| 摘要 |
Highly reliable direct contacts may be formed by defining a direct contact area within a larger area purposely implanted and diffused for ensuring electrical continuity in the semiconductor. Patterning may define the contacting polysilicon within an implanted direct contact area so that the definition edges thereof fall on a gate oxide layer thus preventing an etching of the semiconductor during the unavoidable over-etching that concludes the polysilicon patterning step. Preferably, a pre-definition of the direct contact area is performed through a first, deposited layer of polysilicon, which effectively protects a gate oxide layer during a HF wash prior to depositing a second, contacting layer of polysilicon of adequate thickness.
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