Method of producing cavity structures
AssigneePharmacia Biotech AB
InventorH.ang.kan Elderstig
Life of this patent
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Abstract
A method of producing sealed cavity structures in the surface layer of a selectively etchable substrate (1), comprises: a) depositing a masking layer (2) of etchable material on the substrate (1), b) by means of etching, opening at least one hole (3) in the masking layer (2) down to the substrate surface, c) through said hole or holes (3) in the masking layer (2) selectively etching the substrate (1) in under the masking layer (2) so as to form one more cavities (4) which extend under the masking layer, and d) sealing said hole or holes (3) in the masking layer (2).
Claims11
A method of producing sealed cavity structures in the surface layer of a selectively etchable substrate, comprising the steps of:
- a) depositing a masking layer of etchable polysilicon material on the substrate wherein said substrate is silicon dioxide,
- b) etching at least one hole in the masking layer down to the substrate surface,
- c) selectively etching the substrate in under the masking layer through said hole or holes so as to form one or more cavities which extend under the masking layer;
- and
- d) sealing said hole or holes in the masking layer by oxidation of polysilicon to silicon dioxide, and thereby expansion of the masking layer.
Dependencies are inferred from the claim text.