As the semiconductor industry navigates through what most will remember as its worst downturn in history, industry observers are rushing back to check their scorecards in the "micron wars" that highlighted the boom days of the late '90s.
Certainly there is no denying the importance of the continued advancement of process geometries to the 90nm level and below. The constant decrease in feature sizes to provide increased functionality at lower prices has been the unique factor that has made the semiconductor industry so successful.
From the standpoint of inspiring new design activity and furthering the convergence of applications onto system-on-chip solutions, technology nodes of 90nm and below are absolutely required. Given that the cost of building a state-of-the-art fab to develop and reliably produce these advanced technology nodes is well above $2 billion, the value and role of the outsourced foundry becomes increasingly important.
Both fabless semiconductor companies and integrated device manufacturers (IDMs) are betting their futures on their foundry partners' ability to deliver reliable and volume wafers at these levels.
However, such leading-edge technologies are not always the optimal solution. It is clear that this new era of convergence products has a different set of requirements and drivers, and past metrics born of the stand-alone, simple discrete chips of the PC era may not apply. In fact, many convergence products are a combination of once-separate devices.
With today's multifunction, multi-application, and highly connected products, the system solution is more important than the semiconductor technology node, and the systems aren't homogeneous in terms of their technology needs.
The need for manufacturing solutions that optimally balance cost, performance, and low power, while meeting stringent and rapidly narrowing time-to-market windows, puts an even greater emphasis on the time required to develop these complex SoC solutions. Therefore, some products are more likely and better suited to be implemented in multiple chips rather than having everything on a single chip.
Consider a couple of examples: the notebook PC produced today in large volumes, and the emerging class of Bluetooth-equipped devices targeted for handheld consumer and computer peripheral products. Both require lower costs and smaller sizes while at the same time increased functionality, higher bandwidth, and improved battery life.
These market requirements can generally be met through higher levels of integration using both leading-edge CMOS technologies (0.15 micron and below) and mature digital CMOS processes (0.35 micron and higher). Specialized analog and mixed-signal technologies are also needed because of the power management and high-voltage constraints of peripherals and RFICs.
In the case of the notebook PC, the high level of integration is clearly demonstrated by the increased functionality of the microprocessor and graphics chipset, both of which are currently produced at 0.15 micron and below. However, some critical functions are implemented through discrete chips manufactured on mature technologies.
For example, clock chips are generally manufactured on 0.5-micron technology. The V92 modem"still among the most popular modems shipped today"generally uses 0.35-micron technology. The battery power management chips and LCD driver chips utilize 0.35-micron high- voltage technology. Multimedia functionality, such as audio playback and codecs, and USB ports are often implemented with 0.35-micron mixed-signal chips.
Devices equipped with Bluetooth wireless technology have similar requirements. Consider a current Bluetooth product targeted at office automation applications. It has a baseband controller chip, an RF transceiver chip, and other peripheral circuits.
The baseband chip, which integrates an ARM CPU with memory and various interfaces such as PCM, UART, and USB, is manufactured on advanced technology. However, because the baseband section poses significant challenges in the areas of power, frequency, and noise, RF circuitry is implemented as a separate entity manufactured with 0.35-micron RF CMOS. Other peripheral devices required for the multichip product solution, such as voltage regulators, are also fabricated with mature, specialized technologies.
The cost and performance (including voltage) requirements, as well as the system-level interface issues for chips in convergence products, favor going a different route than that offered by the most advanced processes.
Further, the time-to-market demands in the consumer markets, as well as the pressure to quickly deliver derivative products, make more mature processes a very attractive time-saving alternative. So, it's important that the foundry industry not take its eye off the ball when it comes to what may be considered "less exciting" processes and technology.
Foundries such as Chartered have done well by offering a broad-based technology portfolio that not only consists of leading-edge technologies but also, equally important, offering mature, off-the-shelf processes for applications that are optimized along price/performance and reliability factors.
This saves precious time and money for systems companies, and frees up their resources to address the more demanding SoC design challenges. And, the savings yield higher profits, which in turn generates increased spending on more advanced technologies and fuels a new growth cycle in the industry.
Mike Rekuc is president of the Americas at Chartered Semiconductor Manufacturing Ltd. in Milpitas, Calif.