Semiconductor device and method of manufacturing the same
AssigneeFujitsu Microelectronics Limited
InventorWensheng Wang
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Abstract
An upper electrode film includes a first conductive oxidation layer made of an oxide expressed by a chemical formula M1Ox2, a second conductive oxidation layer made of an oxide expressed by a chemical formula M2Oy2 and a third conductive oxidation layer. Here, the second conductive oxidation layer is formed to have a degree of oxidation higher than the first conductive oxidation layer and the third conductive oxidation layer, and among the composition parameters x1, x2, y1, y2, z1 and z2, there are the following relations, y2/y1>x2/x1, y2/y1>z2/z1, and z2/z1≧x2/x1.
Claims20
A semiconductor device, comprising:
- a semiconductor substrate;
- and
- a capacitor structure formed over said semiconductor substrate and structured by the capacitor film being sandwiched between an upper electrode and a lower electrode,
- wherein said upper electrode, comprising:
- a first layer made of an oxide, of which stoichiometric composition is expressed by a chemical formula M1Ox1 using a composition parameter x1, and of which practical composition is expressed by a chemical formula M1Ox2 using a composition parameter x2;
- a second layer made of an oxide formed on said first layer, and its stoichiometric composition is expressed by a chemical formula M2Oy1 using a composition parameter y1, and its practical composition is expressed by a chemical formula M2Oy2 using a composition parameter y2;
- and
- a third layer made of an oxide formed on said second layer, and its stoichiometric composition is expressed by a chemical formula M3Oz1 using a composition parameter z1, and its practical composition is expressed by a chemical formula M3Oz2 using a composition parameter z2,
- where the symbols M1, M2 and M3 are respectively expressed as one or plural metal elements,
- wherein said second layer has a degree of oxidation higher than said first layer and said third layer;
- and
- wherein said composition parameters x1, x2, y1, y2, z1 and z2 have the following relations therebetween,
- y2/y1>x2/x1, y2/y1>z2/z1, and z2/z1≧x2/x1.
A method of manufacturing the semiconductor device having a capacitor structure comprising:
- forming a lower electrode having said capacitor structure over a semiconductor substrate;
- forming a capacitor film over said lower electrode;
- and
- forming an upper electrode over said capacitor film by stacking at least a first conductive oxidation layer, a second conductive oxidation layer and a third conductive oxidation layer sequentially,
- wherein forming said first conductive oxidation layer and said third conductive layer is conducted under the oxidation content lower than that in depositing said second conductive oxidation layer.
Dependencies are inferred from the claim text.