| 摘要 |
<p>In a method for fabricating a polysilicon resistor structure, a layer of polysilicon (14) is formed over an insulation layer (11) on a substrate (10). The insulation layer may have windows through which the polysilicon may extend to contact the substrate. Selected regions of the polysilicon layer are implanted to form conductive regions, for interconnections, buses, and the like, and the polysilicon layer is patterned to remove portions of the polysilicon layer to create a desired resistor network pattern. A layer of undoped oxide (25) is formed overall, to fully encapsulate the top and sides of the layer of polysilicon. The thickness of the undoped oxide is selected to enable a dopant implantation energy to be determined, which will result in dopant being implanted through the undoped oxide, as a screen, with a peak concentration of dopant located at a central depth in the layer of polysilicon. Thereafter, a layer of BPSG (43) is formed over the oxide and reflowed to produce a planarized structure. <IMAGE></p> |
