Patent ID: 6400002
Filing Date: 2002-06-04
Classification: H01L,Y10S

Abstract:
A PMOS field effect transistor comprising:a substrate active area; a pair of spaced-apart, conductively-doped polysilicon blocks disposed over the substrate active area, individual blocks having outwardly facing sidewalls and a generally planar block top which extends between the sidewalls, individual sidewalls of the pair of blocks facing one another and defining a first opening; a pair of sidewall spacers, individual spacers being disposed over the respective individual sidewalls which define the first opening, the spacers defining a second opening which is smaller in dimension than the first opening; source/drain diffusion regions received within the substrate beneath respective blocks of the pair of blocks and comprising a first conductivity type of dopant, the individual source/drain diffusion regions comprising a bottom most portion, a lightly-doped drain region, and a side portion joined with the bottom most portion, side portions of the source and drain diffusion regions facing one another; a surface region comprising the first conductivity type, the surface region being electrically coupled to the source/drain diffusion regions; a halo region comprising a second conductivity type of dopant opposite from the first conductivity type received within the substrate adjacent the source/drain diffusion regions and joined with at least one of the side portions and disposed entirely within an area between the side portions and touching edges of the surface region; a gate oxide layer disposed over the substrate between the sidewall spacers and atop the surface region; and conductively-doped, n-type polysilicon disposed within the second opening and defining at least a portion of a transistor gate, the transistor gate comprising a pair of extensions which are respectively disposed over the individual blocks, and further comprising: a first implanted region having a first depth and including a dopant of the first conductivity type, the first implanted region being contained in the first opening; a second implanted region having the first conductivity type and a second depth greater than the first depth, the second implanted region extending beyond the first opening; a third implanted region having a third depth greater than the first depth but less than the second depth, the third implanted region having the second conductivity type, the third implanted region being contained in the second opening and partially compensating the first and second implanted regions over at least a portion of the first opening; and a fourth implanted region having a fourth depth greater than the first, second or third depths, the fourth implanted region having the second conductivity type and extending beyond the second opening, the fourth implanted region partially compensating a lower portion of the second implanted region, outermost edges of the first implanted regions forming the lightly doped drain region and outermost edges of the second implanted regions forming the halo region.