Dry release for surface micromachining with HF vapor-phase etching

Fabrication of metallic micromirror using electroplating technology

“…This failure mode of microstructures is referred to as stiction. Many practical methods have been developed to address the stiction issue (Srinivasan et al 1998;Abe et al 1995;Yee et al 1995;Lee et al 1998;Kim et al 2001). In this work, we adopted a novel release method that combines dry and wet etching processes.…”

Microtunneling sensors for vacuum level evaluation of field emission display devices

“…There are some methods to avoid the stiction problem like as a selfassembled monolayer ͑SAM͒ coating, vapor phase etching, evaporation method, CO 2 supercritical drying, polymerization method, high temperature treatment method, reduction of the contact area method, and antistiction structure method. [18][19][20][21][22][23][24][25][26][27][28][29][30][31] Sublimation drying avoids the surface effects which exists at the interface between liquid and gas phase by making the solution to the solid phase, then, direct sublimation not via the liquid phase. So the stiction induced by the capillary force was removed.…”

<title>Surface preparation for selective tungsten deposition on MEMS structures</title>

“…This HF step is required to strip off the SiO 2 which is grown during the UPW rinse step that follows the aqueous HF release etch, as well as any additional oxide grown during the O 2 plasma process. Although vapor phase etching of sacrificial oxide layers has been reported [3][4][5] , the process is difficult to control in a manner such that liquid condensation does not occur (resulting in stiction), at least when performed at atmospheric pressure. The methods employed in this study capitalize on the robustness of aqueous phase etching followed by supercritical CO 2 drying.…”