Novel semiconductor system and device

A 3D IC device comprising:

• a first semiconductor layer comprising first mono-crystallized transistors,
• wherein said first mono-crystallized transistors are interconnected by a plurality of metal layers comprising aluminum or copper;
• a second layer comprising second mono-crystallized transistors and overlaying said plurality of metal layers;
• a plurality of thermally conductive paths from said second mono-crystallized transistors to an external surface of said device,
• wherein said plurality of metal layers is disposed between said first semiconductor layer and said second layer, and
• wherein said first mono-crystallized transistor channels comprise a first atomic material, and said second mono-crystallized transistor channels comprise a second atomic material,
• wherein said first atomic material is substantially different from said second atomic material.

A 3D IC device comprising:

• a first semiconductor layer comprising first mono-crystallized transistors,
• wherein said first mono-crystallized transistors are interconnected by a plurality of metal layers comprising aluminum or copper;
• and
• a second layer comprising second mono-crystallized transistors and overlaying said plurality of metal layers,
• wherein said plurality of metal layers is in-between said first semiconductor layer and said second layer, and
• wherein said second mono-crystallized transistors comprise a silicided source and drain.