Heterojunction Region Transistor Leakage Reduction

The patent merges the gate electrode formation processes for PMOS and NMOS transistors into a single unified process. By forming both gate electrodes simultaneously using the same deposition and patterning steps, the patent eliminates the need for separate gate formation processes, thereby reducing manufacturing complexity while maintaining the ability to achieve different work functions through selective material deposition or doping in subsequent steps.

The patent applies local quality by making the gate electrode properties spatially variable. After forming a common gate electrode structure, the patent selectively modifies the work function in different regions - for example, by selective doping, selective deposition of additional layers, or selective etching - to create PMOS-appropriate work functions in one region and NMOS-appropriate work functions in another, thus achieving local optimization while maintaining a unified fabrication process.

The patent introduces an intermediary approach by using a carefully engineered gate electrode structure or interface layer that mediates between the lightly doped channel and the gate. This intermediary structure - such as an ultra-thin dielectric layer, a specific gate material composition, or an interface dipole layer - allows the gate to exert effective control over the channel despite the light doping, thereby preventing excessive leakage while maintaining process simplicity.

The patent applies preliminary anti-action by implementing compensatory measures before the harmful effect of drain induced barrier lowering becomes significant. This may include pre-doping the channel region with specific dopant profiles, creating raised source/drain structures, or engineering the gate electrode work function and voltage characteristics in advance to counteract the expected barrier lowering effect, thus preventing leakage increase even as device dimensions are scaled down for faster switching.