An Introduction to Contact Resistance

Contact resistance is both an old and new topic. It is old because fundamentals of the semiconductor-metal contacts were established in the 1930s even earlier than the study on Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). The new knowledge is on material and integration aspects for contact resistance reduction. As the MOSFETs become smaller and smaller, device parasitics start to domoniate performance since the 2010s. The resistance part in MOSFET RC delay is mainly from external parasitics particularly the contact resistance. In the past decade, 3D MOSFETs, also named FinFETs, became the device structure in leading semiconductor technology. The 3D structure brings a unique opportunity for engineering the contact resistance. In physics, this book introduces MOSFET device electronics and contact physics. In material science, a variety of contact metals and silicides are covered. In electrical characterization, test structures and measurements of contact resistance are discussed in depth. In technology, state-of-the-art process techniques, material engineering, and integration for contact resistance reduction are introduced. This book can serve as a reference book for students in electrical engineering and material science major and professionals in semiconductor industry.