Silicon Nanowire Field Effect Transistor Sensors with Minimal Sensor-to-Sensor Variations and Enhanced Sensing Characteristics.
ACS Nano
; 12(7): 6577-6587, 2018 07 24.
Article
in En
| MEDLINE
| ID: mdl-29932634
ABSTRACT
Silicon nanowire field effect transistor (FET) sensors have demonstrated their ability for rapid and label-free detection of proteins, nucleotide sequences, and viruses at ultralow concentrations with the potential to be a transformative diagnostic technology. Their nanoscale size gives them their ultralow detection ability but also makes their fabrication challenging with large sensor-to-sensor variations, thus limiting their commercial applications. In this work, a combined approach of nanofabrication, device simulation, materials, and electrical characterization is applied toward identifying and improving fabrication steps that induce sensor-to-sensor variations. An enhanced complementary metal-oxide-semiconductor-compatible process for fabricating silicon nanowire FET sensors on 8 in. silicon-on-insulator wafers is demonstrated. The fabricated nanowire (30 nm width) FETs with solution gates have a Nernst limit subthreshold swing (SS) of 60 ± 1 mV/decade with â¼1.7% variations, whereas literature values for SS are ≥80 mV/decade with larger (>10 times) variations. Also, their threshold voltage variations are significantly (â¼3 times) reduced, compared to literature values. Furthermore, these improved FETs have significantly reduced drain current hysteresis (â¼0.6 mV) and enhanced on-current to off-current ratios (â¼106). These improvements resulted in nanowire FET sensors with the lowest (â¼3%) reported sensor-to-sensor variations, compared to literature studies. Also, these improved nanowire sensors have the highest reported sensitivity and enhanced signal-to-noise ratio with the lowest reported defect density of 2.1 × 1018 eV-1 cm-3, in comparison to literature data. In summary, this work brings the nanowire sensor technology a step closer to commercial products for early diagnosis and monitoring of diseases.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Silicon
/
Transistors, Electronic
/
Nanowires
Type of study:
Prognostic_studies
/
Screening_studies
Language:
En
Journal:
ACS Nano
Year:
2018
Document type:
Article