Method of thinning a semiconductor structure

A method of thinning a semiconductor structure, comprising the steps of:

• providing a first semiconductor structure having a first layer of silicon, an intermediate layer of an oxide of silicon and a third layer of silicon, said third layer having an outer surface;
• providing a second semiconductor structure also having an outer surface;
• providing a coating of predetermined material on said outer surface of said third layer of silicon and on said outer surface of said second semiconductor structure;
• bonding said first and second semiconductor structures together at said coatings;
• mechanically removing around 80% to 90% of said first layer of silicon;
• after said removal of around 80% to 90% of said first layer of silicon, removing the remaining first layer of silicon to a thickness of no less than around 10 mm, by a first plasma etch;
• and
• subjecting the remainder of said first layer to a plasmaless dry etch of a fluorine containing compound so as to remove any remaining first silicon layer and to expose the surface of said intermediate layer of oxide.