In the era of AI and 5G, how does GlobalFoundries create the future of the silicon photonics world?

When we talk about GlobalFoundries, everyone in the industry knows that they are one of the world's leading wafer foundries. In terms of product lines, they not only have mature planar transistor manufacturing processes, but also have high-performance FinFET processes. In addition, GlobalFoundries has also made a name for itself in FD-SOI and many special processes over the years. This has helped them expand their presence in markets such as AI, 5G, and the Internet of Things, and position themselves for the next round of technological revolution.

But in fact, in addition to the above technologies, GlobalFoundries has quietly gained a lot of market share in a new process that has attracted much attention, that is, silicon photonics manufacturing. According to a report by Digitimes in May this year, GlobalFoundries has a 10% share of the global silicon photonics wafer foundry market, and all this stems from a decision made by the company many years ago.

Nine years of hard work, two major platforms

Before talking about GlobalFoundries' silicon photonics layout, let's first understand this technology.

According to CCID's report, silicon photonics, or silicon-based optoelectronics, refers to a new technology that uses silicon CMOS technology to develop and integrate optoelectronic devices on silicon and silicon-based substrate materials. Because it has the foundation of mature microelectronics technology, high integration, and low price, and also has the advantages of extremely high bandwidth, ultra-fast rate, anti-interference, and low power consumption of optoelectronics, in the post-Moore's Law era when microelectronics technology is approaching a bottleneck, it is favored by companies such as Intel, Huawei, Cisco, and Nokia. GlobalFoundries is an important part of this market because they provide customers with highly competitive silicon photonics product manufacturing solutions.

Anthony Yu, vice president of Silicon Photonics Product Line at GlobalFoundries, also told several media including Semiconductor Industry Watch at a media conference held earlier that their silicon photonics development history can be traced back to 2012. At that time, they agreed to cooperate with IME to realize the production of 180nm SiPh (SiPh is the English abbreviation of Silicon Photonics) hybrid solutions on the company's eight-inch CMOS product line in Singapore.

In the following years, GlobalFoundries has made steady progress in SiPh manufacturing, especially after the acquisition of IBM Microelectronics in 2015, which has further strengthened GlobalFoundries' strength in silicon photonics manufacturing.

Data shows that GlobalFoundries acquired approximately 16,000 patents and applications in the acquisition of IBM Microelectronics, including IBM's IP in silicon photonics and their more than ten years of R&D experience in the SiPh field, which laid the foundation for their subsequent development of silicon photonics.

After years of accumulation, GlobalFoundries has finally launched the 90WG first-generation silicon photonics platform and the next-generation silicon photonics manufacturing platform based on 45RFSOI. It provides support for multiple fields such as data centers, 5G, communications, high-performance computing, TOF sensors and lidar. Anthony Yu told reporters: "From the current development, the company's process applications in the three fields of data centers, 5G, and communications are relatively mature, both in terms of IP and packaging technology. But in other application areas, all technologies still need to be further promoted." 

Among them, the 90WG platform is a process platform built by the company using the 90nm RFSOI process.

They point out that this platform can support 100Gb/s per wavelength, so it can support client data rates of up to 800Gbps. Specifically, it has the following advantages:

1. Single-chip integration of RF, digital, silicon photonics and fiber coupling; 2. Optoelectronic PDK, currently supporting the co-design of optoelectronic components at 1310nm wavelength; 3. Significant investment in wafer manufacturing to package integration, including wafer characterization, which can fine-tune the SiPh manufacturing process based on real-time measurement results; 4. Rapid prototyping;

Anthony Yu also said in May this year: "In the Fishkill factory, GlobalFoundries has achieved mass production of this process on 300mm wafers. GlobalFoundries has done a lot of work not only to position itself as a trusted manufacturing service provider, but also to design and prepare various related optical transmission components for commercial mass production."

GlobalFoundries' next-generation silicon photonics platform will be based on the 45RFSOI process.

According to reports, a major optimization of this generation of process is the germanium module, which helps to improve performance. At the same time, it can also help customers build truly high-performance photodetectors. Achieve first-class optoelectronic performance. In an interview, Anthony Yu, vice president of GlobalFoundries, revealed that the company's next-generation monolithic integrated silicon photonics technology based on 45RFSOI will be produced in Fab 8 in Malta, New York, and is scheduled to complete production process certification in the second half of 2021.

During the discussion, Anthony Yu repeatedly emphasized the advantages of "monolithic integration" of GF's silicon photonics platform. He pointed out that unlike other competitors who simply package discrete optical and electrical components together when manufacturing silicon photonics devices, GF's silicon photonics solution directly implements optoelectronic devices on a single die. "This solution not only solves the problems of parasitic capacitance and ESD caused by multi-chip packaging, but also has many advantages such as smaller package size, better cost and reliability," said Anthony Yu.

"In addition to providing silicon wafers, we can also provide services such as silicon photonics integration, packaging and testing. Our goal is to become a solution provider, not just a silicon wafer provider," Anthony Yu told reporters.

Hand in hand with customers

The reason why GlobalFoundries has invested in the field of silicon photonics and its business has developed rapidly in the past four years has a lot to do with the huge development prospects of this industry.

According to data from the well-known analysis agency Yole, the global silicon photonics market was $480 million in 2019, of which data center optical modules dominated. However, they estimate that by 2025, the entire market size is expected to reach $3.9 billion, of which data center optical modules will account for more than 90% of the market.

Yole also expressed its optimism in the report about co-packaged optics that use digital chips to package optical inputs and outputs. This is exactly what GlobalFoundries and its partners are working towards. For example, Ayar Labs and GlobalFoundries are working together to develop a single-chip solution that can be mass-produced, which is one of the representatives.

As the world's first company to use silicon photonics technology to achieve signal optical interconnection between chips, Ayar Labs hopes to replace copper cables with optical I/O "chips" and multi-port, multi-wavelength lasers to achieve orders of magnitude improvement in data transmission density, bandwidth, latency, and energy efficiency. Terabit PHY is their first product, and GlobalFoundries' 45nm RF SOI is the driving force.

According to Mark Wade, CEO of Ayar Labs, RF SOI CMOS is an enabling technology because it allows us to build transistors and optical devices in the same planar layer. In addition, the SOI process also helps to achieve ultra-fast transistors, which are faster than most advanced process nodes.

Now, Ayar Labs and GF are working together to develop GF's next-generation silicon photonics platform based on 45 RFSOI. Wade said: "We are working with GF on a number of projects, hoping to combine the results of the pilot phase work on 45nm RF SOI with some of the technologies and processes that GF acquired through the acquisition of IBM Research to create a highly reliable and manufacturable process to build our solutions in the next-generation platform."

In addition, GlobalFoundries is also working with companies such as MACOM to apply silicon photonics technology to more fields. At this critical point in technological change, let us look forward to the arrival of a better world of silicon photonics.