US Patent 7416908 Method for fabricating a micro structure

A method for fabricating a micro structure includes depositing a first layer of a first material over a substrate; patterning a first hard mask over the first layer; depositing a second layer of a second material over the first layer and the first hard mask; patterning a second hard mask over the second layer; and selectively removing the first material and the second material not covered by any of the first mask and the second mask to produce over the substrate the micro structure having a first structure portion having a first height and a second structure portion having a second height.