Under the guidance of Moore's Law, the line width of integrated circuits is constantly reducing, to 70% of the original size every two years. For example, it reached 45nm in 2007, 32nm in 2009, and 22nm in 2011. The 28nm process is between 32nm and 22nm. At 45nm (HKMG) and 32nm nodes, the industry introduced the high-k/metal gate process, which laid the foundation for the gradual maturity of 28nm. 2013 was the year of 28nm process popularization. Between 2015 and 2016, the 28nm process began to be used in mobile phone application processors and basebands at scale. The wafer planar process can be most cost-effective at 28nm. For the subsequent 16/14nm requiring FinFET process, the cost of wafer manufacturing will increase by at least 50%. Only applications with huge volumes such as mobile phones can absorb the cost. In many related non-consumer applications, 28nm offers good value for money for its balance between reliability, performance, and cost.
With the maturity of 28nm process technology, the market demand for 28nm products has seen explosive growth, which continued to 2017. From 2015 to 2016, the main applications for 28nm process were still mobile phone processors and basebands. After 2017, although the application of 28nm technology in the mobile area declined, its applications in other fields such as OTT boxes and smart TVs increased rapidly. Worldwide production capacity by supplier is shown below. The huge capacity makes these suppliers well prepared for future development of more emerging applications.
Figure 1: Advanced technology capacity, 28 nanometer and below (includes 32-nanometer)
Main 28nm chips in China and new chips likely to be seen in the next five years
From the global pure-play foundry revenue trends, except for the high gross profit of the most advanced technology led by TSMC, the revenue of most global foundries mainly comes from reliable and mature process. Pure-play foundries such as UMC, Global Foundries, and SMIC have steadily improved performance and introduced new products on 28nm (and related derivative processes) to meet different customer demands.
Figure 2: Pure-play foundry revenue growth rates 2013‒23
Omdia observed that the following will be the most common 28nm products, and 28nm is expected to have a long lifespan on these products due to its perfect balance between cost and performance.
With the improvement of mobile phone configuration and the continuous growth of global OLED panel production capacity, OLED growth will drive demand for OLED drivers. Currently, OLED drivers come mainly from Korean manufacturers. 28nm will become the mainstream for high-end OLED drivers in the next three to five years (low power consumption, smaller SRAM size).
Figure 3: Smartphone OLED long-term demands
The explosion of IoT applications and traditional home appliance upgrades is driving demand for wireless connections such as Wi-Fi and Bluetooth from various devices. At present, the mainstream wireless connection technologies are migrating to 28nm. Future upgrades of industrial and consumer products will inevitably drive high demand for wireless connection.
FPGA has a huge space in various proprietary application areas, such as hybrid computing centers, wireless base stations, and autonomous vehicles, in which the 28nm process, featuring high performance and low power consumption, is an ideal option.
Navigation (GNSS, BeiDou, GPS)
With the success of China's homegrown BeiDou Navigation Satellite System, more BeiDou-compatible devices will be available. At present, all navigation chips, especially those supporting BeiDou navigation systems, use 28nm or more advanced processes, which means the prospect of 28nm in this area is bright.
5G mobile phones have entered a period of rapid growth; however, there is still huge potential for 4G phones to achieve sales growth, and most 4G transceivers use 28nm process.
There is growing demand for the combination of cloud and edge and local edge computing. At present, edge computing generally has basic artificial intelligence analysis capabilities. 28nm has its advantage in this kind of scenario requiring relatively strong local data collection and preliminary logic computing capabilities.
NB-IoT, LoRA, Cat.1, eMTC
SoC chips conforming to commonly used IoT protocols are mainly on 28nm, which will continue to be the mainstream choice for a long time.
Emerging applications and market trends in the next five years
Hardware upgrades of mobile phones, the rise and popularization of Internet of Things, and more emerging applications in recent years are giving birth to the next period of strong demand for 28nm.
Figure 4: Key applications 2023 market size
While 28nm process is good value for money, competition among OEMs at this node is increasingly fierce. In addition to TSMC, UMC, Samsung, GlobalFoundries, and SMIC, Hua Hong has also entered this battlefield.
When the semiconductor industry moves to 28nm, Moore's Law meets a different situation: for more advanced nodes such as 20, 16, 14, 10, and 7nm, the cost of each transistor in the integrated circuit will not fall but rise.
In the face of FinFET challenges, Samsung and GlobalFoundries launched FD-SOI successively. For the SOI process, 28nm provides more advantages and lasts longer. Moreover, as the process evolves further, SOI will be more advantageous. 28nm can be regarded as a turning point, at which the process can be easily converted to SOI.
In the future, commercial 5G will help to build a fully digital connected world. As the basic, chips will increasingly be used in various technology upgrades and innovations. The evolution of advanced process driven by the mobile phone industry and the ubiquitous computing and connectivity from the Internet of Everything will be key drivers for the future semiconductor industry. Undoubtedly, 28nm will provide a solid foundation for Internet of Everything.