Kurka Marcin, Rygała Michał, Sęk Grzegorz, Gutowski Piotr, Pierściński Kamil, Motyka Marcin
Laboratory for Optical Spectroscopy of Nanostructures, Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Łukasiewicz Research Network-Institute of Electron Technology, Al. Lotników 32/48, 02-668 Warszawa, Poland.
Materials (Basel). 2020 Jul 12;13(14):3109. doi: 10.3390/ma13143109.
The precise determination of carrier concentration in doped semiconductor materials and nanostructures is of high importance. Many parameters of an operational device are dependent on the proper carrier concentration or its distribution in both the active area as well as in the passive parts as the waveguide claddings. Determining those in a nondestructive manner is, on the one hand, demanded for the fabrication process efficiency, but on the other, challenging experimentally, especially for complex multilayer systems. Here, we present the results of carrier concentration determination in InGaAs layers, designed to be a material forming quantum cascade laser active areas, using a direct and contactless method utilizing the Berreman effect, and employing Fourier-transform infrared (FTIR) spectroscopy. The results allowed us to precisely determine the free carrier concentration versus changes in the nominal doping level and provide feedback regarding the technological process by indicating the temperature adjustment of the dopant source.
精确测定掺杂半导体材料和纳米结构中的载流子浓度至关重要。操作器件的许多参数取决于有源区以及诸如波导包层等无源部分中合适的载流子浓度或其分布。一方面，以无损方式确定这些参数对于制造工艺效率是必需的，但另一方面，在实验上具有挑战性，特别是对于复杂的多层系统。在此，我们展示了使用利用贝里曼效应的直接且非接触式方法并采用傅里叶变换红外（FTIR）光谱法来测定旨在构成量子级联激光器有源区的InGaAs层中载流子浓度的结果。这些结果使我们能够精确确定自由载流子浓度与标称掺杂水平变化的关系，并通过指示掺杂源的温度调节为工艺过程提供反馈。
