Effect of Cl2- and HBr-based inductively coupled plasma etching on InP surface composition analyzed using in situ x-ray photoelectron spectroscopy

Abstract

Articles you may be interested in X-ray photoelectron spectroscopy analysis of the effect of temperature upon surface composition of InP etched in Cl2-based inductively coupled plasma A Cl 2 -HBr-O 2 /Ar inductively coupled plasma (ICP) etching process has been adapted for the processing of InP-based heterostructures in a 300-mm diameter CMOS etching tool. Smooth and anisotropic InP etching is obtained at moderate etch rate ($600 nm/min). Ex situ x-ray energy dispersive analysis of the etched sidewalls shows that the etching anisotropy is obtained through a SiO x passivation mechanism. The stoichiometry of the etched surface is analyzed in situ using angle-resolved x-ray photoelectron spectroscopy. It is observed that Cl 2 -based ICP etching results in a significantly P-rich surface. The phosphorous layer identified on the top surface is estimated to be $1-1.3-nm thick. On the other hand InP etching in HBr/Ar plasma results in a more stoichiometric surface. In contrast to the etched sidewalls, the etched surface is free from oxides with negligible traces of silicon. Exposure to ambient air of the samples submitted to Cl 2 -based chemistry results in the complete oxidation of the P-rich top layer. It is concluded that a post-etch treatment or a pure HBr plasma step may be necessary after Cl 2 -based ICP etching for the recovery of the InP material.

X-ray photoelectron spectroscopy analysis of the effect of temperature upon surface composition of InP etched in Cl2-based inductively coupled plasma

“…Using energy-dispersive x-ray spectroscopy coupled with a transmission electron microscope (EDX-TEM), we showed in a previous study that anisotropic etching of InP in plasma containing Cl 2 /H 2 or HBr is generally due to the deposition of a silicon oxide passivation layer on the etched sidewalls, which occurs when silicon and oxygen are present in small quantities in the gas phase. [10][11][12] However, the composition of the InP surface itself, which may impact the sidewall passivation process, could not be analyzed with this technique.…”

“…21 More recently, the chemical composition of the etched surface of bare InP samples was studied using angle-resolved quasi-in-situ XPS analysis, demonstrating that Cl 2 -based ICP etching of InP results in a significantly P-rich surface. 12 A phosphorus top layer was clearly identified, with a typical thickness estimated to be $1-1.3 nm. However, the sample temperature could not be accurately controlled with the ICP reactor used in the study.…”

“…However, the sample temperature could not be accurately controlled with the ICP reactor used in the study. 12 We use ex-situ XPS analysis in this work to investigate the surface composition of InP samples etched in Cl 2 and Cl 2 /Ar inductively coupled plasmas and observe the evolution of the In/P ratio as a function of the sample temperature. First, we show that the surface stoichiometry can be determined in a reliable manner using an adapted ex-situ procedure.…”

Improvement of the surface quality of semi-insulating InP substrates through a novel etching and cleaning method

“…[6][7][8][9] However, these methods are not very effective and unsuitable for a practical molecular beam epitaxy (MBE) growth process used in the preparation of high electron mobility transistor and heterojunction bipolar transistor devices.…”

Study of Inductively Coupled Plasma Etching of ZnS Materials

“…(such as C2H6/H2 or CH4/H2) [4] [5]. The etching rate up to several hundred nm/min with the first type of gas etching II-VI compound semiconductor material [6] [7], The faster etching rate is not conducive to the manufacture of nano-scale fine structures, and the halogen elements are corrosive and toxic and have a certain impact on the environment. The second type of gas is neither toxic nor corrosive.…”