Semiconductor production set to become greener

On the one hand, semiconductor solutions help to save energy and lower emissions, but on the other, manufacturing them uses up considerable resources. Stakeholders along the entire semiconductor value chain are therefore increasing their efforts to make microchip production more sustainable. 

Semiconductors are a key technology when it comes to climate protection. In photovoltaic cells they generate electricity from light, and they convert energy in converters such that it can be fed into the electricity grid with minimal losses. Semiconductors make drive systems more efficient, monitor all manner of systems integrated into the energy chain in sensors, and use the Internet of Things to link sustainable energy generation up to consumers in such a way that the supply and demand are in perfect balance with each other. 

A large ecological footprint

On the other hand, however, semiconductor production is a field that consumes huge amounts of resources. Perfluorocarbons (PFCs), chemicals and gases are responsible for considerable emissions of a wide range of greenhouse gases. There is a high consumption of water and chemicals, and recycling by-products is complex and expensive. During dry etching or cleaning of the chambers for chemical vapour deposition (CVD), for example, greenhouse gases such as fluorinated compounds are used. Gases such as SF6 and NF3 have a global warming potential that is many times higher than CO2. According to the Interuniversity Microelectronics Centre (IMEC) in Belgium, studies have shown that almost 75 per cent of the CO2 emissions generated by a mobile device during its entire lifetime are caused during production – and almost half of this can be traced back to the chip production. 

Furthermore, due to the cleanroom conditions required and the extremely complex systems, the semiconductor industry is a particularly high consumer of energy. Greenpeace estimates, for example, that TSMC’s annual electricity consumption is 4.8 per cent of the total electricity consumption of Taiwan – which is more than the capital Taipei consumes. According to the IMEC, the consumption of resources is also increasing in line with ever-smaller chip patterns. If you compare the production of a 28-nanometre pattern with that of a 2-nanometre pattern, the electricity consumption increases by a factor of 3.46, the consumption of ultra-pure water by a factor of 2.3 and greenhouse gas emissions by a factor of 2.5 per wafer. 

Value chain is set to become more sustainable

However, the semiconductor industry is already starting to have a rethink. More and more companies feel a sense of commitment to the aim of making the value chain within semiconductor production more sustainable. The large foundries such as TSMC and Samsung, and IDMs such as Intel, have now launched specific programmes for this. TSMC thus announced it is striving to operate emission free by 2050 and to increase the proportion of renewable energy sources to 40 per cent by 2030. In July 2020, TSMC signed, for example, a 20-year contract with the Danish company Ørsted to buy up the entire energy produced by two wind turbines.

Globalfoundries (GF) is also aiming to reduce its greenhouse gas emissions – by 25 per cent from 2020 to 2030, whilst at the same time expanding global production capacities. “We recognise climate change is an unprecedented global challenge, and Journey to Zero Carbon is GF’s commitment to growing responsibly and reducing our emissions in a meaningful way,” said GF CEO Tom Caulfield.

Reducing greenhouse gas emissions

According to the European ­Semiconductor Industry Association (ESIA), in Europe the ­industry was able to reduce absolute emissions of fluorinated gases by 42 per cent from 2010 to 2020. In the same period, the European semiconductor industry also reduced its overall emissions by 54 per cent. This was achieved by measures including optimising the manu­facturing process so that fewer PFCs are used and emitted, using alternative chemicals with a lower global warming potential, as well as installing systems for ­reducing ­emissions.

Green solvents

Suppliers also play an important part in the efforts of the semiconductor industry to improve its environmental footprint. Merck, for example, has launched “green” solvents on the market for use in photolithographic processes during the manufacture of semiconductors. Each time materials are applied to a silicon wafer, it is necessary to carefully clean the wafer to remove any unwanted residues from it. Here, solvents are indispensable as a cleaning agent. “Our new chemical products are completely environmentally friendly. This improves the environmental footprint of the production plants in which they are used considerably, and also simplifies wet-chemical processes for the customer,” explained Anand Nambiar, Global Head of the Semiconductor Materials business unit at Merck. “As varnishes can therefore be removed with less than a third of the amount of solvent usually required, the customer can save costs and the environmental damage associated with such substances entering global waste streams is reduced.” 

More energy-efficient production plants

The manufacturers of the systems required for chip production are also playing a part in fabs being able to reduce their consumption of resources. Lam Research, a provider of systems and services for wafer production, has launched new plasma etching systems which enable the energy needed for each etched wafer to be reduced by 10 to 20 per cent. Furthermore, in collaboration with ASML and IMEC, Lam Research has introduced dry photoresist technology for patterning with extreme ultraviolet, which needs five to ten times fewer chemicals and two times less energy.

Semiconductor customers demand sustainability

The efforts of the semiconductor industry to improve its environmental footprint are also being driven by its customers’ demands. More and more companies are looking at their suppliers’ sustainability. Apple is one example – the company has set itself the ambitious target of being climate neutral across the entire supply chain and the product life cycle by 2030. “Every company should be a part of the fight against climate change, and together with our suppliers and local communities, we’re demonstrating all of the opportunity and equity green innovation can bring,” said Tim Cook, CEO of Apple.