Peter S Lyman, 6966 Uxbridge Rd, Mendon, MA 01756

6818928, Nov 16, 2004

Dec 5, 2002

10/310207

William E. Hoke - Wayland MA
Peter S. Lyman - Mendon MA

Raytheon Company - Waltham MA

H01L 310328

257191, 257190, 257192, 257194

A semiconductor structure is provided having a III-V substrate, a buffer layer over the substrate, such buffer layer having a compositional graded quaternary lower portion and a compositional graded ternary upper portion. In one embodiment, the lower portion of the buffer layer is compositional graded AlGaInAs and the upper portion is compositional graded AlInAs.

6368983, Apr 9, 2002

Apr 9, 1999

09/291577

William E. Hoke - Wayland MA
Peter S. Lyman - Mendon MA
John J. Mosca - Carlisle MA

Raytheon Company - Lexington MA

H01L 2131

438761, 438763, 438799, 438602, 117108

The invention provides a method of fabricating a wafer including growing a single crystal layer comprising a III-V compound in a first chamber at a temperature above 350Â C. A temperature of a surface of the single crystal layer is reduced to below about 350Â C. in the first chamber. An indium arsenide layer is deposited on the single crystal layer, to form an intermediate structure, in the first chamber at a temperature below 350Â C. and above 100Â C. The intermediate structure is transferred to a second chamber. A surface of the intermediate structure is heated to a temperature above about 600Â C. to remove substantially all of the indium arsenide layer and impurities collected in the indium arsenide layer during the transfer to the second chamber. Another material is deposited on the single crystal layer in the second chamber.