Semiconductor wafer having multi-layered buffer region formed from compound semiconductor materials

A semiconductor element comprising:

• a substrate;
• a buffer region formed on one main surface of the substrate and formed from a compound semiconductor;
• a main semiconductor region formed on the buffer region and formed from a compound semiconductor;
• and
• an electrode arranged on the main semiconductor region;
• wherein
• the buffer region includes a first multi-layer structured buffer region and a second multi-layer structured buffer region and a first single layer structured buffer region arranged between the first multi-layer structured buffer region and the second multi-layer structured buffer region, both multi-layer structured buffer regions being stacked with a plurality of alternating first layers and second layers;
• the first layer is formed from a compound semiconductor which has a lattice constant smaller than a lattice constant of a material which forms the substrate;
• the second layer is formed from a compound semiconductor which has a lattice constant between a lattice constant of a material which forms the substrate and a lattice constant of a material which forms the first layer;
• and
• the first single layer structured buffer region is thicker than the first layer and the second layer, and is formed from a compound semiconductor which has a lattice constant between a lattice constant of a material which forms the first layer and a lattice constant of a material which forms the second layer.