| 摘要 |
PURPOSE: A forming method of a capacitor is provided to prevent undesirable phenomena such as hillock, bubbling or void in a capacitor electrode. CONSTITUTION: First a diffusion barrier(11) such as titanium or titanium oxide is deposited on an insulating layer(10) having contact holes filled with polysilicon. Next, a first pure platinum layer, an impurity layer composed of such as Ir, Ru, Rh, or W, and a second pure platinum layer are formed on the diffusion barrier(11) and then heat-treated at about 500 to 900°C. Therefore, atoms in the impurity layer are diffused into the first and second platinum layers, and consequently a platinum alloy layer(20) to be used for a lower electrode is formed. Next, a dielectric layer(30) is deposited on the platinum alloy layer(20). After that, a pure platinum layer, an impurity layer, and another pure platinum layer are successively deposited on the dielectric layer(30) and heated. Therefore, another platinum alloy layer(40) to be used for an upper electrode is formed.
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