In addition to the company’s efforts to get its own next generation FinFET process technology up and running, GlobalFoundries announced that will continue to pursue FD-SOI process technology with the addition of a 12nm FD-SOI (FDX in GlobalFoundries parlance) node to its roadmap with a slated release of 2019 at the earliest.
FD-SOI stands for Fully Depleted Silicon On Insulator and is a planar process technology that uses a thin insulator on top of the base silicon which is then covered by a very thin layer of silicon that is used as the transistor channel. The promise of FD-SOI is that it offers the performance of a FinFET node with lower power consumption and cost than other bulk processes. While the substrate is more expensive with FD-SOI, it uses 50% of the lithography layers and companies can take advantage of reportedly easy-to-implement body biasing to design a single chip that can fulfill multiple products and roles. For example, in the case of 22FDX – which should start rolling out towards the end of this year – GlobalFoundries claims that it offers the performance of 14 FinFET at the 28nm bulk pricing. 22FDX is actually a 14nm front end (FEOL) and 28nm back end of line (BEOL) combined. Notably, it purportedly uses 70% lower power than 28nm HKMG.
A GloFo 22nm FD-SOI "22FDX" transistor.
The FD-SOI design offers lower static leakage and allows chip makers to use body biasing (where substrate is polarized) to balance performance and leakage. Forward Body Biasing allows the transistor to switch faster and/or operate at much lower voltages. On the other hand, Reverse Body Biasing further reduces leakage and frequency to improves energy efficiency. Dynamic Body Biasing (video link) allows for things like turbo modes whereby increasing voltage to the back gate can increase transistor switching speed or reducing voltage can reduce switching speeds and leakage. For a process technology that is aimed at battery powered wearables, mobile devices, and various Internet of Things products, energy efficiency and being able to balance performance and power depending on what is needed is important.
22FDX offers body biasing.
While the process node numbers are not as interesting as the news that FD-SOI will continue itself (thanks to marketing mucking up things heh), GlobalFoundries did share that 12FDX (12nm FD-SOI) will be a true full node shrink that will offer the performance of 10nm FinFET (presumably its own future FinFET tech though they do not specify) with better power characteristics and lower cost than 16nm FinFET. I am not sure if GlobalFoundries is using theoretical numbers or compared it to TSMC’s process here since they do not have their own 16nm FinFET process. Further, 12FDX will feature 15% higher performance and up to 50% lower power consumption that today’s FinFET technologies. The future process is aimed at the “cost sensitive mobile market” that includes IoT, automotive (entertainment and AI), mobile, and networking. FD-SOI is reportedly well suited for processors that combine both digital and analog (RF) elements as well.
Following the roll out of 22FDX GlobalFoundries will be preparing its Fab 1 facility in Dresden, Germany for the 12nm FD-SOI (12FDX) process. The new process is slated to begin tapping out products in early 2019 which should mean products using chips will hit the market in 2020.
The news is interesting because it indicates that there is still interest and research/development being made on FD-SOI and GlobalFoundries is the first company to talk about next generation process plans. Samsung and STMicroelectronics also support FD-SOI but have not announced their future plans yet.
If I had to guess, Samsung will be the next company to talk about future FD-SOI as the company continues to offer both FinFET and FD-SOI to its customers though they certainly do not talk as much about the latter. What are your thoughts on FD-SOI and its place in the market?
Also read: FD-SOI Expands, But Is It Disruptive? @ EETimes