High speed semiconductor photodetector

Abstract

A first semiconductor mesa structure having a photoactive region and a second semiconductor mesa structure are formed side by side on a semi-insulating substrate and surrounded with a photoresist layer. The mesa structures and the surrounding photoresist layer are covered with a metal layer, on which is placed a photoresist mask. Conductive material is deposited through the photoresist mask to form a number of metallized regions on the metal layer. After removing the photoreist mask, the metallized regions are used as a mask for patterning the underlying metal layer into metal regions corresponding to the metallized regions. The metallized regions and the underlying patterned metal regions form two laminated metal structures for positive and negative electrodes. One of the laminated metal structures forms an interconnect metal line along the sidewalls of a valley between the two mesa structures or across the valley to form a bridge.