AVS 51st International Symposium
    Applied Surface Science Monday Sessions
       Session AS-MoP

Paper AS-MoP13
XPS Characterization of Ingaalp/ingap Quantum Well Structures

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: Y.J. Yoon, Samsung Electro-mechanics Co., Ltd, Korea
Authors: Y.J. Yoon, Samsung Electro-mechanics Co., Ltd, Korea
L.V. Yashina, Samsung Electro-mechanics Co., Ltd, Korea
B.Y. Kim, Samsung Electro-mechanics Co., Ltd, Korea
V. Kureshov, Samsung Electro-mechanics Co., Ltd, Korea
Correspondent: Click to Email
InGaAlP/InGaP heterostructures are important for light emission in laser diodes. Post growth characterization of InGaAlP solid solution composition is actual problem in the optimization of growth parameters due to compositional dependent mismatch and Eg value. The mismatch is mostly influenced by Ga/In ratio, whereas Eg is governed by Al/Ga ratio. In practice the set of accessible diagnostic procedures is limited by photoluminescence study and XRD. For the quasibinary solid solution composition can be estimated using lattice constant or Eg dependences on mole fraction whereas for the quaternary solid solution this approach can not be applied rigorously. The use of direct analytical techniques is complicated by many factors such as low thickness of layers, restrictions in depth resolution, surface preparation problem. InGaAlP/InGaP multilayered structures with layer thickness ~ 5 nm were studied by XPS. The superlattices were obtained by MOCVD on GaAs(100) substrate. XPS study was carried out using monochromatic Al Ka source in Quantera SXM. Two independent procedures were applied: (1) sputtering depth profiling and (2) Angle dependent photoemission registration for the samples containing well/barrier interface in the layer under analysis. In 3d, Ga 2p, Al 2s, P 2s peak intensities were calibrated using the set of reference alloy samples InGaP, InAlP and pure compounds InP, GaP. Sputtering rate compositional dependence was also taken into account. Sputtering was carried out using Zalar rotation to reach maximal depth resolution. For the depth profiles analysis attenuation length and surface roughness after sputtering, estimated by AFM, were taken into consideration. The obtained results are compared with SIMS data.