摘要 |
Tapered openings are formed in silicon oxide layers on a substrate by first saturating the silicon oxide layers with water, such as by immersing the substrates and the silicon oxide layers in water. The silicon oxide layers are then heated to dehydrate them to a desired water content at which a desired adhesion of a resist layer to the silicon oxide layer is achieved. A photoresist layer is then coated on the silicon oxide layers and photolithographically defined to provide them with openings therethrough over the area of the silicon oxide layers where the tapered openings are to be provided. The exposed area of the silicon oxide layers are then etched with an etchant for silicon oxide, such as buffered hydrofluoric acid, containing a component for lifting the edge of the resist from the silicon oxide, such as an acid, to etch tapered openings through the silicon oxide layers. Saturating the silicon oxide layers with water and then dehydrating them ensures that the openings have walls of uniform taper etched therethrough.
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