Basics of wet cleaning mixtures and cleaning recipes
Rita Vos, IMEC

During the manufacturing of integrated circuits on silicon wafer substrates, different contaminations such as particles, metallic or organic residues, can have a detrimental effect upon the quality and the yield of the fabricated chips. Therefore, cleaning of the wafer surface has become one of the most repeated and imported steps in the manufacturing cycle.  In this tutorial, the  different wet-chemical processes that are used to clean the Si substrate will be presented and explained. The basic principles to remove different kinds of contaminations will be highlighted.

Fundamentals of mechanical cleaning forces
Steven Brems, IMEC

The course will address the removal of solid residues from surfaces, typically referred to as particles. As pure chemical cleaning tends to be too aggressive for sensitive surfaces, micro-mechanical forces are used to assist in particle removal. Since such forces could potentially also damage devices and structures the force window is reviewed. The tutorial focuses particularly on the insight on the use of high-frequency acoustic agitation of the cleaning liquid and the use of high velocity liquid aerosol spray. A short overview of other alternative methods will be given as well.

Coffee break

Surface passivation: Si, Ge and III-V
Marc Meuris, IMEC

This tutorial will review semiconductor surface passivation, more specifically the chemical surface state. This will be covered for a variety of semiconductors currently in use and considered for future industrial application. The correlation between  different surface treatments and the resulting surface passivation will be explained. The chemical nature, stability and electrical performance will be discussed.

Pre-ALD cleaning
Annelies Delabie, IMEC

Atomic Layer Deposition (ALD) is a thin film deposition technique with a number of unique capabilities, such as growth control at the atomic level and conformal deposition over complex nanostructures. First, the basic principle of ALD, the use of self-limiting surface reactions, will be introduced. The tutorial will then focus on the impact of surface preparation on the ALD growth characteristics. Examples of ideal and non-ideal ALD growth on different starting surfaces (obtained by different surface cleans) will be discussed, as well as the impact on the final quality of the interface (e.g. interface state density) and deposited layer.

Short break

Wet chemical processing for silicon based photovoltaic applications
Klaus Wolke, Wolke Consulting

The tutorial provides an overview on wet chemical processing in manufacturing of Multi-crystalline  and Mono-crystalline Si solar cells.  Requirements and typical processes for cleaning, saw damage removal, alkaline and acidic texturization as well as PSG removal will be covered. For each applications their role in the manufacturing process is discussed including process schemes, performance factors  and process margins. In particular differences between wet chemical processing in semiconductors and PV are reviewed and explained.
In the final part recent developments in PV wet applications for high efficiency cells are introduced and discussed with respect to their potential in the near future of PV manufacturing.

Marc Meuris received the M.S. degree in physics and the Ph.D. degree in physics from the Katholieke Universiteit Leuven, Leuven, Belgium, respectively in 1983 and 1990.

In 1984, he started in imec, Leuven. In the first year, he did RTP anneal process development of dopants in III–V material. Then, he transferred to the analysis group at IMEC, headed by Wilfried Vandervorst, where he did his Ph.D. work on Secondary Ion-Mass Spectroscopy. From 1990 to 1999, he was with the group of Marc Heyns on cleaning technology for improving the gate oxide integrity, resulting in the development of the IMEC Clean as a pre-gate and pre-diffusion clean for CMOS processing. From 1997 to 2002, he was the CMP Group Leader at IMEC. In 2002, he was the Technical Advisor for IMEC CMOS projects in collaboration with Flemish industry. Since 2003, he was the Program Manager of the Ge program at IMEC. In 2006, this program enlarged its focus to Ge and III–V materials for scaling CMOS devices with high-mobility materials. In 2010 he moved to the PhotoVoltaics research department of Jef Poortmans in imec to start up a Thin Film PV team on CIGS technology.

Annelies Delabie is staff scientist at IMEC, the Belgian research institute for nanoelectronics and nanotechnology. Her research focuses on the deposition of thin films by means of Atomic Layer Deposition (ALD), mainly high-k dielectric layers for both high performance CMOS and memory applications.

Klaus Wolke has finished his Ph.D. in Experimental Physics in 1988 in Münster, Germany. From 1989 to 1995 Klaus Wolke worked as process engineer and section head in IBM’s Dram and Logic manufacturing sites in Böblingen, Germany and Burlington, Vt, USA.  with major responsibilities for plasma and wet process engineering.  In 1995 he became Head of Product development at STEAG Microtech (later Mattson Wet products, SCP Global Germany) leading new process and equipment development for critical cleaning and etch application in semiconductor application.
Since 2004 Klaus Wolke formed Technology Consulting Wolke (TCW), which is providing strategic advisory for technology based industries like Bosch, NXP, TI and Chartered, as well as various equipment companies. TCW primarily focusses on business and new product development, production ramp and productivity improvement in semiconductor, photovoltaics and other technology driven industries.