Monocrystalline three-dimensional integrated circuit

Abstract

A monocrystalline monolith contains a 3-D array of interconnected lattice-matched devices (which may be of one kind exclusively, or that kind in combination with one or more other kinds) performing digital, analog, image-processing, or neural-network functions, singly or in combination. Localized inclusions of lattice-matched metal and (or) insulator can exist in the monolith, but monolith-wide layers of insulator are avoided. The devices may be self-isolated, junction-isolated, or insulator-isolated, and may include but not be limited to MOSFETs, BJTs, JFETs, MFETs, CCDs, resistors, and capacitors. The monolith is fabricated in a single apparatus using a process such as MBE or sputter epitaxy executed in a continuous or quasicontinuous manner under automatic control, and supplanting hundreds of discrete steps with handling and storage steps interpolated. 'Writing' on the growing crystal is done during crystal growth by methods that may include but not be limited to ion beams, laser beams, patterned light exposures, and physical masks. The interior volume of the fabrication apparatus is far cleaner and more highly controlled than that of a clean room. The apparatus is highly replicated and is amenable to mass production. The product has unprecedented volumetric function density, and high performance stems from short signal paths, low parasitic loading, and 3-D architecture. High reliability stems from contamination-free fabrication, small signal-arrival skew, and generous noise margins. Economy stems from mass-produced factory apparatus, automatic IC manufacture, and high IC yield. Among the IC products are fast and efficient memories with equally fast and efficient error-correction abilities, crosstalk-free operational amplifiers, and highly paralleled and copiously interconnected neural networks.