The Dry Etching Characteristics of HfAlO₃Thin Films in CF₄/Cl₂/Ar Inductively Coupled Plasma

Abstract

In this study, the etching characteristics of HfAlO 3 thin film were investigated by varying the etch parameters such as the gas mixing ratio, the radio frequency power, the direct current bias voltage, and the process pressure in an inductively coupled plasma. The maximum etch rate of HfAlO 3 thin film and the selectivity of HfAlO 3 to SiO 2 were 20.55 nm/min and 0.38 in the CF 4 /Cl 2 /Ar (2:6:14 sccm) plasma, respectively. The plasma was analyzed by using optical emission spectroscopy. The chemical states on the surfaces of the etched HfAlO 3 thin film were investigated with X-ray photoelectron spectroscopy. The etching of HfAlO 3 thin films is performed by the interaction of Hf and Al atoms with the Cl and F radical in the CF 4 /Cl 2 /Ar plasma. However, their byproducts were remained at the surface because Hf-F and Al-F were non-volatile. Therefore, the plasma etching of the HfAlO 3 films follows the ion assisted chemical reaction.

Characteristics and mechanism of phase change material W0.03Sb2Te etched by Cl2/BCl3 inductively coupled plasmas

“…Etching processes with a high etch rate, smooth surface, and highly anisotropic profiles are required to meet requirements of application for PCM cell fabrication. Previous reports demonstrate that Cl-based plasma is effectively applied for etching Albased alloy due to forming volatile AlCl 3 at high temperature (N 180°C ) or Al 2 Cl 6 at room temperature [5]. Although a high etch rate can be achieved by Cl-based plasma, the etching process is usually isotropic as a result of its chemical mechanism.…”

BCl3-Based Dry Etching of Exfoliated (100) ß-Ga2O3 Flakes

“…BCl 3 -based gas chemistry is widely used to etch metal oxide materials such as HfO 2 , Al 2 O 3 , Y 2 O 3 , and InSnO 3 because boron (B) acts as an oxygen scavenger, thus producing BOCl x volatile etch products. [15][16][17] There have been a few reports on dry etching of β-Ga 2 O 3 with various gas chemistry. [18][19][20][21][22] Hogan et al reported that inductively coupled plasma (ICP) etching with pure BCl 3 gas was effective to obtain etch rate of 43 nm min −1 at 400 W ICP and 100 W bias rf powers.…”