3D Circuits To Keep Up With Moore's Law

from the exponential-growth dept

The limits of Moore's Law won't start closing in until about 2020-2030, according to reports from Intel researchers, when either silicon-based chips are expected to be made using 10-15 nanometer scale manufacturing processes or chipmakers figure out how to use other elements in the periodic table to control electrons. By using current materials, though, transistors smaller than about 5 nanometers begin to lose their ability to perform reliably due to quantum effects interfering. So while finding more exotic materials to incorporate into chips could help to extend performance, the ultimate demise of Moore's Law as it applies to transistors may be brought on by other revolutionary technologies in computation -- such as optical computing, quantum computing, etc.

That said, Stanford researchers have made some notable progress with nanotube-based 3D circuits which demonstrates the feasibility of using carbon nanotubes for logic circuits. The prototype nanotube chip is still primitive compared to commercial silicon processors, but the newly-developed techniques to process nanotubes are the first that could be scaled beyond a one-of-a-kind demonstration chip. The process used to make this 3D nanotube circuit is compatible with the industrial VLSI (very large scale integration) manufacturing standard, and so the researchers call their method a VLSI-compatible Metallic Nanotube Removal (VMR) process. One of the problems of using nanotube transistors is that the composition of nanotubes often contains undesirable tubes that have metallic behavior. Removing these metallic nanotubes is necessary to avoid short-circuits, and doing so opens up the possibilities for incorporating carbon structures in chips.

Obviously, nanotube manipulation and synthesis techniques will have to be much better to start competing with commercial silicon processor performance. But creating 3D circuit designs using molecular materials could result in extremely high-density connections with improved speed and energy efficiency.