Inductively coupled plasma reactive ion etching of ZnO using C₂F₆and NF₃-based gas mixtures

Abstract

Inductively coupled plasma reactive ion etching (ICP RIE) of ZnO film using C 2 F 6 and NF 3 -based gas mixtures was investigated as a function of ICP power, bias power, pressure, and plasma chemistry. An etch rate of about 410 nm min −1 in the case of C 2 F 6 plasma and about 380 nm min −1 in the case of NF 3 plasma was obtained at the optimum condition, with vertical sidewalls and smooth surfaces, which is about 30% higher than the etch rates obtained in the previous reports on ICP RIE of ZnO using CH 4 or chlorine-related gas mixtures. Basically no chamber contamination and corrosion was observed, indicating that fluorine plasmas are more suitable for ZnO dry etching than previously studied CH 4 or BCl 3 plasma. The addition of 40% or more CH 4 to the C 2 F 6 plasma improved the etch rate and sidewall verticality of the etched mesas, but resulted in rough surface morphology.

Reconfigurable locally resonant surface acoustic demultiplexing behavior in ZnO-based phononic crystal

“…and by high precision procedures. 43,44 Moreover, studying the systematic variations in the critical dimensions, we have scaled up/down the in-plane dimensions of the design for ±5% and show that the central peak frequencies change inversely by the scaling factor and the peak intensities show an overall drop between 1 and 3 dB, which is acceptable.…”

Studies of optical emission in the high intensity pumping regime of top‐down ZnO nanostructures and thin films grown on c‐sapphire substrates by pulsed laser deposition

“…The thin film was then selectively etched using ICP RIE (custom Plassys system) with C 2 F 6 [6] with the metallic mesas acting as a mask. Parameters were adjusted so as to remove the metal and etch 65-70 nm down into the ZnO film.…”

Inductively coupled plasma etching of ZnO

“…Lee, et al, 13 has recently reported ICP etching of ZnO in C 2 F 6 and NF 3 plasmas. One might expect the etch rate in fluorinated gases to be lower than in chlorinated gases due to the differences in the vapor pressures of possible etch products such as zinc fluoride and zinc chloride (7.5 mTorr or 1 Pa at a temperature of 731°C and 305°C respectively), 14 however, etch rates near 400 nm/min, with smooth surfaces and reasonably vertical sidewalls were obtained for both gases.…”

“…al., has reported even higher etch rates (~400 nm/min) with smooth and anisotropic profiles in C 2 F 6 and NF 3 chemistries. 13 …”