• 054351 - MICRO AND NANOSTRUCTURE FABRICATION

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 on the basic and advanced processing techniques. In the first part different deposition techniques for the realization of films and heterostructures are presented, whereas the second part is focused on the realization of devices by conventional and advanced lithography. Applicative examples from different fields (electronics, spintronics, optics) are reported and discussed. The main goal is to provide the student with the ability to design a conventional process flow for the fabrication of simple electrical and magneto-electrical 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 basic lithography and etching techniques

- understands the difference between the main deposition techniques

- understands the difference between the main lithography 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 heterostructure

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

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

Making judgements

Upon passing the exam, the student:

- is able to design a conventional process flow for the fabrication of simple electrical and magneto-electrical devices

Part I - Deposition

• Introduction to micro and nanofabrication: objectives, examples.
• Vacuum technology: kinetic theory of gases, gas transport and pumping, vacuum pumps, vacuum systems
• Surface thermodynamics: surface properties, homogeneous and heterogeneous nucleation, film growth modes, nucleation
• Epitaxy: mechanisms, lattice orientation, strain
• Physical Vapor Deposition: introduction, difference between techniques
• Thermal Evaporation: rate and uniformity, electrically heated and e-beam sources, MBE, PLD
• Sputtering: sputtering mechanisms, introduction to plasma physics, DC, RF, reactive and magnetron sputtering
• Chemical Vapor Deposition: introduction, types of reactions, thermodynamic and gas flow, classification of thermally- and plasma-activated CVD techniques
• Characterization techniques: optical methods (ellipsometry), mechanical methods (profilometry, quartz microbalance), XRD, microscopies, electron spectroscopies (AES, XPS), electron diffraction (RHEED, LEED)

 Part II - Lithography

• Introduction to lithography: device scaling, Moore’s law
• Optical lithography: process flow and technology
• Physics of optical exposure: diffraction, numerical aperture, types of illumination
• Resolution enhancement technologies: 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
• CMOS process flow and other examples

 Laboratory activities

The main deposition and lithography techniques will be shown to students in the clean-room at the PoliFab laboratory.

 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 Engineering Physics course. Students from Electronic Engineering, Biomedical Engineering, Material Engineering and Nanotechnology may also benefit from this course. A good knowledge of solid state physic is required.

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

Textbook for Part I- Deposition

Textbook for Part II- Lithography