Episode 31 features German ALD professor, Dr. Martin Knaut. Martin is the chair for the Institute of Semiconductor and Microsystems Technology at TU Dresden and the atomic layer processing group leader. He is also a founding member of the Atomic Layer Process Innovation Network, or ALPIN, organizer of the annual ALD for Industry event, and runs a small in situ tool development company, called ALS Metrology. With a long career working with ALD in Dresden, at the likes of Infineon and Qimonda, Martin has witnessed the ebbs and flows of the semiconductor industry in the state of Saxony.

Martin and Tyler discuss the goal of the Silicon Saxony organization, how we can better recruit students in microelectronics, and why he originally started the Atomic Layer Process Innovation Network. They also discuss his company, ALS Metrology, the importance of using in situ monitoring for process development, and his work on flash-enhanced ALD.

In this episode:

00:00 Intro

01:48 Martin’s background & semiconductors in Dresden

10:00 Recruiting issues for microelectronics

17:29 ALPIN & ALD for Industry events

29:34 ALS Metrology

34:57 Importance of in situ monitoring

41:59 Flash-Enhanced ALD

53:55 Concluding remarks

In this episode, Tyler is joined by Professor Carl Hägglund from Uppsala University. They discuss Carl’s motivations for pursuing ultrathin solar cells, how he learned ALD at Stanford in Stacey Bent’s lab, and an unlikely research connection through his child’s school. They also talk about why ALD is useful for plasmonic solar cells, optimization of SnS ALD and his planned path towards a fully realized ultrathin photovoltaic. 

00:00 Introduction 

01:45 Motivation for fabricating plasmonic solar cells 

09:58 Learning ALD at Stanford 

22:46 Optimizing SnS ALD process 

30:33 Path towards an ultrathin solar cell 

Dr. Suvi Haukka, former executive technologist at ASM, ASM Fellow and ALD Innovator Awardee, joins Tyler for Episode 29. Suvi began her ALD career at Microchemistry in Finland working on atomic layer epitaxy on catalysts for under the direction of ALD technology inventor, Tuomo Suntola. She continued with Microchemistry as head of the thin film development group before spending most of her time teaching the world’s biggest semiconductor companies, like Intel and Samsung, about ALD. Suvi is one of the integral people in introducing ALD to the semiconductor industry in the 2000s. 

Suvi and Tyler discuss how she started working with ALD, what it was like to do a PhD with Tuomo Suntola, and how the make up of Microchemistry changed over the years. We also discuss the circumstances surrounding the ASM acquisition, how development changed under new leadership, and how it felt pitching ALD to the semiconductor industry.

In this episode: 

00:32 Introduction to Microchemistry 

06:01 Doing a PhD with Tuomo Suntola 

19:00 Visiting semiconductor companies 

25:37 Post-ASM acquisition 

In Episode 28 of ALD Stories, Tyler is joined by Aalto University’s Hele Savin. Hele is a professor in the department of Electronics and Nanoengineering where she uses ALD to engineer photovoltaics and semiconductor devices. In 2017, Hele was awarded the women’s innovation prize from the Finnish parliament after fabricating a black silicon solar cell with a record-breaking 22.1% efficiency and currently uses ALD to create induced junction photodiodes with over 100% external quantum efficiency.  

Hele and Tyler discuss how she was first exposed to ALD by Beneq, a mindset that using ALD was dirty, and how mind-blowing early ALD passivation results were. We also talk about why ALD oxides are better than thermal SiO2, the theoretical implications of breaking 100% EQE, and upcoming work in up conversion in her lab. 

In this episode: 

00:00 Intro 

07:45 First experience with ALD 

16:37 Passivation of Black Si Solar cells 

29:52 ALD for Induced Junction Diodes 

39:06 Theoretical Implications of High EQE 

47:35 Future Up Conversion work

For Ep. 27, Dr. Rob Clark from Tokyo Electron joins to discuss his rise from an equipment know-nothing to ALD process engineer extraordinaire. Rob, the self-proclaimed Manipulator of Matter, is a Senior MTS and Technology Director at TEL where he leads process and integration of thin film deposition methods for next-generation semiconductor devices.  

Recorded live at ALD ALE 2023 in Washington, Rob and Tyler discuss how he first learned ALD on CVD equipment, the early days of high-k ALD process development, and his work in making some of the first hafnium precursors for ALD integration in semicon at Schumacher. They also talk about his time as the only engineer at NanoFab North in Albany, how incredibly advanced semiconductor technology has become, and what the next decade of ALD research might look like. 

In this episode: 

00:00 Introduction  

01:58 Post-grad at Schumacher 

13:23 Learning the ALD ropes 

19:16 Early HfO2 process development 

23:40 Albany, NY Semi ecosystem 

32:32 ALD process development insights 

42:24 How cool are semiconductors?!’ 

49:44 Rob’s ALD Outlook

In Episode 26, Professor Stacey Bent from Stanford University joins to discuss all aspects of her career, including early area selective deposition work, how her different academic appointments in chemistry and engineering have influenced the direction of her work, and how ALD can be used in energy applications. Stacey and Tyler also chat about how Stacey finds the best paths for her students, how being a professor and Vice Provost feedback to each other, and new programs she has initiated in her Vice Provost position.

In this episode:

00:00 Introduction

03:45 Area Selective Work

15:40 Chemistry & Engineering Backgrounds

21:20 ALD for energy applications

33:54 Stacey as an advisor

36:19 Vice Provost position

In its short 50 years of existence, the history of ALD has been of great interest, being heavily researched and documented in the last decade. One can follow the story from many lenses: one in particular is to view the technology’s development is through an equipment perspective. Each milestone in process technology was accompanied and enabled by new ALD tools. Without innovative equipment design, we would not have the vast ALD ecosystem we do today. Via patents and literature, this ALDeep Dive will journey the evolution of the ALD reactor. It starts from Tuomo Suntola’s original reactor and IP, moves through the early days of commercial reactors, explore the introduction of plasma, powder and spatial tools, and wrap up with today’s equipment landscape and thoughts on the personal aspect of ALD reactors. 

In this episode: 

00:00 - Intro 

01:33 – Suntola’s 1st Reactor 

03:15 – Suntola’s Patented Configurations 

07:38 – The First Commercial Reactor 

10:50 – Plasma, Please 

15:20 – Powder ALD Reactors 

20:37 – Reintroduction of Spatial ALD 

24:10 – Today’s ALD Tool Landscape 

25:43 – Concluding Thoughts 

Important Papers & Patents 

Chem. Vap. Dep. 2014, 20, 10-11-12, 332-344 

T. Suntola, J. Antson, International patent, FIN 52359, US 4 058 430, priority Nov 29, 1974, publication Nov 15, 1977. 

T. Suntola, A. Pakkala, S. Lindfors, International patent, FIN 57975, US 4 413 022, priority Feb 28, 1979, publication Nov 1, 1983. 

J. Vac. Sci. Technol. A, Vol.29, No.5, Sep/Oct 2011 

J. Vac. Sci. Technol. A 25 (5) Sep/Oct 2007 

Applied Physics Letters 92, 192101 (2008) 

Journal of Vacuum Science & Technology A 30, 021502 (2012)

Dr. Fred Roozeboom joins ALD Stories for Ep. 24. Fred spent most of his career in the semiconductor industry at Philips and NXP working on rapid thermal processing and passive integration. He pivoted to ALD at the TNO Holste Centre and now finds himself at his alma mater, University of Twente. Fred was recently awarded the Gordon E. Moore Medal for Outstanding Achievement in Solid State Science and Technology from the ElectroChemical Society. Fred and Tyler talk about the semiconductor industry in the 80’s, his original RTP work at Phillips, and the importance of passive integration. They also discuss the Medtronic pacemaker, his world record during the great reintroduction of spatial ALD and the applications he’s most excited to see come to life with atomic layer deposition. 

In this episode: 

00:00 Introduction 

01:43 Semiconductor Industry in the 80’s 

07:59 Rapid Thermal Processing & Creation of NXP 

19:32 Passive Integration & 3D Silicon 

33:41 Pivot to ALD 

46:48 Fred’s ALD Outlook 

#ALDep #semiconductors #nanotechnology 

In Episode 23 of ALD Stories, Dr. Harm Knoops joins Tyler to discuss his dual role at Eindhoven University and Oxford Instruments Plasma Technologies. As an Atomic Scale Specialist, Harm routinely advises on processes in ALD, ALE and 2D materials while informing their work with supplemental research at Eindhoven. Harm and Tyler talk about alternatives careers to the traditional industry and academia binary, how scientists can leverage their technical knowledge, and how working in a cross-institute position makes for efficient science. We also touch on Harm’s work with plasmas, tackle misconceptions about plasma conformality, and how Harm approaches learning new topics. 

In this episode: 

00:00 Intro 

01:20 Working in both industry & academia 

11:45 Careers leveraging technical backgrounds 

24:20 Misconceptions about plasma conformality 

43:20 How to learn new fields quickly 

#ALDep #ALEtch #nanotechnology  

Professor Sean Barry from Carleton University joins Tyler on Episode 22 of ALD Stories. Sean recalls his time working at the University of Helsinki and a mishap or two in Mikko Ritala’s lab, how the Finnish ethos inspires him, and why he considers Helsinki his second city. Sean also talks about how knowledge of fundamental chemistry is important for understanding atomic layer deposition, why he decided to write a book on the topic, and how chemistry informed the evolution of gold ALD. 

In this episode: 

00:00 Intro 

01:22 Living in Helsinki 

09:30 Sean’s background and Harvard ALD 

21:00 Evolution of Au ALD 

32:05 Sean’s book 

45:17 What material is Sean’s dream? 

50:23 Sean’s sage wisdom 

#ALDep #nanotechnology #chemistry #ALDStories