Reliability and Advanced Characterization of Nano-sized Biofinfets

Leuven - PhD
More than two weeks ago

In-depth investigation of the degradation mechanisms and random telegraph noise of nano-sized biofinFETs


Finfets are promising versatile biomolecule sensors. Massively parallel reading of DNA was recently made possible by implementing genomics-on-a-chip. The cost of reading all of a human’s DNA was reduced to a couple of thousand dollars. Current DNA sequencing techniques offer high throughput access to genomic information, but a further improvement of the throughput and the reduction in cost are limited by the optical basis of the techniques. Moreover, the current optical techniques do not suffice for obtaining molecular information from another important class of molecules in the body, proteins.  Proteomics, the large scale analysis of proteins, has not gone through such a revolution yet.


Nanoscale transistor-based sensors which can be integrated on a large scale for a massively parallel analysis of biological systems are a prominent candidate for the next generation of omics-on-a-chip. A finfet sensor consists of a finfet with a liquid electrolyte as gate instead of metal or poly gate. Charges binding to the gate dielectric surface will be sensed by the bioFET. A CMOS-based bio-electronic sensor chip could provide for a major increase in parallelization and deliver a more complete view of a biological system at a lower cost. At present, several challenges still need to be tackled to achieve such a large-scale bio-electronic sensor chip.


The introduction of a liquid electrolyte in contact with the gate introduces many stability and reliability challenges that are not present in solid-state devices.

The goal of this PhD is to perform an in-depth investigation of the various degradation mechanism of  biofinFETs, such as Bias Temperature Instability (BTI), threshold drift, dielectric breakdown, ion adsorption, corrosion, and dissolution of nano-sized biofinfets remain largely unstudied compared to their solid state counterparts. An in-depth understanding of these mechanisms and which of these is the most relevant for bioFETs is of key importance for breakthrough applications.    


Random Telegraph Noise (RTN) is a type of noise which finds its origin in the trapping of single electrons. This type of noise is expected to strongly interfere with biosignals of interest. The second goal of this PhD is to obtain understanding of RTN in biofets as well as how to reduce or compensate this type of noise which is strongly related to charge trapping induced degradation mechanisms.


Fig.1 : Artist’s impression of a biosensor (nanowire FET) used to sequence DNA molecules in an electrolyte solution. (Image credit: Peter Allen, UCSB).




Required background: Electrical engineering, nanotechnology, physics


Type of work: 70% experimental characterization, 30% modeling

Supervisor: Guido Groeseneken, Koen Martens

Daily advisor: Geert Hellings

The reference code for this position is 1812-53. Mention this reference code on your application form.


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