In situ observation of reconstruction related surface stress during molecular beam epitaxy (MBE) growth of III-V compounds

Anisotropic surface stress associated with the different surface reconstructions of(0 0 1)GaAs is measured in situ in an MBE system. We use an optical deflection technique on [1 (1) over bar 0] and [1 (1) over bar 0] oriented cantilevers fabricated on thinned wafer areas. Changes of surface stress, associated with the As and Ga dimer surface coverage for c(4 x 4), 2 x 4, 3 x 1 and 4 x 2 reconstructions, are observed as substrate temperature and impinging molecular flux are being varied. Deflection oscillations can be detected also during MBE growth relating surface stress to surface roughness or step density. Sensitivity and stability of this technique demonstrates its usefulness as new tool to study in situ a variety of surface kinetics and incorporation phenomena. (C) 1999 Elsevier Science B.V. All rights reserved.