Ferroelectric Memory Cell Structure for Higher Density and On-Current

The semiconductor device is divided into multiple stacked layers including first and second semiconductor layers, first and second trench isolation layers, and source/drain regions positioned at different depths. This vertical segmentation allows functional density to increase without proportionally increasing lateral fabrication complexity, as each layer can be processed relatively independently through selective etching and deposition steps.

The invention transitions from planar device architecture to a three-dimensional stacked configuration where source and drain regions are positioned at different vertical levels. The first source/drain region is formed in the first semiconductor layer while the second source/drain region is formed in the second semiconductor layer, separated by a trench isolation layer. This dimensional transition enables higher device density without requiring proportional reduction in feature sizes, thereby maintaining manufacturing feasibility.

The device structure is segmented into multiple isolated functional units stacked vertically. Each semiconductor layer with its associated source/drain regions and trench isolation forms a discrete functional block. This segmentation allows each unit to operate independently with reliable electrical isolation, preventing failure propagation while maintaining high functional density through vertical stacking.

Trench isolation layers are introduced as intermediary structures between the first and second semiconductor layers. These isolation layers provide electrical separation and prevent unwanted interactions between adjacent stacked devices, thereby maintaining signal integrity and device reliability. The trench isolation acts as a mediator that enables close spacing of components while preserving their independent operation.