SoylentNews

takyon [soylentnews.org] writes:

Researchers at three different schools have created a microprocessor that integrates transistors and photonic components for on-chip communication [hpcwire.com]:

In the paper – "Single-chip microprocessor that communicates directly using light" – researchers from UC Berkeley, University of Colorado, and MIT report fabricating an electronic–photonic system on a single chip integrating over 70 million transistors and 850 photonic components that work together to provide logic, memory, and interconnect functions. Most significantly, they did it with standard CMOS manufacturing techniques.

Talking about the impact of the work, Miloš Popovic a co-author on the study from the University of Colorado told HPCwire, "This work is directly aimed at the energy problem in supercomputers. It will enable reducing the communication energy by about an order of magnitude, and will make communication energy independent of distance of a link — up to 100's of meters. So, it's definitely part of the exascale computing story."

The chip was fabricated using a commercial high-performance 45-nm complementary metal–oxide semiconductor (CMOS) silicon-on-insulator (SOI) process. The authors write: "No changes to the foundry process were necessary to accommodate photonics and all optical devices were designed to comply with the native process-manufacturing rules. This 'zero-change' integration enables high-performance transistors on the same chip as optics, reuse of all existing designs in the process, compatibility with electronics design tools, and manufacturing in an existing high-volume foundry."

[...] The new chip has a bandwidth density of 300 gigabits per second per square millimeter, about 10 to 50 times greater than packaged electrical-only microprocessors currently on the market.

The big news is the relative ease of manufacture. "This "zero change" approach to integration enables complex electronic-photonic systems on chip to be designed today, in an advanced CMOS foundry. This means high yield, immediate transition to volume production, and the most advanced transistors of any photonic chip (and the largest number of them). These qualities should open up research into systems on chip in many applications including RF signal processing, radar/lidar applications, sensing and imaging, etc.

The authors note, "By showing that a microprocessor with photonic I/O is possible to build today, we're illustrating the power of this approach. Incidentally, while we expected photonic devices to not perform as well using this approach as using fabrication customized to photonics, it turns out that in a number of cases they perform better — leveraging the high resolution implant masks, controlled sub-100nm CMOS deep UV lithography, and rich set of material and mask levels available in CMOS."

Single-chip microprocessor that communicates directly using light [nature.com] (DOI: 10.1038/nature16454)

Related: Light-based Memory Chip is the First Ever to Store Data Permanently [soylentnews.org]

Original Submission