PhD Defense of Romain BANGE

Keywords:
biosensor, DNA, transistor, field effect, nanowire, silicon carbide

Abstarct:
Sensing of low concentrations of nucleic acids is essential to a variety of applications such as bio-medical analysis, in which case it allows the diagnosis of pathologies by identifying specific biomarkers. Compared to traditional sensing techniques based on biochemistry, the advantage of electrical field-effect detection is that it relies on a direct, label-free, and fast-response measurement.  Transistors based on semiconducting nanowires are promising devices that theoretically enable very low detection limits and a high sensitivity, thanks to their high surface-to-volume ratio and unique electronic properties. Silicon carbide (SiC) is a semiconductor material with qualities such as very high physical and chemical stability and high biocompatibility, which make it particularly suited for aforementioned applications.
In this thesis, field-effect transistors based on Si and SiC nanowires were designed with a top-down approach to be fabricated using photolithography techniques. The Si-based process was developed and optimized in order to fabricate reproducible devices made of nanowires and nanoribbons. A detailed study was conducted to demonstrate the superior chemical stability of SiC nanowires over Si nanowires under physiological conditions. Based on these results, we investigated two ways of elaborating a thin SiC layer around these Si nanostructures to provide them with its chemical resistance in liquid medium. These reproducible core-shell Si/SiC devices were eventually functionalized and integrated into a microfluidic system in order to achieve novel measurements of DNA detection in real time and in liquid media.
 

• Mrs Edwige BANO – IMEP-LAHC, Grenoble – Supervisor
• Mrs Valérie STAMBOULI – LMGP, Grenoble – Co-supervisor
• Mrs Anne-Marie HAGHIRI – C2N, Palaiseau – Reviewer
• M. Konstantinos ZEKENTES – FORTH Institute, Héraklion (Grèce) – Reviewer
• M. Arnaud MANTOUX – SIMAP, Grenoble – Examiner
• M. Stephen SADDOW – University of South Florida, Tampa (États-Unis) – Examiner
• M. Pascal MAILLEY – CEA Leti DTBS, Grenoble – Guest