By Pete Singer, Editor-in-Chief

A new roadmap, the Heterogeneous Integration Technology Roadmap for Semiconductors (HITRS), aims to integrate fast optical communication made possible with photonic devices with the digital crunching capabilities of CMOS.

The roadmap, announced publicly for the first time at The ConFab in June, is sponsored by IEEE Components, Packaging and Manufacturing Technology Society (CPMT), SEMI and the IEEE Electron Devices Society (EDS).

Speaking at The ConFab, Bill Bottoms, chairman and CEO of 3MT Solutions, said there were four significant issues driving change in the electronics industry that in turn drove the need for the new HITRS roadmap: 1) The approaching end of Moore’s Law scaling of CMOS, 2) Migration of data, logic and applications to the Cloud, 3) The rise of the internet of things, and 4) Consumerization of data and data access.

“CMOS scaling is reaching the end of its economic viability and, for several applications, it has already arrived. At the same time, we have migration of data, logic and applications to the cloud. That’s placing enormous pressures on the capacity of the network that can’t be met with what we’re doing today, and we have the rise of the Internet of Things,” he said. The consumerization of data and data access is something that people haven’t focused on at all, he said. “If we are not successful in doing that, the rate of growth and economic viability of our industry is going to be threatened,” Bottoms said.

These four driving forces present requirements that cannot be satisfied through scaling CMOS. “We have to have lower power, lower latency, lower cost with higher performance every time we bring out a new product or it won’t be successful,” Bottoms said. “How do we do that? The only vector that’s available to us today is to bring all of the electronics much closer together and then the distance between those system nodes has to be connected with photonics so that it operates at the speed of light and doesn’t consume much power. The only way to do this is to use heterogeneous integration and to incorporate 3D complex System-in-Package (SiP) architectures.

The HITRS is focused on exactly that, including integrating single-chip and multi­chip packaging (including substrates); integrated photonics, integrated power devices, MEMS, RF and analog mixed signal, and plasmonics. “Plasmonics have the ability to confine photonic energy to a space much smaller than wavelength,” Bottoms said. More information on the HITRS can be found at: http://cpmt.ieee.org/technology/heterogeneous-integration-roadmap.html

Bottoms said much of the technology exists today at the component level, but the challenge lies in integration. He noted today’s capabilities (Figure 1) include Interconnection (flip-chip and wire bond), antenna, molding, SMT (passives, components, connectors), passives/integrated passive devices, wafer pumping/WLP, photonics layer, embedded technology, die/package stacking and mechanical assembly (laser welding, flex bending).

Building blocks for integrated photonics.

“We have a large number of components, all of which have been built, proven, characterized and in no case have we yet integrated them all. We’ve integrated more and more of them, and we expect to accelerate that in the next few years,” he said.

He also said that all the components exist to make very complex photonic integrated circuits, including beam splitters, microbumps, photodetectors, optical modulators, optical buses, laser sources, active wavelength locking devices, ring modulators, waveguides, WDM (wavelength division multiplexers) filters and fiber couplers. “They all exist, they all can be built with processes that are available to us in the CMOS fab, but in no place have they been integrated into a single device. Getting that done in an effective way is one of the objectives of the HITRS roadmap,” Bottoms explained.

He also pointed to the potential of new device types (Figure 2) that are coming (or already here), including carbon nanotube memory, MEMS photonic switches, spin torque devices, plasmons in CNT waveguides, GaAs nanowire lasers (grown on silicon with waveguides embedded), and plasmonic emission sources (that employ quantum dots and plasmons).

New device types are coming.

The HITRS committee will meet for a workshop at SEMICON West in July.