Novel shadow mask molecular beam epitaxial regrowth technique for selective doping

Abstract

We present a novel molecular beam epitaxial regrowth technique which provides a simple and convenient way for the in situ lateral structuring of the doping profiles and growth rates on a μm scale. We achieve excellent selective contacts to the respective doping layers for device dimensions varying from several 100 μm down to several μm. Keldysh based n-i-p-i modulator structures, fabricated with our new method, exhibit an on/off ratio of 6:1 for a voltage swing of 7 V without enhancement by additional Bragg mirrors.