Dry Etching Characteristics of Zinc Oxide Thin Films in Cl₂-Based Plasma

Abstract

We investigated the etching characteristics of zinc oxide (ZnO) and the effect of additive gases in a Cl 2 -based inductively coupled plasma. The inert gases were argon, nitrogen, and helium. The maximum etch rates were 44.3, 39.9, and 37.9 nm/min for Cl 2 (75%)/Ar(25%), Cl 2 (50%)/N 2 (50%), and Cl 2 (75%)/He(25%) gas mixtures, 600 W radiofrequency power, 150 W bias power, and 2 Pa process pressure. We obtained the maximum etch rate by a combination of chemical reaction and physical bombardment. A volatile compound of Zn-Cl. achieved the chemical reaction on the surface of the ZnO thin films. The physical etching was performed by inert gas ion bombardment that broke the Zn-O bonds. The highly oriented (002) peak was determined on samples, and the (013) peak of Zn 2 SiO 4 was observed in the ZnO thin film sample based on x-ray diffraction spectroscopy patterns. In addition, the sample of Cl 2 / He chemistry showed a high full-width at half-maximum value. The root-mean-square roughness of ZnO thin films decreased to 1.33 nm from 5.88 nm at Cl 2 (50%)/N 2 (50%) plasma chemistry.

Fabrication of ZnO Nanobrushes by H2–C2H2 Plasma Etching for H2 Sensing Applications

“…Dry etching of zinc oxide has been performed by using different gases as reactive species: chlorine-, bromine-, and flourine-based plasma chemical agents . However, combination of hydrogen and a hydrocarbon compound is most widely used in plasma-based reactive ion etching of zinc oxide.…”

“…17 Additionally, reactive ion or dry etching plasma processes of ZnO have been used in the fabrication of devices 18−20 as well as modification of surface morphology. 21,22 Dry etching of zinc oxide has been performed by using different gases as reactive species: chlorine-, 23 bromine-, 24 and flourine-based plasma chemical agents. 25 However, combination of hydrogen and a hydrocarbon compound is most widely used in plasma-based reactive ion etching of zinc oxide.…”

Study of Inductively Coupled Plasma Etching of ZnS Materials

“…One is chlorine-containing gas (such as Cl2, BCl3, CCl4, SiCl4, or CCl3F, etc.) [2] [3], the other is hydrocarbon gas. (such as C2H6/H2 or CH4/H2) [4] [5].…”