Phase changeable memory cells and methods of fabricating the same
AssigneeSamsung Electronics Co., Ltd.
InventorsYongho Ha, Jihye Yi, Hyunjo Kim
Life of this patent
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Abstract
A phase changeable memory cell is disclosed. According to embodiments of the invention, a phase changeable memory cell is formed that has a reduced contact area with one of the electrodes, compared to previously known phase changeable memory cells. This contact area can be a sidewall of one of the electrodes, or a perimeter edge of a contact opening through the electrode. Thus, when the thickness of the electrode is relatively thin, the contact area between the electrode and the phase changeable material pattern is relatively very small. As a result, it is possible to reduce power consumption of the phase changeable memory device and to form reliable and compact phase changeable memory cells.
Claims51
A phase changeable memory cell, comprising:
- a transistor including a source region coupled to a source contact, a drain region coupled to a drain contact, and a gate electrode;
- and
- a variable resistor including a first electrode, a second electrode having a top, bottom, and a sidewall, and a phase changeable material intermediate the first and second electrode, the phase changeable material covering at least a portion of the sidewall of the second electrode.
A phase changeable memory cell, comprising:
- a transistor including a source region coupled to a source contact, a drain region coupled to a drain contact, and a gate electrode;
- and
- a variable resistor including a first electrode, a second electrode having a top, bottom, and a sidewall, and a phase changeable material intermediate the first and second electrode, the phase changeable material covering less than 5000 square nanometers of the sidewall of the second electrode.
A variable resistor in a non-volatile memory cell, the variable resistor comprising:
- a first electrode;
- a phase changeable material adjacent the first electrode;
- and
- a second electrode having a top surface, a bottom surface, and one or more side surfaces, wherein one of the side surfaces of the second electrode is adjacent to the phase changeable material.
A phase changeable memory cell, comprising:
- a substrate having a source region and a drain region, and having a channel region therebetween;
- a transistor gate disposed over the channel region;
- a cell insulating layer covering portions of the source and drain regions, and covering at least a portion of the transistor gate;
- a source contact formed through the cell insulating layer and coupled to the source region;
- a drain contact formed through the cell insulating layer and coupled to the drain region;
- and
- a variable resistor, including:
- a first electrode,
- a phase changeable material, and
- a second electrode coupled to the source contact, at least a portion of a side surface of the second electrode covered by the phase changeable material.
A pair of phase changeable memory cells, comprising:
- a substrate having a first cell transistor and a second cell transistor, the first and second cell transistor each having a separate source and gate, and the first and second cell transistor sharing a common drain;
- a cell insulating layer covering the first and second cell transistors;
- and
- a first and a second variable resistor, each of the resistors including:
- a first electrode,
- a phase changeable material, and
- a second electrode coupled to the source of a respective cell transistor, a side surface of the second electrode adjacent to the phase changeable material.
A method for forming a non-volatile memory cell, the method comprising:
- in a substrate, forming a cell transistor;
- forming an insulating layer adjacent to the cell transistor;
- forming a first electrode on the insulating layer and coupled to the cell transistor;
- forming a trench in the insulating layer, a sidewall of the trench adjacent to a sidewall of the first electrode;
- filling the trench with a phase changeable material, a portion of the phase changeable material adjacent the sidewall of the first electrode;
- and
- forming a second electrode on the phase changeable material.
A method for forming a pair of non-volatile memory cells, the method comprising:
- in a substrate, forming a first cell transistor and a second cell transistor;
- forming an insulating layer adjacent to the first and second cell transistors;
- forming a first bottom electrode on the insulating layer and coupled to the first cell transistor;
- forming a second bottom electrode on the insulating layer and coupled to the second cell transistor;
- forming a first trench in the insulating layer, a sidewall of the first trench adjacent to a sidewall of the first bottom electrode;
- forming a second trench in the insulating layer, a sidewall of the second trench adjacent to a sidewall of the second bottom electrode;
- filling the first and second trenches with a phase changeable material, a portion of the phase changeable material adjacent the sidewall of the first bottom electrode and the second bottom electrode;
- forming a first top electrode on the phase changeable material;
- and
- forming a second top electrode on the phase changeable material.
A method for forming a non-volatile memory cell, comprising:
- in a substrate, forming a source region, a drain region and a channel region portion lying therebetween;
- forming a transistor gate disposed on the channel region portion of the substrate;
- depositing a first insulating material over the source region, the drain region, and transistor gate;
- forming a source contact through the first insulating material, the source contact electrically coupled to the source region;
- forming a first variable resistor electrode adjacent to and electrically coupled to the source contact;
- forming a second insulating material over the resulting substrate surface;
- forming an opening in the second insulating material;
- exposing a sidewall of the first variable resistor electrode to the opening in the second insulating material;
- filling the opening in the second insulating material with a phase changeable material;
- and
- forming a second variable resistor electrode on the phase changeable material and separate from the first variable resistor contact.
Dependencies are inferred from the claim text.