Hybrid orientation technology (HOT) substrates for CMOS ICs include (100)-oriented silicon regions for NMOS and (110) regions for PMOS for optimizing carrier mobilities in the respective MOS transistors. Boundary regions between (100) and (110) regions must be sufficiently narrow to support high gate densities and SRAM cells. This invention provides a method of forming a HOT substrate containing regions with two different silicon crystal lattice orientations, with boundary morphology less than 40 nanometers wide. Starting with a direct silicon bonded (DSB) wafer of a (100) substrate wafer and a (110) DBS layer, NMOS regions in the DSB layer are amorphized by a double implant and recrystallized on a (100) orientation by solid phase epitaxy (SPE). Crystal defects during anneal are prevented by a low temperature oxide layer on the top surface of the wafer. An integrated circuit formed with the inventive method is also disclosed.