The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor fiel...The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor field effect transistors （MOSFETs）, and also the integration of Si-based monolithic photonics. The TDD of Ge epitaxial layer is analyzed by etching or transmission electron microscope （TEM）. However, high-resolution x-ray diffraction （HR-XRD） rocking curve provides an optional method to analyze the TDD in Ge layer. The theory model of TDD measurement from rocking curves was first used in zinc-blende semiconductors. In this paper, this method is extended to the case of strained Ge-on-Si layers. The HR-XRD 2θ/ω scan is measured and Ge （004） single crystal rocking curve is utilized to calculate the TDD in strained Ge epitaxial layer. The rocking curve full width at half maximum （FWHM） broadening by incident beam divergence of the instrument, crystal size, and curvature of the crystal specimen is subtracted. The TDDs of samples A and B are calculated to be 1.41108 cm-2 and 6.47108 cm-2, respectively. In addition, we believe the TDDs calculated by this method to be the averaged dislocation density in the Ge epitaxial layer.展开更多
基金Project supported by the Research Plan in Shaanxi Province,China(Grant No.2016GY-085)the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences(Grant No.90109162905)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.17-H863-04-ZT-001-019-01)the National Natural Science Foundation of China(Grant Nos.61704130 and 61474085)
文摘The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor field effect transistors （MOSFETs）, and also the integration of Si-based monolithic photonics. The TDD of Ge epitaxial layer is analyzed by etching or transmission electron microscope （TEM）. However, high-resolution x-ray diffraction （HR-XRD） rocking curve provides an optional method to analyze the TDD in Ge layer. The theory model of TDD measurement from rocking curves was first used in zinc-blende semiconductors. In this paper, this method is extended to the case of strained Ge-on-Si layers. The HR-XRD 2θ/ω scan is measured and Ge （004） single crystal rocking curve is utilized to calculate the TDD in strained Ge epitaxial layer. The rocking curve full width at half maximum （FWHM） broadening by incident beam divergence of the instrument, crystal size, and curvature of the crystal specimen is subtracted. The TDDs of samples A and B are calculated to be 1.41108 cm-2 and 6.47108 cm-2, respectively. In addition, we believe the TDDs calculated by this method to be the averaged dislocation density in the Ge epitaxial layer.
