Dresden 2014 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 31: Poster: Nitrides

HL 31.13: Poster

Montag, 31. März 2014, 17:00–20:00, P2

Development of a dedicated low noise EBIC measurement system — •Manuel Knab¹, Matthias Hocker¹, Ingo Tischer¹, Junjun Wang², Ferdinand Scholz², and Klaus Thonke¹ — ¹Institute of Quantum Matter / Semiconductor Physics Group, University of Ulm — ²Institute of Optoelectronics, University of Ulm

The homogeneity of the active region has a major impact on the efficiency of semiconductor-based light emitting devices. Electron beam induced current (EBIC) is a measurement technique for the characterization of semiconductors inside a scanning electron microscope (SEM). It is mainly used to visualize and locate the active region of light emitting diodes (LED) and for other regions with built-in fields. It also allows to determine the minority carrier diffusion length in semiconductors.

The concept of our system is the amplification of the signal directly inside the SEM in close vicinity of the sample to avoid stray capacitances, and to obtain a low noise EBIC signal with maximum bandwidth. An optimized current amplifier is integrated directly into the sample holder in order to amplify the electron beam induced current in the nA range. Furthermore, it is possible to obtain sample images by recording directly the current absorbed by the specimen. The advantage of this method is to have no detector shading contrast by the sample surface shape.