| 摘要 |
Methods of forming electrical connections between conductive layers include the steps of forming a first electrically conductive layer on a substrate and then forming a first protective layer (e.g., Si3N4, poly-Si) which is resistant to a first etchant, on the first electrically conductive layer. A second protective layer (e.g., SiO2) is then formed on the first protective layer. The second protective layer is preferably resistant to a second etchant which is capable of etching the first protective layer. A mask is then patterned on the second protective layer. The mask is preferably patterned to have an opening therein which extends opposite the first electrically conductive layer. The second protective layer is then selectively etched using the first etchant, to expose a portion of the first protective layer extending opposite the first electrically conductive layer. The exposed portion of the first protective layer is then etched using the second etchant, to define a contact hole which exposes a portion of the first electrically conductive layer. A second electrically conductive layer is then formed in the contact hole, on the exposed portion of the first electrically conductive layer and in ohmic contact therewith.
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