Infrared Spectroscopy Studies Of Electron Induced Reaction Mechanisms In Euv Photoresists

Extreme ultraviolet (EUV) lithography, with approximately 13.5 nm photons is the new standard of the semiconductor industry. The use of EUV photons allows for further miniaturization of integrated circuits, enabling industry and researchers alike to explore the 1 – 10 nm regime. Despite the desire to begin mass producing devices with EUV tools by 2020, a clear direction for the best EUV capable photoresists is not understood. In this dissertation, a novel class photoresist material is investigated to understand key areas of their reaction mechanisms for next-generation photolithography. These photoresists are composed of a hybrid nanocluster architecture with a small HfOx core surrounded by methacrylic acid ligand (HfMAA) and can achieve high sensitivity and etch-resistance due to their small molecular nature, high-absorption metal core, and ease of ligand tunability. However, many aspects about their properties and reactivity are still poorly understood. To investigate the reaction mechanisms, the photoresists were probed with a bream of energetic electrons, corresponding to primary and secondary energies produced during EUV ionizations. Their chemical transformation upon electron irradiation, along with the effects of annealing, were tracked using in situ infrared (IR) spectroscopy. After post-application bake (PAB) to 105 °C, the IR spectra show the formation of new Hf-O-Hf bonds through the consumption of terminal hydroxyl groups. This bond formation negatively affects the intrinsic solubility characteristic of the photoresists. Additionally, a crosslinking pathway is initiated by a decarboxylation mechanism of the methacrylate ligands (MAA) under electron irradiation. To understand further the role of secondary electrons in HfMAA, a ligand exchange procedure was employed to change ~20% of the MAA with 4-hydrobenzoic acid (HBA) and phenyl acetic acid (PAA). In situ IR spectroscopy was used to monitor the amount of alkyl CH produced by both 90 and 20 eV electron irradiations. The addition of the co-ligand enhanced the secondary electron sensitivity by 40% when compared to HfMAA. In addition, using mass spectrometry, two different reaction pathways are observed for each co-ligand due to the benzene ring of each ligand decomposes differently. Finally, a number of fundamental studies were performed to investigate EUV/electron-induced resist chemistry in thin-film model systems. Using methacrylic acid (MAA), isobutyric acid (IBA), and 4-hydrobenzoic acid (HBA) as prototypical probe molecules, we find spectroscopic evidence for a decarboxylation mechanism among each of the grafted carboxylate molecules. Differences in selection rules for EUV absorption vs impact ionization for 90 eV electrons are found to play an important role in the reactivity of ligands with different metal centers. Lastly, ab initio model calculations are compared to experimental data and demonstrate their potential use to screen reactivity of different carboxylate ligands and provide validation of first principles method for predicting reactivity of candidate resist chemistries. Additionally, we successfully grafted trivinyl-, dimethylsilamine on SiO2 to fundamentally study the effect of electron irradiation of organosilane based molecules. Results show with FTIR spectroscopy we can study reactivity of the silicon-vinyl groups by spin coating a thin siloxane based polymer layer on top of the monolayer. We demonstrated interaction between the two layers can occur with electron irradiation through the formation of Si-C and Si-O bonds.

Ultrafast time-resolved infrared spectroscopy provides a powerful tool for studying the photochemistry of organometallic complexes. The studies described herein focus on the mechanisms of photochemically initiated organometallic reactions with a particular emphasis on two topics: the role of spin states and spin state changes in organometallic reactions, and the primary photochemical dynamics of complexes containing metal-metal bonds (e.g. transition metal dimers and clusters). Many of these studies seek to uncover trends in reactivity based on the spin states of organometallic reaction intermediates, with the goal of being able to offer some level of predictive insight into the reactivity of complexes as classified by their spin multiplicity. The reactivity of various coordinatively unsaturated reaction intermediates are studied with respect to bond activation, electron transfer, excited state photoisomerization, and other classes of reactions important to organometallic catalysis. A second focus, which shares some degree of overlap with the topic of spin state changes, is the primary photochemistry of complexes containing metal-metal bonds. Several of the studies reported herein use time-resolved infrared spectroscopy to examine the primary photochemical processes occurring upon excitation of transition metal dimers and clusters, and often spin state changes also found to play an important role. Results of computational chemistry calculations are frequently used to facilitate interpretation of the experimental results by computation of structures, relative energies, infrared spectra, and spin-orbit coupling for the complexes studied experimentally. Additional studies outside these two primary areas of focus also investigated the ring-slippage of cyclopentadienyl ligands and the CO-delivery properties of a popular CO-Releasing Molecule.

As the requirements of the semiconductor industry have become more demanding in terms of resolution and speed it has been necessary to push photoresist materials far beyond the capabilities previously envisioned. Currently there is significant worldwide research effort in to so called Next Generation Lithography techniques such as EUV lithography and multibeam electron beam lithography. These developments in both the industrial and the academic lithography arenas have led to the proliferation of numerous novel approaches to resist chemistry and ingenious extensions of traditional photopolymers. Currently most texts in this area focus on either lithography with perhaps one or two chapters on resists, or on traditional resist materials with relatively little consideration of new approaches. This book therefore aims to bring together the worlds foremost resist development scientists from the various community to produce in one place a definitive description of the many approaches to lithography fabrication. Assembles up-to-date information from the world’s premier resist chemists and technique development lithographers on the properties and capabilities of the wide range of resist materials currently under investigation Includes information on processing and metrology techniques Brings together multiple approaches to litho pattern recording from academia and industry in one place

Surveying and comparing all techniques relevant for practical applications in surface and thin film analysis, this second edition of a bestseller is a vital guide to this hot topic in nano- and surface technology. This new book has been revised and updated and is divided into four parts - electron, ion, and photon detection, as well as scanning probe microscopy. New chapters have been added to cover such techniques as SNOM, FIM, atom probe (AP),and sum frequency generation (SFG). Appendices with a summary and comparison of techniques and a list of equipment suppliers make this book a rapid reference for materials scientists, analytical chemists, and those working in the biotechnological industry. From a Review of the First Edition (edited by Bubert and Jenett) "... a useful resource..." (Journal of the American Chemical Society)

This comprehensive volume, edited by a senior technical staff member at SEMATECH, is the authoritative reference book on EUV source technology. The volume contains 38 chapters contributed by leading researchers and suppliers in the EUV source field. Topics range from a state-of-the-art overview and in-depth explanation of EUV source requirements, to fundamental atomic data and theoretical models of EUV sources based on discharge-produced plasmas (DPP) and laser-produced plasmas, to a description of prominent DPP and LPP designs and other technologies for producing EUV radiation. Additional topics include EUV source metrology and components (collectors, electrodes), debris mitigation, and mechanisms of component erosion in EUV sources. The volume is intended to meet the needs of both practitioners of the technology and readers seeking an introduction to the subject.

Lithography is a field in which advances proceed at a swift pace. This book was written to address several needs, and the revisions for the second edition were made with those original objectives in mind. Many new topics have been included in this text commensurate with the progress that has taken place during the past few years, and several subjects are discussed in more detail. This book is intended to serve as an introduction to the science of microlithography for people who are unfamiliar with the subject. Topics directly related to the tools used to manufacture integrated circuits are addressed in depth, including such topics as overlay, the stages of exposure, tools, and light sources. This text also contains numerous references for students who want to investigate particular topics in more detail, and they provide the experienced lithographer with lists of references by topic as well. It is expected that the reader of this book will have a foundation in basic physics and chemistry. No topics will require knowledge of mathematics beyond elementary calculus.

The 3rd edition of this successful textbook continues to build on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field — in a concise format. The 3rd edition offers significant updates throughout, with expanded sections on sustainability, energy storage, metal-organic frameworks, solid electrolytes, solvothermal/microwave syntheses, integrated circuits, and nanotoxicity. Most appropriate for Junior/Senior undergraduate students, as well as first-year graduate students in chemistry, physics, or engineering fields, Materials Chemistry may also serve as a valuable reference to industrial researchers. Each chapter concludes with a section that describes important materials applications, and an updated list of thought-provoking questions.

The fabrication of an integrated circuit requires a variety of physical and chemical processes to be performed on a semiconductor substrate. In general, these processes fall into three categories: film deposition, patterning, and semiconductor doping. Films of both conductors and insulators are used to connect and isolate transistors and their components. By creating structures of these various components millions of transistors can be built and wired together to form the complex circuitry of modern microelectronic devices. Fundamental to all of these processes is lithography, ie, the formation of three-dimensional relief images on the substrate for subsequent transfer of the pattern to the substrate. This book presents a complete theoretical and practical treatment of the topic of lithography for both students and researchers. It comprises ten detailed chapters plus three appendices with problems provided at the end of each chapter. Additional Information: Visiting http://www.lithoguru.com/textbook/index.html enhances the reader's understanding as the website supplies information on how you can download a free laboratory manual, Optical Lithography Modelling with MATLAB®, to accompany the textbook. You can also contact the author and find help for instructors.