Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.

Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.

Abstract: A buried contact module is provided that includes a dopant-diffusion buffer layer. The dopant-diffusion buffer layer is formed with a thin dielectric region fabricated between the polysilicon contact region and the well region. The dielectric region formed of, for example, silicon dioxide, limits the amount of phosphorous diffusion into the well region. Thus, a buried contact junction can be formed in an integrated circuit having a high punch-through voltage characteristic, a low junction leakage current characteristic and a low polysilicon resistance. In addition, the buried contact junction maintains a relatively low buried contact resistance.