Browse Prior Art Database

Local Interconnections by Selective Removal of Sidewall Insulation

IP.com Disclosure Number: IPCOM000099948D
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Starkey, G: AUTHOR [+4]

Abstract

By adding selective removal of sidewall insulation from a polysilicon gate conductor level of wiring, interconnections may be made between diffusions and polysilicon wiring when standard selective silicon plus titanium silicide is grown to make contact surfaces on diffusions. Thus, local wiring is created by the addition of a masking and etching process to a standard process sequence.

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Local Interconnections by Selective Removal of Sidewall Insulation

       By adding selective removal of sidewall insulation from a
polysilicon gate conductor level of wiring, interconnections may be
made between diffusions and polysilicon wiring when standard
selective silicon plus titanium silicide is grown to make contact
surfaces on diffusions.  Thus, local wiring is created by the
addition of a masking and etching process to a standard process
sequence.

      Referring to Fig. 1, standard processing is used to define
polysilicon line 10 over gate insulation 12 on substrate 14 and to
form insulating sidewall spacers 16.

      As shown in Fig. 2, one of the sidewall spacers 16 is removed
by masking with photoresist 18 and removing the exposed insulating
sidewall spacer material in a selective isotropic etching process.

      Referring to Fig. 3, standard processing is used to form
diffusions 20 and 22, and titanium disilicide (TiSi2) 24 and 26.
Connection is thus made from diffusion 20 to polysilicon line 10 via
silicide 24 at the same time that silicide contact surface 26 is
formed on diffusion 22.

      The design of extra lines in the gate conductor wiring mask,
extra diffusions in the diffusion mask, and the addition of a mask to
selectively remove sidewall insulation may thus be used to define
local interconnection wiring.