A method and apparatus are described for forming a first inter-layer dielectric (ILD0) stack having a protective gettering layer (72) with a substantially uniform thickness. After forming device components (32, 33) on a substrate (31), a gap fill dielectric layer of SATEOS (52) is deposited over an etch stop layer of PEN ESL (42) and then planarized before sequentially depositing a gettering layer of BPTEOS (72) and capping dielectric layer (82) on the planarized gap fill dielectric layer (52). Once the ILD0 stack is formed, one or more contact openings (92, 94, 96) are etched through the ILD0 stack, thereby exposing the etch stop layer (42) over the intended contact regions.