MULTIPLE DEPTH SHALLOW TRENCH ISOLATION PROCESS

A method for manufacturing a semiconductor die may have the steps of:-Providing a semiconductor substrate;-Processing the substrate to a point where shallow trench isolation (STI) can be formed;-Depositing at least one underlayer having a predefined thickness on the wafer;-Depositing a masking layer on top of the underlayer;-Shaping the masking layer to have areas of predefined depths;-Applying a photolithograthy process to expose all the areas where the trenches are to be formed; and-Etching the wafer to form silicon trenches wherein the depth of a trench depends on the location with respect to the masking layer area.