Experiments on the Release of CMOS-Micromachined Metal Layers

Figure 2

Microphotograph of a CMOS-MEMS membrane released with hydrofluoric acid ($\text{HF}$). Etching time was 6 min and 30 sec and $\text{HF}$ concentration was $2.5\text{\%}$. The arms and part of the membrane disappeared, but only few nanometers of silicon dioxide were removed.