A new technique for the growth of compositionally graded layers by OMCVD for novel device structures.

The ability to compositionally grade epitaxial semiconductor layers in a desired fashion is important for the fabrication of modern semiconductor devices and structures for device physics studies. Such grading has traditionally been achieved, in chemical vapor deposition, by careful ramping of the mass flow controllers. In this paper, we demonstrate a more flexible technique for achieving compositional grading using a fast switching manifold which allows us to deposit ultra-thin layers of any desired composition. The technique was used to fabricate a hot electron transistor in the AlGaAs alloy system consisting of two electrically ideal triangular potential barriers.