200mm: The State of the Art—Then and Now
Mike Rosa, Ph.D.
For close to a decade, the 200mm semiconductor state-of-the-art has been in a constant cycle of re-invention. Today’s leading consumer, medical, communications, industrial and automotive products are driving brisk demand for all kinds of devices: MEMS sensors and actuators, power, microfluidic and photonic devices, and technologies for ADAS (Advanced Driver Awareness and Safety), 3D imaging and more. In these emerging technology segments, over the next three years the ≤200mm semiconductor market will have spawned many exciting new devices, including the following:
Table 1. A sampling of the devices to come that will be enabled by advancements in materials engineering.
What do all of these devices have in common?
Each of the devices listed above rely on new materials innovation and high-precision processing to unlock the key attribute enabling their functionality. Applied Materials is committed to enabling future 200mm device production with a number of new chamber technologies aimed at delivering next-generation materials capability. Figure 1 below shows CAD models for a few of these new chambers, including those for 200mm DPS DTM DRIE and III-V Etch, 200mm/300mm DRIE etch, 200mm ATM/RP Epi and pDC/RF PVD.
New DRIE technologies will enable customers to etch exotic materials including SiC, GaN, PZT, AlN, ScAlN etc., while the 300mm capability will find use in applications where yields in conventional 200mm chambers have reached their limits. For example, today the transition from ±0.5° sidewall tilt to ±0.2° has prompted the use of 300mm DRIE chambers for the processing of 200mm MEMS gyro wafers. New Epi and PVD chamber technologies will deliver thick silicon layers up to 150µm, reduced pressure void free trench fill for power devices, and finally the deposition of key PVD films that include PZT, AlN, ScAlN, Al2O3, ITO, VOx and NiFe, to name a few.
Figure 1. Applied’s 200mm Equipment Products Group has a growing portfolio of chamber capabilities focused on delivering key advancements in materials engineering.
Applied Materials is working to deliver on key materials and process challenges such as within-wafer thickness non-uniformity ≤ 0.5%, within-wafer stress range ≤± 75MPa for key AlN and ScAlN films, sidewall profile angles of >80° for exotic materials such as PZT, SiC, GaN and the AlN family of materials.
Beyond the ITRS Roadmap
The 200mm segment has changed considerably from when the ITRS roadmap drove the majority of 200mm device technology developments. Figure 2 shows a basic timeline of products that saw the rise of the 200mm WFE market beyond the confines of Moore’s Law.
Figure 2. Key device technologies made on 200mm WFE continue to extend the life of this legacy manufacturing technology base. (Source: Yole Development©, August 2015)
While mainstream memory and microprocessor technologies migrated to 300mm long ago, many of the ancillary device technologies remained at the 200mm wafer node. This is significant and may predict a lot about the future of our industry—especially as we enter a ‘More-than-Moore’ (MTM) world and contemplate increasing 200mm wafer capacities and the future role of legacy 300mm wafer node technologies.
Advanced 300mm nodes continue to evolve, offering continued productivity and device level performance improvements. But, it is those ancillary 200mm device technologies that are ever present and recognizable from the most humble of 1980s/90s personal computers to the most advanced automotive technologies on the market today. So it is not surprising that we are seeing statistics indicating that >70% of ICs in todays end user devices are being made on 200mm!
Growth in the emerging technology / MTM device market means a changed competitive landscape for equipment OEMs. For many years their attention has been on supporting wafer size migration and by definition, focusing on the largest 300mm wafer customers. What went unnoticed was the steady groundswell of emerging technologies being developed on 150mm and 200mm wafers for MEMS, power, CIS, analog, photonics, microfluidics, etc. While the largest equipment OEMs were focused on 300mm, the smaller equipment players were supporting and developing key technologies for these niche application segments.
Fast forward 10+ years to the mid-to-late 2000’s and the now legacy ≤200mm equipment market is alive and well, and on the cusp of a significant comeback. This resurgence caught the larger production tool OEMs mostly flat footed, with a gap in their knowledge around these once niche markets. Meanwhile the smaller OEMs seized the advantage by having all the on wafer know-how and market positioning required to grow with these newly minted application segments. What companies like Applied Materials lacked in on-wafer know-how, it made up for in globally renowned production experience and reliability.
There is no clear roadmap for ≤200mm technology. New device applications are announced all too frequently and in a variety of rapidly growing segments. The variety of new devices creates another challenge in the characterization of the materials and processes used in their development. On wafer performance of new materials and processes needs to be derived from device level characterization, so it is no longer a luxury to partner with an end customer on technology development—it’s a must.
Figure 3. The DNA of the ≤200mm wafer market today and the future of emerging technology / MTM segments is one based on diversity in device technology enabled by advances in materials engineering.
Today, Applied Materials focuses on materials engineering through early stage collaborations with material vendors, start-up companies, established IDMs and foundries. Often, this is a lengthy iterative approach to problem solving. And, it’s one that is welcomed by the customer base as they also realize that early collaboration is key to overall success.
Figure 3 provides a few high growth device application examples that owe their improved performance or capability to advanced materials development.
Figure 4 shows ≤200mm wafer capacities by region in 2006 and how they are forecast to change by 2018.
Figure 4. SEMI forecasts significant ≤200mm wafer capacity increase in emerging regions like China and the Americas by 2018. Source: SEMI, November 2016
China’s forecast capacity growth is impressive (see figure 5). An aggressive governmental investment policy coupled with an increasingly educated workforce and growing population of returning expatriates demonstrates China is rapidly positioning itself to take advantage of the growth in MTM technology segments. With a growing base of OEM device and system level manufacturers in just about every segment of significance, we may see the center of gravity for ≤200mm wafer manufacturing move eastward.
200mm: What lies ahead?
Some of the most impactful end user technologies the world has known have been ushered in on ≤200mm wafer technology – the personal computer, and a myriad of smartphones, wearables, automotive technologies and so on. With all the new device technologies and application segments on the horizon, the real question may not be about the future of ≤200mm but what’s in store for legacy 300mm wafer fab equipment.
Figure 5. The 300mm Impulse PVD chamber is but one example of a transition path available for MTM technologies that originate on ≤200mm wafer node to take advantage of the scale 300mm wafer size brings.
Figure 6 shows a 300mm RF PVD chamber already used for materials such as Aluminum Nitride (AlN). Such materials support a wide variety of device technologies currently under development and, in some cases production, on 200mm and are ideal candidates for transition to the larger wafer size, where economy of scale can bring further benefits to ASP and volume capability. Within Applied Materials’ 200mm Equipment Products Group, there is considerable effort underway to broaden the MTM roadmap and articulate a clear path toward 300mm capability. Current examples include select applications on PVD and DRIE, where MTM technologies are already beginning to shift or show clear benefit from a transition, to legacy 300mm wafer nodes.
Clearly, some selected MTM technologies will transition to legacy 300mm. When will it happen and for which devices? Not easy questions. But the answers will almost surely be for companies like Applied Materials to provide solutions that leverage experience across 200mm and 300mm platforms and their internal resource capability to develop wafer size-agnostic materials and process solutions.
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