PRESERVATION OF RECTANGULAR-PATTERNED INP GRATINGS OVERGROWN BY GAS-SOURCE MOLECULAR-BEAM EPITAXY

The ability to preserve a grating profile during epitaxial overgrowth is vital to the design and operation of devices such as planar wavegui de-coupled Bragg-resonant filters. Intentional preservation of rectang ular-patterned InP gratings during gas source molecular beam epitaxial overgrowth has been accomplished. The use of a low temperature atomic hydrogen-assisted oxide removal technique alleviates the dependence o n elevated temperatures for desorption of the native oxide, and is cru cial to the preservation of the patterned profile. Confirmation of the overgrown grating fidelity is demonstrated via scanning electron micr oscopy and triple axis x-ray diffractometry. (C) 1997 American Institu te of Physics.