Development of real-time microvision system based on three-dimensional LSI technology

The development of the real-time microvision system with three-dimensional (3D) structure is introduced. A number of two-dimensional LSIs (2D-LSIs) which play amplifying and converting image signal and some arithmetic operations are fabricated vertically. The microvision system transfers the two-dimensional (2D) image data arrays as it is using high density vertical interconnections. The image information signals are processed in parallel in each LSI and the processing is performed in pipeline over all the system. In fabrication, grinding and chemical-mechanical polishing techniques are used to thin the wafer to 30 mu m. The thinned wafer with buried interconnections is bonded vertically to a thick wafer through microbumps after careful alignment by the wafer aligner with the alignment tolerance of 1 mu m. The real-time microvision system with 3D structure can be fabricated by repeating such sequence.