Thin Films Of Copper Oxide And Copper Grown By Atomic Layer Deposition For Applications In Metallization Systems Of Microelectronic Devices

Copper-based multi-level metallization systems in today's ultralarge-scale integrated electronic circuits require the fabrication of diffusion barriers and conductive seed layers for the electrochemical metal deposition. Such films of only several nanometers in thickness have to be deposited void-free and conformal in patterned dielectrics. The envisaged further reduction of the geometric dimensions of the interconnect system calls for coating techniques that circumvent the drawbacks of the well-established physical vapor deposition. The atomic layer deposition method (ALD) allows depositing films on the nanometer scale conformally both on three-dimensional objects as well as on large-area substrates. The present work therefore is concerned with the development of an ALD process to grow copper oxide films based on the metal-organic precursor bis(tri-n- butylphosphane)copper(I)acetylacetonate [(nBu3P)2Cu(acac)]. This liquid, non-fluorinated & beta;-diketonate is brought to react with a mixture of water vapor and oxygen at temperatures from 100 to 160°C. Typical ALD-like growth behavior arises between 100 and 130°C, depending on the respective substrate used. On tantalum nitride and silicon dioxide substrates, smooth films and self-saturating film growth, typical for ALD, are obtained. On ruthenium substrates, positive deposition results are obtained as well. However, a considerable intermixing of the ALD copper oxide with the underlying films takes place. Tantalum substrates lead to a fast self-decomposition of the copper precursor. As a consequence, isolated nuclei or larger particles are always obtained together with continuous films. The copper oxide films grown by ALD can be reduced to copper by vapor-phase processes. If formic acid is used as the reducing agent, these processes can already be carried out at similar temperatures as the ALD, so that agglomeration of the films is largely avoided. Also for an integration with.

Offering thorough coverage of atomic layer deposition (ALD), this book moves from basic chemistry of ALD and modeling of processes to examine ALD in memory, logic devices and machines. Reviews history, operating principles and ALD processes for each device.

Microelectronics is a complex world where many sciences need to collaborate to create nano-objects: we need expertise in electronics, microelectronics, physics, optics and mechanics also crossing into chemistry, electrochemistry, as well as biology, biochemistry and medicine. Chemistry is involved in many fields from materials, chemicals, gases, liquids or salts, the basics of reactions and equilibrium, to the optimized cleaning of surfaces and selective etching of specific layers. In addition, over recent decades, the size of the transistors has been drastically reduced while the functionality of circuits has increased. This book consists of five chapters covering the chemicals and sequences used in processing, from cleaning to etching, the role and impact of their purity, along with the materials used in “Front End Of the Line” which corresponds to the heart and performance of individual transistors, then moving on to the “Back End Of the Line” which is related to the interconnection of all the transistors. Finally, the need for specific functionalization also requires key knowledge on surface treatments and chemical management to allow new applications. Contents 1. Chemistry in the “Front End of the Line” (FEOL): Deposits, Gate Stacks, Epitaxy and Contacts, François Martin, Jean-Michel Hartmann, Véronique Carron and Yannick Le Tiec. 2. Chemistry in Interconnects, Vincent Jousseaume, Paul-Henri Haumesser, Carole Pernel, Jeffery Butterbaugh, Sylvain Maîtrejean and Didier Louis. 3. The Chemistry of Wet Surface Preparation: Cleaning, Etching and Drying, Yannick Le Tiec and Martin Knotter. 4. The Use and Management of Chemical Fluids in Microelectronics, Christiane Gottschalk, Kevin Mclaughlin, Julie Cren, Catherine Peyne and Patrick Valenti. 5. Surface Functionalization for Micro- and Nanosystems: Application to Biosensors, Antoine Hoang, Gilles Marchand, Guillaume Nonglaton, Isabelle Texier-Nogues and Francoise Vinet. About the Authors Yannick Le Tiec is a technical expert at CEA-Leti, Minatec since 2002. He is a CEA-Leti assignee at IBM, Albany (NY) to develop the advanced 14 nm CMOS node and the FDSOI technology. He held different technical positions from the advanced 300 mm SOI CMOS pilot line to different assignments within SOITEC for advanced wafer development and later within INES to optimize solar cell ramp-up and yield. He has been part of the ITRS Front End technical working group at ITRS since 2008.

This book provides a comprehensive overview of the science of nanostructured oxides. It details the fundamental techniques and methodologies involved in oxides thin film and bulk growth, characterization and device processing, as well as heterostructures. Both, experts in oxide nanostructures and experts in thin film heteroepitaxy, contribute the interactions described within this book.

Oxides form a broad subject area of research and technology development which encompasses different disciplines such as materials science, solid state chemistry, physics etc. The aim of this book is to demonstrate the interplay of these fields and to provide an introduction to the techniques and methodologies involving film growth, characterization and device processing. The literature in this field is thus fairly scattered in different research journals covering one or the other aspect of the specific activity. This situation calls for a book that will consolidate this information and thus enable a beginner as well as an expert to get an overall perspective of the field, its foundations, and its projected progress.