Semiconductor substrates having useful and transfer layers

• US 20060189095A1
• Filed: 04/12/2006
• Published: 08/24/2006
• Est. Priority Date: 11/27/2000
• 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: Ghyselen, Bruno, Letertre, Fabrice
• Granted Patent: US 7,422,957 B2
• Time in Patent Office: Days
• US Class Current: 438/458
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/3148 Silicon Carbide layers
• CPC Class Codes: H01L 21/318 composed of nitrides
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: H01L 29/1608 Silicon carbide
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/267 in different semiconductor regions , e.g. heterojunctions H01L29/263 takes precedence
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

Methods for fabricating final substrates for use in optics, electronics, or optoelectronics are described. The method includes forming a zone of weakness beneath a surface of a source substrate to define a transfer layer; detaching the transfer layer from the source substrate along the zone of weakness; depositing a useful layer upon the transfer layer; and depositing a support material on the useful layer to form the final substrate. The useful layer may be deposited on the transfer layer before or after detaching the transfer layer from the source substrate. The useful layer is typically made of a material having a large band gap, and comprises at least one of gallium nitride, or aluminum nitride, or of compounds of at least two elements including at least one element of aluminum, indium, and gallium. The zone of weakness may advantageously be formed by implanting atomic species into the source substrate.

Claims

1. A method of fabricating a final substrate for use in optics, electronics, or optoelectronics which comprises:

forming a zone of weakness beneath a surface of a source substrate to define a transfer layer;

detaching the transfer layer from the source substrate along the zone of weakness;

depositing a useful layer upon the transfer layer;

obtaining a bilayer consisting of the useful layer and the transfer layer; and

depositing a support material on one of the useful layer or the transfer layer to form the final substrate.

2. The method of claim 1, wherein the zone of weakness is formed by implanting atomic species into the source substrate.

3. The method of claim 1, wherein the transfer layer is a relatively thin layer of a monocrystalline material and the support material is a relatively thick layer.

4. The method of claim 1, wherein the support material is deposited using at least one of chemical vapor deposition, liquid deposition, or molecular beam deposition.

5. The method of claim 1, wherein the useful layer is made of a material having a large band gap, and comprises at least one of gallium nitride, or aluminum nitride.

6. The method of claim 1, wherein the useful layer is made of compounds of at least two elements including at least one element of aluminum, indium, and gallium.

7. The method of claim 1, wherein the support material is made of at least one of monocrystalline materials, polycrystalline materials, amorphous materials, materials comprising a plurality of phases, and materials that are less expensive than that of the transfer layer.

8. The method of claim 1, wherein the transfer layer is made of at least one of silicon (1,1,1,), silicon carbide, a monocrystalline material, sapphire, diamond, gallium nitride, aluminum nitride, or a combination of at least two of these materials.

9. The method of claim 1, wherein the support material is made of at least one of silicon, silicon carbide, sapphire, diamond, graphite, gallium nitride, aluminum nitride, and a combination of at least two of these materials.

10. The method of claim 1, which further comprises optimizing the conditions under which the support material is deposited so that the support material exhibits at least one of monocrystalline quality, polycrystalline quality, an insulating quality, and a conductive quality.

11. The method of claim 1, which further comprises transferring the transfer layer to an intermediate support prior to obtaining the bilayer by depositing the useful layer thereon.

12. The method of claim 11, wherein the intermediate support includes a plurality of transfer layers.

13. The method of claim 11, which further comprises forming a bonding layer on one of the transfer layer or the useful layer, or both, to facilitate bonding of the useful and transfer layers.

14. The method of claim 13, wherein the bonding layer is made of at least one of amorphous materials, polycrystalline materials, and metallic materials.

15. The method of claim 1, which further comprises transferring the transfer layer to an intermediate support, depositing the useful layer on the transfer layer and then removing the intermediate support to form the final substrate.

16. The method of claim 1, wherein the source substrate is removed after depositing the useful layer.

17. The method of claim 1, wherein the support is of a lower quality than the useful or transfer layers.

18. The method of claim 1, wherein the source substrate is of a lower quality than the useful or transfer layers.