Epitaxial Growth and Characterization of Self-Doping } Multi-Quantum Well Materials

• Published in: Journal of microelectromechanical systems 2014-02, Vol.23 (1), p.213-219
• Main Authors: Jiang, Bo, Dong, Tao, Su, Yan, He, Yong, Wang, Kaiying
• Format: Article
• Language: English
• Subjects: Boron; Crystal growth; Epitaxial growth; Lattices; materials testing; Microelectronics; Quantum well devices; quantum wells; Scanning electron microscopy; Silicon; thin films; X-ray scattering
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2013.2269612

This paper presents self-doping Si 1-x Ge x /Si multiquantum wells (MQWs) with35 nm buffer layers where self-doping occurs to allow free carriers in the quantum well. The film grown through ultra-high vacuum chemical vapor deposition method can easily achieve a good lattice quality. The crystal lattice is verified through scanning electron microscopy, X-ray diffraction,and secondary ion mass spectrometry. Unique structures are applied in the Temperature Coefficient of Resistance (TCR) measurement to obtain electrical characteristics of MQWs. The TCR of Si 0.65 Ge 0.35 /Si obtained in the experiment is about-2.5%/K at 20 °C, which meets the requirements of a thermistor. The TCR decreases from 2.5%/K to 1.1%/K as the size of the MQWs increases from 100 μm×100 μm to 400 μm×400 μm. Annealing is necessary for the formation of an ohmic contact between electrodes and high contact layers.