| 摘要 |
<p>PURPOSE:To enable to inexpensively form a Ta thin film capacitor on an unglazed substrate by specifying two factors of the surface roughness of the substrate and an alpha Ta film thickness. CONSTITUTION:An alpha Ta film 3 of 0.30mum or larger is formed on an unglazed ceramic substrate 1 of 0.15mum or less of center line mean roughness, the film 3 is subjected to an anodic oxidation to form a Ta2O5 film 5, and a conductor electrode film 5 formed thereon is formed. For example, a thermally oxidized Ta2O5 film 2 is formed on the unglazed alumina ceramic substrate 1 having surface roughness of 0.10mum Ra, and an alpha Ta film 3 of 0.40mum thick is formed by a DC sputtering method. Then, after the Ta film is patterned by PR etching technique, the prescribed region of the film 3 is converted by an anodic oxidation method to a Ta2O5 dielectric layer 4. A 3-layer structure film 5 is eventually formed and patterned of an NiCr of 0.1mum thick, Pd film, and an Au film of 0.6mum thick as an upper electrode.</p> |
