A method is provided for fabricating a differential semiconductor substrate. A first structure is provided which comprises a first semiconductor substrate including a first semiconductor region, and a first oxide layer overlying a surface of the first semiconductor substrate. The first semiconductor substrate has a first crystallographic orientation. A second structure is provided which includes a second semiconductor substrate comprising a first layer and a second layer, and a second oxide layer which overlies a surface of the first layer. The second semiconductor substrate has a second crystallographic orientation different than the first crystallographic orientation. The first layer includes a second semiconductor region. The first layer and the second oxide layer are removed from the second structure, and assembled to the first semiconductor substrate to form a composite structure. A bonded composite structure is then formed by exposing the composite structure to a temperature adequate to cause bonding of the first oxide layer and the second oxide layer. Portions of the bonded composite structure are removed to expose the first semiconductor region and the second semiconductor region and thereby form the differential semiconductor substrate.