III-N semiconductor structure and method of manufacturing same

A method for manufacturing a III-N semiconductor structure, the method comprising the steps of:

• preparing a substrate including a silicon material;
• forming a seed layer including an aluminum nitride (AlN) material on the substrate;
• forming a superlattice structure layer in which a plurality of superlattice units are sequentially deposited on the seed layer;
• and
• growing a gallium nitride (GaN) material on the superlattice structure layer to form a cap layer,
• wherein the plurality of superlattice units are each composed of a first layer consisting essentially of an AlxGa1-xN wherein 0≤x≤1 and a second layer consisting essentially of an InyAl1-yN wherein 0<y≤0.4,
• wherein the step of forming the superlattice structure layer is conducted so that superlattice structure layer is controlled to have an average lattice constant between a lattice constant of the seed layer and a lattice constant of the cap layer,
• wherein the step of forming the superlattice structure layer is conducted so that superlattice structure layer is controlled to have a bandgap energy larger than that of the cap layer, and the superlattice structure layer is higher in bandgap energy than the superlattice structure layer composed only of Al, Ga, and N,
• wherein the step of forming the superlattice structure layer is conducted so that the superlattice structure layer is controlled to comprise 50 to 400 superlattice units, and
• wherein the step of forming the superlattice structure layer is conducted so that a superlattice unit deposited on the seed layer farther from the seed layer is controlled to have a larger lattice constant by adjusting the x value of AlxGa1-xN of the first layer and the y value of InyAl1-yN of the second layer.