KR20080089061A - Capacitor with dielectric contained gadolinium and titanium and method for fabricating the same - Google Patents

Abstract

A capacitor with a dielectric containing gadolinium and titanium and a method for manufacturing the same are provided to increase capacitance by forming an equivalent oxide thickness of 5 to 10 Å. A dielectric contains a gadolinium component and a titanium component on a first electrode(100). A second electrode(102) is prepared on the dielectric. The dielectric is a GdTiO3 structure(103). The GdTiO3 structure is a structure of which Gd2O3 and TiO2 are mixed. The GdTiO2 structure is formed by a process for injecting a gadolinium source containing the gadolinium component, and a process for injecting a titanium source containing the titanium component. The dielectric has a thickness of 50 to 150 Å. The first electrode and the second electrode are metal layers. The first electrode and the second electrode are metal materials selected from Ru, TiN, Pt, Ir, and HfN.

Description

Capacitor with a dielectric film containing gadolinium and titanium and a method of manufacturing the same {CAPACITOR WITH DIELECTRIC CONTAINED GADOLINIUM AND TITANIUM AND METHOD FOR FABRICATING THE SAME}

1 shows a capacitor of a MIM structure according to the prior art;

2 is a view showing the structure of a capacitor according to an embodiment of the present invention.

3 is a view for explaining the atomic layer deposition method (ALD) of [GdTiO _x ] according to [Unit Cycle 1].

4 is a view for explaining the atomic layer deposition method (ALD) of [GdTiO _x ] according to [Unit Cycle 2].

5A to 5C are cross-sectional views illustrating a method of manufacturing a MIM capacitor employing a GdTiO ₃ dielectric film according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100: first electrode

101: GdTiO ₃

102: second electrode

TECHNICAL FIELD This invention relates to the manufacturing technique of a semiconductor element. Specifically, It is related with a dielectric film, the capacitor provided with the same, and a manufacturing method.

Recently, due to the rapid development of miniaturized semiconductor processing technology, as the integration of memory products is accelerated, the unit cell area is greatly reduced, and the operating voltage is lowered. However, despite the decrease in cell area, the charging capacity required for the operation of the memory device is required to have a sufficient capacity of 25 fF / cell or more in order to prevent the occurrence of soft errors and shortening of the refresh time. .

Under these circumstances, TiN electrodes and HfO ₂ / Al ₂ O are limited because polysilicon-insulator-polysilicon (SIS) type capacitors employing Al ₂ O ₃ dielectric films are limited in securing the necessary charge capacity for next-generation DRAM products of 512M or more. Capacitors in the form of MIS (Metal-Insulator-Polysilicon) employing ₃ dielectric films or MIM (Metal-Insulator-Metal) employing HfO ₂ / Al ₂ O ₃ / HfO ₂ dielectric films have been mainstream.

However, these capacitors have a limit of equivalent equivalent oxide thickness (Tox: Toxic Oxide Thickness) of about 11Å, so the cell capacities of 25 fF / cell or more in the semiconductor DRAM product line of 60 nm or less metal wiring process are applied. Difficult to obtain).

Therefore, recently, as shown in FIG. 1, a capacitor having a MIM structure employing a noble metal film such as Ru and a single dielectric film such as TiO ₂ , Ta ₂ O ₅ , or HfO ₂ (hereinafter, referred to as a 'MIM capacitor') Abbreviation) The development of the device is in earnest.

1 is a view showing a capacitor of the MIM structure according to the prior art, the conventional capacitor is a first electrode 11, the dielectric film 12 and the plate (plate) that serves as a charge electric field (Storage) It consists of (13). The first electrode 11 and the second electrode 13 are a noble metal layer such as Ru, and the dielectric layer 12 is a single dielectric layer such as TiO ₂ , Ta ₂ O ₅ , or HfO ₂ .

However, in the MIM capacitor as shown in FIG. 1, when the equivalent oxide film thickness is lowered to 10 mA or less, the leakage current increases by 0.5 fA / cell or more. Thus, the practical application of the MIM capacitor is still difficult.

The present invention has been proposed to solve the above problems of the prior art, the equivalent oxide film thickness is lowered to 10Å or less to obtain a charging capacity of 25 fF / cell or more, but the reliability can be ensured under normal operating voltage and more severe operating voltage It is an object of the present invention to provide a capacitor and a method for manufacturing the same, which can secure leakage current characteristics at a stable level of 0.5 fA / cell or less.

Capacitor of the present invention for achieving the above object is a charge storage electrode; A dielectric film containing a gadolinium (Gd) component and a titanium (Ti) component on the charge storage electrode; And a plate electrode on the dielectric layer. The dielectric layer is characterized by containing a gadolinium (Gd) component and titanium (Ti) component, the gadolinium (Gd) component and titanium (Ti) component is characterized in that the GdTiO ₃ structure by combining with the oxygen component, The GdTiO ₃ structure is characterized in that the oxide containing the gadolinium (Gd) component and the oxide containing the titanium component is mixed.

In addition, the method of manufacturing the capacitor of the present invention includes the steps of forming a charge storage electrode; Forming a dielectric film containing a gadolinium (Gd) component and a titanium (Ti) component on the charge storage electrode; And forming a plate electrode on the dielectric layer. The dielectric layer may be formed of a GdTiO ₃ structure containing a gadolinium (Gd) component and a titanium (Ti) component, and the GdTiO ₃ structure may include an oxide containing a gadolinium (Gd) component and a titanium (Ti) component. And the oxide containing the gadolinium (Gd) component and the oxide containing the titanium (Ti) component are subjected to in-situ deposition using atomic layer deposition (ALD). Characterized by mixing through.

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

The present invention is to reduce the equivalent oxide thickness (Tox; Equivalent Oxide Thickness) of the MIM capacitor to less than 10Å to obtain a charge capacity of 25 fF / cell or more in the DRAM product line of 60nm or less metal wiring process is adopted The following methods are used to ensure leakage current characteristics at a stable level of 0.5 fA / cell or less under normal operating voltage and reliability even under more severe operating voltage.

Basically, in the present invention, when the equivalent oxide thickness (Tox) is lowered to 10 kΩ or less, the leakage current increase problem and thermal stability which have been pointed out as problems in the MIM capacitor using TiO ₂ , Ta ₂ O ₅ or HfO ₂ dielectric film to improve the problem, the lack of manufacturing techniques that use a dielectric layer of a capacitor by using a titanium oxide (TiO _x), gadolinium (gadolinium, Gd) doped with gadolinium titanium oxide (GdTiO _x) to within the core. Here, gadolinium (Gd) acts as a kind of conductive lightly donor, and is sufficiently chemically and electrically stable and is combined with titanium (Ti).

Gadolinium (Gd) is one of the lanthanide elements belonging to group 3A of the periodic table.

Gadolinium titanium oxide films (GdTiO _x ) are used for deposition process conditions such as temperature, pressure, flow rate and physical / chemical states of the thin film (eg grain size, film). The dielectric constant value can be adjusted within the range of 40 to 60 according to the change in film thickness and composition. For example, the leakage current generation level and the breakdown voltage level may be controlled according to the doped content of the gadolinium (Gd) component. That is, a charge storage dielectric properties on the specification of the type and the capacitors of the material used as an electrode via the gadolinium titanium oxide (GdTiO _x) deposition control is adopted TiO _2, Ta ₂ O ₅ or HfO ₂ dielectric layer because it can actually Not only can the MIM capacitor's dielectric limit and leakage current generation problems be overcome more effectively, but the thermal stability is enhanced by the gadolinium and oxygen defects (Gd-O bone), which improves the performance and reliability of memory products.

The gadolinium titanium oxide film used in the examples described below has a dielectric constant (ε = -50) of greater than HfO ₂ (ε = 20) or Ta ₂ O ₅ (ε = 25) and leakage from TiO ₂ (ε = 40 to 80). The small current and high breakdown voltage enable high charge capacity values of more than 25 fF / cell in DRAM families up to 60 nm.

When using MIM capacitors with gadolinium titanium oxide as the dielectric film, the equivalent oxide thickness can be lowered to 10Å or less than that of SIS (Polysilicon-Insulator-Polysilicon) or MIS (Metal-Insulator-Polisilicon) capacitors. have. In addition, since the leakage current can be more effectively suppressed than that of the MIM capacitor employing the TiO ₂ , Ta ₂ O ₅ , or HfO ₂ dielectric film, the breakdown field can be increased more than that of the MIM capacitor employing the TiO ₂ . When used in the 512M class or higher integrated product line where the process is adopted, it is possible to achieve high quality and high reliability at the same time.

2 is a view showing the structure of a capacitor according to an embodiment of the present invention.

Referring to FIG. 2, the capacitor includes a first electrode 100 serving as a charge field, a gadolinium titanium oxide film GdTiO _x , 101, and a second electrode 102 serving as a plate. The first electrode 100 and the second electrode 102 may be a noble metal layer such as Ru, and the gadolinium titanium oxide layer 22 may use 'GdTiO ₃ '.

3 is a view for explaining a first deposition method of GdTiO _x .

GdTiO _x has a structure in which a titanium oxide film (Ti _x O _y ) and a gadolinium oxide film (Gd _x O _y ) are mixed.

Atomic layer deposition is used to deposit the mixed structure as described above.

First, unit cycle 1 is as follows.

[Unit cycle 1]

[(Ti source / purge / reactive gas / purge) m (Gd source / purge / reactive gas / purge) n] Q

In unit cycle 1, (Ti source / purge / reactive gas / purge) m means to repeat 'Ti _x O _y unit cycle' m number of cycles, (Gd source / purge / reactive gas / purge) n means to repeat 'Gd _x O _y unit cycle' with the number of cycles n times, [(Ti source / purge / reactive gas / purge) m (Gd source / purge / reactive gas / purge) n] Q Is composed of (Ti source / purge / react gas / purge) m (Gd source / purge / react gas / purge) n '[GdTiO _x ] It means that the unit cycle 'is repeated in the number of Q cycles.

First, in the 'Ti _x O _y unit cycle' consisting of (Ti source / purge / reactive gas / purge) m, 'Ti source' is a step of injecting a Ti source for depositing Ti _x O _y , and 'purge' Injecting a purge gas, 'reaction gas' is a step of injecting a reaction gas for depositing Ti _x O _y .

And, in the 'Gd _x O _y unit cycle' consisting of (Gd source / purge / reactive gas / purge) n, 'Gd source' is a step of injecting a Gd source for depositing Gd _x O _y , 'Purge' Is a step of injecting a purge gas, and a 'reaction gas' is a step of injecting a reaction gas for depositing Gd _x O _y .

By repeating [Ti _x O _y unit cycle] and [Gd _x O _y unit cycle] made as described above with m and n cycles, respectively, Ti _x O _y and Gd _x O _y of a certain thickness are deposited, respectively. (Ti source / purge / reactive gas / purge) m (Gd source / purge / reactive gas / purge) n combined [Ti _x O _y unit cycle] and [Gd _x O _y unit cycle] To determine the total thickness of [GdTiO _x ].

Then, the ratio of the number of iterations of the Ti _x O _y and Gd _x O _y is in order to increase the effect of uniformly mixing the [Ti _x O _y unit cycles; number of repetitions of m and [Gd _x O _y unit cycle] n Is at least 5: 5 or less.

FIG. 3 is a view for explaining atomic layer deposition (ALD) of [GdTiO _x ] according to [Unit Cycle 1]. Specifically, "GdTiO ₃ ", which is an example of a gadolinium oxide film, may be formed by atomic layer deposition. When the gas is supplied into the chamber.

An example of deposition of [GdTiO ₃ ] is described in detail with reference to FIG. 3.

Before explaining the deposition process, [Ti _x O _y unit cycle] is a unit cycle of (Ti / N ₂ / O ₃ / N ₂ ), and the unit cycle is repeated m times. In the unit cycle, 'Ti' is a Ti source, 'N ₂ ' is a purge gas, and 'O ₃ ' is a reaction gas.

[Gd _x O _y unit cycle] uses (Gd / N ₂ / O ₃ / N ₂ ) as a unit cycle, and repeats this unit cycle n times. In the unit cycle, 'Gd' is the Gd source, 'N ₂ ' is the purge gas, and 'O ₃ ' is the reaction gas.

[Ti _x O _y unit cycles] and [Gd _x O _y unit cycles] proceed in an atomic layer deposition chamber which maintains a pressure of 0.1 to 10 tor and a substrate temperature of 100 to 350 ° C, respectively.

In the deposition of Ti _x O _y , the inside of the chamber maintains a pressure of 0.1torr to 10torr and a substrate temperature of 100 ° C to 350 ° C. First, Ti source selected from Ti [OCH (CH ₃ ) ₂ ] ₄ )] or Ti-containing organometallic compound is flowed into the chamber at a flow rate of 50 to 500 sccm to adsorb the Ti source. Next, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove the unreacted Ti source. Subsequently, the reaction gas O ₃ (concentration 200 ± 20 g / m ³ ) is flowed at a flow rate of 0.1 to 1 slm to induce a reaction between the adsorbed Ti source and O ₃ to deposit a Ti _x O _y atomic layer. Finally, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove unreacted O ₃ and reaction byproducts.

The process of Ti source injection, N ₂ purge, O ₃ injection, and N ₂ purge as described above is a unit cycle, and the unit cycle is repeated m times to deposit Ti _x O _y having a predetermined thickness. Meanwhile, in addition to O ₃ , O ₂ , O ₂ plasma, N ₂ O, N ₂ O plasma, or H ₂ O (water vapor) may be used as a reaction gas for oxidation of the Ti source, and in addition to nitrogen (N ₂ ) as a purge gas. An inert gas such as argon (Ar) may be used, and another purge method may use a vacuum pump to discharge residual gas or reaction byproducts to the outside.

Next, will be described for a Gd _x O _y deposition, the deposition chamber and the substrate temperature is 100 ℃ ~350 ℃, pressure is maintained in 0.1torr~10torr. An organometallic compound containing Gd (which is a Gd source) such as Gd (thd) ₃ or Cp (CH ₃ ) ₃ Gd is flowed to adsorb the Gd source onto the substrate. Next, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove the unreacted Gd source, and the reaction gas O ₃ (concentration 200 ± 20 g / m ³ ) is flowed at a flow rate of 0.1 to 1 slm to adsorb. Induce a reaction between the Gd source and O ₃ to deposit a Gd _x O _y atomic layer. Next, a purge process is performed in which nitrogen (N ₂ ) gas is flowed for 0.1 seconds to 5 seconds to remove unreacted O ₃ and the reaction byproduct.

Gd source injection, N ₂ purge, O ₃ injection, N ₂ purge as described above as a unit cycle, this unit cycle is repeated n times to deposit a certain thickness of Gd _x O _y . Meanwhile, in addition to O ₃ , O ₂ , O ₂ plasma, N ₂ O, N ₂ O plasma, or H ₂ O (water vapor) may be used as a reaction gas for oxidation of the Gd source, and nitrogen (N ₂ ) may be used as the purge gas. In addition, an inert gas such as argon (Ar) may be used, and as another purge method, a residual gas or a reaction by-product may be discharged to the outside using a vacuum pump.

As described above, the thickness of GdTiO obtained by performing [Ti _x O _y unit cycle] and [Gd _x O _y unit cycle] is 50 to 150 kPa.

Meanwhile, the reason for lowering the substrate temperature in the range of 100 ° C. to 350 ° C. during deposition of Gd _x O _y and Ti _x O _y is to minimize CVD (Chemical Vapor Deposition) reaction due to thermal decomposition of the Ti source and the Gd source. Atomic layer deposition (ALD) is to lower the substrate temperature as much as possible to have excellent properties of suppressing particle generation compared to chemical vapor deposition (CVD), and to have superior characteristics compared to high temperature chemical vapor deposition.

And, [Ti _x O _y unit cycle; repeat thickness of Gd _x O _y due to the repetition of the Ti _x O _y thickness and [Gd _x O _y unit cycle] in by of the Ti _x O _y and Gd _x O _y is It is mixed (this mixed structure is called Nano-mixed) and adjusted to deposit GdTiO ₃ . For example, the thickness for mixing is in the range of 0.1 to 10 mm 3. On the other hand, when the thickness of each film is larger than 10 GPa, Ti _x O _y and Gd _x O _y are not mixed but become a stack or laminate structure like a Ti _x O _y / Gd _x O _y structure. When the laminated or laminated structure is used in a capacitor differently from the mixed structure, the required EOT and leakage current characteristics are lowered compared to the mixed structure GdTiO ₃ as the film contacting the first electrode or the second electrode is limited to either one.

[Unit cycle 2]

[Ti / Purge / Gd / Purge / Reaction Gas / Purge]

In the unit cycle 2, 'Ti' is a step of injecting a Ti source, 'purge' is a step of injecting a purge gas, 'Gd' is a step of injecting a Gd source, and 'reaction gas' is a reaction gas of oxygen. Injecting the circle.

By repeating the unit cycle 2 made as described above to deposit a certain thickness [GdTiO _x ] of Gd and Ti mixed in a certain ratio.

In order to increase the effect of uniformly mixing Ti and Gd, the Ti source injection step and the Gd source injection step are controlled at a ratio of 5: 5 or less. Preferably the Gd source injection step is the same or less than the Ti source injection step.

FIG. 4 is a view for explaining the atomic layer deposition method (ALD) of [GdTiO _x ] according to [Unit Cycle 2]. Specifically, "GdTiO ₃ ", which is an example of a gadolinium oxide film, may be formed by atomic layer deposition. When the gas is supplied into the chamber.

An example of deposition of [GdTiO ₃ ] is described in detail with reference to FIG. 4.

Before describing the deposition process, the unit cycle shown in FIG. 4 is [Ti / N ₂ / Gd / N ₂ / O ₃ / N ₂ ], where 'Ti' is a Ti source and 'Gd' is a Gd source. , 'N ₂ ' is the purge gas, 'O ₃ ' is the reaction gas.

The unit cycle of [Ti / N ₂ / Gd / N ₂ / O ₃ / N ₂ ] proceeds in an atomic layer deposition chamber maintaining a pressure of 0.1 to 10 tor and a substrate temperature of 100 to 350 ° C.

First, a Ti source selected from Ti [OCH (CH ₃ ) ₂ ] ₄ )] or Ti-containing organometallic compound is flowed into the chamber to adsorb the Ti source.

Next, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove the unreacted Ti source.

Next, an organometallic compound containing Gd (which is a Gd source) such as Gd (thd) ₃ or Cp (CH ₃ ) ₃ Gd is flowed to adsorb the Gd source to the substrate.

Next, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove the unreacted Gd source.

Subsequently, the reaction gas O ₃ (concentration 200 ± 20 g / m ³ ) is flowed at a flow rate of 0.1 to 1 slm to induce a reaction between the adsorbed Ti source and the Gd source and O ₃ to deposit a GdTiO atomic layer.

Finally, a purge process is performed in which nitrogen (N ₂ ) gas is flowed to remove unreacted O ₃ and reaction byproducts.

The above-described processes of Ti source injection, N ₂ purge, Gd source injection, N ₂ purge, O ₃ injection, and N ₂ purge are used as unit cycles, and the unit cycle is repeated several times to deposit GdTiO having a predetermined thickness. Meanwhile, in addition to O ₃ , O ₂ , O ₂ plasma, N ₂ O, N ₂ O plasma, or H ₂ O (water vapor) may be used as a reaction gas for oxidation of the Ti source and the Gd source, and nitrogen (N) may be used as the purge gas. ₂ ) In addition, an inert gas such as argon (Ar) may be used, and as another purge method, a residual gas or a reaction by-product may be discharged to the outside by using a vacuum pump.

As _{above, [Ti / N 2 / Gd} / N 2 / O 3 / N 2] GdTiO 3 is obtained by proceeding the unit cycle is its thickness in 50~150Å.

On the other hand, the reason for lowering the substrate temperature in the range of 100 ℃ to 350 ℃ is to minimize the CVD (Chemical Vapor Deposition) reaction by the thermal decomposition of the Ti source and Gd source. Atomic layer deposition (ALD) is to lower the substrate temperature as much as possible to have excellent properties of suppressing particle generation compared to chemical vapor deposition (CVD), and to have superior characteristics compared to high temperature chemical vapor deposition.

3 and 4, the atomic layer deposition method has been described, but the GdTiO ₃ dielectric film of the present invention can be deposited by the atomic layer deposition method using plasma, that is, PEALD. At this time, the atomic layer deposition method using the plasma is to excite the plasma to at least one pulse during the unit cycle 1, 2, thereby improving the film quality.

After the deposition of GdTiO through the ALD or PEALD method as described above, the post-heat treatment is selectively performed for the purpose of minimizing leakage current and enhancing breakdown voltage. At this time, the post-heat treatment uses any one of plasma annealing, furnace heat treatment, and rapid heat treatment.

First, plasma annealing is performed for 1 to 5 minutes while applying 100 to 500 W of RF (Radio Frequency) power at a temperature in the range of 200 to 500 ° C. and a pressure of 0.1 to 10 torr. At this time, any one selected from N ₂ , H ₂ , N ₂ / H ₂ (mixing of N ₂ and H ₂ ), O ₂ , O _3, or NH ₃ proceeds as an atmosphere gas. Atmospheric gas flows at a flow rate of 5 sccm to 5 slm.

The rapid heat treatment proceeds while flowing the above-mentioned atmosphere gas at a flow rate of 5 sccm to 5 slm while maintaining a temperature of 500 to 800 ° C. in a rapid heat treatment chamber maintaining a pressure of normal pressure (760 to 760 torr) or a reduced pressure (1 to 100 torr). do.

Finally, the electric furnace heat treatment flows the above-mentioned atmosphere gas at a flow rate of 5 sccm to 5 slm while maintaining a temperature of 600 to 800 ° C. in an electric furnace maintaining a pressure of atmospheric pressure (760 to 760 torr) or a reduced pressure (1 to 100 torr). Proceed.

5A to 5C are cross-sectional views illustrating a method of manufacturing a MIM capacitor employing a GdTiO ₃ dielectric film according to an embodiment of the present invention.

As shown in FIG. 5A, the first electrode 100 is formed. Here, the first electrode 100 may have a stack, cylinder, or concave structure. The first electrode 100 may also be referred to as a "charge storage electrode" or a "lower electrode."

The material used as the first electrode 100 is at least one metal material selected from Ru, TiN, Pt, Ir, or HfN.

Next, the purpose of the densification of the film quality of the first electrode 100 or the thin film to within or volatilizing the residual impurities that causes the leakage current on the surface, or to reduce the roughness (roughness) of the surface to avoid the electric field concentration N _2, H ₂ , N ₂ / H ₂ , O ₂ , _{O 3} , NH _{3 The} atmosphere is alternatively subjected to plasma annealing, low temperature heat treatment to an electric furnace (Furnace) or RTP annealing.

Plasma annealing conditions are plasma (RF Power: 100) for 1 to 5 minutes in a chamber placed in an alternative gas atmosphere (5 sccm to 5 slm) of the atmosphere gas in the range of 200 to 500 ° C. and 0.1 to 10 torr. 500 W) Annealing treatment is performed.

Instead of annealing using plasma, 500 to 800 ° C in an atmospheric pressure (700 to 760 torr) or reduced pressure (1 to 100 torr) rapid thermal process (RTP) chamber, and an alternative gas atmosphere (5 sccm to 5 slm) among the atmosphere gases. It can be annealed in the state, or it can be annealed using the electric furnace (600-800 degreeC) of an atmosphere.

As shown in FIG. 5B, GdTiO ₃ 101 is deposited to a thickness of 50 to 150 Å as a dielectric film on the entire surface including the first electrode 100.

At this time, GdTiO ₃ (101) is deposited using ALD or PEALD by unit cycle 1 or unit cycle 2 described above.

As described above, GdTiO ₃ (101) increases the breakdown voltage characteristic that is a problem when employing only TiO ₂ , Ta ₂ O ₅ , and HfO ₂ thin films to 2.0V (@ 1pA / cell), which is a mass-applicable level. The leakage current characteristics can be maintained at a level of 0.5 fA / cell or less.

On the other hand, after the deposition of GdTiO ₃ through the ALD or PEALD method, the post-treatment is selectively performed for the purpose of minimizing leakage current and enhancing breakdown voltage. At this time, the post-treatment uses any one of plasma annealing, furnace heat treatment, and rapid heat treatment.

First, plasma annealing is performed for 1 to 5 minutes while applying 100 to 500 W of RF (Radio Frequency) power at a temperature in the range of 200 to 500 ° C. and a pressure of 0.1 to 10 torr. At this time, any one selected from N ₂ , H ₂ , N ₂ / H ₂ (mixing of N ₂ and H ₂ ), O ₂ , O _3, or NH ₃ proceeds as an atmosphere gas. Atmospheric gas flows at a flow rate of 5 sccm to 5 slm.

The rapid heat treatment proceeds while flowing the above-mentioned atmosphere gas at a flow rate of 5 sccm to 5 slm while maintaining a temperature of 500 to 800 ° C. in a rapid heat treatment chamber maintaining a pressure of normal pressure (760 to 760 torr) or a reduced pressure (1 to 100 torr). do.

Finally, the electric furnace heat treatment flows the above-mentioned atmosphere gas at a flow rate of 5 sccm to 5 slm while maintaining a temperature of 600 to 800 ° C. in an electric furnace maintaining a pressure of atmospheric pressure (760 to 760 torr) or a reduced pressure (1 to 100 torr). Proceed.

As shown in FIG. 5C, the second electrode 102 is formed on the GdTiO ₃ 101. In this case, the second electrode 102 uses polysilicon or a metal electrode doped with N-type impurities, and forms TiN, Ru, Pt, Ir, or HfN as the metal electrode. The second electrode 102 may also be referred to as a "plate electrode" or an "upper electrode."

In this way, using the second electrode 102 as a metal, metal-insulator-metal (MIM) such as RIT (Ru-GTO-TiN), RIR (Ru-GTO-Ru), TIT (TiN-GTO-TiN), or the like. Complete the type capacitor.

On the other hand, the thermal process and curing process in the back-end process of the DRAM manufacturing process on the metal-based second electrode (H ₂ , N ₂ , or N ₂ / H ₂ atmosphere), A protective film (also called a capping film or buffer layer) is formed to improve structural stability from humidity, temperature or electrical shock during the environmental test associated with the outer package process and reliability. At this time, the protective film protects the MIM capacitor by stacking an oxide film such as Al ₂ O ₃ , HfO ₂ , Ta ₂ O ₅ , ZrO ₂ , TiO _2, or the like and TiN and a metal layer having a thickness of about 50 μs to 200 μs.

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

The present invention employs a GdTiO ₃ thin film having a larger dielectric constant value than HfO ₂ (ε = 20) or Ta ₂ O ₅ ((ε = 25) as the dielectric film of the capacitor, so that an equivalent oxide thickness (Tox) of 5 to 10 kW can be obtained. Therefore, it is possible to obtain a relatively large charge capacity value by employing an HfO ₂ or Ta ₂ O ₅ dielectric film to construct a capacitor.

In addition, since conductive Gd has a sufficient chemical and electrical stability and acts as a donor (electron donor) in a state in which it is combined with Ti, the parasitic resistance component in contact with the electrode reduces TiO ₂ (ε = 40 to 80). ) The leakage current can be suppressed more effectively than only the dielectric film is used to form the MIM capacitor.

In addition, due to the Gd-O bond, the electrical strength is improved together with the thermal strength, thereby obtaining excellent breakdown field characteristics.

In conclusion, GdTiO ₃ (GTO) dielectric films have better thermal and electrical stability than HfO ₂ , Ta ₂ O ₅ , and TiO ₂ . You can improve at the same time.

Claims (26)

A first electrode; A dielectric film containing a gadolinium (Gd) component and a titanium (Ti) component on the first electrode; And A second electrode on the dielectric layer Capacitor comprising a. The method of claim 1, The dielectric film has a GdTiO ₃ structure capacitor. The method of claim 2, The GdTiO ₃ structure, Capacitor having a structure in which Gd ₂ O ₃ and TiO ₂ are mixed. The method of claim 1, The dielectric film is a capacitor 50 ~ 150Å thick. The method of claim 1, The first electrode and the second electrode, Capacitor which is a metal film. The method of claim 1, The first electrode and the second electrode, A capacitor which is at least one metal material selected from Ru, TiN, Pt, Ir, or HfN. Forming a first electrode; Forming a dielectric film containing a gadolinium (Gd) component and a titanium (Ti) component on the first electrode; And Forming a second electrode on the dielectric layer Capacitor manufacturing method comprising a. The method of claim 7, wherein The dielectric film has a GdTiO ₃ structure capacitor manufacturing method. The method of claim 8, The GdTiO ₃ structure, A method for producing a capacitor, which is formed by mixing an oxide containing a gadolinium (Gd) component and an oxide containing a titanium (Ti) component. The method of claim 9, And the oxide containing gadolinium (Gd) and the oxide containing titanium (Ti) are mixed through in-situ deposition using atomic layer deposition (ALD). The method of claim 10, The atomic layer deposition method of the oxide containing the gadolinium (Gd) component, A method of manufacturing a capacitor that repeats the unit cycle consisting of a source injection step, a purge step, a reaction gas injection step and a purge step for injecting a gadolinium source. The method of claim 10, The atomic layer deposition method of the oxide containing the titanium (Ti) component, Method of manufacturing a capacitor by repeating the unit cycle consisting of a source injection step, a purge step, a reaction gas injection step and a purge step of injecting a titanium source. The method of claim 8, The GdTiO ₃ structure, Formed by atomic layer deposition (ALD) using a unit cycle comprising a source injection step of injecting a gadolinium source containing the gadolinium (Gd) component and a source injection step of injecting a titanium source containing the titanium (Ti) component Capacitor manufacturing method. The method of claim 13, The atomic layer deposition method, A method of manufacturing a capacitor, which repeats a unit cycle consisting of a source injection step of injecting a gadolinium source, a purge step, a source injection step of injecting a titanium source, a purge step, a reaction gas injection step and a purge step. The method according to any one of claims 11 to 14, The gadolinium source, A method for producing a capacitor, wherein Gd (thd) ₃ or Cp (CH ₃ ) ₃ Gd. The method according to any one of claims 11 to 14, The titanium source is, A process for producing a capacitor, which is an organometallic compound containing Ti [OCH (CH ₃ ) ₂ ] ₄ )] or Ti. The method according to any one of claims 11, 12 or 14, The reaction gas, A method for producing a capacitor, which is any one selected from O ₃ (concentration 200 ± 20 g / m ³ ), O ₂ , O ₂ plasma, N ₂ O, N ₂ O plasma, or H ₂ O (water vapor). The method according to any one of claims 11, 12 or 14, The purge step, Capacitor manufacturing method using an inert gas or a vacuum pump as a purge gas. The method according to any one of claims 11 to 14, The unit cycle, A method for producing a capacitor, which proceeds in an atomic layer deposition chamber that maintains a substrate temperature of 100 ° C to 350 ° C. The method according to any one of claims 11, 12 or 14, And discharging the plasma in at least one of the source injection step, the reaction gas injection step, and the purge step. The method of claim 14, And the number of injections of the gadolinium source is equal to or smaller than the number of injections of the titanium source. The method of claim 7, wherein After the dielectric film is formed, Capacitor manufacturing method further comprising the step of post-heat treatment. The method of claim 22, The post heat treatment, Capacitor manufacturing method of any one selected from plasma annealing, electrothermal treatment or rapid thermal treatment. The method according to claim 7 or 8, And the dielectric film is formed to a thickness of 50 to 150 kHz. The method of claim 7, wherein The first electrode and the second electrode, A capacitor manufacturing method formed from a metal film. The method of claim 7, wherein The first electrode and the second electrode, A method for manufacturing a capacitor formed of at least one metal material selected from Ru, TiN, Pt, Ir, or HfN.

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