KR101740040B1 - A pattern structure, method for forming the same and method for manufacturing a semiconductor device using the same - Google Patents

Abstract

A method of forming a pattern structure, a pattern structure, and a method of manufacturing a semiconductor device using the same, wherein a magnetic material layer including at least one magnetic material is formed on a substrate. A hard mask pattern including a metal is formed on the magnetic material film. A magnetic pattern is formed by plasma-reactive-etching the magnetic material film using an etching gas obtained by mixing a fluorine-containing gas and an ammonia gas and an oxygen gas for preventing consumption of a hard mask. According to the above method, it is possible to form a pattern structure having high reliability and good sidewall profile.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern structure, a method of forming a pattern structure, and a method of manufacturing a semiconductor device using the same,

The present invention relates to a pattern structure, a method of forming the same, and a method of manufacturing a semiconductor device using the pattern structure. More particularly, the present invention relates to a pattern structure including a transition metal having a magnetic property or a phase change material, a method of forming the same, and a method of manufacturing a memory device using the same.

Magnetic memory devices and phase change memory devices are capable of high-speed writing and high-speed reading operations and are floating as next generation memories because they have non-volatility.

The magnetic memory device includes magnetic metal materials not used in conventional semiconductor memory devices. Also, the phase change memory element includes a phase transition metal material having a two-component system or more. Each of the metal materials included in the memory devices is patterned through a reactive etching process or a physical etching process, but the etching rate is very low. In addition, it is difficult to form a hard mask pattern having a high selectivity suitable for performing the etching process. Therefore, the hard mask pattern is excessively removed during etching, and problems such as failure to properly pattern the underlying pattern structures frequently occur. Therefore, in the fabrication of a next-generation memory device, an etching process capable of forming a pattern structure having a vertical sidewall profile while sufficiently leaving the hard mask pattern is required.

It is an object of the present invention to provide a pattern structure comprising a magnetic material.

It is another object of the present invention to provide a method of forming a pattern structure.

Another object of the present invention is to provide a method of forming a pattern structure including a magnetic substance or a phase change material composed of at least three element alloys.

Another object of the present invention is to provide a method of manufacturing a magnetic memory device having excellent operating characteristics and reducing process defects.

According to an aspect of the present invention, a pattern structure includes a magnetic pattern formed on a substrate and including at least one magnetic material. A hard mask pattern including a metal is provided on the magnetic pattern. The surface of the hard mask pattern is provided with a metal oxide.

In one embodiment of the present invention, the metal contained in the metal oxide may be the same as the metal contained in the hard mask pattern.

According to another aspect of the present invention, there is provided a method of forming a pattern structure, comprising: forming a magnetic material layer including at least one magnetic material on a substrate; A hard mask pattern including a metal is formed on the magnetic material film. A magnetic pattern is formed by plasma-reactive-etching the magnetic material film using an etching gas obtained by mixing a fluorine-containing gas and an ammonia gas and an oxygen gas for preventing consumption of a hard mask.

In one embodiment of the present invention, the magnetic material layer may include an alloy material of at least two elements selected from the group consisting of Co, Fe, Tb, Ru, Pd, Pt, and Mn.

In one embodiment of the present invention, the fluorine-containing gas may include at least one selected from the group consisting of SF ₆ , NF ₃ , SiF ₄ and CF ₄ .

In one embodiment of the present invention, the flow rate of ammonia contained in the etching gas may be equal to or greater than the flow rate of the fluorine-containing gas.

The flow rate ratio of the fluorine-containing gas and the ammonia gas may be 1: 1 to 50. The oxygen gas may have a flow rate smaller than 10% of the ammonia gas flow rate.

In one embodiment of the present invention, the oxygen gas may be introduced at a flow rate of 10 to 100 sccm.

In one embodiment of the present invention, the hard mask pattern may include at least one material selected from the group consisting of titanium, titanium nitride, tantalum, tantalum nitride, tungsten, and tungsten nitride.

In one embodiment of the present invention, the plasma etching may further include a subsequent processing step after the plasma reactive etching, and the oxygen gas may be introduced in the subsequent processing step.

In one embodiment of the present invention, in the etching process, an oxide may be generated on the surface of the hard mask pattern.

In one embodiment of the present invention, the magnetic pattern may be formed to have a line width of 30 to 100 nm.

In one embodiment of the present invention, the step of etching the magnetic material film may be performed at a temperature of 10 to 300 DEG C and a pressure of 1 to 10 mTorr.

In one embodiment of the present invention, the oxygen gas may be introduced into a flow rate range such that the surface of the magnetic material film is not oxidized while oxidizing the surface of the hard mask pattern.

According to another aspect of the present invention, there is provided a method of manufacturing a magnetic memory device, comprising: forming a cell selection device on a substrate; And an interlayer insulating film for covering the cell selection device is formed on the substrate. A lower magnetic film, a tunnel barrier film, and an upper magnetic film are formed on the interlayer insulating film. A hard mask pattern is formed on the upper magnetic film. The upper magnetic film, the tunnel barrier film, and the lower magnetic film are sequentially subjected to plasma reactive etching using an etching gas containing a fluorine-containing gas and an ammonia gas and an oxygen gas for preventing hard mask consumption, thereby forming a magnetic tunnel junction structure .

In one embodiment of the present invention, the flow rate of ammonia contained in the etching gas may be equal to or greater than the flow rate of the fluorine-containing gas. The oxygen gas may have a flow rate smaller than 10% of the ammonia gas flow rate.

In one embodiment of the present invention, the oxygen gas may be introduced at a flow rate of 10 to 100 sccm.

According to another aspect of the present invention, there is provided a method of forming a pattern structure, the method comprising: forming a film to be etched on a substrate, the film including any one of a magnetic material and a phase change material comprising at least three element alloys; do. A hard mask pattern including a metal is formed on the etch target film. A pattern structure is formed by plasma-reactive-etching the etch target film using an etching gas containing at least ammonia (NH ₃ ) gas and an oxygen gas having a flow rate smaller than that of the ammonia gas.

In one embodiment of the present invention, the etching target film containing the phase change material may include an alloy material of at least three elements selected from the group consisting of Ge, Sb, Te, In, and Bi.

In one embodiment of the present invention, the etching gas may further include at least one selected from the group consisting of Ar, CF ₄ , CO, Hbr and SF ₆ .

According to the present invention, it is possible to easily form a pattern structure that includes a magnetic material, does not adhere to the side wall, and has a small consumption of the hard mask pattern. In addition, through the method of forming the pattern structure, a magnetic memory device including a magnetic pattern having a narrow pitch, a good vertical profile, and a reduced consumption of the hard mask pattern by etching can be manufactured.

1 is a cross-sectional view of a magnetic pattern according to a first embodiment of the present invention.
FIGS. 2 to 4 are cross-sectional views showing the magnetic pattern forming method shown in FIG.
5 is a timing chart showing influx of a reaction gas when the magnetic material film is etched by the method of the first embodiment.
6 to 10 are cross-sectional views illustrating a method of manufacturing a magnetic memory device according to an embodiment of the present invention.
11 to 13 are cross-sectional views illustrating a method of manufacturing a magnetic memory device according to a second embodiment of the present invention.
14 is a timing chart showing influx of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 3 of the present invention.
FIG. 15 is a timing chart showing influent of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 4 of the present invention. FIG.
16 is a timing chart showing influent of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 5 of the present invention.
17 is a cross-sectional view showing a sample 1 of an MTJ structure formed using the etching method of Example 1 of the present invention.
18 is a cross-sectional view showing a comparative sample 1 of an MJT structure for comparison with the embodiments of the present invention.
19 is a graph showing a resistance-to-resistance ratio measured in the sample 1;
20 is a graph showing a resistance-to-resistance ratio measured in Comparative Sample 1. FIG.
21 shows the etched thickness of the hard mask pattern according to the oxygen inflow in the etching process.
22 to 24 are sectional views showing a method for forming a phase change pattern according to a sixth embodiment of the present invention.
25 to 28 are cross-sectional views illustrating a method of manufacturing a phase-change memory device according to an embodiment of the present invention.
FIGS. 29 to 31 are cross-sectional views illustrating a method for manufacturing a phase change memory device according to a seventh embodiment of the present invention.
32 is a block diagram illustrating an electronic system including memory elements of embodiments of the present invention.
33 is a block diagram showing a memory card including semiconductor elements according to embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings of the present invention, the dimensions of the structures are enlarged to illustrate the present invention in order to clarify the present invention.

In the present invention, the terms first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In the present invention, it is to be understood that each layer (film), region, electrode, pattern or structure may be formed on, over, or under the object, substrate, layer, Means that each layer (film), region, electrode, pattern or structure is directly formed or positioned below a substrate, each layer (film), region, or pattern, , Other regions, other electrodes, other patterns, or other structures may additionally be formed on the object or substrate.

For the embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be practiced in various forms, But should not be construed as limited to the embodiments set forth in the claims.

That is, the present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the following description. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Example 1

1 is a cross-sectional view of a magnetic pattern according to a first embodiment of the present invention.

Referring to FIG. 1, a magnetic pattern 14 comprising at least one magnetic material is provided on a substrate 10. The magnetic pattern 14 may have a line width of 30 to 100 nm. The magnetic pattern 14 has a structure in which a lower magnetic pattern 14a, a tunnel barrier pattern 14b, and an upper magnetic pattern 14c are laminated.

Specifically, the lower magnetic pattern 14a may include at least one of at least two elements selected from the group consisting of Co, Fe, Tb, Ru, Pd, Pt, Mn and Ir. Although the lower magnetic pattern 14a is shown as a single film, it is more preferable that the lower magnetic pattern 14a has a laminated shape of a plurality of materials.

The tunnel barrier pattern 14b may include a metal oxide having an insulating property. For example, the tunnel barrier pattern 14b may include magnesium oxide (MgO), aluminum oxide (AlO _x ), and the like.

The upper magnetic pattern 14c may include alloy materials of at least two elements among Co, Fe, Tb, Ru, Pd, Pt, Mn and Ni. For example, the upper magnetic pattern 14c may be CoFeB, CoFe, or NiFe.

In the present embodiment, the lower magnetic pattern 14a is used as a fixed fixed film pattern having a fixed magnetization direction, and the upper magnetic pattern 14c is used as a free film pattern capable of magnetization inversion. However, the materials of the upper and lower magnetic patterns 14a and 14c are rearranged so that the lower magnetic pattern 14a is used as a free film pattern capable of magnetization inversion and the upper magnetic pattern 14c is fixed It can also be used as a film pattern.

On the magnetic pattern 14, a hard mask pattern 16 including a metal is provided. Examples of the material used as the hard mask pattern 16 include titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, and the like. They may be used alone or may have two or more laminated shapes.

A metal oxide 18 is formed on the surface of the hard mask pattern 16. The metal contained in the metal oxide 18 is the same as the metal contained in the hard mask pattern 16. [ The metal oxide 18 is formed by oxidizing the surface of the hard mask pattern 16. The metal oxide 18 has a thickness of about 100 angstroms or less.

FIGS. 2 to 4 are cross-sectional views showing the magnetic pattern forming method shown in FIG.

Referring to FIG. 2, a magnetic material layer 12 made of at least two element alloy materials and containing a magnetic material is formed on a substrate 10. The magnetic material layer 12 may include an alloy material of at least two elements among Co, Fe, Tb, Ru, Pd, Pt, and Mn.

In the present embodiment, the magnetic material film 12 is described as having a laminated structure for forming a magnetic tunnel junction structure. That is, the magnetic material layer 12 is formed by laminating the lower magnetic layer 12a, the tunnel barrier layer 12b, and the upper magnetic layer 12c.

Specifically, the lower magnetic layer 12a may be formed by depositing at least one of Co, Fe, Tb, Ru, Pd, Pt, Mn and Ir. The magnetization direction of the lower magnetic layer 12a is fixed in one direction. Although the lower magnetic layer 12a is shown as a single layer, it is more preferable that the lower magnetic layer 12a has a laminated structure of a plurality of materials.

The tunnel barrier film 12b may be formed of a metal oxide having an insulating property. For example, the tunnel barrier film 12b may be formed of magnesium oxide (MgO), aluminum oxide (AlO _x ), or the like.

The upper magnetic layer 12c may be formed by depositing alloy materials of at least two elements among Co, Fe, Tb, Ru, Pd, Pt, Mn, and Ni. The magnetization direction of the upper magnetic film can be magnetized and reversed without being fixed in one direction. For example, the upper magnetic layer 12c may be formed of CoFeB, CoFe, or NiFe.

In the present embodiment, the lower magnetic layer 12a is used as a fixed layer having a fixed magnetization direction, and the upper magnetic layer 12c is a free layer capable of magnetization inversion. However, as another example, the lower magnetic layer 12a may be formed of a free layer capable of magnetization inversion, and the upper magnetic layer 12c may be formed of a fixed layer having a fixed magnetization direction.

Referring to FIG. 3, a hard mask film (not shown) is formed on the magnetic material film 12. The hard mask film may comprise a metal. The hard mask film may be formed of a metal or a metal nitride. Examples of materials usable as the hard mask film include titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, and the like. They may be used alone or may have two or more laminated shapes. The hard mask pattern 16 is formed by patterning the hard mask film. The hard mask pattern 16 may have a line width of 30 to 100 nm.

Referring to FIG. 4, the magnetic material layer is plasma-reactive-etched using the hard mask pattern 16 as an etch mask.

For the etching, an etching gas containing a fluorine-containing gas and ammonia (NH ₃ ) gas and an oxygen gas for suppressing the consumption of the hard mask pattern 16 are used as reaction gases. The magnetic pattern 14 including the lower magnetic film pattern 14a, the tunnel barrier film pattern 14b, and the upper magnetic film pattern 14c is formed by the etching.

5 is a timing chart showing influx of a reaction gas when the magnetic material film is etched by the method of the first embodiment.

Examples of the fluorine-containing gas include SF ₆ , NF ₃ , SiF ₄ , CF ₄ , and the like. The fluorine-containing gas may be used alone or in combination of two or more. The fluorine-containing gas serves not only to etch the magnetic material but also to prevent the metallic polymer from adhering to the side wall of the magnetic pattern 14 formed by etching. In order to enhance the effect of suppressing the metallic polymer on the side wall of the magnetic pattern 14, SF ₆ is most preferably used as the fluorine-containing gas. In the following, SF ₆ is used as the fluorine-containing gas.

The ammonia gas reacts with the metal contained in the magnetic material to produce metal ammonium, and the generated metal ammonium is volatilized to thereby etch the magnetic material film. Therefore, by using the ammonia gas, the magnetic material films listed above can be rapidly etched.

The fluorine-containing gas reacts with the metal of the magnetic material to generate metal fluoride, and the generated metal fluoride is volatilized to thereby etch the magnetic material film. For example, the SF ₆ can rapidly etch a specific metal such as platinum (Pt). The sulfur (S) contained in the SF ₆ is combined with the nitrogen contained in the ammonia gas and is volatilized, so that the polymer produced by the nitrogen can be removed. In addition, SF ₆ may remove conductive metal polymers that are attached to the sidewalls again after the magnetic material films are etched by an F group (F-).

However, the fluorine-containing gas rapidly etches the hard mask pattern as well as the underlying magnetic material film. Therefore, increasing the content of the fluorine-containing gas is undesirable because the hard mask pattern 16 is excessively consumed during etching. When the hard mask pattern 16 is consumed, it is difficult for the lower magnetic material film to be patterned in a normal shape. Particularly, even if the fluorine-containing gas is reduced, defective node separation occurs between adjacent magnetic patterns when a magnetic pattern having a narrow line width of 30 to 100 nm is formed due to the consumption of the hard mask pattern 16. Therefore, it is not easy to form a magnetic pattern having a narrow line width of 30 to 100 nm by a general method.

Therefore, as shown in FIG. 5, it is preferable that the main etch gas for etching the magnetic material film 12 is ammonia gas. Therefore, in the etching process, the flow rate of the ammonia gas is preferably equal to or more than that of the fluorine-containing gas. Specifically, the flow rate ratio of SF ₆ and ammonia is preferably 1: 1 to 50.

On the other hand, when the etching process is carried out using only the ammonia gas without using the fluorine-containing gas, the polymer is excessively generated on the side wall of the magnetic pattern 14. Therefore, the fluorine-containing gas must be introduced together so that the side wall polymer of the magnetic pattern 14 can be removed.

In order to suppress the consumption of the hard mask pattern 16, which is generated when the etching process is performed using the fluorine-containing gas and the ammonia gas, oxygen gas is introduced together with the fluorine-containing gas and the ammonia gas during the etching process. The oxygen gas reacts with the surface of the hard mask pattern 16 to form a metal oxide 18 on the surface of the hard mask pattern 16. The metal oxide 18 formed on the surface of the hard mask pattern 16 has a low etching rate due to the fluorine-containing gas as compared with the hard mask pattern 16. Therefore, even if the fluorine-containing gas used as the etching gas is introduced, the hard mask pattern 16 is hardly consumed.

However, when the oxygen gas flows in a large amount, there arises a problem that the surface of the hard mask pattern 16 as well as the surface of the magnetic pattern 14 are oxidized. Therefore, it is preferable that the oxygen gas is introduced into the flow rate range such that the surface of the magnetic pattern 14 is not oxidized while oxidizing the surface of the hard mask pattern 16.

If the oxygen gas flows in at least 10% of the ammonia gas flow rate, it can be oxidized to the magnetic pattern 14 by the oxygen gas, and the etching of the magnetic pattern 14 can be disturbed by the oxygen gas, not. Therefore, it is preferable that the oxygen gas is introduced at a flow rate smaller than 10% of the flow rate of the ammonia gas. Also, it is preferable that the oxygen gas is introduced at a flow rate of 10 to 100 sccm. When the oxygen gas is introduced as described above, the metal oxide 18 may be generated only on the surface of the hard mask pattern 16 having a relatively high reactivity to oxygen. The metal oxide 18 may be formed to have a thickness of 100 Å or less.

As shown in FIG. 5, the oxygen gas preferably flows continuously in the step of performing the etching process. However, as another example, the oxygen gas may be introduced for some time in the step of performing the etching process.

On the other hand, when performing the etching process, an additional inert gas may be further introduced. The inert gas includes argon. The inert gas may physically etch the magnetic material layer 12, control the pressure in the etching chamber, activate the plasma, or the like. However, the inert gas may be selectively used, and in the case of the present embodiment, the magnetic material layer 12 can be effectively etched even when the inert gas is not included.

The etching conditions suitable for etching the magnetic material film 12 are as follows. The etching process may be performed at a temperature of 10 to 300 DEG C and a pressure of 1 to 10 mTorr. Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied during the etching process.

As described above, according to the method of the present embodiment, when the magnetic material is etched, the generation of the conductive polymer can be suppressed by introducing the etching gas and the polymer suppressing gas.

On the other hand, since the chlorine-based gas is not used for etching the magnetic material layer 12, the corrosion problem of the magnetic material layer can be reduced. Since the carbon-based gas is not used as the etching gas, the formation of the metal carbonyl can be suppressed. In addition, since the material is not etched by the physical method, the problem of re-deposition of the magnetic material on the side wall of the pattern structure can be suppressed.

In addition, oxygen can be prevented from flowing into the hard mask pattern 16 during the etching process. When the hard mask pattern 16 is consumed, the sidewall profile of the magnetic pattern may be deteriorated or the pattern may be collapsed due to attack of the pattern. Particularly, when a pattern with a narrow line width is formed, defects that do not allow node separation between neighboring magnetic patterns 14 are generated. In addition, since the magnetic patterns 14 are not formed with a uniform line width and height, problems such as resistance scattering may occur. However, as described above, when the method of this embodiment is performed, it is possible to suppress the hard mask pattern from being consumed, and the above-mentioned problems are reduced. In addition, the thickness of the magnetic pattern 14 remaining under the hard mask pattern 16 can be thicker.

Thus, according to this embodiment, an optimized magnetic pattern having a magnetic tunnel junction structure can be formed.

Manufacture of magnetic memory devices

6 to 10 are cross-sectional views illustrating a method of manufacturing a magnetic memory device according to an embodiment of the present invention.

The magnetic memory device of this embodiment is a Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM). In this embodiment, the etching method described with reference to FIGS. 3 and 4 is used at the same time in forming the magnetic pattern in the element.

Referring to FIG. 6, a device isolation pattern (not shown) is formed in the semiconductor substrate 100 to separate an active region and an element isolation region. A MOS transistor for cell selection is formed in the semiconductor substrate 100. A gate oxide film 102 and a gate electrode film are formed on the semiconductor substrate 100 to form the MOS transistor. Thereafter, the gate electrode film is patterned to form the gate electrode 104. Next, impurities are implanted under the surface of the semiconductor substrate on both sides of the gate electrode 104 to form the impurity region 106. [ The gate electrode 104 may be provided as a word line and may have a shape extending in a first direction. Although not shown, gate spacers may be formed on both sides of the gate electrode 104.

A first interlayer insulating film 108 is formed on the semiconductor substrate 100 to cover the MOS transistor. The first contact plugs 110 which penetrate the first interlayer insulating film 108 and make contact with the impurity regions 106 are formed. Also, a conductive pattern 112 electrically connected to the first contact plugs 110 is formed on the first interlayer insulating film 108.

A second interlayer insulating film 114 is formed on the first interlayer insulating film 108 to cover the conductive pattern 112. A part of the second interlayer insulating film 114 is removed through a photolithography process to form an opening exposing the upper surface of the conductive pattern 112. [ The opening has a shape of a contact hole. A bottom electrode contact (BEC) 116 is formed by filling a conductive material in the opening and polishing the conductive material to expose an upper surface of the second interlayer insulating film 114.

Referring to FIG. 7, thin films provided as an MTJ structure are sequentially stacked on the second interlayer insulating film 114 and the lower electrode contact 116. In this embodiment, the barrier metal film 118, the fixed film structure 120, the tunnel barrier film 122, and the free film 124 are sequentially stacked.

Specifically, the barrier metal layer 118 is provided to prevent abnormal growth of the metal included in the fixed film structure, and includes an amorphous metal material. Examples of the metal material used as the barrier metal film 118 include tantalum, tantalum nitride, titanium, and titanium nitride. The barrier metal layer 118 may be formed of at least one material selected from the illustrated materials.

The fixed film structure 120 includes a pinning layer 120a, a lower ferromagnetic film 120b, an antiferromagnetic coupling spacer film 120c, and an upper ferromagnetic film 120d. The fixed film 120a is formed of a material that fixes the magnetization direction of the lower ferromagnetic film 120b in one direction. Manganese iridium (IrMn), manganese platinum (PtMn), manganese oxide (MnO), manganese sulfide (MnS), tellurium manganese (MnTe) (FeO), iron oxide (FeO), cobalt chloride (CoCl 2), cobalt oxide (CoO), nickel chloride (NiCl 2), nickel oxide (NiO), chromium (Cr) And the like. The fixing film 120a may be formed of at least one selected from the materials exemplified. The upper and lower ferromagnetic films 120b and 120d are preferably formed of a ferromagnetic material containing at least one of iron (Fe), nickel (Ni), and cobalt (Co). For example, the upper and lower ferromagnetic layers may be formed of iron cobalt (CoFe), iron nickel (NiFe) or cobalt boride (CoFeB). The antiferromagnetic coupling spacer film 120c may be formed of ruthenium (Ru), iridium (Ir), or rhodium (Rh).

The tunnel barrier layer 122 may be formed of an aluminum oxide layer or a magnesium oxide layer. When the tunnel barrier film 122 is formed of a magnesium oxide film, the MR ratio is more excellent. Therefore, it is preferable that the tunnel barrier film 122 is formed of a magnesium oxide film.

The free layer 124 is preferably formed of a ferromagnetic material containing at least one of iron (Fe), nickel (Ni), and cobalt (Co). Examples of materials that can be used for the free layer 124 include iron cobalt (CoFe), iron nickel (NiFe), and iron boron cobalt (CoFeB).

A hard mask layer 126 is formed on the free layer 124. The hard mask film 126 is formed of a metal or a metal nitride. Examples of the material used for the hard mask layer 126 include titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride and the like. These may be used alone or as composite membranes.

Referring to FIG. 8, the hard mask layer 126 is anisotropically etched to form a hard mask pattern 126a for etching the thin films provided in the lower MTJ structure. The hard mask pattern 126a is positioned to overlap the upper surface of the lower electrode contact 116. The hard mask pattern 126a may have a line width of 30 to 100 nm.

Referring to FIG. 9, the thin film provided to the lower MTJ structure is etched using the hard mask pattern 126a as an etching mask to form a barrier metal film pattern 118a, a fixed film lamination pattern 121, The free layer pattern 122a and the free layer pattern 124a are stacked.

At this time, the thin films provided to the MTJ structure are etched through plasma reactive etching using an etching gas containing fluorine-containing gas and ammonia (NH ₃ ) gas and an oxygen gas for suppressing consumption of the hard mask pattern. The specific method of the etching process for forming the MTJ structure is the same as that described with reference to FIGS. 3 and 4. FIG. After the thin films are etched, a metal oxide film 127 is formed on the surface of the hard mask pattern 126a by reaction with the oxygen gas.

The MTJ structure completed by performing the etching process of the above-described method has very little consumption of the hard mask pattern 127. Therefore, even if the MTJ structure is formed with narrow linewidths and intervals of about 30 nm to 100 nm, the pattern is not broken, and the nodes are separated.

Although not shown, a capping layer for protecting the MTJ structure may be formed on the surface of the MTJ structure. The capping layer may be formed to have a thickness of 50 to 300 ANGSTROM. In addition, the capping film may be formed of a metal oxide having insulating properties such as aluminum oxide.

Referring to FIG. 10, a third interlayer insulating film 128 covering the MTJ structure is formed. A part of the third interlayer insulating film 128 and the metal oxide film 127 are etched to form a contact hole exposing the upper surface of the hard mask pattern 126a having conductivity. A top electrode contact (TEC) 130 is formed by filling a conductive material in the contact hole and polishing the conductive material to expose an upper surface of the third interlayer insulating film 128.

A bit line 132 is formed by forming and patterning a conductive film on the third interlayer insulating film 128 and the upper electrode contact 130. However, in order to simplify the process, the bit line 132 may be formed to directly contact the hard mask pattern 126a without forming the upper electrode contact 130.

Through the above-described process, the magnetic memory element is completed.

The magnetic memory device has a low resistance when the magnetization direction of the fixed film lamination pattern at both ends of the tunnel barrier film pattern of the MTJ structure is equal to the magnetization direction of the free film pattern (hereinafter referred to as a parallel state) (Hereinafter, referred to as " antiparallel state ") when the magnetization directions of the free layer pattern and the free layer pattern are different from each other. Therefore, it is preferable that the difference in resistance value between the parallel state and the antiparallel state is very large. The change in the resistance value is referred to as a magnetoresistance ratio (MR), and the magnetoresistance ratio is preferably high. Specifically, the magnetoresistance ratio should be at least 50%, preferably at least 80%.

When the conductive polymer is attached to the side wall of the MTJ structure and the fixed film stacked pattern and the free film pattern are shorted, current flows through the shorted sidewall portion even in the antiparallel state, and the MR becomes 0%. Also, when the hard mask pattern 126a is consumed and the linewidth and characteristic variation of the MTJ structure frequently occurs, a magnetic memory element having a very low MR ratio or 0% becomes complicated.

However, according to the method of this embodiment, the MTJ structure hardly adheres to the conductive polymer, and since the hard mask pattern is not consumed, a magnetic memory device having a very high MR characteristic of 90% or more can be manufactured. In particular, since an MTJ structure having a narrow line width of 30 to 100 nm can be formed, a magnetic memory device having high integration and high MR characteristics can be manufactured.

In addition, since the consumption of the hard mask pattern is small, a magnetic memory device with high integration and small characteristic scattering can be manufactured.

Example 2

11 to 13 are cross-sectional views illustrating a method of manufacturing a magnetic memory device according to a second embodiment of the present invention.

The magnetic memory device of this embodiment is a magnetic memory device which magnetizes and inverts using an external magnetic field. In this embodiment, the etching method described in the first embodiment is used equally.

Referring to FIG. 11, a device isolation pattern is formed on a semiconductor substrate 200 to separate an active region and an element isolation region. A MOS transistor for cell selection is formed on the substrate. Although not shown, gate spacers may be formed on both sides of the gate electrode 204 of the MOS transistor.

A first interlayer insulating film 208 is formed on the semiconductor substrate 200 so as to cover the MOS transistor. First contact plugs 210 are formed through the first interlayer insulating film 208 and in contact with the impurity regions 206.

A digit line (212a) is formed on the first interlayer insulating film (208). The digit line 212a may be formed at a position overlapping the gate electrode 204 for high integration. In addition, a pad electrode 212b is formed on the first contact plug 210.

A second interlayer insulating film 214 is formed on the first interlayer insulating film 208 to cover the digit lines 212a and the pad electrodes 212b. A part of the second interlayer insulating film 214 is removed through a photolithography process to form an opening exposing the upper surface of the pad electrode 212b. The opening has a shape of a contact hole.

The second contact plug 216 is formed by filling the inside of the opening with a conductive material and polishing the conductive material so that the upper surface of the second interlayer insulating film 214 is exposed.

A conductive film is formed on the second contact plug 216, and the conductive film is etched to form a bypass line 218. The auxiliary line 218 is provided to form an MTJ structure opposite to the digit line 212a and has a shape extending from the upper surface of the second contact plug 216 to the digit line 212a .

A third interlayer insulating film 219 filling the gap between the auxiliary lines 218 is formed.

 Referring to FIG. 12, thin films provided as an MTJ structure on the third interlayer insulating film 219 and the auxiliary line 218 are sequentially stacked. The thin film provided as the MTJ structure includes a barrier metal film, a fixed film structure, a tunnel barrier film, and a free film.

A hard mask film is formed on the free film, and the hard mask film is etched to form a hard mask pattern 126a. The thin film provided to the lower MTJ structure is etched using the hard mask pattern 126a as an etching mask to form a barrier metal film pattern 118a, a fixed film lamination pattern 121, a tunnel barrier film pattern 122a, The pattern 124a forms the stacked MTJ structure. In the etching process, an etching gas containing a fluorine-containing gas and ammonia (NH ₃ ) gas and an oxygen gas for suppressing consumption of the hard mask are used together. Further, the magnetic material films are etched through plasma reactive etching using the above-mentioned etching gases. The processes described above are the same as those described with reference to Figs. When the etching process is performed, a metal oxide film 127 is formed on the surface of the hard mask pattern 126a.

Referring to FIG. 13, a fourth interlayer insulating film 128a covering the MTJ structure is formed. A part of the fourth interlayer insulating film 128a is etched to form a contact hole exposing the upper surface of the conductive mask pattern. The upper electrode contact 230 is formed by filling a conductive material in the contact hole and polishing the conductive material to expose the upper surface of the fourth interlayer insulating film 128a.

A bit line 232 is formed by forming a conductive film on the fourth interlayer insulating film 128a and the upper electrode contact 230 and patterning the conductive film.

However, in order to simplify the process, the bit line 232 may be formed to directly contact the hard mask pattern 126a without forming the upper electrode contact 230.

Example 3

The magnetic pattern forming method of Embodiment 3 described below performs the same method of forming the magnetic pattern of Embodiment 1, and then performs further processing.

Specifically, the same processes as those described with reference to FIGS. 2 and 3 are performed to form the magnetic material films 12 shown in FIG. Thereafter, as described with reference to FIG. 4, the magnetic material film 12 is etched to form the magnetic pattern 14. FIG.

When the etching process for forming the magnetic pattern 14 is completed, a subsequent process for suppressing the consumption of the hard mask pattern 16 is performed while removing the surface cleaning of the magnetic pattern 14 and the residual polymer . The subsequent process may proceed in situ in the etch chamber where the etch process is performed.

Hereinafter, the following process will be described in more detail.

14 is a timing chart showing influx of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 3 of the present invention.

Referring to FIGS. 4 and 14, the subsequent processing uses ammonia gas, fluorine-containing gas, and oxygen gas. The fluorine-containing gas used in the subsequent treatment step is preferably the same as the gas used in the etching step. However, the fluorine-containing gas may be used as a gas other than the gas used in the etching process. Examples of the fluorine-containing gas include SF ₆ , NF ₃ , SiF ₄ , CF ₄ , and the like. Thus, the subsequent process uses the same gas as the etching process, but the flow rate of each gas differs from that in the etching process.

In order to dry-clean the surface of the magnetic pattern 14 and remove residual polymer, the subsequent treatment process increases the gas containing fluorine and reduces the ammonia gas, which is the etch gas that produces the polymer. Therefore, the flow rate of the fluorine-containing gas is preferably equal to or more than that of the ammonia gas. Specifically, the flow rate ratio of the ammonia and the fluorine-containing gas is preferably 1: 1 to 50.

Further, the subsequent processing process is performed for a shorter time than the etching process so that the hard mask pattern 16 provided on the magnetic pattern 14 is not excessively etched by the fluorine-containing gas.

Further, the flow rate of the oxygen gas can be increased in comparison with the etching process in order to prevent the hard mask pattern 16 provided on the magnetic pattern 14 from being excessively etched by the fluorine-containing gas. Since the subsequent treatment process is performed in a short time, the surface of the magnetic pattern 14 can be prevented from being oxidized even when the inflow of oxygen gas is increased as compared with the etching process. Alternatively, however, the oxygen gas may be supplied at the same flow rate as in the etching process in the subsequent processing process.

In the subsequent processing step, if the oxygen gas is smaller than 0.1 times the flow rate of the fluorine-containing gas, it is difficult to suppress the consumption of the hard mask pattern 16. On the other hand, if the oxygen gas is more than twice the flow rate of the fluorine-containing gas, the effect of removing the conductive polymer by the fluorine-containing gas is lowered and the surface of the magnetic pattern may be oxidized by the oxygen gas. Therefore, it is preferable that the oxygen gas is introduced at a flow rate of 0.1 to 2 times the flow rate of the fluorine-containing gas in the subsequent treatment process.

The subsequent treatment may be carried out at a temperature of from 10 캜 to 300 캜 and a pressure of from 1 to 10 mTorr. In the subsequent processing step, the temperature and pressure conditions are preferably the same as in the previous etching process, but may be different from the etching process.

Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied in the subsequent processing step. In the subsequent processing step, the microwave power and R.F bias power conditions are preferably the same as the previous etching process, but they may be different from the etching process.

According to the above-described method, it is possible to form a magnetic pattern having a magnetic tunnel junction structure and hardly consuming a hard mask pattern without generating a conductive polymer on the side wall.

In addition, a magnetic memory element can be formed using the above-described etching method for forming a magnetic pattern.

For example, after performing the same process as described with reference to FIGS. 6 to 8, the MTJ structure is formed by etching the thin films for the MTJ structure through the etching method according to the third embodiment. Next, the spin injection torque magnetic memory device shown in FIG. 10 can be formed by performing the process described with reference to FIG.

As another example, after performing the same process as described with reference to FIG. 11, thin films and a mask pattern for the MTJ structure are formed. Thereafter, the MTJ structure is etched through the etching method according to the third embodiment. Next, the magnetic memory element shown in FIG. 13 can be formed by performing the process described with reference to FIG.

Example 4

The magnetic pattern forming method of Embodiment 4 described below performs the same method of forming the magnetic pattern of Embodiment 1, and then performs further processing.

FIG. 15 is a timing chart showing influent of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 4 of the present invention. FIG.

4 and 15, only the fluorine-containing gas and the oxygen gas are used in the subsequent treatment process, and ammonia gas is not used.

The fluorine-containing gas used in the subsequent treatment step is preferably the same as the gas used in the etching step. However, the fluorine-containing gas may be used as a gas other than the gas used in the etching process. Examples of the fluorine-containing gas include SF ₆ , NF ₃ , SiF ₄ , CF ₄ , and the like.

In the subsequent processing step, in order to dry-clean the surface of the magnetic pattern 14 and remove the residual polymer, only the fluorine-containing gas is introduced, and the ammonia gas, which is the etching gas for generating the polymer, is not introduced.

It is preferable that the flow rate of the fluorine-containing gas flowing in the subsequent processing step is larger than the fluorine-containing gas flowing in the etching step or more than the fluorine-containing gas flowing in the etching step.

Further, the subsequent processing process is performed for a shorter time than the etching process so that the hard mask pattern 16 provided on the magnetic pattern is not excessively etched by the fluorine-containing gas.

In addition, the flow rate of the oxygen gas can be increased compared with the etching process in order to prevent the hard mask pattern 16 provided on the magnetic pattern from being excessively etched by the fluorine-containing gas. Alternatively, however, the oxygen gas may be supplied at the same flow rate as in the etching process in the subsequent processing process. The flow rate of the oxygen gas may be 0.1 to 2 times of the fluorine-containing gas.

The subsequent treatment may be carried out at a temperature of from 10 캜 to 300 캜 and a pressure of from 1 to 10 mTorr. In the subsequent processing step, the temperature and pressure conditions are preferably the same as in the previous etching process, but may be different from the etching process.

Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied in the subsequent processing step. In the subsequent processing step, the microwave power and R.F bias power conditions are preferably the same as the previous etching process, but they may be different from the etching process.

According to the above-described method, the magnetic pattern 14 having a magnetic tunnel junction structure and hardly producing conductive polymer on the side wall can be formed. In addition, the hard mask pattern 16 on the magnetic pattern 14 is hardly consumed, and a metal oxide is formed on the surface of the hard mask pattern 16.

In addition, a magnetic memory element can be formed by using the same etching method for forming the magnetic pattern.

For example, the MTJ structure is formed by performing the same processes as described with reference to FIGS. 6 to 8, and then etching the thin films for the MTJ structure through the etching method according to the fourth embodiment. Next, the spin injection torque magnetic memory device shown in FIG. 10 can be formed by performing the process described with reference to FIG.

As another example, the same process as described with reference to FIG. 11 is performed, and then the thin films and the mask pattern for the MTJ structure are formed. Thereafter, the MTJ structure is etched through the etching method according to the fourth embodiment. Next, the magnetic memory element shown in FIG. 13 can be formed by performing the process described with reference to FIG.

Example 5

The magnetic pattern forming method of Embodiment 5 described below differs from Embodiment 1 in that the etching method of the magnetic film and the etching process perform subsequent processing.

Specifically, the same processes as those described with reference to FIGS. 2 and 3 are performed to form the magnetic material films 12 shown in FIG. Thereafter, the magnetic material films are etched to form a magnetic pattern 14, and the magnetic pattern 14 is subjected to subsequent processing.

16 is a timing chart showing influent of a reaction gas when etching and subsequent processing of a magnetic material film according to Embodiment 5 of the present invention.

Referring to FIGS. 4 and 16, the magnetic material layer 12 is etched using ammonia (NH ₃ ) and oxygen gas as an etching gas. In the etching step, the oxygen gas is preferably introduced at a flow rate smaller than 10% of the ammonia gas flow rate. The oxygen gas flows at a flow rate of 10 to 100 sccm.

Although not shown, an additional inert gas may be further introduced into the ammonia gas. The inert gas includes argon.

The ammonia gas reacts with the metal of the magnetic material to produce metal ammonium, and the generated metal ammonium is volatilized to thereby etch the magnetic material film. The ammonia gas can quickly etch the magnetic material films 12 listed above. Further, the oxygen gas suppresses the hard mask pattern 16 from being consumed by generating the metal oxide 18 on the surface of the hard mask pattern 16.

The etching process may be performed at a temperature of 10 to 300 DEG C and a pressure of 1 to 10 mTorr. Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied during the etching process.

The magnetic pattern 14 is formed through the etching process.

When the etching process is completed, a fluorine-containing gas is introduced for subsequent processing. During the subsequent treatment, the ammonia gas may not flow. Alternatively, however, the inflow amount of the ammonia gas may be reduced. As described above, by introducing the fluorine-containing gas, the surface of the magnetic pattern 14 can be dry-cleaned and the residual polymer can be removed.

Also, in order to suppress the consumption of the hard mask pattern 16 during the subsequent process, the flow rate of the oxygen gas may be increased compared to the etching process. The oxygen gas may flow at a flow rate of 0.1 to 2 times the flow rate of the fluorine-containing gas.

Through the above-described process, a magnetic pattern 14 having a magnetic tunnel junction structure and hardly producing a conductive polymer on the side wall can be formed. Also, since the hard mask pattern 16 is hardly consumed, the magnetic pattern 14 having an excellent sidewall profile can be formed.

In addition, a magnetic memory element can be formed by using the same etching method for forming the magnetic pattern.

For example, the MTJ structure is formed by performing the same process as described with reference to FIGS. 6 to 8 and etching the thin films for the MTJ structure through the etching method according to the fifth embodiment. Next, the spin injection torque magnetic memory device shown in FIG. 10 can be formed by performing the process described with reference to FIG.

As another example, the same process as described with reference to FIG. 11 is performed and thin films and mask patterns for the MTJ structure are formed. Thereafter, the MTJ structure is etched through the etching method according to the fifth embodiment. Next, the magnetic memory element shown in FIG. 13 can be formed by performing the process described with reference to FIG.

Comparative Experiment 1

Sample 1

17 is a cross-sectional view showing a sample 1 of an MTJ structure formed using the etching method of Example 1 of the present invention.

Sample 1 was prepared by the method described below.

An MTJ material film was formed on the substrate 10, as shown in Fig. Specifically, a barrier metal film made of Ta was formed. A fixed film made of a manganese platinum (PtMn) film was formed on the Ta film. A CoFe film, a Ru film, and a CoFe film were stacked on the fixed film. Also, a tunnel barrier film made of a MgO film was formed on the CoFe film. A free layer of a CoFeB film was formed on the MgO layer.

A hard mask film was formed on the MTJ material film. The hard mask film formed a titanium film and a titanium nitride film. Thereafter, the hard mask film was patterned to form a hard mask pattern 16. The hard mask pattern 16 has a shape in which a titanium / titanium nitride film pattern is laminated. At this time, the line width of the hard mask pattern 16 was about 50 nm.

Subsequently, the MTJ material film was etched through the etching process described with reference to FIG. 4 to form the MTJ structure 14 having a line width of about 50 nm. The etch gases used in the etching process were SF ₆ , NH _3, and oxygen gas. The flow rates of the respective etching gases were 2000 sccm of NH ₃ gas, 50 sccm of SF ₆ gas, and 30 sccm of oxygen gas. When the etching process is performed, a metal oxide 18 is formed on the surface of the hard mask pattern 16.

In the above-described manner, a plurality of samples 1 having different resistances of the tunnel barrier pattern were prepared.

Comparative Sample 1

18 is a cross-sectional view showing a comparative sample 1 of an MTJ structure for comparison with the embodiments of the present invention.

Comparative Sample 1 was prepared in order to compare the difference in consumption of the hard mask pattern due to the flow of oxygen gas. That is, an MTJ material film and a hard mask film were formed on the substrate 10. The hard mask film was patterned to form a hard mask pattern 16a. The MTJ material film and the hard mask pattern 16a were formed in the same manner as described in Sample 1. [

Subsequently, the MTJ material film was etched to form an MTJ structure 14 having a line width of about 50 nm. SF ₆ and NH ₃ were used as etch gases used in the etching process, and no oxygen gas was introduced at this time. The flow rates of the respective etching gases were 2000 sccm of NH ₃ gas and 50 sccm of SF ₆ gas. When the etching process is performed, a metal oxide is not formed on the surface of the hard mask pattern 16a.

Using this method, a plurality of comparative samples having different resistances of the tunnel barrier pattern were prepared.

Resistivity ratios were measured for the sample 1 and the comparative sample 1, respectively.

19 is a graph showing a resistance-to-resistance ratio measured in the sample 1;

Referring to FIG. 19, the magnetoresistance ratio of a plurality of samples 1 was measured to be as high as 80% or more, regardless of the resistance of the tunnel barrier film pattern included in the MTJ structure. Also, the magnetoresistive ratio average of the sample 1 was measured to be as high as about 91.3%. Further, in the samples 1, the fixed film laminated pattern and the free film pattern were short-circuited, and no defects such that the magnetoresistive ratio was lowered to 20% or less did not occur. Also, the dispersion of the magnetoresistive ratio in the sample 1 was 4.4%.

20 is a graph showing a resistance-to-resistance ratio measured in Comparative Sample 1. FIG.

Referring to FIG. 20, in the comparative samples 1, comparative samples having a magnetoresistance ratio of as low as 70% or less were mixed. Further, the fixed film laminated pattern and the free film pattern were short-circuited, and comparative samples were also generated in which the magnetoresistance ratio was measured at 0%. In the comparative samples 1, the magnetoresistance ratio average was measured as low as about 51.5%, and the magnitude ratio of the magnetoresistance ratio was measured as high as 16.5%.

According to the experimental results of FIGS. 19 and 20, it can be seen that an MTJ structure having a high magnetoresistance ratio can be manufactured by etching the magnetic films according to the method of the present invention. That is, it was found that the MTJ structure having a high magnetoresistance ratio can be formed by additionally introducing oxygen gas for suppressing the consumption of the hard mask pattern during the etching process. Particularly, in the case of forming an MTJ pattern structure having a narrow line width of 50 nm, it has been found that the inflow of oxygen gas is very dominant in determining the MR ratio.

Further, it has been found that a magnetic memory device with high performance and high integration can be manufactured by the method of the present invention.

In addition, according to the present invention, occurrence of defects in the MTJ structure is reduced. Therefore, it was found that the manufacturing yield of the magnetic memory device was improved when the present invention was applied.

On the other hand, in the case of forming a relatively large-sized MTJ pattern structure having a line width of 300 nm or more, though not shown, even if oxygen is not introduced, even if SF ₆ and NH ₃ are used as an etching gas, The ratio could be obtained. In particular, it was found that the magnetoresistance ratio characteristics were better than those in the case of using Cl ₂ and argon as the etching gas.

However, as described above, when the MTJ pattern structure having a narrow line width of about 30 to 100 nm is formed, consumption of the hard mask pattern is suppressed by the flow of oxygen gas, and a desired magnetoresistance ratio can be obtained .

Comparative Experiment 2

The thickness of the hard mask remaining in the MTJ structure was compared with respect to the MTJ structure formed by etching the oxygen formed by the method of the present invention and the MTJ structure obtained by etching without introducing oxygen, unlike the present invention. Thus, the difference in consumption amount of the hard mask pattern due to the inflow of the oxygen gas was compared. Samples for experiments were prepared as follows.

Sample 2 was prepared in the same manner as Sample 1, except that the flow rate of oxygen gas differs in the process of etching the MTJ material film. That is, in the etching process, the flow rates of the respective etching gases were 2000 sccm of NH ₃ gas, 50 sccm of SF ₆ gas, and 10 sccm of oxygen gas. The line width of the MTJ structure of Sample 2 was about 50 nm.

The etching gas conditions of each sample

21 shows the etched thickness of the hard mask pattern according to the oxygen inflow in the etching process.

Referring to FIG. 21, it can be seen that the etching thickness of the hard mask pattern decreases as the oxygen inflow amount increases. That is, since the oxygen is introduced, it is possible to suppress the removal of the hard mask pattern during etching.

Hereinafter, an etch method suitable for forming a phase change pattern by etching a phase change material film and a method for manufacturing a phase change memory device using the same will be described.

Example 6

22 to 24 are sectional views showing a method for forming a phase change pattern according to a sixth embodiment of the present invention.

Referring to FIG. 22, a phase change film 52 including a phase change material is formed on a substrate 50. The phase change film 52 may be formed of an alloy material of at least three elements of Ge, Sb, Te, In, and Bi. For example, the phase change film 52 may be formed of an alloy material (Ge ₂ Sb ₂ Te ₅ , GST) of Ge, Sb and Te, an alloy material (IST) of In, Sb and Te, (GBT). ≪ / RTI > In this embodiment, the phase change film is formed of GST. The GST is a material that has been widely used in commercially available phase change type optical information storage devices (CD-RW, DVD, etc.) and is therefore considered to be very stable, so that it is suitable as the phase change film 52.

Referring to FIG. 23, a first mask film (not shown) is formed on the phase change film 52. The first mask layer may be formed of a metal or a metal nitride. Examples of materials usable as the first mask film include titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, and the like. They may be used alone or may have two or more laminated shapes.

A second mask film (not shown) is formed on the first mask film. The second mask film is used as an etching mask for patterning the first mask film. The second mask film may be formed of silicon nitride.

A second mask pattern 56 is formed by patterning the second mask film. The first mask film is etched using the second mask pattern 56 as an etch mask. The first mask pattern 54 used as a mask for etching the phase change film is formed by the above process. At this time, the spacing distance d between the first mask patterns 54 may be narrower than 1000 angstroms. In addition, the line width of the first mask pattern 54 may be 30 to 100 nm.

Referring to FIG. 24, the first and second mask patterns 54 and 56 are used as an etching mask, ammonia (NH ₃ ) gas is used as an etching gas, and the consumption of the first and second mask patterns is suppressed And the oxygen-containing gas is used together to etch the phase-change film. Thereby, the phase change pattern 52a is formed. The line width of the phase change pattern 52a may be 30 to 100 nm.

The ammonia gas reacts with the phase change materials contained in the phase change film 52 and the phase change film 52 is etched by volatilization of the reactant.

When the ammonia gas is used as an etching gas, specific elements among the Ge, Sb and Te elements contained in the phase change film 52 are not rapidly etched, and the elements are etched at a uniform rate. Therefore, during the etching process, the composition of each element contained in the phase change film 52 is hardly changed. That is, when the etching process is performed, etching damage rarely occurs in the phase change film 52. Specifically, the component of each of the elements included in the phase change pattern 52a may have a difference of 5% or less when compared with the component of each of the elements included in the phase change film 52 in the deposition state . That is, the Ge, Sb, and Te elements in the state after the deposition and the etching process may have a difference of 5% or less.

In addition, even if the width of the portion to be etched is very narrow, the etching rate is not slowed down. Therefore, the phase change pattern 52a can have a narrow pitch as well as a good vertical profile. Specifically, the acute angle R between the sidewall of the phase change pattern 52a and the flat surface between the phase change patterns 52a may be 80 degrees or more. In addition, the interval between the phase change patterns 52a may be smaller than 1000 angstroms. In this way, even if the phase change patterns 52a having narrow intervals are formed, hardly any free etch failure that does not etch between the phase change patterns 52a is generated.

In order to suppress the consumption of the first and second mask patterns 54 and 56 generated when the etching process is performed using the ammonia gas, oxygen gas is simultaneously introduced into the etching process. The oxygen gas reacts with the surfaces of the first and second mask patterns 54 and 56 to form an oxide 57 on the surfaces of the first and second mask patterns 54 and 56. In the etching process, the oxide 57 generated on the surfaces of the first and second mask patterns 54 and 56 has a lower etching rate than the first and second mask patterns 54 and 56. Therefore, it is possible to suppress the removal of the first and second mask patterns 54, 56 during the etching process.

When the oxygen gas flows in a large amount, there arises a problem that the surface of the phase change pattern 52a as well as the surfaces of the first and second mask patterns 54 and 56 are oxidized. Therefore, it is preferable that the oxygen gas is introduced into the flow rate range such that the surface of the phase change pattern 52a is not oxidized, while oxidizing the surfaces of the first and second mask patterns 54 and 56. [

When the oxygen gas flows in at least 10% of the ammonia gas flow rate, the oxygen gas may be oxidized to the phase change pattern 52a and the etching of the phase change pattern 52a may be disturbed by oxygen gas It is not preferable. Therefore, it is preferable that the oxygen gas is introduced at a flow rate smaller than 10% of the flow rate of the ammonia gas.

The etching conditions suitable for etching the phase change film 52 are as follows. The etching process may be performed at a temperature of 10 to 300 DEG C and a pressure of 1 to 10 mTorr. Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied during the etching process.

Unlike the method of the present embodiment, when halogen-based gases such as chlorine and fluorine, which are generally used for etching the phase change film 52, are used, due to the difference in reactivity between the elements included in the phase change film, The etch rates between the two are different. This greatly changes the composition of the elements in the phase change pattern generated after the etching process. If the specific component of the elements included in the phase change pattern is increased or decreased, the phase change pattern may deteriorate the phase change characteristic or fail to exhibit the phase change characteristic. In addition, when a specific element is insufficiently short in the phase change pattern, the coupling force of the elements in the phase change pattern becomes weak, and the phase change pattern collapses.

However, as described above, according to the method of this embodiment, ammonia gas is used for etching the phase change film 52 without using a halogen-based gas such as chlorine and fluorine, The reactivity between the elements involved is nearly identical. Therefore, even after the etching process, the composition of the elements included in the phase change pattern 52a can be uniformly maintained without being greatly changed. In addition, since the bonding force of the elements in the phase change pattern 52a is not weakened by the etching process, the phase change pattern 52a is hardly collapsed. Therefore, the phase change pattern 52a has good phase change characteristics and excellent sidewall profile of the pattern.

Unlike the present invention, when the phase-change film is etched through a general etching process, the phase-change pattern continues after the etching process is completed by the etching gas containing fluorine or chlorine remaining on the surface of the completed phase- It is damaged. Therefore, the reliability of the phase change pattern is greatly reduced. However, when the phase change film 52 is etched using ammonia gas as in the present embodiment, the nitrogen component remains in the completed phase change pattern 52a, and the surface of the phase change pattern 52a Protected. Therefore, the phase change pattern 52a is hardly damaged by the residual etching gas. As a result, the reliability of the phase change pattern 52a is enhanced.

When a general physical etching process is performed, the composition of the phase change pattern is not changed after the etching, but the sidewall profile is poor at the time of pattern formation, and when the gap between the phase change patterns is narrow, However, as described above, according to the method of this embodiment, since the phase change film is not etched through the physical etching process, the phase change pattern 52a having a narrow pitch can be easily formed.

Further, by introducing oxygen gas in the etching process, it is possible to suppress the consumption of the first and second mask patterns 54 and 56, thereby forming a phase change pattern having a desired width and shape. Therefore, it is possible to reduce the dispersion of the characteristics of the phase change pattern 52a.

Thus, according to this embodiment, it is possible to form a phase change pattern with a narrow pattern pitch and a good vertical profile without changing the composition of the phase change material before and after etching.

Manufacturing phase-change memory devices

25 to 28 are cross-sectional views illustrating a method of manufacturing a phase-change memory device according to an embodiment of the present invention.

When manufacturing the phase change memory element of this embodiment, the same etching method as described with reference to FIGS. 23 and 24 is used.

Referring to FIG. 25, an impurity region 302 is formed by implanting N-type impurity into the substrate 300. A part of the substrate 300 is etched to form an element isolation trench 304 extending in a first direction. A device isolation film is formed so as to fill the inside of the device isolation trench 304 and the device isolation film pattern 306 is formed by planarizing the device isolation film.

A first interlayer insulating film 308 is formed on the substrate 300. The first interlayer insulating film 308 is partially etched to form a first opening (not shown) exposing the impurity region 302. A silicon film is formed to fill the first opening and then the silicon film is polished so that the upper surface of the first interlayer insulating film 308 is exposed to form a silicon film pattern in the first opening.

Then, the P-type impurity is implanted into the upper portion of the silicon film pattern, and the N-type impurity is implanted into the lower portion of the silicon film pattern. Thereby, a P-N diode 310 including a silicon film pattern doped with an N-type impurity and a silicon film pattern doped with a P-type impurity is formed in the first opening.

A pad electrode 312 having a metal silicide 312a and a metal 312b stacked on the P-N diode 310 is formed.

Referring to FIG. 26, a second interlayer insulating film 314 is formed on the first interlayer insulating film 308 and the pad electrode 312. A portion of the second interlayer insulating film 314 is etched to form a second opening (not shown) exposing a part of the upper surface of the pad electrode 312.

A lower electrode contact 316 filling the inside of the second opening is formed. Specifically, a barrier metal film is formed along the sidewalls and the bottom surface of the second opening, and a metal film is formed on the barrier metal film to fill the inside of the second opening. Thereafter, the metal film and the barrier metal film are polished so that the upper surface of the second interlayer insulating film is exposed, thereby forming the lower electrode contact 316 including the barrier metal film pattern 316a and the metal pattern 316b. The barrier metal film pattern 316a may include titanium, titanium nitride, and the like. These barrier metal film patterns 316a may be formed solely or two or more layers may be stacked. In addition, the metal pattern 316b may include tungsten, aluminum, copper, or the like.

A phase change film 318 is formed on the second interlayer insulating film 314 and the lower electrode contact 316. The phase change layer 318 may be formed of an alloy material of at least three elements selected from Ge, Sb, Te, In, and Bi. In this embodiment, a chalcogenide compound, GST, is formed by vapor deposition. The phase change layer 318 may be formed using a physical vapor deposition process, a chemical vapor deposition process, a sol-gel process, an atomic layer deposition process, a cyclic chemical vapor deposition process, or the like.

The upper electrode layer 320 is formed on the phase change layer 318. The upper electrode layer 320 may be formed by depositing titanium nitride. A hard mask film 322 is formed on the upper electrode film 320. The hard mask layer 322 may be formed by depositing silicon nitride.

Referring to FIG. 27, the hard mask film 322 is patterned to form a hard mask pattern 322a. In addition, the upper electrode 320a is formed by patterning the upper electrode film 320 using the hard mask pattern 322a as an etching mask. The hard mask pattern 322a may have a line width of 30 to 100 nm.

Subsequently, the phase change film 318 is etched using the upper electrode 320a and the hard mask pattern 322a as an etching mask. Specifically, the phase-change film 318 is plasma-reactive-etched using an ammonia (NH ₃ ) gas as an etch gas and an oxygen gas to reduce consumption of the hard mask pattern. Thereby, a phase change pattern 318a is formed. The step of etching the phase change film 318 is the same as that described with reference to Fig.

The phase change pattern 318a formed through the above process has almost no component change when compared with the phase change film 318. [ That is, the phase change pattern 318a scarcely causes etching damage on the surface. The phase change pattern 318a has a very good vertical profile. In addition, even if the interval between the phase change patterns 318a is very narrow, there is hardly any defect that the gap portion between the phase change patterns 318a is exposed.

In addition, an oxide 321a is formed on the surfaces of the hard mask pattern 322a and the upper electrode 320a by the introduction of the oxygen gas. Therefore, the consumption of the hard mask pattern 322a is reduced, and the phase change pattern 318a can have a target line width and a sidewall profile, and the characteristic scatter is small.

Referring to FIG. 28, a third interlayer insulating film 324 is formed on the second interlayer insulating film 314 to cover the upper electrode 322a.

A part of the third interlayer insulating film 324 is etched to form a contact hole partially exposing the upper surface of the upper electrode 320a. An upper electrode contact 326 is formed by depositing a conductive material within the contact hole. The upper electrode contact 326 may be formed of a metal material. Specifically, the upper electrode contact 326 may be formed of tungsten. Wiring (not shown) is formed on the upper electrode contact 326.

As described above, according to the present embodiment, a highly integrated phase-change memory device can be realized with reduced process defects.

Example 7

FIGS. 29 to 31 are cross-sectional views illustrating a method for manufacturing a phase change memory device according to a seventh embodiment of the present invention.

In manufacturing the phase change memory element of this embodiment, the etching method described with reference to FIGS. 25 and 26 is used equally. That is, the method of etching the phase change film in this embodiment is the same as that of the sixth embodiment. However, the structure of the phase-change memory element is different from that of the sixth embodiment.

First, the processes described with reference to FIG. 25 are performed in the same manner.

Referring to FIG. 29, a second interlayer insulating film 314 is formed on the first interlayer insulating film 308 and the pad electrode 312. A lower electrode contact 316 penetrating the second interlayer insulating film 314 and contacting the pad electrode 312 is formed. This process is the same as that described with reference to Fig.

A third interlayer insulating film 350 is formed on the second interlayer insulating film 314 and the lower electrode contact 316. The third interlayer insulating film 350 may be formed of silicon oxide and may be formed of silicon oxide having high density. For example, the third interlayer insulating layer 350 may be formed of silicon oxide formed through a high-density plasma process.

A portion of the third interlayer insulating film 350 is etched to form an opening 352 exposing an upper surface of the lower electrode contact 316. It is preferable that the opening 352 is formed so as to have an inner width narrower toward the bottom by having a side wall inclination. In this case, the contact area between the lower electrode contact 316 and the phase change pattern formed in the subsequent process is reduced.

Referring to FIG. 30, a phase change film 354 is formed on the third interlayer insulating film 350 while filling the openings 352. An upper electrode film 356 is formed on the phase change film 354. A hard mask film 358 is formed on the upper electrode film 356.

Referring to FIG. 31, the hard mask film 358 is patterned to form a hard mask pattern 358a. The upper electrode film 356 is patterned to form an upper electrode 356a. At this time, it is preferable that the upper electrode 356a covers the entire opening of the opening 352.

Thereafter, the phase change layer 354 is etched using the upper electrode 356a and the hard mask pattern 358a as an etching mask to form a phase change pattern 354a. More specifically, the phase-change film 354 is plasma-reactive-etched using an ammonia (NH ₃ ) gas as an etch gas and an oxygen gas for suppressing consumption of the hard mask. The step of etching the phase change film 354 is the same as that described with reference to Fig.

Then, a fourth interlayer insulating film 360 is formed on the third interlayer insulating film 350 to cover the upper electrode 356a. Further, an upper electrode contact 362 is formed through the fourth interlayer insulating film 360. Wiring (not shown) is formed on the upper electrode contact 362.

Example 8

The method of forming a phase change pattern of Example 8 described below is the same as the method of forming a magnetic pattern of Example 6 except for the etching gas condition. Therefore, it will be described with reference to Figs. 22 to 24.

Specifically, the same processes as those described with reference to FIGS. 22 and 23 are performed to form the phase change film 52, the first and second mask patterns 54 and 56 shown in FIG.

Subsequently, ammonia (NH ₃ ) gas, oxygen gas, and auxiliary etching gas are introduced to form a phase change pattern 52a by plasma-reactive etching the phase change film. At this time, the oxygen gas can flow into 10% or less of the ammonia gas. The auxiliary etching gas includes CF ₄ , CO, HBr and SF ₆ , and at least one of them may be used. In addition, the inert gas can be introduced during the etching process. Examples of the inert gas include argon, helium, and the like. The etching atmosphere in the etching chamber can be controlled by introducing the inert gas.

The shape of the phase change pattern 52a can be easily adjusted by introducing the auxiliary etching gas. That is, the auxiliary etching gas can control the inflow amount in consideration of the width and height of the phase change pattern 52a to be formed, the interval between the phase change patterns 52a, the side wall inclination of the phase change patterns 52a, and the like. Further, the etching rate of the phase change layer can be controlled by adjusting the inflow amount of the auxiliary etching gas.

The etching process may be performed at a temperature of 10 to 300 DEG C and a pressure of 1 to 10 mTorr. Microwave power of 700 to 1500 W and R.F bias power of 200 to 700 W can be applied during the etching process.

Even if the phase change pattern is formed by the method of this embodiment, the specific elements among the Ge, Sb, and Te elements included in the phase change film 52 are not rapidly etched, and the respective elements are etched at a uniform rate. Therefore, the composition of each element contained in the phase change film is hardly changed during the etching process. That is, in the etching process, etching damage rarely occurs in the phase change film.

In addition, even if the width of the portion to be etched is very narrow, the etching rate is not slowed down. Therefore, the phase change pattern has a good vertical profile.

The phase change memory element can be formed using the etching method according to this embodiment.

For example, after performing the same process as described with reference to FIGS. 25 and 26, the phase change film is etched through the etching method according to the eighth embodiment to form a phase change pattern. Next, the phase change memory element shown in Fig. 28 can be formed by performing the process described with reference to Fig.

As another example, after performing the same process as described with reference to FIGS. 29 and 30, the phase change film is etched through the etching method according to the embodiment 8 to form a phase change pattern. Next, the phase change memory element shown in Fig. 31 can be formed by performing the process described with reference to Fig.

32 is a block diagram illustrating an electronic system including memory elements of embodiments of the present invention.

32, the electronic system 400 may include a controller 410, an input / output device 420, and a storage device 430.

The controller 410, the input / output device 420, and the storage device 430 may be coupled to each other via a bus 450.

The bus 450 corresponds to a path through which data and / or operational signals travel. The controller 410 may include at least one of at least one microprocessor, a digital signal processor, a microcontroller, and logic elements capable of performing similar functions.

The input / output device 420 may include at least one selected from a keypad, a keyboard, and a display device.

The storage device 430 is a device for storing data. The storage device 430 may store data and / or instructions executed by the controller 410, and the like. The storage device 430 may include a magnetic memory device manufactured by the method of the embodiment described above. The electronic system 400 may further comprise an interface 440 for transmitting data to or receiving data from the communication network. The interface 440 may be in wired or wireless form. For example, the interface 440 may include an antenna or a wired / wireless transceiver.

The electronic system 400 may be implemented as a mobile system, a personal computer, an industrial computer, or a system that performs various functions. For example, the mobile system may be a personal digital assistant (PDA), a portable computer, a web tablet, a mobile phone, a wireless phone, a laptop computer, a memory card A digital music system, or an information transmission / reception system. When the electronic system 400 is a device capable of performing wireless communication, the electronic system 400 may be used in a communication interface protocol such as a third generation communication system such as CDMA, GSM, NADC, E-TDMA, WCDAM, CDMA2000 .

33 is a block diagram showing a memory card including semiconductor elements according to embodiments of the present invention.

Referring to FIG. 33, the memory card 500 includes a memory device 510 and a memory controller 520.

The storage device 510 may store data. Preferably, the storage device 510 has a nonvolatile characteristic that retains the stored data even if power supply is interrupted. The storage device 510 may include the magnetic memory device manufactured by the above-described embodiments. The memory controller 520 may read data stored in the storage device 510 or store data in the storage device 510 in response to a host read / write request.

10: substrate 12: magnetic material film
100, 200: semiconductor substrate 104, 204: gate electrode
108, 208: first interlayer insulating film 110: first contact plug
112: conductive pattern 114: second interlayer insulating film
118: Barrier metal film 120: Fixed film structure
122: tunnel barrier film 124: free film
126a: Hard mask pattern 128: Third interlayer insulating film
130: upper electrode contact 132, 232: bit line
212a: digit line 212b: pad electrode
50: substrate 52: phase change film
54: first mask pattern 56: second mask pattern
300: substrate 302: impurity region
308: first interlayer insulating film 310: PN diode
312: pad electrode 314: second interlayer insulating film
318: phase change film 320: upper electrode film
322: hard mask film 324: third interlayer insulating film
326: upper electrode contact

Claims (10)

Forming a magnetic material film on the substrate, the magnetic material film including at least one magnetic material;
Forming a hard mask pattern including a metal on the magnetic material film;
Forming a magnetic pattern by plasma-reactive-etching the magnetic material film using an etching gas obtained by mixing a fluorine-containing gas and an ammonia gas and an oxygen gas for preventing consumption of a hard mask pattern, Way. The method according to claim 1, wherein the magnetic material layer comprises an alloy material of at least two elements selected from the group consisting of Co, Fe, Tb, Ru, Pd, Pt and Mn. The method according to claim 1, wherein the fluorine-containing gas comprises at least one selected from the group consisting of SF ₆ , NF ₃ , SiF _4, and CF ₄ . The method according to claim 1, wherein the flow rate of the ammonia gas contained in the etching gas is equal to or greater than the flow rate of the fluorine-containing gas. 5. The method according to claim 4, wherein the flow rate ratio of the fluorine-containing gas and the ammonia gas is 1: 1 to 50. 5. The method of claim 4, wherein the oxygen gas has a flow rate less than 10% of the ammonia gas flow rate. 2. The method of claim 1, wherein the oxygen gas is introduced at a flow rate between 10 and 100 sccm. The method of claim 1, wherein the hard mask pattern comprises at least one material selected from the group consisting of titanium, titanium nitride, tantalum, tantalum nitride, tungsten, and tungsten nitride. The method according to claim 1, wherein in the step of plasma-reactive-etching the magnetic material film using an etching gas mixed with the fluorine-containing gas and the ammonia gas and an oxygen gas to prevent consumption of the hard mask pattern, To form an oxide in the pattern structure. delete

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