Student Projects

Co‐supervisor: Fabio Bersano

Overview

This project aims to optimize key nanofabrication steps in the production of spin qubit devices in silicon. The student will receive training in our academic cleanroom and will be tasked with fine-tuning the engineering parameters of the fabrication process to enhance device quality. Prerequisites include a thorough understanding of semiconductor physics and a general knowledge of basic microfabrication techniques.

Co‐supervisor: Ali Gilani

Project Overview
Graphene’s exceptional properties, such as high electrical conductivity, large surface area, and atomic-scale thickness, make it ideal for biosensing applications. Functionalizing graphene with aptamers—synthetic oligonucleotides and antibody that selectively bind to cortisol, a critical stress biomarker—enables the development of a sensitive, selective, and scalable sensing platform. This project focuses on optimizing the aptamer functionalization process, characterizing the sensor’s performance, and integrating it into a hardware and software-based sensing system for real-time cortisol monitoring.

Objectives
• Functionalization: Optimize the binding of aptamers to graphene to preserve its electronic properties.
• Characterization: Analyze the graphene-aptamer interaction using Raman spectroscopy, XPS, SPR, QCM, and electrical measurements.
• Integration: Develop and test a complete hardware and software-based system for real-time cortisol sensing.

Methodology
• Conduct advanced characterization techniques (Raman, XPS, SPR, QCM) to validate aptamer functionalization.
• Analyze the electrical response of the graphene sensor to cortisol binding.
• Develop data analysis pipelines and Python-based coding solutions for sensor data interpretation.
• Collaborate on integrating the sensor platform with hardware and software systems for real-time monitoring.

Skills Acquired
Participants will gain expertise in:
• Nanotechnology and material science: Aptamer-functionalized graphene characterization.
• Bioelectronics: Sensing optimization and real-time detection.
• Characterization techniques: Raman, XPS, SPR, and QCM analysis.
• Hardware and software integration: Designing and testing sensing systems.
• Data analysis and Python coding: Developing solutions for sensor data evaluation.

Availability
• 1 Master’s Thesis: Focus on complete system development, from functionalization to integration and testing.
• 2 Semester Projects:
o Project 1: Antidbody functionalization and characterization using Raman, XPS, and QCM.
o Project 2: Electrical performance evaluation and integration of the graphene-based sensor with a hardware and software platform.

Co‐supervisor: Igor Stolichnov

Co‐supervisor: Ali Gilani

Project requirements: basic theoretical knowledge of cleanroom fabrication and biochemistry knowledge

Main tasks: Biosensor characterization

Starting date:  As soon as possible

Recommended type of project:  Master project or internship.

Work breakdown: 10% theory, 20% fabrication, 70% characterization.

Contact person:  Ali Gilani

Co‐supervisor: Vanessa Conti

Overview

VO2 is a phase change material able to pass from an insulating-monocline phase to a conductive-rutile one when reaching a critical carrier concentration, while HfO2 is a commonly used high-k dielectric that exhibits ferroelectricity under particular process conditions (doping, controlled annealing), when crystallizing in an orthorhombic phase. A successful integration of these two materials would help into the development of an efficient way to gate a VO2 transistor, leading to the possibility to realize devices for neuromorphic computing and memory applications.

The aim of this project is to study the structural and electrical properties of Si:HfO2 and VO2 once the former is deposited on top of the latter. Particularly, the student will have the task to study the possibility to anneal the stack using a flash-lamp annealing (FLA) tool, which thanks to its highly localized heat supply should be able to cause a minor number of damages to the underneath VO2 layer with respect to a conventional rapid-thermal process (RTP).

In order to reach the goal, Si:HfO2 and its metallic capping layer will be deposited (ALD, sputtering) on top of an already made VO2 thin film PLD deposited. The stack will be subsequently annealed in different thermal and ambient conditions. Structural characterization of the annealed stack will be done by means of several techniques (SEM, XRD, scanning probe microscopies) and the output will be correlated with the different annealing processes. Subsequently, different set of measurements (ex. CV, PUND, C-AFM, PFM) will be done on the samples with the desired structural properties in order to characterize the ferroelectric properties of the Si:HfO2 and the integrity of the VO2. To fabricate the electrical test structures, the samples will be processed in CMi cleanroom (metal deposition, laser direct writing, etching).

Possibly, different capping layers options could be explored as an alternative to the standard TiN layer.

Expected workload for the student:

• Initial literature review
• Fabrication of the capping layer – ferroelectric – VO2 stack (ALD, sputtering)
• Annealing of the stack (RTP, FLA)
• Structural characterization (mostly SEM, XRD, possibly AFM)
• Fabrication of capacitor structures on the stack (sputtering, MLA, wet etching / IBE)
• Electrical measurements (mostly with a parameter analyzer, possibly C-AFM and PFM)

Expected learning outcome:

• Basic understanding on the design of an experiment procedure
  • How to interpret and communicate the data
• Microfabrication skills in a real cleanroom environment
• Structural and electrical characterization experience
• General knowledge on ferroelectric and phase change materials

Requirements:

• Background in electrical engineering, material science, physics et similar
• General knowledge about semiconductor physics and devices, characterization methods
• Basic understanding of microfabrication processes
• Python/MATLAB/… for data analysis

Starting date: Spring 2024

Recommended type of project:  Master Thesis Project

Contact person: Vanessa Conti

Co-supervisor: Zahra Saadat

• Fine-tune microfabrication process parameters for VO₂ MEMS structures
• Analyzing and reporting results clearly and effectively
• Understanding the resonance frequency dependence on the strain field distribution

• Basic knowledge of MEMS and microfabrication
• Familiarity with cleanroom processes (EPFL- CMI access is a plus)
• Skills in documenting experimental processes, analyzing results, and presenting findings clearly and concisely