Three-dimensional stacked structured ASIC devices and methods of fabrication thereof
A 3D stacked sASIC is provided that includes a plurality of 2D reconfigurable structured structured ASIC (sASIC) levels interconnected through hard-wired arrays of 3D vias. The 2D sASIC levels may contain logic, memory, analog functions, and device input/output pad circuitry. During fabrication, these 2D sASIC levels are stacked on top of each other and fused together with 3D metal vias. Such 3D vias may be fabricated as through-silicon vias (TSVs). They may connect to the back-side of the 2D sASIC level, or they may be connected to top metal pads on the front-side of the 2D sASIC level.
1. An IC assembly, comprising:
two or more structured ASIC dies that are vertically arranged and interconnected by hard-wired vertical vias to form a 3D stack and that are further interconnected by a 3D application-specific interconnection pattern, wherein:
each of the dies includes a plurality of metallization layers;
one adjacent pair of metallization layers in each of the dies is interconnected by a mask-programmed pattern of vias; and
the mask-programmed via patterns of the respective dies collectively define all mask-programmable routing for the 3D application-specific interconnection pattern.
2. The assembly of claim 1 , wherein adjacent dies are bonded together by front-side top-metal pads and by back-side bond pads that are connected to through-silicon vias (TSVs).
3. The assembly of claim 2 , wherein each of the dies includes a regular structured array of top-side vias aligned with a regular back-side array of TSVs, and wherein each of the arrays is arranged symmetrically about at least one horizontal axis.
4. The assembly of claim 1 , wherein at least some of the hard-wired vertical vias are through-silicon vias.
5. The assembly of claim 1 , further comprising a top-side array of contact pads and a bottom-side array of contact pads, wherein each of the contact pads is connected to at least one hard-wired vertical via.
6. The assembly of claim 1 , wherein each of the dies comprises:
a silicon or silicon-on-insulator substrate having a back side;
a vertical sequence of metallization layers that overlie the substrate and are interconnected by vias;
an array of contact pads arranged on the back side and connected to the metallization layers by through-silicon vias; and
an array of contact pads that are arranged on a top side of the die opposite the bottom side and are connected to the metallization layers by a pattern of vias.
7. The assembly of claim 6 , wherein the top-side and bottom-side contact pads are arranged in mutual alignment such that each pad on one side is paired with a corresponding pad on the other side.
8. The assembly of claim 7 , wherein:
each die includes at least one master tile containing logic gates, memory, and metallization patterns for signal and power distribution;
each master tile is adjacent to and connected with some of the paired top-side and bottom-side contact pads; and
each die includes further pairs of top-side and bottom-side contact pads arranged in at least one array situated near an edge of the die.
9. The assembly of claim 8 , further comprising a plurality of vias arranged peripherally on each of the dies, wherein said further vias are connected to corresponding front-side and back-side contact pads and are conformed for power delivery and ground connections.
10. The assembly of claim 9 , further comprising a redundant arrangement of top-side bond pads for the vertical distribution of power and I/O signals.
11. The assembly of claim 9 , wherein the assembly is subdivided into four separate power domain quadrants.
12. A method for making an IC assembly, comprising:
forming two or more structured ASIC dies, wherein each of the dies includes a plurality of metallization layers and wherein one adjacent pair of metallization layers in each of the dies is interconnected by a mask-programmed pattern of vias; and
vertically arranging the structured ASIC dies and interconnecting them by hard-wired vertical vias so as to form a 3D stack,
wherein the forming step comprises programming the mask programmed via pattern in each of the dies so as to collectively define, over all of the programmed patterns, all mask-programmable routing for a 3D application-specific interconnection pattern in the stack.
13. The method of claim 12 , wherein the forming step further comprises adding a top-side array of contact pads and a bottom-side array of contact pads to each of the structured ASIC dies and connecting each of the contact pads to at least one hard-wired vertical via.
14. The method of claim 12 , wherein the forming step further comprises, for each of the structured ASIC dies:
providing a silicon or silicon-on-insulator substrate having a back side;
forming the metallization layers in a vertical sequence that overlies the substrate;
interconnecting the metallization layers with vias;
forming an array of contact pads arranged on the back side and connected to the metallization layers by through-silicon vias; and
forming an array of contact pads that are arranged on a top side of the die opposite the bottom side and are connected to the metallization layers by a pattern of vias,
wherein the top-side and bottom-side contact pads are arranged in mutual alignment such that each pad on one side is paired with a corresponding pad on the other side.
15. The method of claim 14 , wherein the step of vertically arranging and interconnecting
the structured ASIC dies comprises face-to-face stacking of dies and face-to-back stacking of dies.
16. The method of claim 12 , wherein the step of vertically arranging and interconnecting
the structured ASIC dies comprises wafer-to-wafer assembly.
17. The method of claim 12 , wherein the step of vertically arranging and interconnecting
the structured ASIC dies comprises die-to-wafer assembly.
18. The method of claim 12 , wherein the step of vertically arranging and interconnecting
the structured ASIC dies comprises die-to-die assembly.