The control of gate widths is improved for system-on-a-chip (SoC) devices which require multiple gate dielectric “gate” thicknesses, e.g., for analog and digital processing on the same chip. A hard mask is formed to protect a thick gate while the thin gate region is etched to remove oxide (sometimes referred to as a preclean step). The patterned substrate is then processed to selectively deposit a second thickness of gate material. The thin gate may be silicon oxide and the physical thickness of the thin gate may be less than that of the thick gate. In a preferred embodiment, the substrate is not exposed to air or atmosphere after the hardmask is removed.