Coupled quantum dots with self-aligned gates

A method comprising:

• forming a semiconductor structure comprising quantum dots with self-aligned gate structures, wherein forming a semiconductor structure comprising quantum dots with self-aligned gate structure comprises:
• providing silicon-on-isolator substrate comprising a doped silicon layer atop an isolator;
• structuring said doped silicon layer to form one or more structures simultaneously, wherein the one or more structures comprise:
• a source area,
• a linear structure extending from said source area, wherein said linear structure has a first width which is smaller than a main area of said source area, and wherein said linear structure comprises at least two distinct broadened areas, wherein said distinct broadened areas have each a second width which is larger than said first width of said linear structure,
• a first gate structure extending from a first one of said at least two distinct broadened areas, wherein said first gate structure is physically separated from any of said distinct broadened areas, and
• a second gate structure extending from a second one of said at least two distinct broadened areas, wherein said second gate structure is physically separated from any of said distinct broadened areas, wherein elements of said structured doped silicon layer are formed by a single lithography process,
• covering the structures with a blanket oxide layer;
• forming an opening in the blanket oxide layer at a lateral end of the linear structure opposite to the source area;
• etching back semiconductor material of said linear structure and said at least two distinct broadened areas below said blanket oxide until said source area is reached, thereby forming a hollow template between said isolator and said blanket oxide layer;
• and
• filling the hollow template with a semiconductor material different to the silicon such that the at least two broadened areas build quantum dot areas.