METHOD OF ELIMINATING POLY END CAP ROUNDING EFFECT

摘要

A two step mask/etch process for fabricating a poly end cap on field oxide begins with the formation of a layer of polysilicon (106) over the field oxide island (100) and over the gate oxide material (104) on the substrate (102) such that the layer of polysilicon (106) spans the interface between the substrate (102) and the field oxide (100). In a first mask/etch step, the layer of polysilicon is patterned utilizing a photoresist mask to form a line of polysilicon that extends in the x-direction such that the two longitudinal edges of the line are formed over the field oxide and such that the line extends over the field oxide in the x-direction. In a second mask/etch step, the line of polysilicon (106) is patterned utilizing a photoresist mask (108) to define a substantially rectangular poly end cap over the field oxide (100).