With all the talk about 14/16nm and 10nm it is important to realize that older processes are still important. Eventually 16nm may end up being cheaper than 28nm but for the time being 28nm seems to be a sort of sweet spot, not just cheaper than every process that came before it (which was true for every new node) but also cheaper than every process that will come after it (which is new territory for the semiconductor industry). If you are designing an application processor for a smartphone then you will move to the new nodes as fast as you can. But other markets, in particular products for the internet of things (IoT) don’t need that. They need low power, digital/analog/RF integration and so on. This creates new opportunities in the non-bleeding-edge process geometries.
With the explosive growth phase of smartphones over, IoT is expected to provide a lot of the high growth consumption of semiconductor for the coming few years. PC is nearly flat, smartphone growth will mostly be at the low end of the market with the high end now being mostly a replacement market.
TSMC has introduced ultra-low power versions of some of its mature processes. The current status is that ultra low power versions of 0.18um and 90nm are in production and 50nm, 45nm and 28nm ULP processes will take risk production in 2015. There is also integrated RF and flash. These are especially attractive for IoT designs that need extremely low power and connectivity. Some IoT applications (such as automotive) are not all that power sensitive since there is a large battery available, but others such as wearables require very long periods between recharges, and still others are predicted to need a battery that lasts for the life of the product or they scavenge power from their local environment.
Some details of the process. First they operate at a lower Vdd which reduces both standby and active power (and leakage). They are optimized for the 0.5-0.7V range. The tailored eHVT device enables an over 70% reduction in standby power. However they can also work at higher voltages at 1.1V (40LP) and 1.2V (55LP).
Most IoT designs don’t seem to need really high performance nor billions of transistors since both would consume too much power. But they need the combination of very lower power operation, especially in standby where they will spend most of their life, and RF (since they need connectivity through cellular, WiFi, Bluetooth or some other radio interface).
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So the bottom line is that the new processes are compatible with the existing eco-system at 28HPC. But the operating voltage is reduce by over 20%, active power by over 30%, standby power by over 70% and the capability to build an SoC that includes RF and embedded flash, perfect for the IoT market.