iPhone 15 Pro Max: Is TSMC's 3nm Process to Blame for the Heat?

In the race of semiconductor manufacturing, as companies strive for advanced technologies, the latest 3nm devices from TSMC seem to be facing TSMC 3nm overheating challenges. This has come to light especially after iPhone 15 users report devices overheating after just 30 minutes of use. What challenges does shrinking transistors introduce, what has been reported from 3nm devices, and could this be a showstopper?

What challenges do shrinking transistors introduce?

It is well understood by engineers that reducing the size of transistors is essential for creating next-generation technologies. Smaller transistors allow for more active circuits to be put onto a single die and thus allow for more complex applications. 

Reducing the size of transistors is not just about achieving miniaturisation but also about addressing the heat challenges that come with it. While smaller transistors are pivotal in mobile technologies due to their reduced power consumption, which in turn helps to extend battery life, they also present their own set of challenges.

At the same time, reducing the size of transistors reduces the overall energy consumed by each transistor. It is for this reason alone that makes small transistors critical in mobile technologies, as lower power consumption helps to increase battery life, which also allows for smaller batteries to be used. 

But reducing transistors also introduces a number of issues, such as the need for shorter wavelength UV light (used during lithography), challenges faced with quantum tunnelling, and reliability issues with point defects in semiconductor wafers. The result of all these challenges is that modern semiconductor fabrication is monumentally expensive, with only a few companies in the world being able to invest and produce devices.

However, one issue that many often overlook is overheating. Even though smaller transistors consume less energy than their predecessors, the packing of more transistors into the same space actually results in an overall increase in heat generation, and this is commonly seen in desktop computers, which have evolved to require high-capacity heat sinks and fans (in some cases, liquid cooling).

The dilemma of advanced semiconductor nodes and heat dissipation is a growing concern in the industry. As transistors become tinier, the density increases, leading to more heat generation in a confined space, which poses significant challenges for engineers and designers.

Thus, designing smaller semiconductor nodes also requires engineers to think about heat dissipation. In fact, when designing semiconductors, it is important to consider how active key areas are in a design. If hotspots can form in a design, not only is there an increased risk of thermal damage, but the part’s lifespan can also be reduced. 

Recent reports have shed light on the heating issues faced by devices using the TSMC 3nm process. Specifically, the iPhone 15 Pro Max has been observed to experience significant thermal throttling, especially during intensive tasks like gaming. Chinese reviewer Geekerwan's tests showed that the device's surface temperature can reach up to 48°C when playing high-end games like Genshin Impact. This is concerning, especially when considering the potential risks associated with overheating, such as battery damage and reduced device lifespan.

TSMC under fire for hot 3nm parts

Currently, only a handful of devices around the world utilise 3nm parts, and arguably, one of the most iconic of these is the iPhone 15. The use of 3nm has allowed for multiple high-performance cores, AI cores, and much more to be packed into a tiny SoC called the A17 Pro. 

However, users of the iPhone 15 have reported that after 30 minutes of use, the mobile processor reaches temperatures exceeding 48˚C. While this temperature may be perfectly acceptable for semiconductor devices, in a mobile application, this temperature rise is potentially disastrous. 

To start, a hot mobile device carries the risk of damaging internal batteries. As these are based on lithium-ion, it is possible for such a temperature rise to trigger a positive feedback loop that results in total battery failure. Secondly, a 48˚C processor placed in a pocket can get toasty very quickly and may even lead to contact burns if not addressed. Processors that reach this temperature may then need to throttle their performance, and this will see the device suffer significantly when running apps.

But why is the A17 Pro overheating so badly? Well, many have pointed their finger at the TSMCs 3nm process, which may not be suitable for such applications. As transistor heating is a direct result of energy losses through leakage current, and that Apple has no control over the physical construction of transistors, it is likely that the TSMCs 3nm transistor process is flawed when used in high-performance applications.

Some engineers have pointed out that the use of Fin-FET technologies in the 3nm devices by TSMC could be the culprit, and this could very well signal the end of Fin-FET in 3nm and beyond. If TSMC continues to use Fin-FET for its upcoming process nodes, this overheating problem may persist into future devices. However, TSMC has stated that it will be moving towards Gate All Around (GAA) when it releases its future 2nm process. 

Could this be a showstopper for TSMC?

If TSMC doesn’t solve this heating issue immediately, it could send a bad signal to the engineering world, and companies such as Intel and Samsung could rapidly lead the world in semiconductor fabrication. As customers will be looking towards next-generation semiconductors for future mobile and low-power technologies, having a 3nm process that produces excessive heating is simply unacceptable. 

However, customers who are looking for high-performance devices will be less bothered by such heating issues, and so TSMC could see a shift in its customer base. But, even in high-performance applications (such as servers and supercomputers), heat still needs to be removed, and devices that get too hot can see performance impacts, so if the heating issue from TSMCs 3nm process is too severe, it could put such applications in difficulty. 

Overall, as devices become more complex, they will undoubtedly hit all kinds of problems, and just because tiny transistors can be fabricated doesn’t mean that they can be used. In the case of TSMC, they will need to figure out how to make changes to their process so that heat can be more easily extracted or produce less heat. 

The ongoing debate of TSMC vs. Intel semiconductor technology and their respective approaches to addressing these challenges is a testament to the importance of this issue in the industry. With the spotlight on TSMC's 3nm process and its potential overheating problems, it's crucial for the company to find effective solutions to maintain its competitive edge.

It's crucial for TSMC to address these heating issues promptly. If left unresolved, it could impact their reputation and market position, especially with competitors like Intel and Samsung continuously innovating. The heating problem of the A17 Pro, as highlighted in the recent reports, indicates a potential flaw in the TSMC 3nm process, which needs immediate attention.