Lace Lithography

Atoms instead of photons: Norwegian startup Lace Lithography is developing a chip-making technology that could one day succeed ASML's #EUV tools. For the foreseeable future, the EUV machine is the only tool capable of printing ultra-fine chip patterns. But the huge demand for #AI computing is encouraging inventors to explore alternatives to ASML's approach, in which #EUV light is generated by firing a powerful laser at tin droplets (#LPP). Techniques such as #nanoimprint (stamping) and #ebeam (writing with electrons) are not suited for mass production. xLight Inc. wants to generate EUV light using an electron accelerator. Chinese companies like Huawei may be trying to produce EUV light by creating a spark near a bath of tin (#LDP), and startup Substrate wants to use X-rays. But in Norway, it's different. "Where light stops, atoms begin," says Bodil Holst, founder of Lace Lithography, a startup based in Bergen. She explains it in a call with NRC, along with co-founder and CTO Adrià Salvador Palau. The #wavelength of light determines how precisely you can 'print'. EUV uses a wavelength of 13.5 nanometers and further reduces that beam using mirrors. The wavelength of helium atoms is less than 0.1 nanometer and could achieve better resolution. Today's best-in-class tool is High-NA EUV, with a half pitch currently at 8 nm. Lace presented 50 nm but could, in theory, shrink to 0.5 nm. By fitting more transistors on the same surface, chips become more efficient and powerful. In practice, you will also need metrology and inspection to verify that all the lines still fit neatly together, otherwise the chip will not work. And that must also happen at high speed, since chipmakers want productivity and need to keep stamping wafers. Lace drives metastable #helium atoms, carrying higher energy in one of their electrons, through a mask with holes. The atoms that are not blocked, hit the light-sensitive layer of a silicon wafer and thus draw the pattern. That mask with holes reminded Bodil Holst of lace making (in Dutch: kantklossen). Lace just raised €40 million in a new investment round. The #EU already provided a grant for research together with imec in Belgium. Holst presented those results at #SPIE, in a room where ASML researchers were also seated. "They said they found it an interesting approach." Around 2030, a Lace prototype capable of printing multiple chip layers should be ready. For a roadmap beyond EUV, Lace has to address issues like #pattern transfer (the chemical process in the #photoresist), as well as #mask creation and inspection and accurate placement of IC features. It requires a great deal of computing work to design that perforated mask so that the chip lines still come out correctly. You need AI and fast chips, explains Adrià Salvador Palau. "Without the powerful chips from EUV machines, we would never have been able to solve that problem." #semiconductors #lithography John Petersen #compute link to article in NRC in comments