The mood at the conference this week can be summed up in one word: happy. We were all just happy to be here, with smiles visible everywhere, even under masks.
Thursday morning began with a quite philosophical keynote talk in the metrology session on the role of MI (metrology and inspection) in semiconductor manufacturing by Younghoon Sohn of Samsung. He touched on broad subjects like the role of sampling (depends on the failure rate), the dilemma between resolution and speed in inspection (and the wide gulf in both between optical and e-beam inspection), and the basic roles of MI (define a process window, identify cause and effect, and process monitoring and control).
A joint session between Optical/EUV and Etch provided several nice papers. Angelique Raley gave an overview of three techniques being promoted by TEL: a spin-on SiC underlayer for EUV to prevent pattern collapse, a development process (not really explained) called ESPERT for Inpria resists that also prevents pattern collapse by improving the sidewall profile, and a cryogenic etch for lower LCDU (local critical dimension uniformity) and defectivity. Roberto Fallica of imec gave a quote that I like (and often say myself), “Stochastics is the major roadblock for EUV Lithography”. He then talked about a “healing” etch process that reduces contact hole LCDU through an aspect ratio dependent etch rate (high aspect ratio resist patterns etch faster, causing narrow holes to widen, while low aspect ratio resist patterns etch mode slowly, causing wide holes to narrow). One interesting (and confusing) result was that the dose that provided smallest LCDU was not the dose that gave the lowest defectivity. Finally, Qinghuang Lin of Lam talked about the application of Lam’s new dry-deposited and dry-developed resist to contact holes (I was not able to catch Rich Wise’s earlier paper on its application to lines and spaces).
Since I left after lunch to catch a plane home, I was not able to see what I’m sure were some good papers on the last afternoon of the symposium. After a valuable and rewarding week here in San Jose, I was still anxious to get home. Looking back two years, here is how I ended my Advanced Lithography Diary in February of 2020:
“The week has also seen an escalating concern over the new coronavirus, COVID-19. Like everyone else I am monitoring developments with morbid fascination, but also to see how it will impact my immediate future. And it has. If there is any positive to the spreading fear over the spreading virus, it is that I will soon be traveling far less. I have started asking customers if we could schedule our meetings, demos, and courses using video conferencing rather than in-person, and they are readily agreeing. Maybe such accommodations will be a permanent trend, with the significant savings in time and resources that come with less travel (not to mention a better quality of life when I spend more time with my family). I will look to this thought as a small consolation.”
That prediction proved true. Like everyone, I have spent much of the last two years living my life on Zoom. But since my life before the pandemic involved far too much travel, I am grateful for the respite that the pandemic forced upon me. I am very glad to be back at ALP live and in person, and am glad that I can start visiting customers again (most of them, anyway). But the much-accelerated use of video meeting technology has permanently changed the way I do business, and I am happy for the family time it will enable. Like most of us, this pandemic has triggered a reckoning in my life/work balance, and I am happy for the result.
So, for those of you who wanted to but could not come to San Jose this week, I hope to see you next year. But if not, maybe I’ll see you on Zoom.