  Note that PVD Si
may be used instead of BN and can  stripped  use  RIE etching
methods  or with a wet etch using KOH, for example.  The resulting
structure is shown in step F.

      The disclosed process, in the case of planar substrates using
chemical mechanical polishing (CMP),  is  as  follows:  Deposit
oxide  or  suitable ...