JP4169249B2 - Method of manufacturing phase change type memory device and memory device manufactured by the method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a phase change memory element used in a mass storage device such as a DVD, and a memory element manufactured by the method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a large capacity phase change optical disc such as a DVD using a three-component chalcogenide material of tellurium (Te), germanium (Ge), and antimony (Sb) as a recording material is known.
[0003]
FIG. 5 is a diagram for explaining the relationship between the phase change of the optical disk recording material and the optical constant.
Phase change optical disks are heated by heating a recording thin film on a substrate by laser light irradiation, and record and erase information by causing crystallographic phase changes in the structure, resulting from changes in optical constants between the phases. Information is reproduced by detecting a change in reflectance.
[0004]
In the case of a phase change between amorphous and crystal, the amorphous state is obtained by heating the recording thin film to a temperature higher than the melting point by laser light irradiation, melting and rapidly cooling. The crystalline state can be obtained by heating above the crystallization temperature and removing the temperature. Although rapid cooling and cooling are relative, it is generally said that a cooling rate of about 10 @ ⁷ ` ⁹ K / sec is required to obtain a stable amorphous state.
[0005]
FIG. 6 is a diagram showing the temperature dependence of the electrical conductivity of the chalcogenide-based material, where the vertical axis represents the logarithmic electrical conductivity and the horizontal axis represents the reciprocal temperature.
As can be seen from this graph, the electrical conductivity of the chalcogenide-based material varies greatly with temperature due to the phase change between the crystalline state and the amorphous state, and the resistance value is low in the crystalline state and the resistance value in the amorphous state. Get higher. It is known that the change in the resistance value corresponds to “0” and “1” to provide a memory element.
[0006]
[Problems to be solved by the invention]
However, the conventional wiring formation of the memory element is miniaturized by an etching work, so that the manufacturing apparatus is expensive and waste liquid is generated. There was a problem of becoming expensive.
The present invention has been made to solve the above-described problems, and an object of the present invention is to make it possible to manufacture a phase change memory element at a very low cost by using a replication technique.
[0007]
[Means for Solving the Problems]
The present invention relates to a method of manufacturing a phase change type memory element, in which a curable resin is applied to an original plate in which convex portions having a concavo-convex section form a stripe pattern, and the resin cured by a curing means is used as an original plate Forming a resin substrate in which the convex portions having a concave-convex cross section form a stripe pattern, forming an electrode layer pattern on the surface of the resin substrate, and the convex portions having a concave / convex cross section form a stripe pattern Forming a first contact layer substrate formed; forming a second contact layer substrate in which an electrode layer and a chalcogenide layer are formed on the surface of the resin substrate, and convex portions having a concavo-convex shape form a stripe pattern; The step of generating, the step of bringing the first contact layer substrate and the second contact layer substrate face each other, and bringing the two stripe patterns into contact with each other so as to be orthogonal to each other And wherein the Rukoto.
In addition, the present invention is characterized in that a photocurable resin is used as the curable resin.
Further, the present invention is characterized by using a thermosetting resin as the curable resin.
In addition, the present invention is characterized in that the striped electrode layer pattern of the first contact layer substrate in contact with the chalcogenide layer is formed to have a sharp tip.
In the first aspect of the present invention, the electrode layer pattern is formed on the surface of the resin substrate on which the convex portions having the concavo-convex shape form a stripe pattern, and the convex portions having the concavo-convex shape form the stripe pattern. The electrode layer and the chalcogenide layer are formed on the contact layer substrate and the resin substrate surface on which the convex portions having the concave-convex section form a stripe pattern, and the convex portions having the concave-convex section form the stripe pattern. The stripe-shaped patterns of the first contact layer substrate and the second contact layer substrate face each other so as to be orthogonal to each other.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining a method of manufacturing a phase change type memory element according to the present invention. FIG. 1A is a cross-sectional view of an original plate 1 on which a stripe pattern is formed. A photocurable resin is formed on the original plate 1. The layer is applied with a predetermined thickness, and light is irradiated from the back side of the applied resin layer (FIG. 1B). Next, the cured resin layer 2 is peeled from the original plate 1 to form a resin substrate (FIG. 1C). Next, an electrode layer 3 made of nickel or the like is formed on the resin substrate 2 (FIG. 1D). Thus, the first contact layer 10 is obtained by forming the striped electrode layer pattern on the resin substrate 2. Further, a second contact layer 11 is formed by forming a chalcogenide layer 4 made of, for example, ternary Ge, Te, Sb or the like on the electrode layer 3 (FIG. 1 (e)), and has a stripe on the surface. A chalcogenide layer pattern is formed.
[0009]
Next, as shown in FIG. 2, the first contact layer 10 and the second contact layer 11 face each other so that the stripe pattern intersects, and the electrode layer 3 of the first contact layer 10 and the chalcogenide layer of the second contact layer 11 4 is brought into contact with each other to form a memory element.
[0010]
As shown in FIG. 3, when a current having a steep pulse-like characteristic A is caused to flow between the first contact layer 10 and the second contact layer 11, the chalcogenide layer 4 in the portion where the current flows is crystallized due to a rapid temperature rise. When a current of characteristic B that causes a moderate temperature rise between the first contact layer and the second contact layer is flowed from the amorphous state to the amorphous state, the chalcogenide layer in that portion changes from the amorphous state to the crystalline state. Changes to low resistance.
[0011]
Thus, each stripe electrode of the first contact layer and the second contact layer is addressed as an address electrode, the resistance value at the addressed position is set to high resistance or low resistance, and the change in resistance value is “0”, “1”. , Data can be written and erased, and a memory element can be obtained.
[0012]
Note that when the degree of integration of the memory is increased, if the contact area between the electrode layer and the chalcogenide layer is large, the power consumption increases. Therefore, as shown in FIG. 4, the electrode layer pattern in contact with the chalcogenide layer has a sharp tip. It is desirable to reduce power consumption by using a striped pattern.
[0013]
In the present invention, as the original plate shown in FIG. 1 (a), a substrate in which chromium or the like is placed on a substrate glass and etched to form a stripe pattern can be used. The resin shown in FIG. 1 (c) It is also possible to apply a photocurable resin to the substrate 2, irradiate light, and use it as an original plate. In the present invention, a thermosetting resin may be used instead of the photocurable resin layer.
[0014]
【The invention's effect】
As described above, according to the present invention, a phase change type memory device can be easily manufactured by using a replication technique used for manufacturing an optical card or the like instead of a conventional semiconductor process. Thus, it can be manufactured at a very low cost.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for manufacturing a phase change memory element according to the present invention.
FIG. 2 is a diagram illustrating a configuration of a memory element of the present invention.
FIG. 3 is a diagram illustrating current characteristics for writing and erasing data.
FIG. 4 is a diagram showing an electrode layer pattern with a sharp tip.
FIG. 5 is an explanatory diagram of a relationship between a phase change of an optical disk recording material and an optical constant.
FIG. 6 is a graph showing the temperature dependence of the electrical conductivity of a chalcogenide-based material.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Original plate, 2 ... Resin substrate, 3 ... Electrode layer, 4 ... Chalcogenide layer, 10 ... 1st contact layer, 11 ... 2nd contact layer.

Claims (5)

In a method of manufacturing a phase change memory element,
A curable resin is applied to the original plate in which the convex portions of the concavo-convex section form a stripe pattern, the resin cured by means for curing is peeled off from the original plate, and the concavo-convex convex portions are formed in the stripe pattern. Producing a resin substrate forming
Forming an electrode layer pattern on the resin substrate surface, and generating a first contact layer substrate in which convex portions having a concavo-convex section form a stripe pattern;
Forming a second contact layer substrate in which an electrode layer and a chalcogenide layer are formed on the surface of the resin substrate, and a convex portion having an uneven cross section forms a stripe pattern;
The first contact layer substrate and the second contact layer substrate face each other, and the stripe-shaped patterns of the two contact each other so as to be orthogonal to each other;
A method of manufacturing a phase change memory element, comprising:   2. The method according to claim 1, wherein a photocurable resin is used as the curable resin.   2. The method according to claim 1, wherein a thermosetting resin is used as the curable resin. 2. The method according to claim 1, wherein the striped electrode layer pattern of the first contact layer substrate in contact with the chalcogenide layer is formed to have a sharp tip. A first contact layer substrate in which the electrode layer pattern is formed on the resin substrate surface on which the convex portions of the cross-sectional concavo-convex shape form a stripe pattern, and the convex portion of the cross-sectional concavo-convex shape forms the stripe pattern;
A second contact layer substrate in which an electrode layer and a chalcogenide layer are formed on the surface of the resin substrate on which the convex portions having a concave-convex section form a stripe pattern, and the convex portion having a concave-convex section forming a stripe pattern; Consists of
A phase change type memory device, wherein the stripe-like patterns of the first contact layer substrate and the second contact layer substrate face each other so as to be orthogonal to each other.

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