KR101015144B1 - Method for forming magnetic tunnel junction device - Google Patents

Abstract

The present invention relates to a method for manufacturing a magnetic tunnel junction device capable of preventing an increase in critical current density (J _c ) due to an anisotropic effect, and the magnetic tunnel junction of the present invention for this purpose. A device manufacturing method includes forming an insulating film on a substrate having a first electrode; Selectively etching the insulating layer to form an open region having a vertical profile of the sidewall and exposing the first electrode; And forming a magnetic tunnel junction layer in the open region and forming a second electrode on the magnetic tunnel junction layer. According to the present invention, the magnetic tunnel junction layer is embedded in the open region. By doing so, there are effects that can solve the problems caused by the anisotropic shape effect.

Magnetic Tunnel Bonding, Lift Off, Flattening, Chemical Mechanical Polishing

Description

Magnetic tunnel junction device manufacturing method {METHOD FOR FORMING MAGNETIC TUNNEL JUNCTION DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing technology of a semiconductor device. In particular, a magnetic tunnel junction device capable of preventing an increase in critical current density (J _c ) due to anisotropic shape effect is provided. device, MTJ device).

Recently, as semiconductor devices are highly integrated, magnetic random devices (MRAMs) are attracting attention as next-generation semiconductor memory devices that are advantageous for reducing cell area and have high speed and non-volatile operation. The magnetic memory device includes a transistor for performing a switching operation and a magnetic tunnel junction device (MTJ device) for storing information. In the magnetic tunnel junction device, the magnetoresistance (MR) varies depending on the magnetization direction of the two ferromagnetic films. The magnetic tunnel junction device uses a voltage change or a current change according to the magnetoresistance ratio to the magnetic tunnel junction device. It can be determined whether the stored information is a logic "1" or a logic "0".

1 is a cross-sectional view showing a magnetic tunnel junction device according to the prior art.

Referring to FIG. 1, a method of manufacturing a magnetic tunnel junction apparatus according to the related art is formed. A magnetic tunnel junction layer 15 is formed on a first electrode 10. The magnetic tunnel junction layer 15 is made of a pinning layer 11 made of an antiferromagnetic material and a ferromagnetic material on the first electrode 10 and has a magnetization direction by the pinning film 11. It consists of a pinned layer 12, a tunnel insulator 13, and a ferromagnetic material, and the magnetization direction is changed by an external stimulus such as a magnetic field or spin transfer torque (STT). The free layer 14 to be formed is a laminated film sequentially stacked.

Next, after the second electrode 16 is formed on the magnetic tunnel junction layer 15, the magnetic tunnel junction layer 15 is etched using the second electrode 16 as an etch barrier to form the first electrode. (10), the magnetic tunnel junction layer 15 and the second electrode 16 are sequentially formed to form a magnetic tunnel junction layer.

However, although the top line width and the bottom line width of the magnetic tunnel junction layer 15 are the same in the above-described conventional magnetic tunnel junction device, the trapezoidal sidewalls are inclined due to the difference in the etching selectivity between the thin films. The magnetic tunnel junction layer 15 is formed. The trapezoidal magnetic tunnel junction layer 15 having the inclined sidewall causes an anisotropic effect to increase the critical current density (J _c ) of the magnetic tunnel junction device. .

Specifically, the anisotropic shape effect is due to the inclined sidewall profile of the magnetic tunnel junction layer 15 as in the 'X' region of FIG. 1. The magnetization direction of the edges of the free layer 14 and the pinned layer 12 is vortex. ) Means having a magnetization direction. In the region where the free layer 14 and the pinned layer 12 overlap, interference occurs between the aligned magnetization directions and the borx magnetization directions formed at their edges, thereby increasing the critical current density of the magnetic tunnel junction device. Cause problems.

In addition, since the magnetic tunnel junction device has a trapezoidal shape, the pinned layer 12 and the free layer 14 are larger than the area A1 of the predetermined magnetic tunnel junction unit such that the pinned layer 12 and the free layer 14 overlap each other. The area A2 of the magnetic tunnel junction apparatus increases by an area where) does not overlap each other. This causes a problem that the critical current density for the magnetic tunnel junction device further increases.

In addition, there is a problem that plasma damage occurs on the sidewalls of the magnetic tunnel junction layer 15 during the patterning process for forming the magnetic tunnel junction layer 15.

In addition, the pinning layer 11, the pinned layer 12, and the free layer 14 constituting the magnetic tunnel junction layer 15 are made of a metal material or a metal compound, and the conductive etching by-products generated during the patterning process are etched. byproduct) has a problem of deteriorating the electrical characteristics of the magnetic tunnel junction device as it is redeposited on the sidewalls of the magnetic tunnel junction layer 15.

The present invention has been proposed to solve the above problems of the prior art, to provide a method for manufacturing a magnetic tunnel junction device which can prevent the increase in the critical current density of the magnetic tunnel junction device by anisotropic shape effect.

In addition, another object of the present invention is to provide a method for manufacturing a magnetic tunnel junction device that can prevent the area of the magnetic tunnel junction device from increasing in area than a preset magnetic tunnel junction device.

In addition, another object of the present invention is to provide a method for manufacturing a magnetic tunnel junction device capable of preventing plasma damage from occurring on the sidewall of the magnetic tunnel junction device.

In addition, another object of the present invention is to provide a method for manufacturing a magnetic tunnel junction device which can prevent the etching by-products generated during the patterning process from being redeposited on the side walls of the magnetic tunnel junction device.

According to an aspect of the present invention, there is provided a method of manufacturing a magnetic tunnel junction device, including forming an insulating film on a substrate having a first electrode; Selectively etching the insulating layer to form an open region having a vertical profile of the sidewall and exposing the first electrode; Forming a magnetic tunnel junction layer in the open region and forming a second electrode on the magnetic tunnel junction layer.

The forming of the magnetic tunnel junction layer may include forming a discontinuous magnetic tunnel junction layer on an upper surface of the sacrificial pattern formed on the insulating layer and the first electrode to form the open region, and forming the sacrificial pattern. And removing the magnetic tunnel junction layer formed on the sacrificial pattern. In this case, the sacrificial pattern may include a photoresist.

The forming of the magnetic tunnel junction layer may include forming a discontinuous magnetic tunnel junction layer on the upper surface of the insulating layer and the first electrode; The method may include forming a protective film on the entire surface of the structure including the magnetic tunnel junction layer and performing a planarization process until the top surface of the insulating film is exposed. In this case, the planarization process may be performed using chemical mechanical polishing or etch back. The protective film may be formed using an insulating film or a conductive film, and when the protective film is formed of an insulating film, the protective film may further include removing the protective film remaining after the planarization process.

The thickness of the magnetic tunnel junction layer is preferably smaller than the thickness of the insulating film.

The discontinuous magnetic tunnel junction layer may be formed by sputtering, forming a base pressure lower than at least 5 × 10 ⁻⁷ torr, and then depositing in the range of 1 × 10 ⁻³ torr to 50 × 10 ⁻³ torr. It can be formed by applying a bias power in the range of 500W ~ 1000W to the chamber under pressure.

According to the present invention based on the above-described problem solving means, by forming the magnetic tunnel junction layer inside the open area having a vertical profile of the side wall, both the top line width and the bottom line width of each thin film can be formed the same, There is an effect that can prevent an increase in the critical current density of the magnetic tunnel junction device due to the isotropic shape effect. In addition, it is possible to prevent the occurrence of regions that do not overlap between the thin films, thereby effectively preventing the increase in the critical current density of the magnetic tunnel junction device.

As described above, the present invention can prevent the critical current density of the magnetic tunnel junction device from increasing, thereby reducing the drive current density of the magnetic memory device including the magnetic tunnel junction device. As a result, power consumption of the magnetic memory device may be reduced. In addition, the degree of integration may be improved by reducing the size of transistors and wirings constituting the magnetic memory device. In addition, it is possible to improve the thermal stability of the device by reducing the heat generation amount of the magnetic memory device.

In addition, the present invention is formed by embedding the magnetic tunnel junction layer in the open region, and by removing the magnetic tunnel junction layer formed in the unnecessary area by using a lift-off or planarization process, plasma damage occurs on the sidewalls of the magnetic tunnel junction layer At the same time there is an effect that can prevent the occurrence of the conductive etching by-product at the same time.

DETAILED DESCRIPTION Hereinafter, the most preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the technical idea of the present invention. .

The present invention described below relates to a method for manufacturing a semiconductor device, and in particular, a magnetic tunnel junction device (Magnetic Tunnel) capable of preventing an increase in critical current density (J _c ) due to an anisotropic effect. It relates to a method of manufacturing a junction device (MTJ device). To this end, the present invention is a technical principle that the magnetic tunnel junction layer is formed in the open area of the side wall has a vertical profile.

2A to 2D are cross-sectional views illustrating a method of manufacturing the magnetic tunnel junction apparatus according to the first embodiment of the present invention.

As shown in FIG. 2A, a substrate 21 having a first electrode 22 is prepared. The substrate 21 may include a switching transistor (not shown) connected to the first electrode 22 to drive a magnetic tunnel junction device to be formed through a subsequent process.

The first electrode 22 may be a plug connecting a magnetic tunnel junction device and a transistor (not shown), and may be formed using a conductive material, for example, a metal material or a metal compound. Titanium (Ti), tantalum (Ta), platinum (Pt), copper (Cu), tungsten (W) or aluminum (Al) may be used as the metal material, and a titanium compound film (TiN) or tantalum nitride film may be used as the metal compound. (TaN) or tungsten silicide (WSi) or the like can be used.

Next, an insulating film 23 is formed over the entire surface of the substrate 21 including the first electrode 22. The insulating film 23 is for electrical insulation between adjacent magnetic tunnel junction devices, and any material having an insulating property can be used. For example, the insulating film 23 may be formed of any one selected from the group consisting of an oxide film, a nitride film, and an oxynitride, or a laminated film in which these layers are stacked. Oxides include silicon oxide (SiO ₂ ), Boron Phosphorus Silicate Glass (BPSG), Phosphorus Silicate Glass (PSG), Tetra Ethyle Ortho Silicate (TEOS), Un-doped Silicate Glass (USG), Spin On Glass (SOG) A plasma oxide film (High Density Plasma, HDP) or SOD (Spin On Dielectric) may be used. As the nitride film, a silicon nitride film (Si ₃ N ₄ ) may be used. As the oxynitride film, a silicon oxynitride film (SiON) may be used. In addition, the insulating film 23 may use any material having insulating properties.

The insulating film 23 can be formed to have a thickness in the range of 200 mW to 1500 mW.

Next, after the sacrificial pattern 24 is formed on the insulating film 23, the insulating film 23 is etched using the sacrificial pattern 24 as an etch barrier to expose the upper surface of the first electrode 22. The open area 25 is formed. The sacrificial pattern 24 may be formed of photoresist (PR).

The etching process for forming the open region 25 is preferably performed using a dry etch such that the sidewall of the open region 25 has a vertical profile. At this time, since the insulating film 23 has a thin thickness, for example, in the range of 200 Å to 1500 Å, the open area 25 having the vertical profile of the sidewall may be easily formed by using a known technology of manufacturing a semiconductor device.

As shown in FIG. 2B, a pinning layer 26 and a pinned layer are formed on the upper surface of the sacrificial pattern 24 and the lower surface of the first electrode 22 or the open region 25. 27, a discontinuous magnetic tunnel junction layer 30 in which a tunnel insulator 28 and a free layer 29 are sequentially stacked is formed. In this case, the magnetic tunnel junction layer 30 may be formed of a laminated film stacked in the order of the free layer 29, the tunnel insulating layer 28, the pinned layer 27, and the pinning layer 28.

Here, the discontinuous magnetic tunnel junction layer 30 has no magnetic tunnel junction layer 30 formed on the sidewalls of the sacrificial pattern 24 sidewalls and the open region 25 where the magnetic tunnel junction layer 30 is not embedded. it means. This is because when the magnetic tunnel junction layer is formed along the surfaces of the insulating film 23 and the sacrificial pattern 24, anisotropic shape effects may occur in the magnetic tunnel junction layer 30.

The pinning layer 26 serves to fix the magnetization direction of the pinned layer 27 and may be formed using a material having antiferromagnetic. For example, materials having antiferromagnetic properties include IrMn, PtMn, MnO, MnS, MnTe, MnF ₂ , FeF ₂ , FeCl ₂ , FeO, CoCl ₂ , CoO, NiCl ₂ Or NiO or the like can be used. The pinning film 26 may be formed of a single film made of any one of the above-described antiferromagnetic materials, or may be formed of a laminated film in which they are stacked.

The pinned film 27 having the magnetization direction fixed by the pinning layer 26 and the free layer 29 having the magnetization direction changed by an external stimulus such as a magnetic field or spin transfer torque (STT). ) May be formed using a material having ferromagnetic. For example, ferromagnetic materials include Fe, Co, Ni, Gd, Dy, NiFe, CoFe, MnAs, MnBi, MnSb, CrO ₂ , MnOFe ₂ O ₃ , FeOFe ₂ O ₃ , NiOFe ₂ O ₃ , CuOFe ₂ O ₃ , MgOFe ₂ O ₃ , EuO or Y ₃ Fe ₅ O ₁₂ Etc. can be used. In this case, the pinned layer 27 and the free layer 29 may be formed of a single layer made of any one of the above-described ferromagnetic materials, or may be formed of a laminated layer in which these layers are stacked. In addition, the pinned layer 27 and the free layer 29 may be formed as a laminated layer in which any one of the above-described ferromagnetic materials and the ruthenium layer Ru are stacked (eg, CdFe / Ru / CoFe).

In addition, the pinned layer 27 and the free layer 29 may include a synthetic anti-ferromagnetic layer (SAF) in which a ferromagnetic layer, an anti-ferromagnetic coupling spacer layer, and a ferromagnetic layer are sequentially stacked. layer).

The tunnel insulating layer 28 serves as a tunneling barrier between the pinned layer 27 and the free layer 29, and any material having an insulating property may be used. For example, the tunnel insulating film 28 may be formed of a magnesium oxide film (MgO).

The thickness T2 of the magnetic tunnel junction layer 30 is preferably smaller than the height of the open area 25, that is, the thickness T1 of the insulating film 23. If the thickness T2 of the magnetic tunnel junction layer 30 is larger than the thickness T1 of the insulating film 23, the second electrode and the magnetic tunnel junction to be formed on the magnetic tunnel junction layer 30 through a subsequent process. This is because there is a fear that mutual interference occurs between the layers 30, thereby lowering the electrical characteristics of the magnetic tunnel junction device. Specifically, the magnetic tunnel junction device is operated by a current (Current Perpendicular to Plane, CPP) flowing in the vertical direction to the magnetic tunnel junction layer 30 through the first electrode 22 and the second electrode, the open region ( When the free layer 29 of the magnetic tunnel junction layer 30 embedded in 25 protrudes over the insulating layer 23, the magnetic tunnel junction device may be caused by a current flowing in a horizontal direction from the side surface of the protruding free layer 29. Electrical properties may be degraded. In addition, when the tunnel insulating film 28 or the pinned film 27 protrudes over the insulating film 23 in addition to the free film 29, the electrical characteristics of the magnetic tunnel junction device become worse and thus the magnetic tunnel junction device does not operate normally. It may not.

In addition, the magnetic tunnel junction layer 30 formed in the open region 25 is preferably formed to have the same overlapping area between the thin films in order to prevent an increase in the critical current density due to the anisotropic shape effect. That is, it is preferable that the top line width and bottom line width of each thin film are formed to be the same. To this end, the magnetic tunnel junction layer 30 is preferably formed using physical vapor deposition (PVD), for example, sputtering.

Hereinafter, a method of forming a discontinuous magnetic tunnel junction layer 30 having the same top line width and bottom line width of each thin film using the sputtering method will be described in detail.

First, prior to the deposition process, a vacuum in which the base pressure in the chamber is less than 5 × 10 ⁻⁷ torr is established. This is to prevent impurities in the chamber from being mixed in the magnetic tunnel junction layer 30 in the process of depositing the magnetic tunnel junction layer 30.

Next, a bias power of 500 W to 1000 W is applied to the chamber, and the pinning film 26 and the pinned film are formed under a working pressure of 1 × 10 ⁻³ torr to 50 × 10 ⁻³ torr. (27), the tunnel insulating film 28 and the free film 29 are sequentially deposited. At this time, when the deposition pressure is greater than 1 × 10 ^-3 torr, the deposition rate of the thin film may increase, and the film quality may decrease, and it is difficult to control the thickness of the thin film. On the other hand, when the deposition pressure is less than 50 × 10 ^-3 torr, the deposition rate of the thin film is reduced, so that it takes a long time to deposit the thin film, which may lower the productivity of the magnetic tunnel junction device. The bias power applied to the chamber may vary depending on the area of the substrate 21 (eg, the diameter of the substrate). That is, it is preferable to increase the bias power applied to the chamber as the area of the substrate 21 increases.

Through the above-described process, it is possible to form the magnetic tunnel junction layer 30 having the same top line width and bottom line width of each thin film in the open area 25, that is, the overlapping area between the thin films.

Meanwhile, the method may further include forming a capping layer (not shown) on the free layer 29. The capping film prevents oxidation or corrosion of a material (ie, a metal material or a metal compound) constituting the free layer 29 due to a process error occurring in forming a magnetic tunnel junction device. It may be formed of tantalum (Ta) or tantalum nitride film (TaN).

Specifically, when the material constituting the free layer 29 is oxidized or corroded due to a process error, the magnetoresistance (MR) ratio of the magnetic tunnel junction element may decrease. As a result, the characteristics of the memory cell including the magnetic tunnel junction element may be deteriorated. Thus, the capping layer may be prevented. For reference, the magnetoresistance ratio refers to a value defined as a percentage of the resistance value in the low resistance state when the magnetic tunnel junction element is in the high resistance state and the low resistance state.

The method may further include forming a heating film (not shown) between the first electrode 22 and the magnetic tunnel junction layer 30 or on the magnetic tunnel junction layer 30. The heating film serves to reduce the critical current density of the magnetic tunnel junction device by supplying thermal energy to the magnetic tunnel junction device. The heat generating film includes an aluminum oxide film (Al ₂ O ₃ ), an undoped silicon layer, a silicon carbide layer (SiC), a silicon oxide film (SiO ₂ ), a silicon oxynitride film (SiON), and a chalcogenide film. It can be formed of any one selected from the group consisting of (chalcogenide layer) or a laminated film in which these are laminated. Here, the chalcogenide layer may be a compound containing germanium (Ge), antimony (Sb), and tellurium (Te) (ie, a compound layer containing germanium, stibium and tellurium), that is, a GST layer.

As shown in FIG. 2C, the sacrificial pattern 24 is removed using a lift off method and the magnetic tunnel junction layer 30 formed on the sacrificial pattern 24 is removed. Through this, the magnetic tunnel junction layer 30 formed in the unnecessary area except for the magnetic tunnel junction layer 30 formed in the open area 25 may be neatly removed.

The sacrificial pattern 24 may be removed using a dry etch or a wet etch. For example, when the sacrificial pattern 24 is formed of a photoresist, a gas plasma containing oxygen may be used as a dry etching method. As the gas containing oxygen, O ₂ , H ₂ O, or NO may be used. As the wet etching method, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) may be used. Here, since sulfuric acid may damage the free layer 29 made of a metal material, it is preferable to form an protective layer on the free layer 29 and then perform an etching process.

As shown in FIG. 2D, the second electrode 31 is formed on the magnetic tunnel junction layer 30. The second electrode 31 may be formed using a conductive material, for example, a metal material or a metal compound. Titanium (Ti), tantalum (Ta), platinum (Pt), copper (Cu), tungsten (W) or aluminum (Al) may be used as the metal material, and a titanium compound film (TiN) or tantalum nitride film may be used as the metal compound. (TaN) or tungsten silicide (WSi) or the like can be used.

Through the above-described process, it is possible to complete the magnetic tunnel junction apparatus according to the first embodiment of the present invention.

As described above, the present invention embeds the magnetic tunnel junction layer 30 inside the open area 25 having the vertical profile of the sidewall, and forms the same top line width and bottom line width of each thin film, thereby reducing the anisotropic shape effect. Due to the increase in the critical current density of the magnetic tunnel junction device can be prevented. In addition, it is possible to prevent the occurrence of regions that do not overlap between the thin films, thereby more effectively preventing the increase in the critical current density of the magnetic tunnel junction device.

As described above, the present invention can prevent the critical current density of the magnetic tunnel junction device from increasing, thereby reducing the drive current density of the magnetic memory device including the magnetic tunnel junction device. As a result, power consumption of the magnetic memory device may be reduced. In addition, the degree of integration may be improved by reducing the size of transistors and wirings constituting the magnetic memory device. In addition, it is possible to improve the thermal stability of the device by reducing the heat generation amount of the magnetic memory device.

In addition, the present invention is formed by embedding the magnetic tunnel junction layer 30 in the open region 25, and by removing the magnetic tunnel junction layer 30 formed in the unnecessary area by using the lift-off method, the magnetic tunnel junction layer (30) It is possible to prevent the occurrence of plasma damage on the sidewall and to prevent the generation of the conductive etch byproduct at the same time.

3A to 3D are cross-sectional views illustrating a method of manufacturing a magnetic tunnel junction apparatus according to a second embodiment of the present invention. For convenience of description, detailed description of parts similar to those of the first embodiment of the present invention will be omitted.

As shown in FIG. 3A, a substrate 41 having a first electrode 42 is prepared. The substrate 41 may include a switching transistor (not shown) connected to the first electrode 42 to drive a magnetic tunnel junction device to be formed through a subsequent process.

The first electrode 42 may be a plug connecting a magnetic tunnel junction device and a transistor (not shown), and may be formed using a conductive material, for example, a metal material or a metal compound. Titanium (Ti), tantalum (Ta), platinum (Pt), copper (Cu), tungsten (W) or aluminum (Al) may be used as the metal material, and a titanium compound film (TiN) or tantalum nitride film may be used as the metal compound. (TaN) or tungsten silicide (WSi) or the like can be used.

Next, an insulating film 43 is formed over the entire surface of the substrate 41 including the first electrode 42. The insulating layer 43 is for electrical insulation between adjacent magnetic tunnel junction devices, and any material having insulating characteristics may be used. For example, the insulating film 43 can be formed of any one selected from the group consisting of an oxide film, a nitride film, and an oxynitride film or a laminated film in which these layers are stacked.

The insulating film 43 can be formed to have a thickness in the range of 200 kV to 1500 kV.

Next, after the photoresist pattern 44 is formed on the insulation layer 43, the insulation layer 43 is etched using the photoresist pattern 44 as an etch barrier to expose the upper surface of the first electrode 42. The open area 45 is formed.

Here, the etching process for forming the open region 45 is preferably performed using a dry etching method so that the side wall of the open region 45 has a vertical profile. At this time, since the insulating layer 43 has a thin thickness, for example, in the range of 200 Å to 1500 Å, the open region 45 having the vertical profile of the sidewall may be easily formed by using a known semiconductor device manufacturing technique.

Next, the photosensitive film pattern 44 is removed. The photoresist pattern 44 may be removed using a dry etching method or a wet etching method. As a dry etching method, a gas plasma containing oxygen, a so-called ashing process, may be used. As the gas containing oxygen, O ₂ , H ₂ O, or NO may be used. As the wet etching method, a mixed solution of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ ) may be used. Here, since sulfuric acid may damage the surface of the first electrode 42 made of a metal material, it is preferable to perform an etching process after forming a protective film on the first electrode 42.

As shown in FIG. 3B, a pinning layer 46, a pinned layer 47, and a tunnel insulator 48 are formed on the upper surfaces of the first electrode 42 and the insulating layer 43. And a discontinuous magnetic tunnel junction layer 50 in which free layers 49 are sequentially stacked. In this case, the magnetic tunnel junction layer 50 may be formed of a laminated film stacked in the order of the free film 49, the tunnel insulating film 48, the pinned film 47, and the pinning film 48. Since the role and constituting material of each thin film have been described in detail in the first embodiment of the present invention, detailed descriptions thereof will be omitted here (see FIG. 2B).

The thickness T2 of the magnetic tunnel junction layer 50 is preferably smaller than the height of the open region 45, that is, the thickness T1 of the insulating film 43. If the thickness T2 of the magnetic tunnel junction layer 50 is larger than the thickness T1 of the insulating layer 43, the second electrode and the magnetic tunnel junction to be formed on the magnetic tunnel junction layer 50 through a subsequent process. This is because mutual interference between the layers 50 may occur, which may lower the electrical characteristics of the magnetic tunnel junction device. Specifically, the magnetic tunnel junction device is operated by a current (Current Perpendicular to Plane, CPP) flowing in the vertical direction to the magnetic tunnel junction layer 50 through the first electrode 42 and the second electrode, the open region ( When the free layer 49 of the magnetic tunnel junction layer 50 embedded in 45 protrudes over the insulating layer 43, the magnetic tunnel junction device may be caused by a current flowing in a horizontal direction from the side surface of the protruding free layer 49. Electrical properties may be degraded. In addition, when the tunnel insulating film 48 or the pinned film 47 protrudes over the insulating film 43 together with the free film 49, the electrical characteristics of the magnetic tunnel junction device are further deteriorated and the magnetic tunnel junction device operates normally. You may not.

In addition, the magnetic tunnel junction layer 50 formed in the open region 45 is preferably formed to have the same overlapping area between the thin films in order to prevent an increase in the critical current density due to the anisotropic shape effect. That is, it is preferable to form so that the top line width and bottom line width of each thin film may be the same. To this end, the magnetic tunnel junction layer 50 is preferably formed using physical vapor deposition (PVD), for example, sputtering.

Since the method of forming the discontinuous magnetic tunnel junction layer 50 having the same top line width and bottom line width of each thin film using the sputtering method has been described in detail in the first embodiment of the present invention, a detailed description thereof will be omitted herein. (See FIG. 2B).

Next, a protective film 51 is formed along the surface of the resultant product including the magnetic tunnel junction layer 50. The passivation layer 51 serves to protect the magnetic tunnel junction layer 50 embedded in the open region 50 during the subsequent planarization process for removing the magnetic tunnel junction layer 50 formed in the unnecessary region. Therefore, the protective film 51 is preferably formed so as to completely fill the empty space of the open area 45.

The protective film 51 may be formed of any one selected from the group consisting of an oxide film, a nitride film, an oxynitride film, and an amorphous carbon film. In addition, the protective film 51 may be any material having an insulating property.

In addition, the protective film 51 may be formed using a conductive material. As the conductive material, polysilicon (poly Si), copper (Cu), tantalum (Ta), titanium (Ti), tungsten (W), aluminum (Al), tungsten silicide (WSi), or tungsten nitride film (WN) may be used. Can be.

Meanwhile, the method may further include forming a capping layer (not shown) on the free layer 49. The method may further include forming a heating film (not shown) between the first electrode 42 and the magnetic tunnel junction layer 5 or on the free layer 49 (see FIG. 2B).

As shown in FIG. 3C, the planarization process is performed until the upper surface of the insulating film 43 is exposed to remove the magnetic tunnel junction layer 50 formed on the insulating film 43. Through this, the magnetic tunnel junction layer 50 formed in the unnecessary region except for the magnetic tunnel junction layer 50 formed in the open region 45 may be neatly removed. The magnetic tunnel junction layer 50 embedded in the open region 45 may prevent the damage between the planarization processes due to the passivation layer 51.

The planarization process can be carried out using chemical mechanical polishing (CMP) or etchback. In this case, it is preferable to use a chemical mechanical polishing method in order to minimize the damage of the etch by product and the upper surface of the insulating film 43 generated during the planarization process.

As shown in FIG. 3D, the remaining protective film 51 is removed. In this case, when the protective film 51 is formed of a material having an insulating property, the remaining protective film 51 must be removed. On the other hand, when the protective film 51 is formed as a conductive film, the subsequent process may be performed without removing the remaining protective film 51.

Next, the second electrode 31 is formed on the magnetic tunnel junction layer 50. The second electrode 31 may be formed using a conductive material, for example, a metal material or a metal compound. Titanium (Ti), tantalum (Ta), platinum (Pt), copper (Cu), tungsten (W) or aluminum (Al) may be used as the metal material, and a titanium compound film (TiN) or tantalum nitride film may be used as the metal compound. (TaN) or tungsten silicide (WSi) or the like can be used.

Through the above-described process, the magnetic tunnel junction device according to the second embodiment of the present invention can be completed.

As described above, in the present invention, the magnetic tunnel junction layer 50 is embedded in the open region 45, and the top line width and the bottom line width of each thin film are formed to be the same, so that the magnetic tunnel junction device is caused by the anisotropic shape effect. It is possible to prevent the increase of the critical current density. In addition, it is possible to prevent the occurrence of regions that do not overlap between the thin films, thereby more effectively preventing the increase in the critical current density of the magnetic tunnel junction device.

As such, the present invention can prevent the critical current density of the magnetic tunnel junction device from increasing, thereby reducing the drive current density of the magnetic memory device including the magnetic tunnel junction device. As a result, power consumption of the magnetic memory device may be reduced. In addition, the degree of integration may be improved by reducing the size of transistors and wirings constituting the magnetic memory device. In addition, it is possible to improve the thermal stability of the device by reducing the heat generation amount of the magnetic memory device.

In addition, the present invention is formed by embedding the magnetic tunnel junction layer 50 in the open region 45, and by removing the magnetic tunnel junction layer 50 formed in unnecessary areas using a planarization process, for example, chemical mechanical polishing. In addition, the plasma damage may be prevented from occurring on the sidewalls of the magnetic tunnel junction layer 50, and at the same time, the conductive etching byproduct may be prevented from occurring.

Although the technical spirit of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will appreciate that various embodiments within the scope of the technical idea of the present invention are possible.

1 is a cross-sectional view showing a magnetic tunnel junction device according to the prior art.

2A to 2D are cross-sectional views illustrating a method of manufacturing the magnetic tunnel junction apparatus according to the first embodiment of the present invention.

3A to 3D are cross-sectional views illustrating a method of manufacturing a magnetic tunnel junction apparatus according to a second embodiment of the present invention.

* Description of symbols on the main parts of the drawings *

21 and 41: substrate 22 and 42: first electrode

23, 43: insulating film 24: sacrificial pattern

25, 45: open area 26, 46: pinning film

27, 47: pinned film 28, 48: tunnel insulation film

29, 49: free layer 30, 50: magnetic tunnel junction layer

31, 52: second electrode 51: protective film

Claims (13)

Forming an insulating film on a substrate having a first electrode; Selectively etching the insulating layer to form an open region having a vertical profile of the sidewall and exposing the first electrode; Forming a discontinuous magnetic tunnel junction layer on the insulating film and on the first electrode; Removing the magnetic tunnel junction layer formed on the insulating layer to leave the magnetic tunnel junction layer only in the open region; And Forming a second electrode on the magnetic tunnel junction layer Magnetic tunnel junction device manufacturing method comprising a. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, Forming a discontinuous magnetic tunnel junction layer on an upper surface of the sacrificial pattern formed on the insulating layer and on the first electrode to form the open region, Remaining the magnetic tunnel junction layer only in the open area, Removing the sacrificial pattern and simultaneously removing the magnetic tunnel junction layer formed on the sacrificial pattern. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, Forming a discontinuous magnetic tunnel junction layer on the insulating film upper surface and the first electrode; And Forming a protective film on the front surface of the structure including the magnetic tunnel junction layer; Remaining the magnetic tunnel junction layer only in the open area, And a planarization process until the top surface of the insulating film is exposed. The method of claim 1, And a thickness of the magnetic tunnel junction layer is smaller than a thickness of the insulating layer. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, A method for manufacturing a magnetic tunnel junction device using the sputtering method. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, A method of manufacturing a magnetic tunnel junction device at a base pressure of at least 5 × 10 ⁻⁷ torr. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, A method for manufacturing a magnetic tunnel junction device under a deposition pressure in the range of 1 × 10 ⁻³ torr to 50 × 10 ⁻³ torr. The method of claim 1, Forming the discontinuous magnetic tunnel junction layer, A method of manufacturing a magnetic tunnel junction device by applying a bias power in a range of 500W to 1000W to a chamber. The method of claim 2, And the sacrificial pattern comprises a photoresist. The method of claim 3, The planarization process is a method of manufacturing a magnetic tunnel junction device using a chemical mechanical polishing method or an etch back. The method of claim 3, The protective film is a magnetic tunnel junction device manufacturing method using an insulating film or a conductive film. The method of claim 11, And removing the protective film remaining after the planarization process, when the protective film is formed of an insulating film. The method of claim 1, The magnetic tunnel junction layer includes a pinning layer, a pinned layer, a tunnel insulation layer and a free layer.

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