Chlorine-Based Smooth Reactive Ion Beam Etching of Indium-Containing III-V Compound Semiconductor

Abstract

Very smooth and vertical etching of InP by Cl2 reactive ion beam etching has been achieved under high temperature (≈200°C), high ion energy (≈1 keV) and low Cl2 pressure (∼10-5 Torr). The roughness is estimated to be a few nm by scanning tunneling microscopy and no contamination except for Cl was observed by in situ Auger electron spectroscopy. Under these etching conditions, the etched depth is precisely controlled (σ=22 nm) by simply monitoring the electrode curtent of the ion accelerating grid. Other III-V compound semiconductors, such as GaAs, InGaAs, AlGaInP and InAlAs have also been etched smoothly and vertically. Multilayers of these materials, such as InP/InGaAsP, AlGaInP/GaInP, and InAlAs/InGaAs/InP have been etched without steps between the layers on the sidewalls.

Deep dry etching process development for photonic crystals in InP-based planar waveguides

“…From figure 3, a transition from positively to negatively sloped sidewall is apparent. A similar transition was observed previously as a function of Cl 2 content in the plasma 14 and was attributed to the balance between the physical and chemical etch component. At 190 o C, the etching is balanced and sidewalls are straight.…”

Dry etching and consequent burring regrowth of nanosize quantum wells stripes using an in situ ultrahigh vacuum multichamber system

“…9 A high accelerating voltage was necessary to etch InGaAs/InP because of the greater difference in the desorption rate between In and P, or its chloride. 10 To reduce the differences in desorption rate, the etching temperature was kept at 200°C and the accelerating voltage was increased to 900 V. The etching pressure was 2ϫ10 Ϫ5 Torr.…”

Solid Source Dry Etching Process for GaAs and InP

“…However, Cl 2 ion energies in excess of 0.5 -1 keV and a substrate temperature of 250 C are required to obtain a vertical etching profile and a smoothly etched surface of InP. [1][2][3] Although a high-substrate temperature has been thought to be required to desorb etching products, such as InCl x , in inductively coupled plasma (ICP) etching processes, we demonstrated the vertical and smooth etching of InP at 90 C in hydrogen iodide (HI)-ICP etching by forming InI 3 as a high-volatility product. 4) However, an etching process without hydrogen, using simple etching equipment without control systems or plumbers of reactive etching gases is desired.…”