High time-resolution three-dimensional reciprocal-space mapping during MBE growth of InGaAs

Hu, W.; Takahashi, Masamitsu; Kozu, Miwa*; Suzuki, Hidetoshi*; Sasaki, Takuo*

In situ X-ray diffraction during growth is promising for understanding the details of the strain relaxation process without inducing the thermal strain during quenching. In this work, the authors developed a high time-resolution three-dimensional RSM data-acquisition technique. After removal of the oxide layer of the GaAs(001) substrate and the growth of a 100-nm-thick buffer layer, InGaAs was deposited at a rate of 0.2 ML/s at a growth temperature of 470C. X-ray wavelength used was 0.8270. Diffracted X-rays were measured with a two-dimensional (2D) charge coupled device (CCD) camera. While the sample was continuously rotated in the vicinity of 022 Bragg point, the CCD detector took 60 frames for each scan with different exposure time from 0.08s to 0.3s. The results indicate that the new fast technique provides an accuracy of 0.007 degree in peak position and 0.0184 degree in peak width.