Abstract: A semiconductor chip having a crack stop structure is disclosed. The crack stop structure includes one or more recesses formed in the semiconductor chip. The one or more recesses extend adjacent to and along a periphery of the semiconductor chip. The one or more recesses are filled with a metal material. The metal material has an intrinsic tensile stress at room temperature that induces compressive stress in at least a region of the periphery of the semiconductor chip.

Abstract: A Gunn diode includes an active layer having a top and a bottom, a first contact layer disposed adjacent to the top of the active layer, a second contact layer disposed adjacent to the bottom of the active layer, wherein the first and second contact layers are more heavily doped than the active layer, and at least one outer contact layer disposed at an outer region of at least one of the first and second contact layers, the at least one outer contact layer being more heavily doped than the first and second contact layers, wherein the first and second contact layers, the active layer, and the at least one outer contact layer include a base material that is the same.