| 摘要 |
A method for formation of openings in semiconducting devices not limited by constraints of photolithography include forming a first dielectric layer over a semiconducting substrate, depositing a polysilicon layer over the first dielectric layer, forming a second dielectric layer over the polysilicon layer, forming a third dielectric layer over the second dielectric layer, etching a dielectric window through the third dielectric layer, forming a fourth dielectric layer into the dielectric window and over the third dielectric layer, the fourth dielectric layer being of a material dissimilar to the second dielectric layer, etching the fourth dielectric layer anisotropically using an etchant with a high selectivity ratio between the fourth dielectric layer and the second dielectric layer thereby forming a spacer, and etching portions of the first and second dielectric layers and the polysilicon layer anisotropically, the portions underlying an area bounded by a periphery of the spacer thereby forming the opening.
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