System Bits: Dec. 16

High rise chip
For decades, the mantra of the semiconductor industry has been ‘smaller, faster, cheaper.’ Stanford researchers are also adding ‘taller’ to the mix, and describing how to build high-rise chips that promise to leapfrog the performance of the single-story logic and memory chips on today’s circuit cards.

Stanford researchers said their approach would end the ‘logjams’ between logic and memory by building layers of logic atop layers of memory to create a tightly interconnected high-rise chip. Many thousands of nanoscale electronic “elevators” would move data between the layers much faster, using less electricity, than the bottleneck-prone wires connecting single-story logic and memory chips today.

Stanford engineers have created a four-layer prototype high-rise chip. In this representation, the bottom and top layers are logic transistors. Sandwiched between them are two layers of memory. The vertical tubes are nanoscale electronic “elevators” that connect logic and memory, allowing them to work together to solve problems. (Source: Stanford University)

The researchers’ innovation leverages three breakthroughs, the first of which is a new technology for creating transistors. Second is a new type of computer memory that lends itself to multi-story fabrication. Third is a technique to build these new logic and memory technologies into high-rise structures in a radically different way than previous efforts to stack chips.

The researchers said the work is an early stage, but the design and fabrication techniques are scalable. They believe with further development this architecture could lead to computing performance that is much, much greater than anything available today, and can be mass produced in a way that they said is truly a paradigm shift. Carbon nanotubes are leveraged in their design.

They are describing their work further at at the IEEE International Electron Devices Meeting being held this week.

Organic electronics
In the space of wearable electronics, there are various pulse oximeters already on the market that measure pulse rate and blood-oxygen saturation levels, but those devices use rigid conventional electronics, and they are usually fixed to the fingers or earlobe. Now, UC Berkeley researchers are developing a new organic optoelectronic sensor.

By switching from silicon to an organic, or carbon-based, design, the researchers said they were able to create a device that could ultimately be thin, cheap and flexible enough to be attached like a Band-Aid during a jog or a hike up a hill.

The engineers put the new prototype up against a conventional pulse oximeter and found that the pulse and oxygen readings were just as accurate.

UC Berkeley engineers have created a pulse oximeter sensor composed of all-organic optoelectronics that uses red and green light. The red and green organic light-emitting diodes (OLED) are detected by the organic photodiode (OPD). The device measures arterial oxygen saturation and heart rate as accurately as conventional, silicon-based pulse oximeters. (Source: UC Berkeley)