Patent ID: 6693014
Filing Date: 2004-02-17
Classification: H01L

Abstract:
A method of forming a device, the device comprising a gate structure provided on a surface of a semiconductor substrate, said method comprising the steps of:performing a first blanket implant into the substrate to form first and second diffusion regions underneath the surface of the substrate on opposite sides of the gate structure, with a portion of the first and second diffusion regions extending underneath a portion of said gate structure, thereby forming respective first and second overlap regions; performing a re-ox step to form oxidized sidewalls on the gate structure and oxide regions on the substrate; performing a second blanket implant through the oxide regions and into the substrate at locations of the first and second diffusion regions to add additional dopant to the first and second diffusion regions, the oxidized sidewalls on the gate structure preventing dopants from the second blanket implant from diffusing underneath the gate structure, thereby forming respective diffusion regions on opposite sides of the gate structure each having a graded dopant concentration.