Optical control of growth of AlxGa1−xAs by organometallic molecular beam epitaxy

Using spectroellipsometry, we obtain information on the near‐surface composition x of epitaxial AlxGa1−xAs layers during crystal growth by organometallic molecular beam epitaxy and use this information to regulate the flow of triethylaluminum to the growth surface. The resulting closed‐loop control system maintains the imaginary part of the dielectric response of thick AlxGa1−xAs films constant to an equivalent compositional precision better than ±0.001 over extended periods of time.