Composition for memory cell containing chalcogen compound, structure thereof, method for manufacturing same, and method for operating same
An object of the present invention is to provide a composition, a memory structure suitable for the composition, a manufacturing method, and an operating method for stable operation in a memory element including a chalcogen compound. In order to achieve the object, in a memory array with a cross-point structure including a first electrode line and a second electrode line intersecting each other, and a selective memory element disposed at each intersection of the first electrode line and the second electrode line and being a chalcogen compound, the present invention may provide the memory array with a cross-point structure including the first electrode line formed on a substrate, a first functional electrode formed between the first electrode line and the selective memory element, and a second functional electrode formed between the second electrode line and the selective memory element, wherein the first functional electrode is formed as a line along the first electrode line.
1. A method of initializing a memory cell including a two-terminal selector or a selective memory, which is a chalcogen compound, the method comprising:
(a) applying an initialization voltage to the memory cell;
(b) determining whether the memory cell is turned-on;
(c) when the memory cell is not turned-on;
(i) increasing the initialization voltage;
(ii) determining whether the increased initialization voltage exceeds a first voltage;
(iii) when the increased initialization voltage does not exceed the first voltage, repeating steps (a), (b), and (c) with the increased initialization voltage;
(d) terminating the initializing of the memory cell when either:
(i) the memory cell is determined to be turned-on in step (b), or
(ii) the increased initialization voltage is determined to exceed the first voltage in step (c) (ii);
wherein the initialization voltage applied in the first iteration of step (a) is less than or equal to a maximum threshold voltage of a memory cell in a set state before drift, and
the first voltage is within a drift reading window range, which is the voltage range between a minimum threshold voltage of the memory cell in a reset state expected after the drift and the maximum threshold voltage of the memory cell in the set state expected after the drift.
2. The method of claim 1 , wherein the initialization voltage applied in the first iteration of step (a) is a minimum threshold voltage of the memory cell in the set state before the drift.
3. The method of claim 1 , wherein in the step (c) (i), the initialization voltage is increased by 5 mV to 200 mV at a time.
4. The method of claim 1 , wherein a ratio of a voltage difference between the first voltage and a maximum threshold voltage of the memory cell in the set state expected after the drift is in the range of 0.50 to 0.95 with respect to the drift reading window range.