Memory device using semiconductor element
View Patent ↗A memory device includes pages in a column direction on a substrate and memory cells in each page in a row direction in plan view. Each memory cell includes a semiconductor base, first and second impurity regions, connected to a source line and a bit line, respectively, at both ends of the semiconductor base, and first and second gate conductor layers, one of which is connected to a word line and the other of which is connected to a plate line. A continuous operation of a page erase operation and a page write operation is performed by controlling voltages applied to the source line, the bit line, the word line, and the plate line without performing a reset operation for returning the voltage applied to the plate line to a ground voltage.
1. A memory device using a semiconductor element in which, in plan view, a plurality of pages are arranged in a column direction on a substrate, each of the plurality of pages including a plurality of memory cells arranged in a row direction, wherein
each of the memory cells included in each of the pages comprises:
a semiconductor base standing vertically or extending horizontally on the substrate;
a first impurity region and a second impurity region at both ends of the semiconductor base;
a gate insulating layer in contact with a side surface of the semiconductor base between the first impurity region and the second impurity region;
a first gate conductor layer covering a part or an entirety of the gate insulating layer; and
a second gate conductor layer adjacent to the first gate conductor layer and in contact with a side surface of the gate insulating layer,
in each of the memory cells, the first impurity region is connected to a source line, the second impurity region is connected to a bit line, one of the first gate conductor layer and the second gate conductor layer is connected to a word line, and the other of the first gate conductor layer and the second gate conductor layer is connected to a plate line,
in a page erase operation, a first voltage higher than a ground voltage is applied to a plate line of the page, a second voltage equal to or higher than the ground voltage is applied to the word line, a third voltage equal to the ground voltage is applied to the source line, and a fourth voltage higher than the ground voltage is applied to all the bit lines,
in a page write operation, a fifth voltage higher than the ground voltage is applied to the plate line, a sixth voltage higher than the ground voltage is applied to the word line, a seventh voltage equal to the ground voltage is applied to the source line, an eighth voltage equal to the ground voltage is applied to the bit line of any memory cell among the memory cells to maintain an erase state, and a ninth voltage higher than the ground voltage is applied to the bit line of any memory cell among the memory cells to be in a write state, and
the page erase operation and the page write operation are continuously performed without performing a reset operation for returning the voltage applied to the plate line to the ground voltage.
2. The memory device using the semiconductor element according to claim 1 , wherein the ground voltage is zero volts.
3. The memory device using the semiconductor element according to claim 1 , wherein
in the page erase operation, some of a group of positive holes in the semiconductor base of each of the memory cells of the page are eliminated to reduce a number of positive holes, and
in the page write operation, the number of positive holes in the semiconductor base of a selected memory cell among the memory cells of the page is increased by an impact ionization phenomenon.
4. The memory device using the semiconductor element according to claim 1 , wherein
the word line and the plate line are arranged in parallel in plan view, and
the bit line is arranged in a direction perpendicular to the word line and the plate line in plan view.
5. The memory device using the semiconductor element according to claim 1 , wherein a first gate capacitance between the semiconductor base and the other of the first gate conductor layer and the second gate conductor layer, to which the plate line is connected, is larger than a second gate capacitance between the semiconductor base and the one of the first gate conductor layer and the second gate conductor layer, to which the word line is connected.
6. The memory device using the semiconductor element according to claim 1 , wherein the source line is isolated for each of the memory cells arranged in the row direction and is arranged in parallel with the word line and the plate line in plan view.
7. The memory device using the semiconductor element according to claim 1 , wherein the source line is connected in common to all the memory cells of adjacent pages among the pages in plan view.
8. The memory device using the semiconductor element according to claim 1 , wherein the semiconductor base is a P-type semiconductor layer, and the first impurity region and the second impurity region are N-type semiconductor layers.
9. The memory device using the semiconductor element according to claim 1 , wherein data in the memory cells connected to at least two pages among the pages is selectively erased in the page erase operation.
10. The memory device using the semiconductor element according to claim 1 , wherein the word line and the plate line are connected to a row decoder circuit, a row address is to be input to the row decoder circuit, and any page among the pages is to be selected in accordance with the row address.
11. The memory device using the semiconductor element according to claim 1 , wherein the bit line is connected to a sense amplifier circuit with a switch circuit interposed therebetween, the sense amplifier circuit is connected to a column decoder circuit, a column address is to be input to the column decoder circuit, and the sense amplifier circuit is to be selectively connected to an input/output circuit in accordance with the column address.
12. The memory device using the semiconductor element according to claim 11 , wherein in the page write operation, inverse logical data of data in the page write operation is written in the sense amplifier circuit.
13. The memory device using the semiconductor element according to claim 1 , wherein the first voltage and the fifth voltage are equal.
14. The memory device using the semiconductor element according to claim 1 , wherein one or both of the first gate conductor layer and the second gate conductor layer are divided into two or more isolated gate conductor layers in plan view or in a vertical direction, and the isolated gate conductor layers are to be operated synchronously or asynchronously.
15. The memory device using the semiconductor element according to claim 14 , wherein in plan view or in the vertical direction, the isolated gate conductor layers of one of the first gate conductor layer and the second gate conductor layer are arranged on both sides of the other of the first gate conductor layer and the second gate conductor layer.