The following courses are undergraduate and graduate-level Engineering Science (E SC) courses taught by Dr. Lenahan. The material learned in these courses is directly related to the research performed in the Semiconductor Spectroscopy Lab.
E SC 312: Engineering Applications of Wave, Particle, and Ensemble Concepts
This course covers the engineering applications of the wave and ensemble pictures of the physical world. Students in this course will learn about:
- Wave phenomena and Electromagnetic Waves
- Designing for Lithography
- Photons and Solids
- Geometrical Optics
- Reconciliation of Particle and Wave Concepts
- Quantum Mechanics
- Free particles
- Step barriers
- Square well
- Hydrogen atom
- Multi-electron atom
- Laboratory Work
- Spin Resonance
- Magnetic resonance
- Quantum Theory of Metals, Semiconductors, and Insulators
- Engineering Applications of Quantum Mechanics and Statistical Mechanics
- Designing solid state electronic devices
- Statistical Mechanics:
- Statistical Mechanics and Kinetics
E SC 314: Engineering Applications of Materials
This course is intended primarily for Electrical Engineering and Materials Science and Engineering majors, as a core-level exposure to the electron-based properties of materials and their engineering applications. Building upon a basic foundation from early Physics courses, it offers an introduction to the behavior of electrons in crystalline as well as non-crystalline solids, and its impact on properties. A comprehensive treatment of electrons in solids is essential to understand the electronic, optical, thermal, magnetic and other properties of materials and their incorporation in functional devices. The topics are chosen to deal with all the basic facets of electrons in solids and their response to external fields and waves, and lead up to a broad range of elementary device applications.
It thaws upon the results of quantum mechanics and band theory of solids that provide the broad umbrella needed for understanding the properties of materials and designing them into practical devices including the new class of nanosystems. The development of the energy band diagram is shown to offer a convenient model for understanding the properties of materials and designing device structures. The overwhelming role of semiconductors as building blocks of modern electronics is emphasized by introducing the key concepts of doping, electron transport by drift and diffusion, and electron-photon interactions. The students are shown the strong link connecting atomic bonding, physical structure and material properties in order that they understand the need for and emergence of artificially synthesized structures and new device phenomena.
Along with a detailed coverage of semiconductors due to their widespread applications and their dominance in modern micro- and optoelectronics, a basic introduction to dielectric and magnetic properties is also included. Engineering applications involving sensing and transduction as well as signal amplification and energy conversion will be interspersed in the discussions of properties throughout the course. The role of defects, impurities and interfaces on electrical, optical and other properties are introduced briefly, along with corresponding applications in device structures The devices discussed include p-n junctions, metal-semiconductor contacts, bipolar and field effect transistors, optical detectors and light emitting diodes.
The broad topical coverage will prepare students for advanced studies in a variety of fields including micro- and optoelectronics and functional microsystems. The course provides essential background for senior technical electives on semiconductor devices and processing as well as nanotechnology, and also complements courses that deal with atomic structure and mechanical properties of materials.
E SC 597A: Electron Paramagnetic Resonance in Solids
E SC 597B: Reliability Physics in Semiconductor Devices
This course will provide an introduction to semiconductor device reliability. Students must have taken E SC 312, E SC 314 or one of their equivalents as a prerequisite. The class begins with a review of semiconductor and insulator physics, including topics such as band theory, device defects, relevant statistical mechanics and kinetics, recombination, MOSFET physics fundamentals, MOS electrical characterization techniques, charge pumping, electronic transport in insulators such as tunneling and variable range hopping, and analytical measurements of defect structures – primarily via magnetic resonance.
After reviewing the relevant background physics, the main body of the course, reliability issues in MOSFETs will be covered. Topics to be studied include negative bias temperature instability, total ionizing dose radiation effects, time-dependent dielectric breakdown, stress induced leakage current, hot carrier problems, and instabilities in high-K dielectric MOSFETs. Reliability issues in low-K interlayer dielectrics will also be discussed, such as TDDB, SILC, and mechanical stability.
Towards the end of the course, students will examine failure in metallization, particularly electromigration and stress-induced voiding. The last topic of the course is a brief introduction and analysis of reliability statistics and their application to the topics covered earlier in the course. If time, reliability problems in solar cells, and other topics of student interest may be examined.
Some important questions addressed in this course:
- What happens when an extremely thin dielectric (such as the gate oxide in a MOSFET) is exposed to a very high electric field?
- What role does temperature play in fundamental limitations of device reliability?
- Does the semiconductor device oxide composition matter?
- What happens when a large current flows through a tiny wire?
Students will leave this course having a greater understanding of the materials science of reliability problems in complementary metal oxide semiconductor CMOS integrated circuits while covering a wide variety of other reliability issues in solid state electronics and their analytical methods.