Method of making nanosheet fringe capacitors or MEMS sensors with dissimilar electrode materials

A method for forming a semiconductor device comprising:

• providing a stack of alternating first and second nanosheet structures on a substrate, where each first nanosheet structure comprises a first semiconductor layer and where each second nanosheet structure comprises a tri-layer sandwich of top, middle and bottom nanosheet layers;
• selectively etching the stack of alternating first and second nanosheet structures to form a nanosheet transistor stack and a nanosheet device stack on the substrate;
• forming dielectric layers on peripheral sides of the nanosheet transistor stack which replace peripheral portions of each second nanosheet structure in the nanosheet transistor stack, thereby leaving remnant second nanosheet structures in the nanosheet transistor stack;
• forming first electrodes from each first nanosheet structure on a first side of the nanosheet device stack by replacing a peripheral end portion of each first semiconductor layer on a second side of the nanosheet device stack with one or more first dielectric layers, thereby leaving remnant first semiconductor layers on the first side of the nanosheet device stack which form the first electrodes;
• forming second electrodes from each second nanosheet structure on the second side of the nanosheet device stack by replacing a peripheral end portion of each tri-layer sandwich on the first side of the nanosheet device stack with one or more second dielectric layers to leave a remnant tri-layer sandwich on the second side of the nanosheet device stack and selectively removing top and bottom nanosheet layers from the remnant tri-layer sandwich, thereby leaving the middle nanosheet layers which form the second electrodes;
• and
• forming gate electrode structures which replace the remnant second nanosheet structures in the nanosheet transistor stack.