The objective of the course is to introduce the student to the theory and technology of micro- and nano-fabrication, providing her/him with the essential knowledge and experimental skills on the basic and advanced processing techniques. A first section of the course is devoted to the film and heterostructure realization by different deposition techniques, whereas a second section is focused on the realization of devices by conventional and advanced lithography. The experimental activity is carried out at the Polifab micro- and nano-technology center of the Politecnico di Milano. The main goal of the course is to provide the student with the ability to design and realize a conventional process flow for the fabrication of simple electronic and spintronic devices.

Knowledge and understanding

Upon passing the exam, the student:

- knows the principles of vacuum technologies

- knows the foundations of surface thermodynamics and epitaxy

- knows the basic physical vapor deposition (PVD) and chemical vapor deposition (CVD) techniques

- knows the physical and operational basis of the lithographic and etching techniques

- understands the difference between the main deposition techniques

- understands the difference between the main lithographic techniques

- understands the difference between the main etching techniques

Applying knowledge and understanding

Upon passing the exam, the student:

- is able to design a simple vacuum system

- is able to predict the growth dynamics of a film and an heterostructures

- is able to design a simple lithographic process flow

- is able to choose between different deposition techniques depending on the application

- is able to choose between different lithographic techniques depending on the application

- is able to choose between different etching techniques

Making judgements

Upon passing the exam, the student:

- is able to design and realize the process flow for fabricating simple electronic or spintronic devices

Part I - Deposition

• Introduction: objectives, examples of micro and nano-fabrication
• Vacuum technology: kinetic theory of gases, gas transport and pumping, vacuum systems
• Surface thermodynamics: surface properties, homogeneous and heterogeneous nucleation, film growth modes
• Film epitaxy: mechanisms, lattice orientation, strain
• Thermal evaporation: calculation of rate and uniformity, examples of electrically heated and e-beam sources, molecular beam epitaxy, pulsed laser deposition
• Sputtering deposition: plasma physics, sputtering techniques (DC, RF, reactive and magnetron)
• Chemical Vapor Deposition: reactions, basics of thermodynamics and gas flow, CVD techniques (thermally- and plasma-activated)
• Characterization techniques: film thickness, structure, stoichiometry

Part II - Lithography

• Introduction to lithography: device scaling, Moore’s law
• Optical lithography: process flow and technology
• Physics of optical exposure and resolution enhancement technologies: diffraction, numerical aperture, illuminations, masks, lenses, resists
• Advanced photolithographic techniques: maskless optical lithography, extreme ultraviolet lithography, X-ray lithography
• Electron beam lithography: physical principles, process flow and technology
• Other advanced lithographic techniques: soft and nanoimprint lithography, focused ion beam, scanning probe lithography
• Pattern transfer: dry and wet etching
• Examples of lithographic process flows

Laboratory activities

An experimental activity will be carried out at Polifab, the micro- and nanotechnology center of the Politecnico di Milano, allowing the student to practice the design and realization of a conventional process flow for the fabrication of a simple spintronic device, such as a Hall bar or a GMR sensor. The student will actively participate to the fabrication process, using some of the deposition and patterning techniques discussed in the course.

Schedule

The course will be held in the second half of the first semester, from November to December.

The program is designed for students of the Engineering Physics course. Students from Electronic Engineering, Biomedical Engineering, Material Engineering and Nanotechnology may also benefit from this course. Basic knowledge of solid state physic is recommended.

The examination is oral, on the topics of the course (Part I and Part II).