Shadow-masked growth and its applications

In this paper we will review the shadow masked growth technique and its applications. The technique enables us to change the layer thicknesses over a substrate by the variation in dimensions of windows in the shadow mask. One of the major application areas is the realization of photonic integrated circuits where materials with a different bandgap have to be integrated on the same substrate. The combination of thickness variations with the use of quantum wells results in the required bandgap changes. In the paper we will first start with an overview of the basic technology of shadow masked growth and in a second part we will discuss some of the important applications. Note that we will limit ourselves to the shadow masked growth technique and no review will be given on other technologies such as selective growth.