摘要 |
Lumped passive components including a capacitor having a silicon nitride dielectric, a tantalum film resistor, and a capacitor having a tantalum oxide dielectric are formed on a semi-insulating substrate by first providing an insulating layer, here of silicon nitride, over the substrate and metal contacts having previously been formed on such substrate. The metal contacts provide a first plate for each one of such capacitors. A tantalum layer is reactively sputtered on the insulating layer, and a protective masking layer is next provided on such tantalum layer. An area where the anodized tantalum capacitor is to be formed is then opened in the protective masking layer over a selected one of the metal contacts. A portion of the tantalum is anodized in such area to form an area of a tantalum oxide (Ta2O5). The area where the tantalum oxide is formed is confined generally to the area in the tantalum layer over the contact. The masking layer is removed and a second masking layer is patterned to provide an etching mask used to etch the tantalum layer to define each one of such capacitors, and to provide a strip of tantalum, defining a region for said tantalum resistor. Top metal contacts are then provided aligned with the first set of such contacts, and thus providing a second metal plate of the anodized tantalum capacitor and a second metal plate of the silicon nitride capacitor. Further, a set of metal contacts is provided to each end of the tantalum strip to provide the tantalum resistor.
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