SAN JOSE, Calif. — ASML showed stepwise progress in an update on the performance of its latest extreme ultraviolet (EUV) lithography system and its roadmap at the SPIE Advanced Lithography conference here. The talks showed that getting EUV into production will be a nail-biter, and keeping it useful in the next generation will require multiple field upgrades.

Over the weekend, the NXE 3400B system delivered 140 wafers/hour with a 245-W light source integrated in a system at the company’s headquarters in the Netherlands. ASML aims to tune the light source to 250 W for throughput of 150 wafers/hour and ship it to customers before June for use on 7-nm process nodes.

The lab demo was conducted without use of a protective pellicle on the wafers. The tests exposed a full field with 96 fields using a dose of 20 mJ/cm2 .

A test using an 83% transmissive pellicle reached 100 WPH. ASML targets a 90% transmissive pellicle with 125-WPH throughput that can withstand a 300-W light source.

In its efforts to reduce defects from contaminating particles, ASML is working in parallel on the pellicle and a cleaner scanner that doesn’t need a pellicle. Last year, it eliminated all but six particles in a run of 10,000 wafers and aims to reduce it to one particle per 10,000 wafers next year.

ASML showed two upgrades to the 3400B and a new model debuting in 2020. Click to enlarge. Images: ASML.

The company targets a greater-than-90% uptime for the system by 2018–2019, when it should be in volume production. A day earlier, a Globalfoundries executive said that productivity levels were the key gating item on the first commercial use of the systems.

To meet the needs of 5-nm nodes, ASML plans three upgrades to the system delivered over the next two years.

Late this year, ASML aims to deliver a so-called overall and focus improvement package that enables overlays down to 1.7 nm, slightly below the required 1.9-nm target for 5 nm. In mid-2019, it plans a productivity enhancement package that boosts throughput to 145 WPH.

ASML is considering a model 3400C that it could deliver in 2020 with additional improvements, boosting throughput to 155 WPH. Details of the system are still under discussion with the small handful of big chip vendors who would be its users.