Abstract:
At least one isolation trench formed in a layer stack including substrate, channel, and upper gate layers define a channel in the channel layer. Lateral etching from the isolation trench(es) can form lateral cavities in the substrate and upper gate layer to substantially simultaneously form self-aligned lower and upper gates. The lower gate undercuts the channel, the upper gate is narrower than the channel, and a source and a drain can be formed on opposed ends of the channel. As a result, source-drain capacitance and gate-drain capacitance can be reduced, increasing speed of the resulting FET.
Abstract:
Methods for bonding substrate surfaces, bonded substrate assemblies, and design structures for a bonded substrate assembly. Device structures of a product chip are formed using a first surface of a device substrate. A wiring layer of an interconnect structure for the device structures is formed on the product chip. The wiring layer is planarized. A temporary handle wafer is removably bonded to the planarized wiring layer. In response to removably bonding the temporary handle wafer to the planarized first wiring layer, a second surface of the device substrate, which is opposite to the first surface, is bonded to a final handle substrate. The temporary handle wafer is then removed from the assembly.
Abstract:
Device structures and design structures for a bipolar junction transistor. A first isolation structure is formed in a substrate to define a boundary for a device region. A collector is formed in the device region, and a second isolation structure is formed in the device region. The second isolation structure defines a boundary for the collector. The second isolation structure is laterally positioned relative to the first isolation structure to define a section of the device region between the first and second isolation structures.