Why Heat May Spell Trouble for 3D Integrated Circuits

Mar 5, 2015
Michael Taylor

In a recent article about how "3D stacking offers an extension for Moore's Law," Engineering & Technology Magazine suggests that a move to 3D integrated circuits could offer the closest thing to Moore's Law by reducing the average wire length, and therefore energy. But a computer scientist at UC San Diego cautions in the same article that heat produced by that energy could be a potential major problem. Transistors produce copious amounts of heat when they switch, resulting in big increases in heat production when running at high frequencies. "If you look at graphs of long-term growth in transistor performance," said CSE Prof. Michael Taylor, "you would think we would be able to operate them at 15GHz by now." Instead, even the processors in large servers do not run at more than 3GHz. Added Taylor: "Transistors have this inherent capability but we can't use it because the transistors can't use it becaause they have to stay within a power envelope." The article continues that the "situation has reached the point where, to be able to remove enough heat from the chip to stop individual transistors from cooking themselves to death, a large fraction of the overall device needs to be doing nothing."

Read the original article in Engineering & Technology Magazine.