Semiconductor device having self-aligned asymmetric source/drain regions and method of fabrication thereof

A process of forming a semiconductor device, comprising:

• forming a gate electrode on a substrate;
• implanting a first dopant into the substrate to form lightly-doped regions in the substrate adjacent the gate electrode;
• forming a dielectric layer over the substrate and adjacent the gate electrode leaving an upper surface of the gate electrode exposed;
• forming an asymmetric implant mask directly on the gate electrode and extending further over a first side of the gate electrode than a second side of the gate electrode;
• removing portions of the dielectric layer adjacent the mask;
• implanting, using the implant mask for alignment, a second dopant into the substrate to form asymmetric heavily-doped regions adjacent the gate electrode, the asymmetric heavily-doped regions including a first heavily-doped region adjacent the first side of the gate electrode and a second heavily-doped region adjacent the second side of the gate electrode, the first heavily-doped region being spaced further from the gate electrode than the second heavily-doped region;
• and
• forming a conductive contact to the gate electrode using the implant mask.