Three-dimensional memory device and manufacturing method thereof
A three-dimensional memory device and a manufacturing method thereof are provided. The three-dimensional memory device includes a plurality of bottom control gate lines, a plurality of bottom source lines, a stacked structure on the bottom source lines, a plurality of bit lines disposed on the stacked structure, and a plurality of pillar structures passing through the stacked structure. The stacked structure includes a plurality of stacked layers insulated from one another and respectively located at different levels. Each stacked layer includes a plurality of word lines. Each word line and the corresponding pillar structure, which is connected between the corresponding bit line and the corresponding bottom source line, define a memory cell. Each pillar structure includes an outermost ferroelectric layer, a conductive core gate column, and a surrounding channel layer disposed therebetween. The conductive core gate column is electrically connected to the corresponding bottom control gate line.
1. A three-dimensional memory device comprising:
a plurality of bottom control gate lines extending in a first horizontal direction and arranged in parallel; and
a plurality of bottom source lines disposed over the bottom control gate lines, wherein the bottom source lines extend in a second horizontal direction and intersect with the bottom control gate lines;
a stacked structure disposed on the bottom source lines, wherein the stacked structure includes a plurality of stacked layers which are insulated from one another and respectively located at different levels, each of the stacked layers includes a plurality of word lines extending in the second horizontal direction, and each of the word lines corresponds to at least one of the bottom source lines;
a plurality of bit lines disposed on the stacked structure and extending in the first horizontal direction, wherein the orthogonal projections of the bit lines intersect the bottom source lines; and
a plurality of pillar structures passing through the stacked structure, wherein each of the pillar structures is connected between the corresponding one of the bit lines and the corresponding one of the bottom source lines, and each of the word lines and the corresponding one of the pillar structures define a memory cell;
wherein each of the pillar structures includes an outermost ferroelectric layer, a conductive core gate column, and a surrounding channel layer disposed between the outermost ferroelectric layer and the conductive core gate column, and the conductive core gate column is electrically connected to the corresponding one of the bottom control gate lines.
2. The three-dimensional memory device according to claim 1 , wherein the conductive core gate column passes through the corresponding one of the bottom source lines to be electrically connected to the corresponding one of the bottom control gate lines.
3. The three-dimensional memory device according to claim 1 , wherein each of the pillar structures further includes an inner dielectric layer and an outer dielectric layer, the inner dielectric layer is disposed between the surrounding channel layer and the conductive core gate column, and the outer dielectric layer is disposed between the surrounding channel layer and the outermost ferroelectric layer.
4. The three-dimensional memory device according to claim 3 , wherein each of the materials of the inner dielectric layer and the outer dielectric layer is silicon oxide, silicon nitride, or silicon oxynitride.
5. The three-dimensional memory device according to claim 1 , wherein the surrounding channel layer is electrically connected between the corresponding one of the bottom source lines and the corresponding one of the bit lines.
6. The three-dimensional memory device according to claim 1 , wherein the outermost ferroelectric layer is in contact with the corresponding one of the word lines, and the material of the outermost ferroelectric layer includes a ferroelectric material and dopants, the ferroelectric material is hafnium oxide, hafnium zirconium oxide, or zirconium titanium oxide, and the dopants are silicon, aluminum, lanthanum, yttrium, strontium, gadolinium, niobium, nickel, tantalum, or any combination thereof.
7. The three-dimensional memory device according to claim 1 , further comprising a bottom insulating layer by which each bottom control gate line and each bottom source line are insulated from each other.
8. The three-dimensional memory device according to claim 1 , wherein each pillar structure further includes a core insulating portion by which the conductive core gate column is insulated from the bit line connected to the pillar structure.