NOVELTY - The semiconductor structure (174) has a layer of semiconductor material bonded to a substrate (102) with a layer of dielectric oxide material between the layer and substrate. Fluidic microchannels (124A-124C) are extended in a lateral direction through a layer of dielectric oxide material between the layer of semiconductor material (122) and substrate. The fluidic microchannel includes a laterally extending section comprising a transverse cross-sectional shape is entirely surrounded by the layer of dielectric oxide material.    USE - Three dimensional integrated semiconductor structure used as heat sink for attachment to semiconductor device (all claimed). Can also be used in electronic signal processing device, memory device, application specific integrated circuit (ASIC) device, photoactive device such as LED, solar cell etc.    ADVANTAGE - The density of heat generating devices can be increased in three dimensional integration processes, without a proportional increase in heat-dissipating outer surface area. The impurity levels are reduced while improving the quality of the crystal lattice in the layer of semiconductor material. The configuration of the recesses and resulting fluidic microchannels is selected to optimize mass transport of a cooling fluid during operation, hence heat exchange between the cooling fluid and the semiconductor structure. The structure is formed by selectively etching entirely through the dielectric material and stopping on the substrate, or by etching only partially through the dielectric material when forming the recesses, so as to avoid exposing the underlying surface of the substrate, by avoiding any potential need to deposit additional dielectric material.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of semiconductor material bonded over a substrate with a solid and continuous layer of dielectric material between the layer of semiconductor material and substrate.    Substrate (102)    Dielectric material (104)    Semiconductor material (122)    Fluidic microchannels (124A-124C)    Semiconductor structure (174)