Low dose separation by implanted oxygen (SIMOX) donor wafers with (100) crystal orientation were fabricated by the modified two step O⁺ implantation process. The quasi direct Si bonded (DSB) hybrid orientation substrate was fabricated by transferring the top Si layer of the (100) SIMOX donor wafer upside down onto a bare (110) Si handle wafer by the separation by implanted oxygen layer transfer process. The quasi DSB hybrid orientation substrate with (100) superficial Si/(110) handle wafer and a 3.5 nm interfacial oxide layer was observed by cross-sectional transmission microscopy (XTEM). Then, the quasi DSB hybrid orientation substrates were annealed in oxygen-containing and oxygen-free ambient, respectively. The XTEM results show the oxide-free (100)/(110) bonding interface, indicating the direct Si to Si bonded structure of the DSB hybrid orientation substrates realized by these two process.