Operating CMOS after a Si-MBE process: a precondition for future three-dimensional circuits

Complete CMOS integrated circuits grown by Si molecular beam epitaxy (MBE) are discussed. The morphology of the MBE films and the electrical performance of the CMOS transistors were investigated. The CMOS time-keeping circuits work after an MBE process. Indications of radiation damage (threshold shift up to 200 mV) induced by the Si electron-beam evaporator at epitaxial temperatures of 550 degrees C are observed. These are completely gone at 750 degrees C, at which temperature virtually no effect of the MBE process on the CMOS characteristics could be determined. The observed compatibility of Si-MBE with CMOS ICs is an important prerequisite for the monolithic integration of Si-based devices with the complexity level provided by MOS technologies.<
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