A short history of atomic layer deposition: Tuomo Suntola's atomic layer epitaxy

The author thanks Tuomo Suntola for sharing these and other details of the development of ALE and EL. It has been a great honor and privilege to work with him and to write this history. Writing this history was triggered by the parallel-running worldwide Virtual Project on the History of ALD (VPHA). Warmest thanks to Tuomo Suntola for his support for the VPHA, too. The author also acknowledges Tapio Alvesalo for checking the details related to NAPS, Dr. Marko Tuominen for the details related to ASM Microchemistry, Juhana Kostamo for the details related to Picosun, Prof. Victor Drozd for confirming the timing of Suntola's visit to Leningrad, Prof. Yukihiro Shimogaki and Prof. Markku Leskelä for identifying the second-left participant in the ALE-1 photograph, and Prof. David Cameron for polishing the language in this article. Funding by the Academy of Finland's Centre of Excellence in Atomic Layer Deposition (ALDCoE) is gratefully acknowledged.