Buffer structure for semiconductor device and methods of fabrication

A semiconductor device comprising:

• a first semiconductor layer;
• a buffer structure formed on the first semiconductor layer comprising:
• a first buffer layer formed on the first semiconductor layer;
• a first blocking member formed on a top surface of the first buffer layer, the first blocking member having a top surface and sidewalls extending from top surface of first blocking member to top surface of first buffer layer;
• and
• a second buffer layer formed onto the first blocking member and the top surface of first buffer layer;
• and
• a second semiconductor layer formed on the buffer structure, wherein the buffer structure prevents defects in the first semiconductor layer or second semiconductor layer.

A method of forming a semiconductor device comprising:

• providing a first semiconductor layer;
• depositing a first buffer layer on the semiconductor layer;
• forming a plurality of blocking members on a top surface of the first buffer layer, the plurality of blocking members defining a plurality of openings that expose portions of the top surface of first buffer layer;
• depositing a second buffer layer onto the plurality of blocking members and exposed portions of top surface of first buffer layer;
• and
• forming a second semiconductor layer on the second buffer layer.