Development And Advanced Characterization Of Novel Chemically Amplified Resists For Next Generation Lithography

The microelectronics industry has made remarkable progress with the development of integrated circuit (IC) technology which depends on the advance of micro-fabrication and integration techniques. On one hand, next-generation lithography (NGL) technologies which utilize extreme ultraviolet (EUV) and the state-of-art 193 nm immmersion and double patterning lithography have emerged as the promising candidates to meet the resolution requirements of the microelectronic industry roadmap. On the other hand, the development and advanced characterization of novel resist materials with the required critical imaging properties, such as high resolution, high sensitivity, and low line edge roughness (LER), is also indispensable. In conventional multi-component chemically amplified resist (CAR) system, the inherent incompatibility between small molecule photoacid generator (PAG) and the bulky polymer resin can lead to PAG phase separation, PAG aggregation, non-uniform PAG and acid distribution, as well as uncontrolled acid migration during the post-exposure baking (PEB) processes in the resist film. These problems ultimately create the tri-lateral tradeoff between achieving the desired lithography characteristics. Novel resist materials which can relief this constraint are essential and have become one of the most challenging issues for the implementation NGL technologies. This thesis work focuses on the development and characterization of novel resist materials for NGL technologies. In the first part of the thesis work, advanced characterization techniques for studying resist fundamental properties and lithographic performance are developed and demonstrated. These techniques provide efficient and precise evaluations of PAG acid generation, acid diffusivity, and intrinsic resolution and LER of resist materials. The applicability of these techniques to the study of resist structure-function relationships are also evaluated and discussed. In the second part of the thesis work, the advanced characterization and development of a novel resist system, the polymer-bound-PAG resists, are reported. The advantages of direct incorporation of PAG functionality into the resist polymer main chain are investigated and illustrated through both experimental and modeling studies. The structure-function relationships between the fundamental properties of polymer-bound-PAG resists and their lithographic performance are also investigated. Recommendations on substantial future works for characterizing and improving resist lithographic performance are discussed at the end of this thesis work.

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

Many problems exist in current photoresist designs that will limit their ability to obtain the performance required for future generations of integrated circuit devices. In order to overcome these challenges, novel resist designs are required, along with advancement in the fundamental understanding of the source of these problems. A mesoscale kinetic Monte Carlo simulation of resists was developed to probe the effects of changes in resist formulation and processing. A detailed SEM simulator was developed in order to better understand the effect of metrology on the characterization of the final resist relief image. Several important structure-property relations were developed for the prediction of glass transition temperature in molecular resists and the prediction of the solubility of molecular resists in developer. Five new families of molecular resists were developed that provide solutions to some of the limitations in current resist designs. Single component molecular resists have all of the functional groups required to act as a chemically amplified resist contained in a single molecule. This eliminates inhomogeneities in the resist and provides improved line edge roughness. Non-chemically amplified molecular resists were developed that have very good sensitivity due to the unique dissolution properties of molecular resists. Negative tone molecular resists were developed that have an excellent combination of resolution, sensitivity, and line edge roughness with better resolution than has been previously seen in negative tone resists. Control methods were also developed to improve the resolution of these types of negative tone resists even further.

Editorial Review Dr. Bakshi has compiled a thorough, clear reference text covering the important fields of EUV lithography for high-volume manufacturing. This book has resulted from his many years of experience in EUVL development and from teaching this subject to future specialists. The book proceeds from an historical perspective of EUV lithography, through source technology, optics, projection system design, mask, resist, and patterning performance, to cost of ownership. Each section contains worked examples, a comprehensive review of challenges, and relevant citations for those who wish to further investigate the subject matter. Dr. Bakshi succeeds in presenting sometimes unfamiliar material in a very clear manner. This book is also valuable as a teaching tool. It has become an instant classic and far surpasses others in the EUVL field. --Dr. Akira Endo, Chief Development Manager, Gigaphoton Inc. Description Extreme ultraviolet lithography (EUVL) is the principal lithography technology aiming to manufacture computer chips beyond the current 193-nm-based optical lithography, and recent progress has been made on several fronts: EUV light sources, optics, optics metrology, contamination control, masks and mask handling, and resists. This comprehensive volume is comprised of contributions from the world's leading EUVL researchers and provides all of the critical information needed by practitioners and those wanting an introduction to the field. Interest in EUVL technology continues to increase, and this volume provides the foundation required for understanding and applying this exciting technology. About the editor of EUV Lithography Dr. Vivek Bakshi previously served as a senior member of the technical staff at SEMATECH; he is now president of EUV Litho, Inc., in Austin, Texas.

Integrated circuits, and devices fabricated using the techniques developed for integrated circuits, have steadily gotten smaller, more complex, and more powerful. The rate of shrinking is astonishing – some components are now just a few dozen atoms wide. This book attempts to answer the questions, “What comes next? and “How do we get there? Nanolithography outlines the present state of the art in lithographic techniques, including optical projection in both deep and extreme ultraviolet, electron and ion beams, and imprinting. Special attention is paid to related issues, such as the resists used in lithography, the masks (or lack thereof), the metrology needed for nano-features, modeling, and the limitations caused by feature edge roughness. In addition emerging technologies are described, including the directed assembly of wafer features, nanostructures and devices, nano-photonics, and nano-fluidics. This book is intended as a guide to the researcher new to this field, reading related journals or facing the complexities of a technical conference. Its goal is to give enough background information to enable such a researcher to understand, and appreciate, new developments in nanolithography, and to go on to make advances of his/her own. Outlines the current state of the art in alternative nanolithography technologies in order to cope with the future reduction in size of semiconductor chips to nanoscale dimensions Covers lithographic techniques, including optical projection, extreme ultraviolet (EUV), nanoimprint, electron beam and ion beam lithography Describes the emerging applications of nanolithography in nanoelectronics, nanophotonics and microfluidics

Many bottom-up and top-down techniques for nanomaterial and nanostructure generation have enabled the development of applications in nanoelectronics and nanophotonics. Handbook of Nanophysics: Nanoelectronics and Nanophotonics explores important recent applications of nanophysics in the areas of electronics and photonics. Each peer-reviewed c