Accurate and rapid threading dislocation density (TDD) characterization of III-V photovoltaic materials using electron channeling contrast imaging (ECCI) is demonstrated. TDDs measured using ECCI showed close agreement with those from electron beam-induced current mapping (EBIC) and defect selective etching (DSE). ECCI is shown to be well-suited for measuring TDD values over a range of ~ 5×10 6 to 5×10 8 cm-2. ECCI can distinguish individual dislocations in clusters closer than 0.2 µm, highlighting its excellent spatial resolution compared to DSE and EBIC. Taken together, ECCI is shown to be a versatile and complementary method to rapidly quantify TDD in III-V solar cells.

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Proton (H+) implantations are used in power semiconductor devices to introduce recombination centers (Hazdra et al., Microelectron. J. 32(5), 449–456 (2001)) or to form hydrogen related donor complexes (Zohta et al., Jpn. J. Appl. Phys. 10, 532–533 (1991)). Proton implantations are also used in the 'smart cut' process to generate defects that can be used to cleave thin wafers (Romani and Evans, Nucl. Instrum. Methods Phys. Res. B 44, 313–317 (1990)). However, the implantation damage resulting from H+implantations is not completely understood. In this study, protons with energies from 400 keV up to 4 MeV and doses up to 1016 H+/cm² were implanted into highly ohmic boron doped m:Cz silicon (100). Electron Beam Induced Current (EBIC) measurements were performed to locally determine the minority charge carrier diffusion length. The diffusion length decreases with increasing implantation dose and incorporated damage. Spreading Resistance Profiling (SRP) measurements were performed to analyze the charge carrier concentration profiles for different annealing procedures. The electrical activation and growth of the defect complexes varies strongly with the annealing parameters. Transmission Electron Microscopy measurements were made to investigate the microscopic structures formed by the high dose implantation processes. Due to the high local damage density resulting from low energy and high dose H+ implants, platelet structures are formed. During high‐energy high‐dose H+implantations, the implanted hydrogen generates strain in the crystal lattice resulting in changes in the distances between atomic planes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Hydrogen implantation has become an important application in the fabrication of power semiconductor devices. With the product requirement of a well-defined implantation profile, adequate control of the incident beam angle is necessary in order to avoid channeling effects. With respect to the different scan systems of commercial implanters and the crystal alignment of the bulk material the implant tilt and twist angles have to be adapted. We used commercially available <100>-oriented silicon wafers to examine planar channeling along a {110}-plane for proton energies in the range of 0.52.5 MeV. The critical angle as a function of proton energy is determined from photothermal response measurements (TWIN)