Method of localized modification of the stresses in a substrate of the SOI type, in particular FD SOI type, and corresponding device

Patent metadata

Field	Value
Publication number	US-9653538-B2
Application number	US-201414220542-A
Country	US
Kind code	B2
Filing date	Mar 20, 2014
Priority date	Mar 21, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A substrate of the silicon on insulator type includes a semi-conducting film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate. The semi-conducting film includes a first film zone of tensile-stressed silicon and a second film zone of tensile-relaxed silicon. Openings through the buried insulating layer permit access to the unstressed silicon support substrate under the first and second film zones. An N channel transistor is formed from the first film zone and a P channel transistor is formed from the second film zone. The second film zone may comprise germanium enriched silicon forming a compressive-stressed region.

First claim

What is claimed is:

1. A method of localized stress modification in a substrate of the initially tensile-stressed silicon on insulator type, said substrate comprising an initially tensile-stressed semi-conducting silicon film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate, the method comprising:
forming at least one opening in the initially tensile-stressed semi-conducting silicon film and in the underlying buried insulating layer until the unstressed silicon support substrate is reached,
performing a silicon epitaxy in the at least one opening from the unstressed silicon support substrate so as to fill in the at least one opening,
performing a localized amorphization of a zone of the initially tensile-stressed semi-conducting silicon film including the silicon epitaxy in the at least one opening, and
recrystallizing the localized amorphized zone by a solid-phase epitaxy from the unstressed silicon support substrate situated in the at least one opening so as to obtain at least one localized film zone comprising tensile-relaxed silicon.

2. The method according to claim 1 , wherein the substrate is of fully depleted initially tensile-stressed silicon on insulator type.

3. The method according to claim 1 , wherein the opening is formed at the level of a well for allowing a contact with the unstressed silicon support substrate from the upper face of the initially tensile-stressed semi-conducting silicon film.

4. The method according to claim 1 , further comprising forming a germanium silicon alloy in at least one part of the localized film zone comprising tensile-relaxed silicon, so as to form a compressive-stressed film zone.

5. A method for producing transistors of the N channel type and transistors of the P channel type in a substrate of initially stressed silicon on insulator type, said substrate comprising an initially tensile-stressed semi-conducting silicon film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate, the method comprising:
forming at least one opening in the initially tensile-stressed semi-conducting silicon film and in the underlying buried insulating layer, said at least one opening extending to reach the unstressed silicon support substrate,
performing a silicon epitaxy in the at least one opening from the unstressed silicon support substrate so as to fill in the at least one opening,
performing a localized amorphization of a zone of the initially tensile-stressed semi-conducting silicon film including the silicon epitaxy in the at least one opening,
recrystallizing the localized amorphized zone by a solid-phase epitaxy from the unstressed silicon support substrate situated in the at least one opening so as to obtain at least one localized film zone comprising tensile-relaxed silicon,
producing a P channel transistor in the localized film zone comprising tensile-relaxed silicon, and
producing an N channel transistor in a region of the initially tensile-stressed semi-conducting silicon film.

6. A method for producing transistors of the N channel type and transistors of the P channel type in a substrate of initially stressed silicon on insulator type, said substrate comprising an initially tensile-stressed semi-conducting silicon film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate, the method comprising:
forming at least one opening in the initially tensile-stressed semi-conducting silicon film and in the underlying buried insulating layer, said at least one opening extending to reach the unstressed silicon support substrate,
performing a silicon epitaxy in the at least one opening from the unstressed silicon support substrate so as to fill in the at least one opening,
performing a localized amorphization of a zone of the initially tensile-stressed semi-conducting silicon film including the silicon epitaxy in the at least one opening,
recrystallizing the localized amorphized zone by a solid-phase epitaxy from the unstressed silicon support substrate situated in the at least one opening so as to obtain at least one localized film zone comprising tensile-relaxed silicon,
forming a germanium silicon alloy in at least one part of the localized film zone comprising tensile-relaxed silicon so as to form a compressive-stressed film zone,
producing a P channel transistor in the compressive-stressed film zone, and
producing an N channel transistor in a region of the initially tensile-stressed semi-conducting silicon film.

7. A method, comprising:
forming an opening in a silicon on insulator substrate, said substrate comprising an initially tensile-stressed semi-conducting silicon film disposed on a buried insulating layer which is disposed on an unstressed silicon support substrate, said opening extending completely through both the initially tensile-stressed semi-conducting silicon film and the buried insulating layer;
epitaxially growing silicon material to fill said opening;
locally amorphizing a region including a portion of the epitaxially grown silicon material and a portion of the initially tensile-stressed semi-conducting silicon film;
recrystallizing the locally amorphized region by a solid-phase epitaxy so as to obtain a tensile-relaxed silicon region adjacent a tensile-stressed region formed from the initially tensile-stressed semi-conducting silicon film.

8. The method of claim 7 , further comprising:
forming an N channel transistor in the tensile-stressed region; and
forming a P channel transistor in the tensile-relaxed silicon region.

9. The method of claim 7 , further comprising: epitaxially growing silicon-germanium material on the tensile-relaxed silicon region.

10. The method of claim 9 , further comprising performing a condensation to drive germanium from the silicon-germanium material into the tensile-relaxed silicon region to form a compressive-stressed region.

11. The method of claim 10 , further comprising:
forming an N channel transistor in the tensile-stressed region; and
forming a P channel transistor in the compressive-stressed region.

Assignees

• St Microelectronics Crolles 2 Sas
• Commissariat Energie Atomique

Inventors

• Boeuf Frederic
• Weber Olivier

Classifications

• H10P14/3802 Primary

  Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth · CPC title

• H10P14/3411

  Silicon, silicon germanium or germanium · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title

• H10P14/271

  characterised by the preparation of substrate for selective deposition · CPC title