Reasons Why ASML's EUVs Are Not the Cause of TSMC's Massive Power Bill
Taiwan Semiconductor Manufacturing Company's power consumption is through the roof, and the culprit is commonly believed to be its "EUV" systems. But ASML sees things differently. Why is the power draw of EUVs not as high as believed?
Shortly after CommonWealth Magazine published this column in August, the public relations representative of the global EUV leader ASML contacted me to say that a senior manager at their headquarters in the Netherlands was shocked to read how much electricity their products were purported to consume. The truth, says ASML, may not be what we were led to believe.
Three Reasons Why EUVs Are Not to Blame
Based on interviews with and data provided by ASML, there are three misconceptions that need to be cleared up.
One, TSMC's spiking power bill cannot be solely blamed on EUV.
TSMC forecasts that the semiconductor industry will use 640MW (megawatts) more power than the previous year in 2024. The cause is expanded production capacity. But how much of that is connected to EUV?
Industry experts point out that, in preparation for the mass production of 2-nanometer chips, TSMC is expected to purchase 70 EUV systems in 2024 and 2025. The newest model of EUV machines consumes 1.2MW of power annually. Even if all 70 were to come online in 2024, that would only make up 13% of the anticipated increase.
"I think people have been unfair to EUV," says consultant Cheng-Feng Li (李政鋒), who has worked at the tech company MediaTek and the banking company Yuanta. In his opinion, the external water cooling systems that support EUV systems and the upkeep of TSMC's clean rooms are other factors that may add to TSMC's power consumption.
He's spearheading a project called "Power Taiwan" with Massachusetts Institute of Technology alumni to offer solutions for Taiwan's power shortage crisis.
Two, TSMC's power bill would rise even without EUV.
Based on data provided by ASML, modern EUV systems use seven times more power than traditional immersion lithography technology. But in practice, the difference is much smaller. Why is that?
The truth is, the traditional production method cannot keep up with advanced manufacturing past the 7-nm threshold. Without EUV, repeated exposure will be necessary to achieve the same result. The pattern may be separated into three or even four sections to avoid interference from diffraction. It is commonly believed that Huawei's 7-nm chips were made through such a brute-force method.
The higher number of exposures will consume more electricity. If the entire manufacturing process is taken into consideration, EUV only requires two to three times more power than traditional lithography.
The next generation of High NA EUV, which can offer even better resolution, will also be able to produce smaller chips more efficiently.
ASML VP Greet Storms, who oversees the High NA EUV product line, estimates that when High NA systems launch in 2028, the reduction in manufacturing complexity will result in each wafer costing 200kWh less electricity to produce.
Three, EUV has been maligned by the public.
ASML published a paper during the 2023 IEDM Conference that revealed the details of an EUV system's power consumption. While it confirmed that EUV is the most power-intensive method of production, things are not as bad as everyone seems to think.
ASML calculates that the average amount of electricity it takes for the entire value chain to create one wafer was over 800kWh in 2023. This was two times more than what it was a decade ago. Optical lithography, which revolves around EUV, consumes around a third of the power—almost 300kWh.
Other manufacturing processes, such as etching, chemical-mechanical polishing (CMP), and ion implantation, which is also very power-consuming, make up the remaining two-thirds of the quota.
These numbers are shocking. "It's different from the common understanding," says a former senior manager in the applied materials sector.
So, why is the industry so afraid of the EUV technology?
Perhaps a different perspective will help us understand the widespread fear.
Although it "only" uses one-third of the power, the industry was accustomed to conventional optical lithography, which spent negligible amounts of electricity. In 2019, when the industry progressed into the 7-nm era, TSMC and Samsung began using EUV technology. As a result, their power bills grew exponentially.
The science of optical lithography is like this: Wafers coated with photoresist are exposed to special lights that create the needed patterns. But why has the transition from conventional argon fluoride laser, with its 193-nm wavelength, to extreme ultraviolet, with its 13.5-nm wavelength, led to such a spike in power consumption, despite the fact that they are doing the same tasks?
The paper puts forth that traditional optical lithography refracted the laser through a series of glass lenses to reach the wafer surface. However, due to its short wavelength, EUV must be channeled with optical mirrors rather than glass lenses.
This is why ASML provides ultra-smooth optical mirrors made up of a hundred interfolding layers of molybdenum and silicon, developed by Carl Zeiss AG, for use in semiconductor production. Each layer is only a few nanometers thick in order to prevent disrupting the light waves.
Nevertheless, the reflectivity of EUV is only 70%. After being reflected 11 times, less than 2% of the energy reaches the wafer. This is why EUV consumes so much electricity.
EUV light is generated by bombarding countless miniscule drops of liquid tin with precisely targeted lasers 50,000 times a second. The vaporized tin forms EUV rays that are reflected with an oval mirror 65 centimeters in diameter and beamed into the lithography machine.
One sticky problem is that the vaporized tin tends to adhere to the mirror, rendering the system inoperable. The solution is to pump hydrogen gas around the rim. The hydrogen and tin molecules form a gaseous tin hydride that does not create deposits on the mirror.
A clever invention like this can shave another 20% off energy consumption.
EUV technology is pushing the envelope of human progress. The side effect is its high electricity costs. Even as we are amazed by its capabilities, we are reminded that there is a price for all our modern advancements.
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