InP substrate evaluation by MOVPE growth of lattice matched epitaxial layers.

Conference · Wed Sep 01 04:00:00 EDT 2010

OSTI ID:1027034

Overberg, Mark E; Cederberg, Jeffrey George

InP substrates form the starting point for a wide variety of semiconductor devices. The surface morphology produced during epitaxy depends critically on the starting substrate. We evaluated (1 0 0)-oriented InP wafers from three different vendors by growing thick (5 mu m) lattice-matched epilayers of InP, Gain As, and AlInAs. We assessed the surfaces with differential interference contrast microscopy and atomic force microscopy. Wafers with near singular (1 0 0) orientations produced inferior surfaces in general. Vicinal substrates with small misorientations improved the epitaxial surface for InP dramatically, reducing the density of macroscopic defects while maintaining a low RMS roughness. GaInAs and AlInAs epitaxy step-bunched forming undulations along the miscut direction. Sulfur-doped wafers were considered for singular (1 0 0) and for 0.2 degrees misorientation toward (1 1 0). We found that mound defects observed for InP and GaInAs layers on iron-doped singular wafers were absent for singular sulfur-doped wafers. These observations support the conclusion that dislocation termination at the surface and expansion of the step spiral lead to the macroscopic defects observed.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1027034
• Report Number(s): SAND2010-6178C
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
DEFECTS
DISLOCATIONS
EPITAXY
EVALUATION
INDIUM PHOSPHIDES
MICROSCOPY
MORPHOLOGY
ROUGHNESS
SEMICONDUCTOR DEVICES
SUBSTRATES
VAPOR PHASE EPITAXY