KR20120032909A - Manufacturing apparatus for resistance memory device - Google Patents

Abstract

PURPOSE: A resistive memory device manufacturing apparatus is provided to manufacture oxide layers in different chambers with respect to the composition of each oxide layer, thereby preventing contamination generated by manufacturing the oxide layers in a single chamber. CONSTITUTION: A load-lock chamber(210) receives a substrate from the outside. A movable module chamber(220) comprises a robot arm which transfers the substrate from the load-lock chamber. A first oxide deposition chamber(240) is used for depositing a first buffer layer and a second buffer layer. A second oxide deposition chamber(250) is used for depositing a resistive change layer. A metal electrode deposition chamber(230) is used for depositing a first electrode and a second electrode.

Description

Manufacturing apparatus for resistance memory device

A device specialized for the fabrication of a resistive memory element.

Resistive random access memory (RRAM), which is a nonvolatile memory device, stores data mainly by using resistance change characteristics of transition metal oxides. When a voltage above a set voltage is applied to the resistance change material, the resistance of the resistance change material is lowered. This is called an ON state. When a voltage equal to or greater than a reset voltage is applied to the resistance change material, the resistance of the resistance change material is increased. This is called an OFF state.

In general, a resistive memory device includes a storage node including a resistance change layer and a switching device electrically connected thereto. The switching device controls signal access to the storage node connected thereto.

In the resistive memory element, a plurality of oxide films are formed as memory layers, and manufacturing conditions of these oxide films may be different. In order to prevent contamination and exposure to oxygen during the deposition of oxide films of memory layers having different manufacturing environments, an apparatus for manufacturing a plurality of oxide films in-situ is required.

An apparatus for fabricating resistive memory devices in-situ is provided.

An apparatus for manufacturing a resistive memory device according to an embodiment may include:

A load lock chamber into which a substrate is brought in from outside or carried in to the outside;

A moving module chamber having a robot arm installed to transfer the substrate from the load lock chamber; And

And a metal electrode deposition chamber, an oxide deposition chamber, and a plasma oxidation treatment chamber that surround the moving module chamber with the load lock chamber and are separated from each other. The chamber for oxide deposition includes at least two chambers.

The oxide deposition chamber may include a first chamber for oxide deposition for a buffer; And

And a second chamber for depositing the resistive change layer.

The resistive memory device manufacturing apparatus according to the embodiment of the present invention may further include a third chamber for depositing another resistive change layer.

The process pressure of the plasma oxidation chamber may be lower in vacuum than the process pressures of the metal electrode deposition chamber, the oxide deposition chamber, and the plasma oxidation chamber.

Between the mobile module chamber and the other chamber is provided an entrance to isolate them.

According to the disclosed embodiments, since the resistive memory is manufactured in a state of being blocked from oxygen (vacuum state) in-situ, it is possible to manufacture the resistive memory device having improved durability.

In addition, by manufacturing the oxide layer (buffer layer, resistance change layer, oxygen exchange layer) having a different composition in different chambers, it is possible to prevent contamination that may occur during manufacturing in one chamber.

1 is a cross-sectional view illustrating a nonvolatile memory device 100 manufactured according to an embodiment of the present invention.
2 is a schematic plan view of a resistive memory device manufacturing apparatus 200 according to an embodiment of the present invention.
3 is a graph illustrating the results of experiments of durability of a memory device in which a ZrOx oxygen exchange layer is formed on a resistance change layer of TaOx.
4 and 5 are manufactured in a state exposed to oxygen (atmosphere) during the manufacturing process (Fig. 4), and when the manufacturing process atmosphere is manufactured in a vacuum atmosphere as in the manufacturing apparatus of the present invention (Fig. 5) Is a graph showing the durability of each.

1 is a cross-sectional view illustrating a nonvolatile memory device 100 manufactured according to an embodiment of the present invention.

Referring to FIG. 1, a resistive memory device 100 manufactured according to an exemplary embodiment of the present invention may include a first buffer layer B1 sequentially stacked on a substrate 102 between first and second electrodes E1 and E2. ), A resistance change layer 110, an oxygen exchange layer 120, and a second buffer layer B2. The resistance change layer 110 and the oxygen exchange layer 120 constitute a memory layer M1. The resistance change layer 110 and the oxygen exchange layer 120 may have a resistance change characteristic due to the movement of ionic species.

Reliability, reproducibility, stability, etc. of the memory device 100 may be improved by the first and second buffer layers B1 and B2. The first and second buffer layers B1 and B2 may be omitted as necessary.

The resistance change layer 110 of the memory layer M1 may be formed of a first metal oxide. For example, the resistance change layer 110 may include at least one of Ta oxide, Zr oxide, yttria-stabilized zirconia (YSZ), Ti oxide, Hf oxide, Mn oxide, Mg oxide, and mixtures thereof. When the first metal oxide includes Ta oxide, the first metal oxide may be TaOx, where x is 0 <x <2.5 or 0.5 ≦ x ≦ 2.0. Oxygen ions and / or oxygen vacancies may be present in the resistance change layer 110. The resistance change layer 110 may be referred to as an "oxygen reservoir layer". The thickness of the resistance change layer 110 may be several to several hundred nanometers (nm), for example, several tens of nm or so.

The oxygen exchange layer 120 may exchange layers with the resistance change layer 110 and exchange oxygen ions and / or oxygen vacancy, and induce a resistance change of the memory layer M1. The oxygen exchange layer 120 may be formed of a second metal oxide of the same or different type as the first metal oxide. For example, it may include at least one of Ta oxide, Zr oxide, yttria-stabilized zirconia (YSZ), Ti oxide, Hf oxide, Mn oxide, Mg oxide, and mixtures thereof. The second metal oxide may have a stoichiometric composition or a composition close thereto. As a specific example, the Ta oxide in the second metal oxide may be a Ta ₂ O ₅ layer or have a composition close thereto. The oxygen exchange layer 120 may include oxygen ions and / or oxygen vacancies similar to the resistance change layer 110.

The oxygen mobility (or oxygen diffusion) of the oxygen exchange layer 120 may be similar to or greater than the oxygen mobility (or oxygen diffusion) of the resistance change layer 110. In the ON state where the current path is formed in the oxygen exchange layer 120, the resistance of the memory layer M1 may be determined by the resistance of the resistance change layer 110. In the OFF state with no current path, the resistance of the memory layer M1 may be determined by the resistance of the oxygen exchange layer 120.

The oxygen concentration of the oxygen exchange layer 120 may be higher than the oxygen concentration of the resistance change layer 110. When the oxygen exchange layer 120 is formed of the same metal oxide as the resistance change layer 110, the oxygen concentration of the oxygen exchange layer 120 may be higher than the oxygen concentration of the resistance change layer 110. When the oxygen exchange layer 120 is formed of the resistance change layer 110 and heterogeneous metal oxides, the oxygen concentration of the oxygen exchange layer 120 is not necessarily higher than that of the resistance change layer 110. The oxygen exchange layer 120 may have a thickness of several to tens of nm, for example, about 20 nm or less. Depending on the physical properties of the oxygen exchange layer 120, the resistance change characteristics (speed and ON / OFF ratio, etc.) of the memory device 100 may vary.

The first and second buffer layers B1 and B2 may serve to improve reliability, reproducibility, and stability of resistance change characteristics of the memory layer M1. The first and second buffer layers B1 and B2 may include a material having an interatomic bonding energy greater than that of the memory layer M1. That is, the inter-element coupling energy in the first buffer layer B1 may be greater than the inter-element (ex, Ta-O) coupling energy in the resistance change layer 110. Similarly, the element in the second buffer layer B2 may be The interbond energy may be greater than the intermetallic bond energy in the oxygen exchange layer 120. As a specific example, the first and second buffer layers B1 and B2 may include at least one of AlOx, SiOx, SiNx, ZrOx, HfOx, and mixtures thereof. The first and second buffer layers B1 and B2 may have appropriate compositions and thicknesses that serve as buffers and allow current to flow. The thickness of each of the first and second buffer layers B1 and B2 may be, for example, about 10 nm or less. If the first and second buffer layers B1 and B2 have stoichiometric compositions, their thickness may be about 5 nm or less. This is because when the first and second buffer layers B1 and B2 are excessively thick, their insulating characteristics may be increased. Therefore, as described above, it may be appropriate to form the first and second buffer layers B1 and B2 to a thickness of about 10 nm or less.

The first and second electrodes E1 and E2 may be formed of a non-noble metal such as Ti, Ta, TiN, TiW, TaN, W, Ni, a relatively inexpensive precious metal such as Ru, or an alloy of the aforementioned materials. In addition, the first and second electrodes E1 and E2 may be formed of a conductive oxide. The conductive oxide may be, for example, a ZnO-based oxide such as indium zinc oxide (IZO) or a SnO-based oxide such as indium tin oxide (ITO). Various electrode materials generally used in the semiconductor device field may be used as the first and second electrodes E1 and E2.

2 is a schematic plan view of a resistive memory device manufacturing apparatus 200 according to an embodiment of the present invention.

Referring to FIG. 2, the resistive memory device manufacturing apparatus 200 includes a load lock chamber 210, a metal electrode deposition chamber 230, and a first oxide deposition chamber 240 disposed around the moving module chamber 220. ) And a second oxide deposition chamber 250 and a plasma oxidation treatment chamber 260. A third oxide deposition chamber 270 may be further provided. The first oxide deposition chamber 240 may be used to deposit the first buffer layer (B1 of FIG. 1) and the second buffer layer (B2 of FIG. 1) of FIG. 1, and the second oxide deposition chamber 250 may be resistive. It can be used for the deposition of the change layer (110 in FIG. 1).

In the load lock chamber 210, a substrate (wafer) (102 of FIG. 1) not shown for moving to the moving module chamber 220 is introduced from the outside, or a memory device manufactured in each chamber is transferred to the moving module chamber 220. It is a space to be moved out of) and taken out. The load lock chamber 210 is maintained in a vacuum state for carrying in the substrate 102. The degree of vacuum is maintained at approximately 10 ^-6 torr. The load lock chamber 210 includes a first entrance 212 for entering and exiting the outside and a second entrance 214 for entering and exiting the moving module chamber 220. The load lock chamber 210 may be provided with a separate vacuum device to be distinguished from the moving module chamber 220.

The moving module chamber 220 has a vacuum degree of approximately 10 ^-6 torr or higher when the substrate 102 is loaded from the load lock chamber 210 or the substrate 102 is removed from the load lock chamber 210. To keep. At least one robot arm 222 not shown is disposed in the moving module chamber 220. The robot arm 222 moves the substrate 102 from the load lock chamber 210 into the moving module chamber 220 and then sequentially moves to another chamber. The mobile module chamber 220 may be provided with a separate vacuum device, such as a vacuum pump, to maintain the vacuum state. The moving module chamber 220 may be configured to form a vacuum system together with the chambers other than the plasma oxidation chamber 260 and the load lock chamber 210.

The metal electrode deposition chamber 230 may be used to deposit the first electrode E1 and the second electrode E2 of FIG. 1. The first electrode E1 and the second electrode E2 are deposited at a process pressure of 10 ⁻⁵ to 10 ⁻² torr vacuum in a chamber maintaining a base vacuum of 10 ⁻⁶ torr or less. . For this purpose, a separate vacuum device may be installed. In the metal electrode deposition chamber 230, an entrance 232 through which the substrate 102 enters and exits by the robot arm 222 is installed between the moving module chamber 220.

The first and second electrodes E1 and E2 may be formed of non-noble metals such as Ti, Ta, TiN, TiW, TaN, W, Ni, Al, or relatively inexpensive precious metals such as Ru, or alloys of the aforementioned materials. . In addition, the first and second electrodes E1 and E2 may be formed of a conductive oxide. The conductive oxide may be, for example, a ZnO-based oxide such as indium zinc oxide (IZO) or a SnO-based oxide such as indium tin oxide (ITO). Precious metals such as Pt, Ir, Pd, and Au may be used as the first and second electrodes E1 and E2. Therefore, the first and second electrodes E1 and E2 are formed of Pt, Ir, Pd, Au, Ru, Ti, Ta, TiN, TiW, TaN, W, Ni, Al, alloys thereof, and various conductive oxides. It may include at least one selected from the group consisting of). In addition, although not disclosed herein, various electrode materials generally used in the semiconductor device field may be used as the first and second electrode E1 and E2 materials.

The first oxide deposition chamber 240 may be used to deposit the buffer layers B1 and B2 of FIG. 1. The buffer layers B1 and B2 are deposited at a process pressure of 10 ⁻⁵ to 10 ⁻² torr vacuum in a chamber maintaining a base vacuum of 10 ⁻⁶ torr or less. For this purpose, a separate vacuum device may be installed. In the first oxide deposition chamber 240, an entrance 242 through which the substrate 102 enters and exits by the robot arm 222 is installed between the moving module chamber 220.

The first and second buffer layers B1 and B2 may include at least one of AlOx, SiOx, SiNx, ZrOx, HfOx, and mixtures thereof. The first and second buffer layers B1 and B2 may have a stoichiometric composition, but may not. The first and second buffer layers B1 and B2 may have appropriate compositions and thicknesses that serve as buffers and allow current to flow. The thickness of each of the first and second buffer layers B1 and B2 may be, for example, about 10 nm or less.

The second oxide deposition chamber 250 may be used to deposit the resistance change layer 110 of FIG. 1. The resistive change layer 110 is deposited at a process pressure of 10 ⁻⁵ to 10 ⁻² torr vacuum in a chamber maintaining a base vacuum of 10 ⁻⁶ torr or less. For this purpose, a separate vacuum device may be installed. The second oxide deposition chamber 250 is provided with a shutter 252 through which the substrate 102 enters and exits by the robot arm 222 between the moving module chambers 220.

The resistance change layer 110 of the memory layer M1 may be formed of a first metal oxide. For example, it may include at least one of Ta oxide, Zr oxide, yttria-stabilized zirconia (YSZ), Ti oxide, Hf oxide, Mn oxide, Mg oxide, and mixtures thereof. When the first metal oxide includes Ta oxide, the first metal oxide may be TaOx, where x is 0 <x <2.5 or 0.5 ≦ x ≦ 2.0. The resistance change layer 110 may be deposited at several to several hundred nanometers (nm), for example, at several tens of nm.

The third oxide deposition chamber 270 may be used to deposit the oxygen exchange layer 120 of FIG. 1. The oxygen exchange layer 120 is deposited at a process pressure of 10 ⁻⁵ to 10 ⁻² torr vacuum in a chamber maintaining a base vacuum of 10 ⁻⁶ torr or less. For this purpose, a separate vacuum device may be installed. The third oxide deposition chamber 270 is provided with an entrance 272 through which the substrate 102 enters and exits by the robot arm 222 between the moving module chambers 220.

The oxygen exchange layer 120 may exchange layers with the resistance change layer 110 and exchange oxygen ions and / or oxygen vacancy, and induce a resistance change of the memory layer M1. The oxygen exchange layer 120 may be formed of the same material as the resistance change layer 110, but the oxygen concentration on the surface thereof may be different from that of the resistance change layer 110. In this case, the third oxide deposition chamber 270 may not be used.

When the material of the oxygen exchange layer 120 is different from the resistance change layer 110, a third oxide deposition chamber is used for the deposition of the oxygen exchange layer 120. The oxygen exchange layer 120 may be deposited to a thickness of several to tens of nm, for example, a thickness of about 20 nm or less.

The plasma oxidation chamber 260 may be used to increase the oxygen concentration of the oxygen exchange layer 120 by plasma treating the surface of the oxygen exchange layer 120 of FIG. 1. The plasma oxidation chamber 260 is deposited at a process pressure of approximately 10 ⁻⁴ to 10 torr vacuum. For this purpose, a separate vacuum device may be installed. The plasma oxidation chamber 260 is provided with an entrance 262 through which the substrate 102 enters and exits by the robot arm 222 between the moving module chambers 220.

3 is a graph illustrating the results of experiments of durability of a memory device in which a ZrOx oxygen exchange layer is formed on a resistance change layer of TaOx. TaOx was deposited for 400 seconds and ZrOx was deposited for 30 seconds. Plasma oxidation was performed at 60 cycles. The initial ON / OFF value of the memory element and the ON / OFF value after writing and erasing 10 ⁷ cycles are shown. Oxygen supply for the oxygen exchange layer was supplied 1-5 sccm, 100 sccm flow rate in combination with the argon gas supply.

Referring to FIG. 3, it can be seen that durability deteriorates at 2 sccm (2% oxygen) or more. This shows that the durability and reliability of the memory device deteriorate when exposed to the external environment, especially oxygen, during the manufacturing process using a general deposition equipment.

4 and 5 are manufactured in a state exposed to oxygen (atmosphere) during the manufacturing process (Fig. 4), and when the manufacturing process atmosphere is manufactured in a vacuum atmosphere as in the manufacturing apparatus of the present invention (Fig. 5) It is a graph showing the durability. TaOx was used as both the resistance change layer and the oxygen exchange layer, and the oxygen exchange layer was obtained by plasma treatment of the surface of the TaOx layer. The pulse width was 1 Hz.

4 and 5, it can be seen that the durability of the memory device is deteriorated by oxygen exposure.

In the conventional manufacturing apparatus, the resistive memory device is exposed to oxygen by using separate equipment to form an electrode layer, a buffer layer, a resistance change layer, and an oxygen exchange layer. Worsens.

On the contrary, when the resistive memory is manufactured using the resistive memory manufacturing apparatus of the present invention, since the resistive memory is manufactured in a state of being blocked from oxygen (vacuum state) in-situ, it is possible to manufacture the resistive memory element having improved durability.

In addition, by manufacturing the oxide layer (buffer layer, resistance change layer, oxygen exchange layer) having a different composition in different chambers, it is possible to prevent contamination that may occur during manufacturing in one chamber.

While many details are set forth in the foregoing description, they should be construed as illustrative of embodiments rather than to limit the scope of the invention. For example, it will be apparent to those skilled in the art that the structure of the memory device may be variously modified in the embodiments of the present invention. As a specific example, it will be appreciated that at least one additional material layer may be further provided in the memory element of FIG. 1, and the memory element of FIG. 1 may be applied to various other memory elements as well as the cross-point memory element of FIG. It will be appreciated. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

Claims (6)

A load lock chamber into which a substrate is brought in from outside or carried in to the outside;
A moving module chamber having a robot arm installed to transfer the substrate from the load lock chamber; And
And a metal electrode deposition chamber, an oxide deposition chamber, and a plasma oxidation treatment chamber which surround the moving module chamber together with the load lock chamber and are separated from each other.
The oxide deposition chamber comprises at least two chambers. The method of claim 1, wherein the oxide deposition chamber,
A first chamber for buffer oxide deposition; And
Resistive memory layer manufacturing apparatus comprising; second chamber for resistive change layer deposition The method of claim 2,
And a third chamber for depositing another resistive change layer. The method of claim 1,
And a process pressure of the plasma oxidation chamber is lower than a process pressure of the metal electrode deposition chamber, the oxide deposition chamber, and the plasma oxidation chamber. The method of claim 1,
And each chamber is vacuumed by a separate vacuum device. The method of claim 1,
Resistive memory manufacturing apparatus is provided between the mobile module chamber and the other chamber is provided with an entrance to isolate them.

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