Method of forming three dimensional integrated circuit devices using layer transfer technique
A method for formation of a semiconductor device including a first wafer including a first single crystal layer comprising first transistors and first alignment mark, the method including: implanting to form a doped layer within a second wafer; forming a second mono-crystalline layer on top of the first wafer by transferring at least a portion of the doped layer using layer transfer step, and completing the formation of second transistors on the second mono-crystalline layer including a step of forming a gate dielectric followed by second transistors gate formation step, wherein the second transistors are horizontally oriented.
1. A method for formation of a semiconductor device, the method comprising:
providing a first wafer comprising a first single crystal layer comprising first transistors and at least one first alignment mark;
implanting to form a doped layer within a second wafer;
forming a second mono-crystalline layer on top of said first wafer by transferring at least a portion of said doped layer using a layer transfer step, and
completing formation of second transistors on said second mono-crystalline layer comprising a step of forming a gate dielectric followed by a second transistors gate formation step,
wherein said second transistors are horizontally oriented.
2. The method according to claim 1 , comprising providing at least one metal layer overlying said first single crystal layer, wherein said at least one metal layer comprises copper or aluminum; and provides an interconnection for said first transistors.
3. The method according to claim 1 , wherein at least one of said second transistors is a p-type transistor and at least one of said second transistors is an n-type transistor.
4. The method according to claim 1 , comprising:
forming a first logic circuit comprising at least a portion of said first transistors; and
forming a second logic circuit comprising at least a portion of said second transistors, wherein said second logic circuit overlays said first logic circuit, and
performing a step of replacing:
said first logic circuit by said second logic circuit, or replacing said second logic circuit by said first logic circuit.
5. The method according to claim 1 , wherein at least one of said second transistors has a double gate.
6. The method according to claim 1 , wherein at least one of said second transistors is a Finfet type transistor.
7. The method according to claim 1 , comprising a step of forming a thermal contact to said second mono-crystalline layer,
wherein said thermal contact is designed to conduct heat but to not conduct electricity.
8. The method according to claim 1 , comprising a step of depositing at least one electrical isolation region between at least two of said second transistors, wherein said electrical isolation region is designed to conduct heat.
9. The method according to claim 1 , comprising a step of depositing a heat spreader layer between said second mono-crystalline layer and said first single crystal layer.
10. The method according to claim 1 , comprising a step of forming at least one thermally conductive path between a power bus and an isolation layer between two of said second transistors.
11. The method according to claim 1 , comprises a memory array comprising said second transistors, wherein said memory array is a floating body DRAM array.
12. The method according to claim 1 , comprising implementing a logic design on said device, wherein said step of implementing comprises a synthesis step utilizing at least two libraries, wherein one of said libraries utilized more aggressive design rules than the other.
13. The method according to claim 1 , comprising designing at least one power bus based on heat removal criteria.
14. The method according to claim 1 , comprising forming at least three metal layers between said first single crystal layer and said second mono-crystalline layer, wherein said at least three metal layers comprises a metal three layer overlying a metal two layer overlying a metal one layer, said metal three layer comprising a metal three pitch, said metal two layer comprising a metal two pitch, said metal one layer comprising a metal one pitch, and wherein said metal two pitch is smaller than said first metal pitch and said third metal pitch.
15. A method for formation of a semiconductor device, the method comprising:
a first wafer comprising a first mono-crystalline layer comprising first transistors, and
comprising a step of implant to form second transistors within a second mono-crystalline layer, and
transferring the second mono-crystalline layer on top of said first mono-crystalline layer,
wherein said method comprises using at least ten masks, each with its own unique patterns, and
wherein said method is used for formation of at least two devices which each have a substantially different amount of logic, memory or Input-Output cells, and
wherein each of said two devices has been formed using said at least ten masks, and
wherein said two devices have the same number of mono-crystalline layers.
16. The method according to claim 15 , comprising the step of formation of dice lines by etching pre-patterned layers.
17. The method according to claim 15 , wherein at least one of said two devices comprises unused potential dice lines.
18. The method according to claim 15 , wherein the formation of at least one of said two devices comprises the step of using a custom mask to form at least one connection over unused potential dice lines, and wherein the formation of the other of said two devices does not use said custom mask.
19. The method according to claim 15 , wherein at least one of said two devices comprises at least two micro-control-units (MCUs), and wherein said two micro-control-units comprise a fixed interconnection between them.
20. The method according to claim 15 , further comprising the step of forming a Through Silicon Via (TSV) to form a connection between said second transistors and said first transistors.