Method for reclaiming a surface of a substrate

• US 20100200854A1
• Filed: 02/12/2010
• Published: 08/12/2010
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: Soitec Silicon On Insulator Technologies SA (Soitec S.A.)
• Original Assignee: Soitec Silicon On Insulator Technologies SA (Soitec S.A.)
• Inventors: Schwarzenbach, Walter, Kerdiles, Sebastien, Alami-Idrissi, Aziz
• Granted Patent: US 8,435,897 B2
• Time in Patent Office: Days
• US Class Current: 257/49
• CPC Class Codes: H01L 21/02032 by reclaiming or re-processing
• CPC Class Codes: H01L 21/304 Mechanical treatment, e.g. grinding, polishing, cutting H01L21/30625 takes precedence
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

A method for reclaiming a surface of a substrate, wherein the surface, in particular a silicon surface, comprises a protruding residual topography, comprising at least the layer of a first material. By providing a filling material in the non-protruding areas of the surface of the substrate and the subsequent polishing, the reclaiming can be carried out such that the material consuming double-sided polishing step used in the prior art is no longer necessary.

Claims

1. A method for reclaiming a surface of a substrate, wherein a surface comprises a protruding residual topography resulting from a layer transfer process, wherein the substrate comprises at least a layer of a first material, the method comprising the steps of:

a) providing a silicon filling material in the non-protruding areas of the surface of the substrate, and

b) polishing the surface,

wherein the filling material and at least a part of the protruding residual topography are polished simultaneously during polishing step b).

2. The method according to claim 1, wherein the first material and the filling material are such that the polishing in step b) occurs substantially at the same removal rate.

3. The method according to claim 1, wherein the first material is in a monocrystalline phase and the filling material in a polycrystalline phase.

4. The method according to claim 1, wherein step b) comprises a chemical mechanical polishing (CMP).

5. The method according to claim 1, wherein the thickness of the layer with the filling material is in a range of 50% to 150% of the thickness of the first material.

6. The method according to claim 1, wherein the thickness of the layer with the filling material is in a range of 80% to 120% of the thickness of the first material.

7. The method according to claim 1, wherein the thickness of the layer with the filling material corresponds to the thickness of the first material.

8. The method according to claim 1, wherein the protruding topography further comprises a second layer of a second material, in particular SiO2, on the first layer and wherein step a) comprises:

i) depositing, in particular in a reactor using a silicon precursor, the filling material on the second material of the protruding topography and the non-protruding areas, and

ii) removing the second layer, and at the same time, removing the filling material over the protruding topography.

9. The method according to claim 8, wherein the substrate is arranged such that during step i) the surface side opposite to the surface with the protruding topology remains without a layer of the filling material.

10. The method according to claim 1, wherein the protruding topography comprises a second layer of a second material, in particular SiO2, on the first layer and wherein step a) comprises:

depositing, in particular in a reactor using a silicon precursor allowing selective deposition, even more in particular dichlorosilane (SiH₂Cl₂), the filling material only on the non-protruding areas, using the second layer as a mask.

11. The method according to claim 10, further comprising a step of removing the second layer.

12. The method according to claim 8, wherein step ii) comprises a de-oxidation step using in particular a HF bath.

13. The method according to claim 1, wherein during step b) at least a thickness corresponding to the thickness of the first layer is removed.

14. The method according to claim 13, wherein, during step b), the material removal goes beyond a region with implantation defects.

15. The method according to claim 13, wherein the material removal is in a range of 2000 Å

to 12000 Å

.

16. The method according to claim 1, further comprising an edge polishing step to remove an ion implanted region in a chamfered edge area of the substrate.

18. A substrate according to claim 15, wherein the first material is in a monocrystalline phase and the filling material in a poly crystalline phase.

17. A substrate comprising a base, an ion implanted region as well as a non ion implanted region over the base, in particular in an edge region of the base, a first layer of a first material on the ion implanted region, and a filling layer of a filling material on the non ion implanted region.