If iPhone overheating is due to TSMC's 3nm, it's an opportunity for Samsung Semiconductor

Apple is reportedly considering diversifying its mobile AP (application processor) supply, which has relied on Taiwanese foundry (semiconductor contract manufacturing) company TSMC, to resolve the overheating issue of its new smartphone, the 'iPhone 15 Pro.'

[Image source=AFP Yonhap News]

On the 22nd, the semiconductor industry is closely monitoring the overheating problem raised with the iPhone 15 Pro equipped with the mobile AP chip 'A17 Pro,' based on TSMC's 3-nanometer (1nm = one billionth of a meter) process. Recently, foreign media reported user reviews stating that the smartphone temperature rose to 48 degrees Celsius within just 30 minutes of playing high-spec games on the iPhone 15 Pro. The AP is a semiconductor that acts as the brain of the smartphone, and its performance directly affects the smartphone's overall performance.

The iPhone 15 Pro is the first smartphone to feature a semiconductor produced using the 3-nanometer process. TSMC was responsible for the semiconductor contract manufacturing. TSMC, which counts Apple as a major client, began operating its 3-nanometer process at the end of last year and supplied the AP chips for the iPhone 15 Pro. Samsung Electronics started mass production of 3-nanometer chips in June last year, the world's first, but Apple partnering with TSMC gave TSMC an edge in securing customers.

However, TSMC is showing vulnerabilities in the 3-nanometer process due to the iPhone 15 Pro overheating issue. Although smartphone overheating has been a persistent issue, consumers had expected that the introduction of the 3-nanometer process would solve the overheating problem and extend battery life.

The market believes that TSMC's use of the FinFET structure, which was also used in previous processes, to quickly stabilize the yield of 3-nanometer semiconductors may have led to the overheating problem. Since the 4-nanometer process, the circuit spacing has become extremely narrow, making current leakage difficult to control. Because TSMC has not made significant changes to the FinFET structure it has used so far, there is a possibility that problems have arisen.

Unlike FinFET, where the channel is vertically raised and the gate contacts three sides of the channel, Samsung Electronics has been using the Gate-All-Around (GAA) structure from the 3-nanometer process, where the gate surrounds all four sides of the channel, making current control more efficient, according to some analyses. TSMC is reportedly planning to use the FinFET structure only up to the 3-nanometer process and will fully apply the GAA structure starting from the 2-nanometer process.

Ryu Hyung-geun, a researcher at Samsung Securities, commented on the iPhone 15 Pro overheating issue, saying, "If the overheating of TSMC's 3nm process implemented with the FinFET structure is the problem, the situation changes," adding, "From the customer's (Apple's) perspective, they should consider multi-sourcing rather than insisting solely on TSMC. This could be meaningful news for Samsung Electronics, a latecomer in the foundry business."

Samsung Electronics is also receiving positive evaluations for significantly overcoming yield management, which was pointed out as a disadvantage compared to TSMC. The yield of semiconductors produced by TSMC in the current 3-nanometer process is known to be around 70%. In early July, Hi Investment & Securities released a report stating that Samsung Electronics' 3-nanometer yield had surpassed 60%. Given that two months have passed, it is highly likely that the yield has increased further.