Depth profiling of interfacial fluctuation with nanometer order in ultrathin silicon-on-insulator structure by classical Rutherford backscattering using 10B ions
Abstract
We quantitatively investigated the thickness fluctuation in nanometer order observed in an ultrathin silicon-on-insulator (SOI) film separated by a shallow oxygen ion implantation in a silicon substrate by classical Rutherford backscattering spectrometry (RBS). We first show that the interfacial fluctuation in nanometer scale cannot be identified by the conventional RBS with high-energy MeV He ions due to poor depth resolution. We then explore the possibility of the improvement in the depth resolution by using the primary ions of relatively heavy 10B projectiles combined with a grazing geometry. As a result, we confirmed the ability to quantify the thin fluctuation in a few nanometers by the classical RBS method using 10B ions. We applied the technique to investigate the evaluation of the interfacial fluctuation in several nanometers at ultrathin SOI/BOX structure synthesized by low-energy separation by implanted oxygen (SIMOX) method. The interfacial roughness estimated by the present RBS was consistent with that estimated by the cross-sectional TEM image in advance.
- Publication:
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Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- July 2019
- DOI:
- 10.1016/j.nimb.2018.02.029
- Bibcode:
- 2019NIMPB.450..118H
- Keywords:
-
- Rutherford backscattering spectroscopy;
- Depth profiling;
- Boron ion;
- Interfacial roughness;
- Silicon-on-insulator;
- SIMOX