Metal-insulator-metal capacitor and method for manufacturing thereof

摘要

The disclosure provides a method for producing a stack of layers on a semiconductor substrate. The method includes producing a substrate a first conductive layer; and producing by ALD a sub-stack of layers on said conductive layer, at least one of said layers of the sub-stack being a TiO2 layer, the other layers of the sub-stack being layers of a dielectric material having a composition suitable to form a cubic perovskite phase upon crystallization of said sub-stack of layers. Crystallization is obtained via heat treatment. When used in a metal-insulator-metal capacitor, the stack of layers can provide improved characteristics as a consequence of the TiO2 layer being present in the sub-stack.

主权项

1. A method for producing a stack of layers on a semiconductor substrate, the method comprising:
providing a substrate having a first electrically conductive layer thereon, by atomic layer deposition, producing on said first electrically conductive layer a TiO2 layer having a thickness in the range of 0.5 nm to 2 nm; and producing on the TiO2 layer a first plurality of layers, the plurality of layers including
one or more metastable strontium-titanium oxide (STO) layers, each metastable STO layer having a Sr/(Sr+Ti) ratio less than about 58%, each metastable STO layer comprising a plurality of alternating sublayers of amorphous strontium oxide and amorphous titanium oxide, the TiO2 layer being distinct from the one or more metastable STO layers, andat least one SrO layer, each SrO layer being distinct from the one or more metastable STO layers, each SrO layer underlying and/or overlying one or more of the metastable STO layers;the method further comprising:
subjecting the substrate including said TiO2 layer and said first plurality of layers to a heat treatment to crystallize the one or more metastable STO layers to form one or more initial crystallized layers and to intermix the at least one TiO2 layer and the at least one SrO layer with the one or more initial crystallized layers, in order to convert the TiO2 layer and the first plurality of layers to a crystallized dielectric STO layer having a cubic perovskite structure on said first electrically conductive layer, and producing a second electrically conductive layer on said crystallized dielectric STO layer,or
producing a second electrically conductive layer on said first plurality of layers, and subjecting the substrate including said TiO2 layer and said first plurality of layers and said second electrically conductive layer to a heat treatment to crystallize the one or more metastable STO layers to form one or more initial crystallized layers and to intermix the TiO2 layer and the at least one SrO layer with the one or more initial crystallized layers, in order to convert the TiO2 layer and the first plurality of layers to a crystallized dielectric STO layer having a cubic perovskite structure on said first electrically conductive layer.