Effect of Cl{sub 2}- and HBr-based inductively coupled plasma etching on InP surface composition analyzed using in situ x-ray photoelectron spectroscopy

Journal Article · Tue May 15 00:00:00 EDT 2012 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3692751· OSTI ID:22054154

Bouchoule, S; Vallier, L; Patriarche, G; Chevolleau, T; Cardinaud, C ^[1]

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1. LPN-CNRS, Route de Nozay, 91 460 Marcoussis (France)

A Cl{sub 2}-HBr-O{sub 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 ({approx}600 nm/min). Ex situ x-ray energy dispersive analysis of the etched sidewalls shows that the etching anisotropy is obtained through a SiO{sub 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{sub 2}-based ICP etching results in a significantly P-rich surface. The phosphorous layer identified on the top surface is estimated to be {approx}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{sub 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{sub 2}-based ICP etching for the recovery of the InP material.

• OSTI ID: 22054154
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 30, Issue 3; Other Information: (c) 2012 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
74 ATOMIC AND MOLECULAR PHYSICS
AIR
ANISOTROPY
CHLORINE
ETCHING
HYDROGEN BROMIDES
ICP MASS SPECTROSCOPY
INDIUM PHOSPHIDES
INTEGRATED CIRCUITS
OXIDATION
PASSIVATION
PHOSPHORUS
PLASMA
SEMICONDUCTOR MATERIALS
SILICON
SILICON OXIDES
STOICHIOMETRY
SURFACES
X-RAY PHOTOELECTRON SPECTROSCOPY