Abstract

The application of micro-Raman spectroscopy was used for characterization of structural features of the high-k stack (h-k) layer of “silicon-on-insulator” (SOI) nanowire (NW) chip (h-k-SOI-NW chip), including Al2O3 and HfO2 in various combinations after heat treatment from 425 to 1000 °C. After that, the NW structures h-k-SOI-NW chip was created using gas plasma etching optical lithography. The stability of the signals from the monocrine phase of HfO2 was shown. Significant differences were found in the elastic stresses of the silicon layers for very thick (>200 nm) Al2O3 layers. In the UV spectra of SOI layers of a silicon substrate with HfO2, shoulders in the Raman spectrum were observed at 480–490 cm−1 of single-phonon scattering. The h-k-SOI-NW chip created in this way has been used for the detection of DNA-oligonucleotide sequences (oDNA), that became a synthetic analog of circular RNA–circ-SHKBP1 associated with the development of glioma at a concentration of 1.1 × 10−16 M. The possibility of using such h-k-SOI NW chips for the detection of circ-SHKBP1 in blood plasma of patients diagnosed with neoplasm of uncertain nature of the brain and central nervous system was shown.

Highlights

  • Raman spectroscopy can be applied in different forms of research, including for the development of biosensors [1,2]

  • The dioxide should be deposited by the plasma-enhanced atomic layer deposition (PEALD) method, followed by post-deposition annealing (PDA) in forming gas in order to not reduce the sensitivity of the sensors

  • Earlier in our study [14], the usage of high-permittivity HfO2 as a protective coating applied by the PEALD method followed by PDA in forming gas was proposed

Read more

Summary

Introduction

Raman spectroscopy can be applied in different forms of research, including for the development of biosensors [1,2]. A biosensor based on nanowire structures “silicon-on-insulator” (NW biosensor) can be considered an example of such a molecular detector [5,6,7] They perform real time label-free detection of biological macromolecules with high sensitivity (at femtomolar and even sub-femtomolar levels) and set forth a promising basis for the development of novel analytical systems. The dioxide should be deposited by the plasma-enhanced atomic layer deposition (PEALD) method, followed by post-deposition annealing (PDA) in forming gas in order to not reduce the sensitivity of the sensors. Experiments with such coatings showed their instability in biofluids, and coating delamination was detected (Figure 1). Micro-Raman spectroscopy is a faster method to control the quality of coatings and the production of such chips

Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call