Three-dimensional memory device containing ferroelectric memory elements encapsulated by transition metal-containing conductive elements and method of making thereof
A three-dimensional ferroelectric memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, where each of the electrically conductive layers contains a transition metal element-containing conductive liner and a conductive fill material portion, a vertical semiconductor channel extending vertically through the alternating stack, a vertical stack of tubular transition metal element-containing conductive spacers laterally surrounding the vertical semiconductor channel and located at levels of the electrically conductive layers, and a ferroelectric material layer located between the vertical stack of tubular transition metal element-containing conductive spacers and the transition metal element-containing conductive liner.
1. A three-dimensional ferroelectric memory device, comprising:
an alternating stack of insulating layers and electrically conductive layers located over a substrate, wherein each of the electrically conductive layers comprises a transition metal element-containing conductive liner and a conductive fill material portion;
a vertical semiconductor channel extending vertically through the alternating stack;
a vertical stack of tubular transition metal element-containing conductive spacers laterally surrounding the vertical semiconductor channel and located at levels of the electrically conductive layers; and
a ferroelectric material layer located between the vertical stack of tubular transition metal element-containing conductive spacers and the transition metal element-containing conductive liner;
wherein the ferroelectric material layer comprises:
an upper horizontally-extending portion that contacts a bottom surface of the respective overlying one of the insulating layers and a top surface of a respective electrically conductive layer;
a lower horizontally-extending portion that contacts a top surface of the respective underlying one of the insulating layers and a bottom surface of the respective electrically conductive layer; and
a tubular portion vertically extending between the upper horizontally-extending portion and the lower horizontally-extending portion, wherein the tubular portion laterally surrounds and contacts a respective one of the tubular transition metal element-containing conductive spacers.
2. The three-dimensional ferroelectric memory device of claim 1 , wherein the transition metal element-containing conductive liner comprises a transition metal element that is selected from iridium, ruthenium, palladium, osmium, rhenium, molybdenum or cobalt.
3. The three-dimensional ferroelectric memory device of claim 2 , wherein the transition metal element-containing conductive liner consists essentially of a conductive oxide of the transition metal element.
4. The three-dimensional ferroelectric memory device of claim 2 , wherein the transition metal element-containing conductive liner consists essentially of the transition metal element.
5. The three-dimensional ferroelectric memory device of claim 1 , wherein the tubular transition metal element-containing conductive spacers comprise a transition metal element that is selected from iridium, ruthenium, palladium, osmium, rhenium, molybdenum or cobalt.
6. The three-dimensional ferroelectric memory device of claim 5 , wherein the tubular transition metal element-containing conductive spacers consist essentially of a conductive oxide of the transition metal element.
7. The three-dimensional ferroelectric memory device of claim 5 , wherein the tubular transition metal element-containing conductive spacers consist essentially of the transition metal element.
8. The three-dimensional ferroelectric memory device of claim 1 , further comprising a tubular insulating spacer layer which contacts an inner sidewall of a respective one of the tubular transition metal element-containing conductive spacers and contacts a portion of an outer sidewall of the vertical semiconductor channel.
9. The three-dimensional ferroelectric memory device of claim 1 , further comprising a vertical stack of tubular insulating spacers, wherein each of the tubular insulating spacers contacts an inner sidewall of a respective one of the tubular transition metal element-containing conductive spacers and contacts a portion of an outer sidewall of the vertical semiconductor channel.
10. The three-dimensional ferroelectric memory device of claim 1 , wherein the vertical semiconductor channel has a straight outer sidewall that extends through each layer within the alternating stack and contacts a set of sidewalls of the insulating layers.
11. The three-dimensional ferroelectric memory device of claim 1 , wherein the vertical semiconductor channel has a laterally-undulating outer sidewall that includes laterally-protruding portions that protrude outward from vertical interfaces with the insulating layers toward a respective one of the electrically conductive layers.