EPITAXIAL SI-GE ETCH-STOP LAYERS WITH ETHYLENE DIAMINE PYROCATECHOL FOR BONDED AND ETCHBACK SILICON-ON-INSULATOR

The etch rate in ethylene diamine pyrocatechol of Si1-xGex (0.2 less-than-or-equal-to x less-than-or-equal-to 0.3) etch stops grown by molecular beam epitaxy was determined using Rutherford backscattering spectrometry. Etch rate selectivities as high as 390 were measured. Such etch stops allow for higher bonding temperatures than those possible with currently used boron-based etch stops. Defect etching was used to determine the maximal thickness of dislocation-free layers.