System comprising a semiconductor device and structure

1. A semiconductor device, comprising:

a first semiconductor layer comprising first transistors, wherein said first transistors are interconnected by at least one metal layer comprising aluminum or copper; and

a second mono-crystallized semiconductor layer comprising second transistors and overlaying said at least one metal layer,

wherein said at least one metal layer is in-between said first semiconductor layer and said second mono-crystallized semiconductor layer,

wherein said second mono-crystallized semiconductor layer is less than 150 nm in thickness, and

wherein at least one of said second transistors is an N-type transistor and at least one of said second transistors is a P-type transistor.

2. A semiconductor device according to claim 1 , further comprising:

a plurality of connection paths between said second transistors and said first transistors,

wherein said plurality of connection paths comprise vias through said second mono-crystallized semiconductor layer, and

wherein at least one of said vias is less than about 150 nm in diameter.

3. A semiconductor device according to claim 1 , further comprising:

a plurality of connection paths between said second transistors and said first transistors, and said first semiconductor layer comprising first alignment marks,

wherein at least one of said connection paths has a contact to said second transistors, and

wherein said contact is aligned to one of said first alignment marks.

4. A mobile phone comprising a semiconductor device according to claim 1 .

5. A semiconductor device according to claim 1 ,

wherein said second transistors form at least one second circuit,

wherein said first transistors form a first circuit substantially the same as the second circuit, and

the semiconductor device further comprises:

a switch operable to cause one of said first and second circuits to be replaced by the other of said first and second circuits.

6. A semiconductor device according to claim 1 , further comprising:

a heat spreader between said first semiconductor layer and said second mono-crystallized semiconductor layer.

7. A semiconductor device according to claim 1 wherein at least one of said second transistors is one of:

(i) a recessed-channel transistor (RCAT);

(ii) a junction-less transistor;

(iii) a replacement-gate transistor;

(iv) a thin-side-up transistor;

(v) a double gate transistor; or

(vi) a horizontally oriented transistor.

8. A semiconductor device comprising:

a first semiconductor layer comprising first transistors, wherein said first transistors are interconnected by at least one metal layer comprising aluminum or copper;

a second mono-crystallized semiconductor layer comprising second transistors and overlaying said at least one metal layer,

wherein said at least one metal layer is in-between said first semiconductor layer and said second mono-crystallized semiconductor layer; and

a plurality of connection paths between said second transistors and said first transistors,

wherein said plurality of connection paths comprise vias through said second mono-crystallized semiconductor layer,

wherein at least one of said vias is less than about 150 nm in diameter, and

wherein said second transistors comprise horizontally oriented transistors.

9. A semiconductor device according to claim 8 , further comprising:

a plurality of connection paths between said second transistors and said first transistors, and said first semiconductor layer comprising first alignment marks,

wherein at least one of said connection paths has a contact to said second transistors, and

wherein said contact is aligned to one of said first alignment marks.

10. A semiconductor device according to claim 8 wherein said second mono-crystallized semiconductor layer is less than about 150 nm in thickness.

11. A mobile phone comprising a semiconductor device according to claim 8 .

12. A semiconductor device according to claim 8 wherein said second transistors comprise a plurality of N-type transistors and P-type transistors.

13. A semiconductor device according to claim 8 , further comprising:

a heat spreader between said first semiconductor layer and said second mono-crystallized semiconductor layer.

14. A semiconductor device according to claim 8 wherein at least one of said second transistors is one of:

(i) a recessed-channel transistor (RCAT);

(ii) a junction-less transistor;

(iii) a replacement-gate transistor;

(iv) a thin-side-up transistor; or

(v) a double gate transistor.

15. A semiconductor device comprising:

a first semiconductor layer comprising first alignment marks and first transistors, wherein said first transistors are interconnected by at least one metal layer comprising aluminum or copper;

a second mono-crystallized semiconductor layer comprising second transistors and overlaying said at least one metal layer, wherein said at least one metal layer is in-between said first semiconductor layer and said second mono-crystallized semiconductor layer, and

a plurality of connection paths between said second transistors and said first transistors,

wherein said second transistors comprise horizontally oriented transistors, and

wherein at least one of said connection paths has a contact to said second transistors wherein said contact is aligned to one of said first alignment marks.

16. A semiconductor device according to claim 15 wherein said second mono-crystallized semiconductor layer is less than about 150 nm in thickness.

17. A mobile phone comprising a semiconductor device according to claim 15 .

18. A semiconductor device according to claim 15 wherein said second transistors comprise a plurality of N-type transistors and P-type transistors.

19. A semiconductor device according to claim 15 ,

wherein said second mono-crystallized semiconductor layer comprises a plurality of thermal contacts, and

wherein said thermal contacts are adapted to conduct heat but not electric current.

20. A semiconductor device according to claim 15 , further comprising:

a heat spreader between said first semiconductor layer and said second mono-crystallized semiconductor layer.

21. A semiconductor device according to claim 15 , further comprising:

a plurality of connection paths between said second transistors and said first transistors,

wherein said connection paths comprise vias through said second mono-crystallized semiconductor layer, and

wherein at least one of said vias is less than about 150 nm in diameter.

22. A semiconductor device according to claim 15 wherein at least one of said second transistors is one of:

(i) a recessed-channel transistor (RCAT);

(ii) a junction-less transistor;

(iii) a replacement-gate transistor;

(iv) a thin-side-up transistor; or

(v) a double gate transistor.

23. A 3D IC based system comprising:

a first semiconductor layer comprising first alignment marks and first transistors, wherein said first transistors are interconnected by at least one metal layer comprising aluminum or copper;

a second mono-crystallized semiconductor layer comprising second transistors and overlaying said at least one metal layer, wherein said at least one metal layer is in-between said first semiconductor layer and said second mono-crystallized semiconductor layer; and

a reusable donor wafer,

wherein said second transistors comprise horizontally oriented transistors, and

wherein said second mono-crystallized semiconductor layer is transferred from said reusable donor wafer.

24. A system according to claim 23 wherein said second mono-crystallized semiconductor layer is less than about 150 nm in thickness.

25. A system according to claim 23 wherein said second transistors comprise a plurality of N-type transistors and P-type transistors.

26. A system according to claim 23 , further comprising:

a heat spreader between said first semiconductor layer and said second mono-crystallized semiconductor layer.

27. A system according to claim 23 ,

wherein said second mono-crystallized semiconductor layer further comprises a plurality of thermal contacts, and

wherein said thermal contacts are adapted to conduct heat but not electric current.

28. A system according to claim 23 , further comprising:

a plurality of connection paths between said second transistors and said first transistors,

wherein said plurality of connection paths comprise vias through said second mono-crystallized semiconductor layer, and

wherein at least one of said vias is less than about 150 nm in diameter.

29. A system according to claim 23 wherein at least one of said second transistors is one of:

(i) a recessed-channel transistor (RCAT);

(ii) a junction-less transistor;

(iii) a replacement-gate transistor;

(iv) a thin-side-up transistor; or

(v) a double gate transistor.

30. A system according to claim 23 , further comprising:

a plurality of connection paths between said second transistors and said first transistors,

wherein at least one of said connection paths has a contact to said second transistors, and

wherein said contact is also aligned to one of said first alignment marks.