Methods for wafer bonding, and for nucleating bonding nanophases

1. A method for bonding substrates comprising

contacting a first bonding surface of a first substrate with a second bonding surface of a second substrate to form an assembly; and

compressing the assembly in the presence of an oxidizing atmosphere under suitable conditions to form a bonding layer between the first surface and the second surface, wherein the conditions comprise application to the assembly of an electromagnetic field; wherein

the first bonding surface comprises a polarized surface layer;

the second bonding surface comprises a hydrophilic surface layer;

the first bonding surface and the second bonding surface are different.

2. The method of claim 1 , wherein the electromagnetic field applied comprises a voltage of at least 10 volts.

3. The method of claim 1 , wherein the compressing is at a pressure between about 0 and about 10 MPa.

4. The method of claim 1 , wherein the compressing is at a temperature less than about 1450° C.

5. The method of claim 1 , wherein the first substrate and the second substrate each independently comprises

(i) an optionally doped group IV element, an optionally doped IV-IV multi-element semiconductor, or an optionally doped IV-IV-IV multi-element semiconductor;

(ii) a polymorphic phase, oxide, nitride, oxynitride, carbide, oxycarbide, oxynitrocarbide, or hydride of an optionally doped group IV element, or an optionally doped IV-IV multi-element semiconductor, or an optionally doped IV-IV-IV multi-element semiconductor; or

(iii) Al, Al 2 O 3 , Ti, TiO 2 , or any oxide, nitride, oxynitride, carbide, oxycarbide, and oxynitrocarbide of Ti, TiW, Nb, Ta, Zr, Er, or La, or mixtures thereof, or a peroskvite compound used in refractory MOS gates,

wherein any of (i)-(iii), each has an optionally hydroxylated-terminated surface or hydride-terminated surface.

6. The method of claim 5 , wherein the first substrate and the second substrate each independently comprises Si, Si x Ge 1-x , GaAs, Si 1-x-y Ge x C y , Si 3 (1-x) Ge 3x N 4(1-δ) , Ge, Ga 1-x Al x As, Si x Ge (1-x) (O y N 1-y ) n , Si 1-x-y Ge x C y (O x N 1-x ) n , (Si 1-x-y Ge x C y ) 3 N 4-x-y , SiO 2 , GeO 2 , Si x Ge 1-x O 2 , Si 1-x-y Ge x C y O 2 , Ge x C 1-x O 2 , Si 3 N 4 , Si 1-x-y Ge x Sn y , Si 1-x-y-z Ge x Sn y C z , Ge x C 1-x , Si 3(1-x) Ge 3x N 4(1-δ) , TiO 2 , or any oxide, nitride, oxynitride, carbide, oxycarbide, and oxynitrocarbide of Ti, TiW, Nb, Ta, Zr, Er, or La, or mixtures thereof.

7. The method of claim 5 , wherein the first substrate and the second substrate each independently comprise Si, SiO 2 , SiGe, SiGe oxide, SiN, SiC, Al, and Al 2 O 3 .

8. The method of claim 1 , wherein the first substrate and the second substrate are each wafers or beads.

9. The method of claim 1 , wherein the oxidizing atmosphere is air.

10. The method of claim 1 , wherein the compressing is maintained for up to 2 hours.

11. The method of claim 1 , wherein the bonding layer has a bonding strength of at least 10 MPa.

12. The method of claim 1 , wherein the first substrate is a Si wafer and the second substrate is a silicate wafer.

13. The method of claim 12 , wherein the first bonding surface is O 2 H 2 Si(1×1)(100) and is formed by cleaning the Si wafer with the Herbots-Atluri clean.

14. The method of claim 13 , wherein the second bonding surface is formed by chemical etching followed by chemical oxidation of the silicate wafer.

15. The method of claim 12 , wherein the bonding layer consists essentially of silicon, oxygen, and hydrogen.

16. The method of claim 1 , wherein the first substrate is a Si wafer and the first bonding surface is O 2 H 2 Si(1×1)(100).

17. The method of claim 1 , wherein the second substrate is a silicate wafer and the second bonding surface is SiOx, where 0<x≦2.

18. The method of claim 1 , wherein the first bonding surface comprises a hydroxy-terminated silicate.

19. The method of claim 1 , wherein the first substrate and the second substrate are both silicate wafers, and the first bonding surface comprises hydroxyl-terminated silicate; and second bonding surface comprises SiOx, where 0<x≦2.

20. The method of claim 1 , wherein

the first bonding surface comprises O 2 H 2 Si(1×1)(100) or hydroxy-terminated SiO 2 surface (SiO 2 —O 2 H 2 Si) wherein about 5% to about 90% H has been desorbed from the first bonding surface; and

the second bonding surface comprises SiOx, where 0<x≦2.

21. A method for bonding substrates comprising

contacting a first bonding surface comprising O 2 H 2 Si(1×1)(100) of a first substrate comprising Si with a second bonding surface of a second substrate comprising a silicate to form an assembly; and

compressing the assembly in the presence of an oxidizing atmosphere under suitable conditions to form a bonding layer between the first and second bonding surfaces, wherein the conditions comprise application to the assembly of an electromagnetic field.

22. The method of claim 21 , wherein the second bonding surface comprises SiOx, where 0<x≦2.

23. A method for bonding substrates comprising

contacting a first bonding surface comprising hydroxy-terminated silica of a first substrate comprising a silicate with a second bonding surface comprising SiOx, where 0<x≦2, of a second substrate comprising a silicate to form an assembly; and

compressing the assembly in the presence of an oxidizing atmosphere under suitable conditions to form a bonding layer between the first and second bonding surfaces, wherein the conditions comprise application to the assembly of an electromagnetic field.

24. A bonded substrate formed according to claim 1 .