Specific Process Knowledge/Etch/Aluminum Oxide/Al2O3 Etch using HF

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 300C) 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.

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