Revision as of 10:14, 26 August 2019

Feedback to this page: click here

THIS PAGE IS UNDER CONSTRUCTION

A wet chemical etch of Al₂O₃ can be done with HF. The etch rate depends on the HF concentration.

Experiment and results

Si samples with about 100 nm of ALD deposited Al₂O₃ (1000 cycles at 300^oC) has been etched in different HF concentrations. After the etching, the thickness of the Al₂O₃ layer has been measured, and the thickness as function of time has been plotted as shown in the graph below.

attempt to dissolve Al<sub

The etch rates:

5% HF: 1.74 nm/s
1vol. H₂O : 1vol. 5% HF 1.05 nm/s
2vol. H₂O : 1vol. 5% HF 0.723 nm/s

Be aware of that the 5% HF etches quite fast - Actually so fast that it can be tricky to control the etch. Just imagine, you take a sample out of solution and place it in a bigger water container to rinse, and during that movement, the etch continues… So the handling things around the fumehood can be a source of errors.

Evgeniy Shkondin, DTU Nanolab, June 2019

@@ Line 10: / Line 10: @@
 Si samples with about 100 nm of [[Specific_Process_Knowledge/Thin_film_deposition/ALD_Picosun_R200|ALD]] deposited Al<sub>2</sub>O<sub>3</sub> (1000 cycles at 300<sup>o</sup>C) has been etched in different HF concentrations. After the etching, the thickness of the Al<sub>2</sub>O<sub>3</sub> layer has been measured, and the thickness as function of time has been plotted as shown in the graph below.
-<gallery caption="attempt to dissolve Al<sub>2</sub>O<sub>3</sub> with HF." widths="5000px" heights="5000px">
+<gallery caption="attempt to dissolve Al<sub>2</sub>O<sub>3</sub> with HF." widths="500px" heights="500px">
 image:AL203_Hf_etch.jpg
 </gallery>