One method of forming replacement gate structures for first and second devices, the first device being a short channel device and the second device being a long channel device, is disclosed which includes forming a first and a second gate cavity above a semiconductor substrate, the first gate cavity being narrower than the second gate cavity, forming a bulk metal layer within the first and second gate cavities, performing an etching process to recess the bulk metal layer within the first and second gate cavities, resulting in the bulk metal layer within the second gate cavity being at its final thickness, forming a masking layer over the bulk metal layer within the second gate cavity, and performing an etching process to further recess the bulk metal layer within the first gate cavity, resulting in the bulk metal layer within the first gate cavity being at its final thickness.