PMN-PT (lead magnesium niobate-lead titanate) piezoelectric material micromachining by excimer laser ablation and dry etching (DRIE).

Ioan Alexandru Ivan (1) , Joël Agnus (1) , Pierre Lambert (1)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

In the attempt to find the appropriate micromanufacturing technology of PMN-PT (lead magnesium niobate-lead titanate) piezo material, whose MEMS-related applications look promising, two methods are investigated: excimer laser ablation (using KrF gas) and inductively coupled plasma (ICP) dry etching, also known as DRIE (using Ar/C4F8 gases). The paper quantitatively reports the optimal parameters for PMN-PT micromachining and compares both methods. KrF excimer laser ablation threshold fluence is of 14 J/cm2, the etching rate may reach 100 m/min (50 nm/pulse) but the ablated surfaces are cone-shaped restricting thus the method to cutting/drilling 2D shapes. Excimer ablation method is found to be more convenient for rapid prototyping with less precise features requirements (>10 m). On the other hand DRIE method on PMN-PT is time-consuming, requires a hard mask deposition but is cleaner and more precise. Dry etching maximum recorded speed is of 0.19 m/min. The nickel hard mask selectivity varies around 8:1. In exchange this method provides flatter surfaces with no etched material redeposition.

Mots clés: ICP; PMN-PT; lead magnesium niobate-lead titanate; xPb(Mg1/3Nb2/3)O3-(1 − x)PbTiO3; piezoelectric single-crystal; etching; KrF excimer; exciplex; laser ablation; dry etching; reactive ion etching; DRIE; inductively coupled plasma; ICP.

Domaines: Micro et nanotechnologies/Microélectronique

Ioan Alexandru Ivan, Joël Agnus, Pierre Lambert. PMN-PT (lead magnesium niobate-lead titanate) piezoelectric material micromachining by excimer laser ablation and dry etching (DRIE).. Sensors and Actuators A: Physical , 2012, 177, pp.37-47. ⟨10.1016/j.sna.2011.09.015⟩. ⟨hal-00797920⟩