Thin film capacitor including perovskite-type oxide layers having columnar structure and granular structure
AssigneeNEC Corporation
InventorsShuji Sone, Yoshitake Kato
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Abstract
The present invention relates to a thin film capacitor that may be used as a stacked capacitor in a memory cell. In a thin film capacitor including a high dielectric constant layer sandwiched by two electrode layers, the high dielectric constant layer includes at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure.
Claims18
A thin film capacitor comprising:
- two electrode layers;
- and
- a high dielectric constant layer, sandwiched by said electrode layers, said high dielectric constant layer comprising at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure.
A thin film capacitor comprising:
- two electrode layers;
- and
- a high dielectric constant layer, sandwiched by said electrode layers, said high dielectric constant layer comprising at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure,
- said high dielectric constant layer is made of (Ba, Sr)mTinO3, where m and n are positive values.
A thin film capacitor comprising:
- a monocrystalline silicon substrate;
- an insulating layer formed on said monocrystalline silicon substrate, a contact hole being perforated in said insulating layer;
- a polycrystalline silicon plug buried in said contact hole of said insulating layer;
- a barrier layer formed on said polycrystalline silicon plug;
- a lower electrode layer formed on said barrier layer;
- a high dielectric constant layer, formed on said lower electrode layer, said high dielectric constant layer comprising at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure;
- and
- an upper electrode layer formed on said high dielectric constant layer.
A thin film capacitor comprising:
- a monocrystalline silicon substrate;
- an insulating layer formed on said monocrystalline silicon substrate, a contact hole being perforated in said insulating layer;
- a polycrystalline silicon plug buried in said contact hole of said insulating layer;
- a barrier layer formed on said polycrystalline silicon plug;
- a lower electrode layer formed on said barrier layer;
- a high dielectric constant layer, formed on said lower electrode layer, said high dielectric constant layer comprising at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure;
- and
- an upper electrode layer formed on said high dielectric constant layer,
- said high dielectric constant layer is made of (Ba, Sr)mTinO3, where m and n are positive values.
A method for manufacturing a thin film capacitor including two electrode layers and a high dielectric constant layer, sandwiched by said electrode layers, said high dielectric constant layer comprising at least one perovskite-type oxide layer having a columnar structure and at least one perovskite-type oxide layer having a granular structure, comprising the steps of:
- forming an amorphous AmBnO3 layer;
- and
- annealing said amorphous AmBnO3 layer in a nitrogen atmosphere to crystallize said amorphous AmBnO3 layer, thus forming said perovskite-type oxide layer having said granular structure,
- wherein A includes at least one of metals belonging to II-group or Pb;
- B includes at least one of metals belonging to IV-group;
- and
- m and n are positive values.
Dependencies are inferred from the claim text.