A method of forming a shallow trench isolation (STI) region in a silicon
substrate creates an STI region that extends above a top surface of the
silicon substrate. A planarizing dielectric layer is formed on the
substrate and extends above the field oxide regions. The planarizing
dielectric layer is removed by chemical mechanical polishing or blanket
etch back, for example, as well as those portions of the field oxide
regions that extend above the top surface of the substrate and the active
regions. The step height is thereby eliminated or significantly reduced.