SIMS Analysis of Compound Semiconductor Superlattice Heterojunction Interface

Abstract

In-depth profiling with secondary ion mass spectrometry has bean used to measure the interface width of OMVPE and LPE InGaAsP/InP, and MBE GaAlAs/GaAs superlattice heterojunctions.
The interface width of InGaAsP/InP heterojunction grown by OMVPE are determined to be ≤16 Å with 1.5 keV Cs⁺ primary ions. The measured interface width of LPE InGaAsP/InP was found to be ~66 Å at the depth of 260 Å.
GaAlAs/GaAs surface are not uniform due to cone formation when sutter etched by 1.5 keV Cs⁺ ions, 1.5 keV O₂⁺ ions and 1.5 keV Cs⁺ ions with oxygen ambient.
Knock-on effect, preferential sputtering and ion induced surface microtopography are discussed with respect to thier influence on depth resolution.