Gradient Ternary or Quaternary Multiple-Gate Transistor

An integrated circuit structure comprising:

• a semiconductor substrate having a first lattice constant;
• a first epitaxy region above the semiconductor substrate, the first epitaxy region having a gradient composition such that a concentration of a first element increases as the first epitaxy region extends away from the semiconductor substrate, a first end of the first epitaxy region closest to the semiconductor substrate having a lattice constant closer to the first lattice constant than a lattice constant of a second end of the first epitaxy region, the second end being opposite the first end;
• insulation regions on opposing sides of the first epitaxy region, the insulation regions extending above a lower surface of the first epitaxy region, the first epitaxy region extending above the insulation regions forming a fin;
• and
• a high-bandgap semiconductor layer on a top surface and sidewalls of the fin, wherein the high-bandgap semiconductor layer has a bandgap greater than a bandgap of the first epitaxy region.

An integrated circuit structure comprising:

• a semiconductor substrate having a first lattice constant;
• a first epitaxy layer over the semiconductor substrate, the first epitaxy layer having a second lattice constant;
• a second epitaxy layer over the first epitaxy layer, the second epitaxy layer having a third lattice constant, the second epitaxy layer having a gradient composition, the second lattice constant being between the first lattice constant and the third lattice constant;
• and
• isolation regions on opposing sides of the first epitaxy layer, an upper surface of the isolation regions extending higher than an interface between the first epitaxy layer and the second epitaxy layer.