Annealing effects on the composition and disorder of Ga(N,As,P) quantum wells on silicon substrates for laser application

In Situ Thermal Annealing Transmission Electron Microscopy (TEM) Investigation of III/V Semiconductor Heterostructures Using a Setup for Safe Usage of Toxic and Pyrophoric Gases

“…By comparing the highest temperature measurement (450°C) with the room temperature measurement, it can been seen that the group V intensities drop within 8 group V layers to the same level that the room temperature measurement reaches within two group V layers. When comparing these results to the aforementioned thermal annealing experiments shown in Gies et al (2014) and Wegele et al (2016 b ), one should keep in mind the difference in annealing procedures. Compared to the in situ annealing system, which allows for a heating rate of 5°C/s, the RTA reactor enables a much faster heating rate of 50°C/s, resulting in very short annealing times on the order of 10 s. Furthermore, the sample annealed in the RTA is bulk material compared with a very thin TEM lamella annealed in the in situ system.…”

“…Changes in the composition and homogeneity take place during this process, which it may be possible to investigate in situ in the TEM. A detailed description of these structural changes and their correlation with the optoelectronic properties of the quantum well during rapid thermal annealing (RTA) is given in Gies et al (2014) and Wegele et al (2016 a ). The samples were prepared for the in situ annealing STEM investigation using a focused ion beam (FIB; JIB 4601 F; JEOL, Freising, Germany) system.…”

“…The positive influence of postgrowth annealing on the performance of devices, such as III/V dilute nitride Ga(NAsP) heterostructures on (001) Si-substrates, is well known and has been investigated by various ex situ techniques (Buyanova et al, 2000; Kunert et al, 2006; Gies et al, 2014). Nevertheless, III/V semiconductor growth and the study of annealing processes under high resolution conditions have not been widely studied in situ in TEM (Wen et al, 2011; Diaz et al, 2012).…”

Preparation and Loading Process of Single Crystalline Samples into a Gas Environmental Cell Holder for In Situ Atomic Resolution Scanning Transmission Electron Microscopic Observation

“…The GaP/Si templates serve as a pseudo substrate consisting of a GaP layer about 100 nm thick nucleated on an exactly oriented Si (001) substrate. A more detailed description of the defect-free nucleation of GaP on Si (001) and on the growth of the Ga(NAsP) laser structure is given in Liebich et al 2011, Volz et al (2011), and Gies et al (2014). It is, of course, important to examine these single crystalline samples in a low-index zone axis for a detailed investigation of, for example, structural changes during annealing processes.…”

In situ Observation of Annealing Effects in Ga(NAsP) Multi Quantum Well Structures

“…Due to the low temperature growth conditions used for this metastable material system, point defects are incorporated in the material upon growth. In particular the thermal annealing procedure after growth can reduce the number of crystal defects and thus increase the efficiency of active regions of the devices [1]. One drawback of the thermal treatment is the gradual blur of the interfaces between the quantum wells and the barriers.…”