Patent ID: 8680575

Claim:
A semiconductor device comprising, a first semiconductor layer having a first lattice constant; a buffer structure disposed on the first semiconductor layer comprising: a first buffer layer disposed directly on and in contact with the first semiconductor layer wherein the first buffer layer has a second lattice constant larger than the first lattice constant; a first plurality of blocking members formed on a top surface of the first buffer layer, the first plurality of blocking members spaced apart from each other so as to expose portions of the top surface of first buffer layer; and a second buffer layer disposed on the first plurality of blocking members and exposed portions of top surface of first buffer layer wherein the second buffer layer has a third lattice constant larger than the second lattice constant; and a second plurality of blocking members formed on a top surface of the second buffer layer, the second plurality of blocking members spaced apart from each other so as to expose portions of the top surface of second buffer layer; and a third buffer layer formed onto the second plurality of blocking members and exposed portions of top surface of second buffer layer; and a second semiconductor layer formed on the buffer structure.