Dummy patterns and method of manufacture for mechanical strength of low K dielectric materials in copper interconnect structures for semiconductor devices

A method for fabricating a semiconductor device, the method comprising:

• providing a semiconductor substrate including a surface region;
• forming a first interlayer dielectric overlying the surface region;
• forming an interconnect layer overlying the first interlayer dielectric layer;
• forming a low K dielectric layer overlying the interconnect layer, the low K dielectric layer having a predetermined shape;
• forming a copper interconnect layer overlying the low K dielectric layer;
• and
• whereupon the low K dielectric layer maintains the predetermined shape using a dummy pattern structure provided within a portion of the low K dielectric layer to mechanically support and maintain the predetermined shape of the low K dielectric layer between the interconnect layer and the copper interconnect layer;
• wherein the dummy pattern structure includes a plurality of first bar structures directed in a first direction and a plurality of second bar structures overlying the first bar structures to form a grid structure.