For wireless applications, silicon is as tough to live with as to live without. It struggles to transmit over the high frequency bands increasingly used in communications, but it is also vital for putting filters, switches, and amplifiers all on the same chip, saving power and space.
GlobalFoundries released on Tuesday new tools that let engineers plan out chips that operate over millimeter waves, which could be used in 5G communications. The company, one of the world’s largest chip manufacturers, can produce the chips based on the blueprints.
The underlying technology is called silicon-on-insulator, more commonly known as SOI. Manufacturing it involves wrapping two layers of silicon around an insulator material - using anything from silicon dioxide to sapphire - slashing power leakage and improving efficiency. It has also been used in computer processors and silicon photonics.
GlobalFoundries offers to manufacture chips based on another flavor called RF SOI, designed for radio components, ranging from switches to low-noise amplifiers. These are major parts of the front ends that decipher wireless signals flowing in and out of smartphones and other applications like satellites.
Its latest manufacturing process, 45RFSOI, involves etching circuits only 45 nanometers long onto specialized wafers, almost four times longer than the most advanced computer chips under development by GlobalFoundries. But those microscopic circuits are enough to lift RF SOI into high frequency bands, from 24 to 100 gigahertz, where wireless carriers plan to move after 4G.
The new process is also reflective of how companies plan to give RF SOI an edge over the competition like gallium arsenide. Peregrine Semiconductor revealed the twelfth generation of its technology in January, with the highest linearity and lowest radio losses yet. It worked with GlobalFoundries to mint it on 300-millimeter wafers.
"5G is expected to become the dominant worldwide mobile communications standard of the next decade and will usher in a new paradigm in mobility, said Bami Bastani, senior vice president of GlobalFoundries' RF business, in a statement. RF SOI "will help play a critical role in bringing 5G devices and networks to reality."
45RFSOI improves on earlier technology that had been developed for simpler communication systems. The passive devices built on the manufacturing process have high resistivity that maximizes quality factor – a measure of energy efficiency also known as the Q factor – and minimizes the disparity between phase and voltage.
One of the first chipmakers to sign onto the new process is Skyworks Solutions, a maker of wireless chips for smartphones and connected devices. The company has previously used RF SOI in its switching products, claiming that its efficiency and switching speed are better suited to operate over the growing number of spectrum bands used to send messages and stream video.
Peter Gammel, Skyworks’ chief technology officer, said in a statement that the more advanced process will enable the company to further “advance the deployment of highly integrated RF front-ends for evolving mmWave applications," using an abbreviation for millimeter waves.
GlobalFoundries will produce the technology on 300mm wafers at a factory in East Fishkill, N.Y., which was included in its acquisition of IBM's Microelectronics unit in 2015. Over 27 billion such chips have been shipped since the technology entered production in 2008, the company says. It also offers a process for making silicon-germanium chips favored for certain power amplifiers.
