Browse Prior Art Database

Selective Silicon for Planarization And Semi-Recessed Oxide Formation

IP.com Disclosure Number: IPCOM000101609D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Chesebro, DG: AUTHOR [+4]

Abstract

By appropriate use of selective silicon deposition, need for polishing or other planarizing methods is reduced. When selective silicon is deposited prior to oxidation, stress and damage to adjacent structure (bird's beak defects) are minimized. Thus, stress and consequent silicon crystal defects (dislocations) near oxidized regions are minimized.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 77% of the total text.

Selective Silicon for Planarization And Semi-Recessed Oxide Formation

       By appropriate use of selective silicon deposition, need
for polishing or other planarizing methods is reduced.  When
selective silicon is deposited prior to oxidation, stress and damage
to adjacent structure (bird's beak defects) are minimized.  Thus,
stress and consequent silicon crystal defects (dislocations) near
oxidized regions are minimized.

      Referring to Fig. 1, a contact opening is made through nitride
10 and oxide 12 to expose silicon 14.  In an isotropic etching
process, lateral etching of oxide 12 takes place.  Silicon 16 is
selectively deposited on exposed silicon to almost completely
planarize the surface.

      Referring to Fig. 2A, an opening is defined in oxide 18 and
diffusion 20 is formed in substrate 22.  Selective silicon 24 is then
deposited.  This process may be used to replace older methods wherein
contacts were made by depositing silicon, then masking and etching.
Or, an oxidation process can be used to convert selective silicon 24
to oxide 26, as shown in Fig. 2B, to create a continuous, nearly
planarized insulating surface over diffusion areas.

      Referring to Fig. 3A, minimization of bird's beak defects
during oxidation of silicon is achieved by applying selective silicon
28 on substrate silicon 30 in the opening in oxide 32 after formation
of sidewall insulation 34 and before the oxidation process.  Thus,
most of the silicon converted...