Tomáš Šamořil oral presentation (RM-Thu2-2-3)
Characterization of InAs/GaSb superlattices with compact TOF-SIMS
1 TESCAN Brno, s.r.o., Libusina trida 1, 62300 Brno, Czech Republic
2 TESCAN ORSAY Holding, Libusina trida 21, 62300 Brno, Czech Republic
3 Faculty of Engineering - Anadolu University, Iki Eylul Campus, 26555 Eskişehir, Turkey
A compact Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) [1,2] uniquely combined with Scanning Electron microscope equipped with a Focused Ion Beam (FIB-SEM) permits a novel quality of correlated microscopy and spectroscopy [3,4] when using a variety of analytical add-ons. The orthogonal extraction design of the spectrometer allows continuous bombardment with a Ga or Xe-FIB, making the acquisition faster compared to a quadrupole mass spectrometer and providing a broad mass range at once.
3D-SIMS measurement with lateral and depth resolution fully comparable to a standalone SIMS analyzer has been demonstrated on semiconductor hetero-structures made of stack of i-GaSb and n-InAs:Si layers with thickness below 3 nm. The sample is type-II InAs/GaSb superlattice (T2SL) structure on GaSb substrate grown by molecular beam epitaxy (MBE). It is a photodetector material for mid-wave infrared detection that is very promising for high performance IR imaging. Since the performance of T2SL device strongly depends on morphological properties, high resolution observation is important for their characterization. The 3D elemental mapping of T2SL shown in Figure 1. was obtained using a 3 kV Xe ion for TOF-SIMS imaging in a positive ion mode. FIB was also used for in-situ preparation of TEM lamella that was followed by ex-situ TEM imaging in atomic scale.
A 2-dimensional hexagonal crystalline MoS2 on SiO2 (300 nm) on Si prepared by using atmospheric pressure chemical vapor deposition (CVD) was also studied. TOF-SIMS mapping provided information about lateral distribution of individual elements that was combined with SEM images.
 J.A. Whitby et al, Advances in Mat. Sci. and Eng., 2012, ID 180437
 D. Alberts et al., Instr. Sci. & Technol. 2014 DOI: 10.1080/10739149.2013.878843.
 T. Sui et. Al., 2015, Nano Energy 17
 F.A. Stevie et al., Surf. Int. Anal. 46 (Issue S1) (2014), pp. 285-287.