6nm takes the "C position" and the battle for the 5G chip market is in full swing

This year, the 6nm process has become a hot topic and a favorite in the market. With its high performance-to-cost ratio in terms of performance and cost, 6nm has been sought after by mobile phone chip manufacturers amid the trend and background of 7nm iteration and tight 5nm production capacity. MediaTek has taken the lead, Qualcomm has quickly followed, and Unisoc has entered the market strongly.

Analysts pointed out that 6nm, as a cost-effective EUV process, is a suitable choice after 7nm and before 5nm, both in terms of R&D cost and time cost. 6nm is therefore expected to become the next widely used and long-term process node. As 5G terminals gradually enter the mainstream consumer price range in the second half of the year, the 6nm race has "fired", marking the full start of competition in the 5G mobile phone chip market.

TSMC’s one-man show

As the only two chip foundries in the industry that have taken the lead in advancing to single-digit process technology, Samsung and TSMC have respectively evolved their processes from 7nm to 5nm, with 6nm being the latter's unique label.

TSMC announced the development of this process in Q2 2019, and it went into trial production in Q1 last year and mass production in Q1 this year. The process technology, code-named N6, is derived from TSMC's 7nm node (N7) and is seen as an optimization and extension of the 7nm process.

Before N6, TSMC's 7nm process mainly includes: N7 (first-generation 7nm), using DUV technology; N7P, based on N7, optimized the front-end (FEOL) and mid-end (MOL) processes, still using DUV technology; N7+, based on 7nm, using EUV technology.

TSMC's N6 is the EUV equivalent process of N7, with one more EUVL layer than N7+ (according to the analysis given by industry research organization wikichip in 2019, N7+ uses 4 layers of EUVL and N5 uses up to 14 layers of EVUL), which makes N6 have an 18% increase in logic density compared to N7.

As a process launched after N7+ and N5, N6 has the advantage of being a latecomer in that it can better draw on the EUV experience accumulated by the latter two during the development process. TSMC has a unique intention of "taking care" of 6nm.

In the opinion of a chip foundry manufacturer, the greatest contribution of 6nm to the industry is that with the support of EUV, the delivery time of chip production is greatly shortened.

"Previously, we used DUV to run three layers of masks, but now we only need one layer of EUV, which has indirectly improved production efficiency, helped speed up product launches, and quickly captured the market. Compared with N7, TSMC's N6 is expected to reduce 12 to 18 layers of masks during the production process. If the production cycle time is calculated at 1.5 days per layer, it is equivalent to shortening the production cycle by 18 to 27 days. At the same time, due to the significant reduction in the number of mask layers, the yield can also be improved." The person said.

6nm does not appear in Samsung's process evolution roadmap, but an industry insider familiar with Samsung's foundry business revealed that Samsung actually has a 6nm node option, but it is not available to the public and is only available to two major customers. 

Samsung's 7nm and 5nm are in the same generation, and both 6nm and 5nm are continuous improvements of 7nm, and all use EUV technology. Although TSMC is currently "exclusively enjoying" the benefits of 6nm, the above-mentioned industry insiders believe that Samsung does not "care" much about 6nm.

"Because EUV equipment is a 'new thing', all processes have unstable factors and it takes three to four years to settle and accumulate experience. Samsung is more concerned about coming up with a competitor to TSMC at the 4nm node next year and pushing FinFET to the peak before switching to GAA at 3nm. Therefore, 6nm is not Samsung's strategic focus." The person said.

A semiconductor industry analyst pointed out that the important nodes in Samsung's foundry process evolution route are 7nm/5nm, 4nm, and 3nm. Compared with TSMC, which optimizes its process every year, Samsung's strategy is to concentrate its advantages to overcome key nodes because of its fewer engineering resources. Its main focus is currently on 4nm and 3nm after 5nm.

High cost performance is popular

A few years ago, when TSMC announced its 6nm process, the industry was concerned about whether chip designers would prefer to use the 6nm process. Some people believe that since N6 is slightly better than N7, companies that first adopt N7 technology may be more willing to directly adopt N7+ or even 5nm process to manufacture the next generation of chip products.

This obviously underestimates the status and value of 6nm. Now 6nm has become a popular process node and is expected to be "continuously output" as a long-cycle process.

The popularity of 6nm is certainly due to the factor of "innovation" in marketing, but the more important reason is that 6nm is between 7nm (iterative evolution) and 5nm (high cost and tight production capacity). The "super-high cost-effectiveness" advantage of technology and cost embodies the mainstream demand of the market.

A person related to technical planning in the marketing department of Unisoc said in an interview with Jiwei.com that TSMC's 5nm is a new generation of process, which has indeed achieved significant improvements in density and performance, and is a complete node upgrade. The first generation of 5nm process currently in mass production, although the theoretical performance and power consumption are better than 6nm, but because it is a first-generation process, there are problems of high cost and insufficient optimization depth, and it is more suitable for flagship products. The current mass production of 5nm has verified this.

"Unlike 6nm, 5nm requires customers to design products from scratch. Therefore, whether in terms of R&D cost or time cost, 6nm is a suitable choice after 7nm and before 5nm. As a cost-effective EUV process, 6nm can be combined with 5nm to achieve a combination of flagship and mid-to-high-end products." The person said.

Another person from a chip design company said that TSMC's N6 and N7 have 100% compatible design rules, and can reuse the same design ecosystem (such as EDA tools, IP) and share production line capacity. Chip manufacturers with 7nm design experience can directly migrate to 6nm seamlessly, thereby reducing design time and economic costs.

"6nm can achieve a better balance between performance and power consumption, and can better meet the high integration and low power consumption requirements of 5G chips. As an optimized extension of the 7nm process, the 6nm process is slightly better than 7nm in terms of integration, power consumption, cost, etc., and can reduce chip power consumption by 8%, chip size by about 15%, and provide longer battery life." The person introduced.

In addition, another reason why 6nm is so popular is that it helps alleviate the capacity constraints currently faced by the chip industry. The advantage in delivery cycle enables chip manufacturers to quickly respond to the challenges brought about by insufficient supply and quickly adjust market strategies.

Last month, Qualcomm released its first 6nm 5G SOC Snapdragon 778G. When Alex Katouzian, senior vice president and general manager of mobile, computing and infrastructure business of Qualcomm, talked about the considerations of choosing 6nm in an interview with Jiwei.com, he first emphasized that the 6nm process will help Qualcomm establish a diversified chip supply structure and ensure sufficient production capacity for OEM manufacturers. Secondly, he also believes that Qualcomm has cooperated with TSMC on the 7nm node, and switching to 6nm is also a relatively natural and easy process.

Expected to become a "long-lived" process

Not only in the field of mobile phone chips, but also in the fields of GPU, high-performance computing, AI, 5G network infrastructure, 6nm is also in widespread demand, just as surging as the wave set off by 7nm.

In addition to Qualcomm, MediaTek, Unisoc and other mobile phone chip manufacturers that have adopted 6nm in large quantities this year, foreign media reported that Intel has placed a large order of 180,000 wafers from TSMC this year, all of which will use 6nm for GPU products; AMD's next-generation CPU and GPU products will also adopt the 6nm process. In addition, mining machines, 5G base stations and other products will also migrate to 6nm.

Recently, TSMC also released the 6nm RF process N6RF for the first time. 5G RF IC and WiFi 6/6e chips are expected to be further upgraded with the help of 6nm, promoting changes in the RF field.

Driven by industry demand, 6nm has rapidly increased its share of TSMC's revenue. According to TSMC's latest information, 6nm only accounted for 15% of 7nm's revenue in the fourth quarter of last year, but by the end of this year, this proportion will reach 48%-50%.

When TSMC launched its 6nm process technology in 2019, it expected that most customers using the N7 process would eventually switch to the N6 node, and we are indeed seeing such a large-scale migration trend. The industry believes that since N7 is more popular, N6 will also be very popular, and the 6nm process will become TSMC's next widely used and long-term process node.

"From the perspective of process development, some key technologies will have nodes with relatively long life cycles. 6nm is the first node to be optimized after the mass production of 5G SoC, and TSMC has already released the 6nm RF process. From the perspective of supported product forms and relatively better integration, power consumption, and cost, the 6nm node is expected to have a relatively long life cycle." The above-mentioned person from Ziguang ZTE told Jiwei.com.

In the view of the above-mentioned industry analysts, TSMC’s positioning for 6nm is to integrate the existing 7nm production capacity into a “cost-effective process” that will be provided in the long term after the withdrawal of 5nm.