| 摘要 |
Narrow trench formation in silicon substrate comprises: (a) engraving to form first trenches separated by silicon ribs; (b) oxidation to form oxide layer to form second trenches and ribs; (c) filling second trenches; (d) engraving oxide to top of second ribs, retaining oxide between material fingers and ribs; (e) removing second ribs and material fingers; (f) oxide engraving to uncover substrate, retaining oxide fingers; (g) engraving substrate to form narrow trenches. Formation of narrow trenches in a silicon substrate (1) comprises: (a) engraving the substrate to form first trenches separated by first ribs of silicon; (b) thermal oxidation of the substrate to form a layer of silicon oxide around the substrate, in order to form some second trenches and some second ribs of silicon; (c) filling of the second trenches with some fingers of an engravable material; (d) engraving of the oxide up to the upper surface of the second ribs whilst conserving portions of the oxide between the fingers of material and the second ribs; (e) elimination of the second ribs of silicon and the fingers of material; (f) the engraving of the oxide to uncover the substrate at the bottom of the oxide portions, conserving the fingers of oxide; (g) engraving of the substrate to form narrow trenches in the substrate.
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