Infinite Selectivity of Wet SiO2 Etching in Respect to Al
| Autor: | Pavel Neužil, Jan Brodský, Imrich Gablech, Jan Pekárek |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
lcsh:Mechanical engineering and machinery 02 engineering and technology 01 natural sciences Article Fume hood chemistry.chemical_compound Etching (microfabrication) 0103 physical sciences Immersion (virtual reality) lcsh:TJ1-1570 Electrical and Electronic Engineering Composite material Sheet resistance 010302 applied physics Microelectromechanical systems SiO2 etching Mechanical Engineering selectivity 021001 nanoscience & nanotechnology Oleum sacrificial layer chemistry Control and Systems Engineering microelectromechanical systems (MEMS) 0210 nano-technology Selectivity Layer (electronics) |
| Zdroj: | Micromachines Volume 11 Issue 4 Micromachines, Vol 11, Iss 365, p 365 (2020) Micromachines. 2020, vol. 11, issue 4, p. 365-371. |
| ISSN: | 2072-666X |
| DOI: | 10.3390/mi11040365 |
| Popis: | We propose and demonstrate an unconventional method suitable for releasing microelectromechanical systems devices containing an Al layer by wet etching using SiO2 as a sacrificial layer. We used 48% HF solution in combination with 20% oleum to keep the HF solution water-free and thus to prevent attack of the Al layer, achieving an outstanding etch rate of thermally grown SiO2 of &asymp 1 µ m· min&minus 1. We also verified that this etching solution only minimally affected the Al layer, as the chip immersion for &asymp 9 min increased the Al layer sheet resistance by only &asymp 7.6%. The proposed etching method was performed in an ordinary fume hood in a polytetrafluorethylene beaker at elevated temperature of &asymp 70 ° C using water bath on a hotplate. It allowed removal of the SiO2 sacrificial layer in the presence of Al without the necessity of handling highly toxic HF gas. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|