An integrated circuit formed with a process that enables multiple types of gate stacks improves a quality factor of metal oxide semiconductor (MOS) varactors at the device level. In one instance, the integrated circuit includes multiple first type transistors having a first gate stack with a first resistance and multiple second type transistors having a second gate stack with a second resistance that is higher than the first resistance. The integrated circuit also includes a metal oxide semiconductor varactor having the first gate stack with the first resistance.