WO2013085290A1

WO2013085290A1 - Method for manufacturing semiconductor device

Info

Publication number: WO2013085290A1
Application number: PCT/KR2012/010508
Authority: WO
Inventors: 권성수; 한정민; 권봉수
Original assignee: 주식회사 테스
Priority date: 2011-12-07
Filing date: 2012-12-06
Publication date: 2013-06-13
Also published as: TW201332015A; TWI489551B

Abstract

Disclosed is a method for manufacturing a semiconductor device having a minute pattern smaller than the smallest pattern that is formable by means of a photolithography process. The method for manufacturing the semiconductor device includes: forming a silicon layer on a substrate; forming a photoresist layer on top of the silicon layer; exposing the photoresist layer; developing the exposed photoresist layer; forming a pattern on the silicon layer by using the photoresist layer as a mask; removing the photoresist layer; forming an insulation layer; and trimming the pattern formed on the silicon substrate.

Description

Semiconductor device manufacturing method

The present invention relates to a semiconductor device manufacturing method, and more particularly to a semiconductor device manufacturing method having a fine pattern and a semiconductor device manufacturing method that can achieve a high etching selectivity.

Semiconductor devices are used in almost all electronic devices. In particular, as electronic devices become more mobile and high performance, fine pattern formation is increasingly required.

In particular, semiconductor devices are manufactured by forming a pattern on a wafer by photolithography. In more detail, after forming a photoresist film on the wafer, the photoresist pattern is exposed and developed to form a photoresist pattern, and the silicon film formed on the wafer is etched using the photoresist pattern to manufacture semiconductor devices by the silicon film.

By the way, the pattern formation by this photolithography process has a limit in the size. This is because it relates to the wavelength of the light source and the photoresist for reacting the photoresist film.

As the semiconductor devices become more directly integrated, patterns have a minimum size of 10-20 nm or less. In the case of such a size, the formation of a pattern by a photographic process is a very technical situation.

On the other hand, when etching a silicon film, a titanium nitride (TiN) pattern for forming a barrier film or an electrode layer, or an oxide film constituting an insulating film is etched to cause defects.

More specifically, the silicon (Si) etching method is a method of anisotropically etching gases such as hydrogen chloride (HCl), hydrogen bromide (HBr) in the RF plasma chamber, sulfur fluoride (SF ₆ ) An isotropic etching method using a remote plasma source (RPS), an isotropic time using a mixture of nitric acid, hydrofluoric acid and acetic acid, and an anisotropic etching method using a KOH solution have been used.

In the case of liquid etching, the etching selectivity of each oxide layer is different. This is because the concentration of hydrogen and carbon of each oxide film type affect the liquid phase etch rate. Generally, the higher the concentration of hydrogen, the faster the etch rate in the liquid phase.

However, these methods may have a poor etching selectivity between amorphous silicon or polysilicon and a silicon oxide film or a titanium nitride (TiN) pattern at the time of etching the silicon film, thereby causing a defect in the titanium nitride pattern.

Therefore, studies on a process having a high selectivity of amorphous silicon or polysilicon and a silicon oxide film or a titanium nitride (TiN) pattern at the time of etching the silicon film are being conducted.

Accordingly, an object of the present invention is to provide a method of manufacturing a semiconductor device having a finer pattern than the minimum pattern that can be formed by photolithography.

In addition, the problem to be solved by the present invention is to provide a method for manufacturing a semiconductor device that can achieve a high etching selectivity.

A semiconductor device manufacturing method according to an exemplary embodiment of the present invention for achieving the above object, forming a silicon layer on a substrate, forming a photoresist film on the silicon layer, and exposing the photoresist film Developing the exposed photoresist film, forming a pattern on the silicon layer using the developed photoresist film as a mask, removing the photoresist film, forming an insulating film, And trimming the pattern formed on the silicon substrate.

Meanwhile, the semiconductor device manufacturing method may further include removing a portion of the insulating film after the insulating film is formed to expose the pattern.

In this case, a silicon oxide film may be used as the insulating film. In this case, in the removing of a part of the insulating film, the insulating film may be removed by supplying hydrogen fluoride (HF) gas and ammonia (NH ₃ ) gas to the insulating film.

In addition, in the step of removing a portion of the insulating film, by-products generated by the reaction between the insulating film, the hydrogen fluoride (HF) gas and the ammonia (NH ₃ ) gas may be removed.

In this case, the by-product may be removed by a heating method using a lamp.

In addition, the method may further include the step of removing the by-products by the heating method, the substrate is transferred to the cooling chamber to cool.

In the trimming, the pattern may be trimmed by supplying chlorine trifluoride (ClF ₃ ) gas to the silicon substrate from which the insulating film is partially removed.

In addition, before supplying the chlorine trifluoride (ClF ₃ ) gas, the chlorine trifluoride (ClF ₃ ) gas may be diluted, wherein the chlorine trifluoride (ClF ₃ ) gas to the nitrogen (N ₂ ) gas Can be diluted.

In addition, the chlorine trifluoride (ClF ₃ ) gas may be trimmed by supplying 1 to 30 sccm, the nitrogen (N ₂ ) gas at 100 to 1000 sccm.

In addition, the trimming may be performed under a pressure of 300 mtorr to 8 torr.

In addition, after the insulating film is removed, the trimming process may be continuously performed without breaking the vacuum state.

According to another aspect of the present invention, there is provided a method of fabricating a semiconductor device, the method comprising: forming a titanium nitride (TiN) film on a substrate, patterning a titanium nitride (TiN) film, Forming a silicon film on a substrate on which patterned titanium nitride (TiN) is formed, and etching the silicon film using chlorine trifluoride (ClF ₃ ) gas, and in the etching of the silicon film, the titanium nitride When (TiN) is exposed, the substrate is kept in the range of -76 to 70.

In this case, in the etching of the silicon film, when the titanium nitride is not exposed, the substrate may be maintained within a range of 70 to 80.

Alternatively, before the etching of the silicon film, the substrate may be transferred to a cooling chamber to lower the temperature of the substrate in the cooling chamber.

Meanwhile, after the forming of the silicon film, the method may further include removing a silicon oxide film naturally formed on the silicon film.

In this case, the removing of the silicon oxide film may include supplying hydrogen fluoride (HF) gas and ammonia (NH ₃ ) gas to the silicon oxide film.

The removing of the silicon oxide film may include removing by-products generated by the reaction between the silicon oxide film, the hydrogen fluoride (HF) gas, and the ammonia (NH ₃ ) gas by a heating method using a lamp. It may further comprise a step.

According to the semiconductor device manufacturing method according to the present invention, it is possible to manufacture a semiconductor device having a pattern finer than the minimum pattern that can be formed by photolithography.

In addition, since the trimming step is a gas phase reaction, the selectivity between silicon and oxide film can be increased.

In addition, the above processes can be carried out in each chamber on a single sheet, thereby improving wafer-to-wafer uniformity.

Further, after removing the insulating film (silicon oxide film), the trimming process can be continuously performed without breaking the vacuum state, thereby minimizing the variation of the process due to the naturally occurring oxide film.

According to the method of manufacturing a semiconductor device according to the present invention, an amorphous silicon film or a polysilicon film can be etched without being damaged by etching a titanium nitride (TiN) pattern.

In addition, after removing the silicon oxide film formed naturally after forming the silicon film, the silicon film can be more easily etched.

1 is a flowchart illustrating a method of manufacturing a semiconductor device in accordance with an exemplary embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a result of performing a step of forming a silicon layer on the substrate shown in FIG. 1.

3 is a schematic cross-sectional view showing a result of performing a step of forming the photoresist film shown in FIG.

4 is a schematic cross-sectional view illustrating the step of exposing the photoresist film shown in FIG. 1.

FIG. 5 is a schematic cross-sectional view illustrating a result of performing the developing of the photoresist film shown in FIG. 1.

FIG. 6 is a schematic cross-sectional view illustrating a result of performing a step of forming a pattern on the silicon layer illustrated in FIG. 1.

FIG. 7 is a schematic cross-sectional view illustrating a result of performing a step of removing the photoresist film shown in FIG. 1.

FIG. 8 is a schematic cross-sectional view showing the result of performing the step of forming the insulating film shown in FIG.

FIG. 9 is a schematic cross-sectional view illustrating a result of performing a step of partially removing the insulating film illustrated in FIG. 1.

FIG. 10 is a schematic cross-sectional view illustrating trimming the pattern illustrated in FIG. 1.

FIG. 11 is a graph illustrating an etching selectivity of polysilicon (poly-Si), silicon nitride (SiN), and oxide (oxide).

12 is a flowchart illustrating a method of manufacturing a semiconductor device in accordance with an exemplary embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating an example of a substrate before forming the titanium nitride film illustrated in FIG. 12.

FIG. 14 is a cross-sectional view after the step of forming the titanium nitride film shown in FIG. 12 on the substrate shown in FIG.

FIG. 15 is a cross-sectional view after the step of patterning the titanium nitride film shown in FIG. 12.

16 is a cross-sectional view after the step of forming the silicon film shown in FIG.

FIG. 17 is a cross-sectional view illustrating a process after removing the silicon oxide film illustrated in FIG. 12.

18 is a cross-sectional view illustrating a step after etching the silicon film illustrated in FIG. 12.

FIG. 19 is a cross-sectional view of a contact plug formed on the barrier film illustrated in FIG. 18.

FIG. 20 is an SEM image illustrating etching characteristics of amorphous silicon, polysilicon, and titanium nitride when the silicon film is etched under the condition that the temperature of the substrate is maintained at 40. FIG.

FIG. 21 is a photograph showing etching characteristics of amorphous silicon, polysilicon, and titanium nitride when the silicon film is etched under the condition that the temperature of the substrate is maintained at 60;

FIG. 22 is a photograph illustrating etching characteristics of amorphous silicon, polysilicon, and titanium nitride when the silicon film is etched under the condition that the temperature of the substrate is maintained at 80;

FIG. 23 is a cross-sectional view illustrating a form in which a titanium nitride pattern formed by patterning a titanium nitride film is formed only on a lower portion of an inside of a hole, and a silicon layer is formed thereon.

FIG. 24 is a cross-sectional view illustrating a silicon layer etched in FIG. 23.

FIG. 25 is a cross-sectional view of a titanium nitride pattern formed by patterning a titanium nitride film formed on a lower side of a hole and a side surface of a hole, and a silicon layer formed on the upper portion thereof.

FIG. 26 is a cross-sectional view illustrating a silicon layer etched in FIG. 25.

FIG. 27 is a cross-sectional view illustrating a titanium nitride pattern formed by patterning a titanium nitride film, a silicon nitride film formed on a lower side of a hole, and a silicon layer formed on a side of a hole.

FIG. 28 is a cross-sectional view illustrating a silicon layer etched in FIG. 27.

The above-described features and effects of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, and thus, those skilled in the art to which the present invention pertains may easily implement the technical idea of the present invention. Could be. The present invention is not limited to the following embodiments and may be implemented in other forms. The embodiments introduced herein are provided to make the disclosure more complete and to fully convey the spirit and features of the present invention to those skilled in the art. In the drawings, the thickness of each device or film (layer) and regions has been exaggerated for clarity of the invention, and each device may have various additional devices not described herein.

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

Method of manufacturing a semiconductor device having a fine pattern

1 is a flowchart illustrating a method of manufacturing a semiconductor device in accordance with an exemplary embodiment of the present invention, and FIGS. 2 to 8 are schematic cross-sectional views showing results of performing each step in FIG. 1.

1 and 2, according to the method of manufacturing a semiconductor device according to an exemplary embodiment of the present invention, a silicon layer is formed on a substrate S on which an insulating film 101 is naturally formed in an oxygen or nitrogen atmosphere. 102 is formed (step S110). The silicon layer 102 may be formed of various silicon layers according to the required semiconductor device, such as crystalline silicon, microcrystalline silicon, amorphous silicon, and the like.

The silicon layer 102 may be formed to a thickness of about 1 micrometer, and may be formed by conventional chemical vapor deposition (CVD). In addition, the silicon layer 102 may be doped with an impurity to form a conductive layer.

1 and 3, a photoresist film 103 of a desired type, such as a positive type or a negative type, is formed on the silicon layer 102 (step S120). The photoresist film 103 may be formed to a thickness of, for example, 6500, and a spray type spin coater device for applying a photoresist through a nozzle while rotating the substrate S may be used. .

1 and 4, the photoresist film 103 formed on the silicon substrate is exposed using the mask M on which the pattern is formed (step S130). Thereby, light L is divided into the part 103a exposed by the pattern of the said mask M, and the part 103b covered by the mask M. As shown to FIG. The exposed portion 103a is chemically changed by light so that the two

portions

103a and 103b have different chemical properties.

1 and 5, the exposed photoresist film is developed (step S140), and as shown in FIG. 6, a pattern is formed on the substrate using the same (step S150). To this end, a mixture of carbon tetrachloride (CCl ₄ ) and argon, a mixture of carbon tetrafluoride (CF ₄ ) and oxygen, CF ₃ Cl gas, a fluorocarbon compound, and a chlorine gas mixture may be used.

1, 6, and 7, the remaining photoresist film 130a is removed through the strip process (step S160). In order to remove the remaining portion 103a of the photoresist film in FIG. 6, a mixture of monoethanolamine and dimethyl sulfoxide maintained at a temperature of about 10 to 40 degrees Celsius was used for about 300 seconds or less. The process can be carried out. Thereafter, washing may proceed.

1 and 8, an insulating film 104 is formed to insulate each electronic device included in the pattern formed on the silicon layer from each other (step S170). In this case, a silicon oxide layer (SiO ₂ ) may be formed as the insulating layer. The insulating film (silicon oxide film) 104 covering the pattern constituted by the silicon pattern forming portion 102b then interferes with the trimming process to be performed. Therefore, it is necessary to remove the insulating film 104 covering the pattern composed of such a silicon pattern forming portion 102b.

1 and 9, a fine pattern is formed by trimming the thus formed pattern (step S190). In order to remove the insulating film 104 of FIG. 8, a part of the insulating film 104 is removed by supplying a source gas G1 such as hydrogen fluoride (HF) gas and ammonia (NH ₃ ) gas to the insulating film 104. can do.

The reaction mechanism at this time is as follows.

HF + NH _3- > NH ₄ F

NH ₄ F + SiO _2- > (NH ₄ ) ₂ SiF ₆ (s) + 2H ₂ O (g) + 4NH ₃ (g)

Meanwhile, an oxide film and ammonium fluoride (NH ₄ F) react on the substrate to form an ammonium hexafluorosilicate ((NH ₄ ) ₂ SiF ₆ ) as a condensation film, which can be removed by a post heat treatment. That is, in step S180 of removing the insulating film, a by-product generated by the reaction of the oxide film, the hydrogen fluoride (HF) gas, and the ammonia (NH ₃ ) gas [(NH ₄ ) ₂ SiF ₆ (s) ] Can be removed. For example, the by-product [hexafluorosilicate (NH ₄ ) ₂ SiF ₆ (s)] can be removed by a heating method using a lamp.

The reaction mechanism at this time is as follows.

(NH ₄ ) ₂ SiF ₆ (s)-> 2NH ₃ (g) + SiF ₄ (g) + 2HF (g)

On the other hand, the temperature of the wafer during heating by the lamp is 150C or more, so cooling of the substrate before subsequent trimming is necessary. To this end, it may be cooled for a long time (1-5 minutes) in the subsequent trimming process chamber, but this reduces the throughput. To this end, the proposed scheme can cool the substrate in the cooling chamber and proceed with subsequent trimming before the trimming process in the trimming chamber.

FIG. 10 is a schematic cross-sectional view illustrating trimming the pattern illustrated in FIG. 1 (S190).

Referring to FIG. 10, a trimming process of removing the outer portion of the pattern is performed to microstructure the pattern formed of the silicon pattern forming part 102b.

Silicon (Si) can be etched by anisotropically etching gases such as hydrogen chloride (HCl) and hydrogen bromide (HBr) in an RF plasma chamber, and by using a remote plasma source such as silicon fluoride (SF ₆ ). The isotropic etching method through (RPS), the liquid phase etching method, isotropic time using a mixture of nitric acid, hydrofluoric acid and acetic acid, and anisotropic etching method using KOH solution can be considered. In the case of liquid etching, the etching selectivity of each oxide layer is different. This is because the concentration of hydrogen and carbon of each oxide film type affect the liquid phase etch rate. Generally, the higher the concentration of hydrogen, the faster the etch rate in the liquid phase. At this time, the method of adjusting the concentration of the solution in the silicon (Si) isotropic etching to minimize the amount of silicon etching during trimming can be examined. This is because when the silicon etching is large, a problem may occur in that the pattern itself is etched.

Therefore, in the etching of silicon for trimming, a high selectivity condition is required for the silicon oxide film 104 in addition to the small amount of silicon etching. In the case of liquid phase, the etching selectivity with oxide cannot be secured.

Therefore, in the present embodiment, the pattern 102 is trimmed by supplying chlorine trifluoride (ClF ₃ ) gas G ₂ to the silicon substrate from which the oxide film is removed. In the case of gas phase etching, such as etching using chlorine trifluoride (ClF ₃ ) gas, since there is no reaction mechanism depending on the concentration of hydrogen and carbon as in liquid etching, the etching rate may have a high etching ratio regardless of the type of oxide film.

The reaction mechanism at this time is as follows.

4ClF ₃ + 3Si-> 2Cl ₂ (g) + 3SiF ₄ (g)

In addition, before supplying the chlorine trifluoride (ClF ₃ ) gas, the chlorine trifluoride (ClF ₃ ) gas may be diluted, wherein the chlorine trifluoride (ClF ₃ ) gas to the nitrogen (N ₂ ) gas Can be diluted. At this time, the chlorine trifluoride (ClF ₃ ) gas may be trimmed by supplying 1 to 30 sccm, the nitrogen (N ₂ ) gas at 100 to 1000 sccm. In addition, the trimming may be performed under a pressure of 300 m torr to 8 torr.

The amount etched under these conditions is approximately 10-30.

On the other hand, the present invention can also be utilized in the process of etching polysilicon 1000 ~ 10,000 or more (high etch amount process). In this case, as shown in the etching selectivity result of FIG. 11, the silicon nitride layer (SiN) and the oxide layer (oxide) are not etched during polysilicon etching. Polysilicon is deposited to form a specific pattern structure during a semiconductor device process. After that, it is used when it is necessary to etch only polysilicon as needed.

11 shows only the results of etching selectivity of polysilicon, silicon nitride film and oxide film, chlorine trifluoride (ClF ₃ ) gas is extremely excellent in etching selectivity with titanium nitride (TiN), so that polysilicon and titanium nitride ( It can also be used if extreme selectivity with TiN) is required.

At this time, for example, chlorine trifluoride (ClF ₃ ) is 300 ~ 1000sccm, nitrogen (N ₂ ) is 100 ~ 1000sccm, pressure is about 1 ~ 20 torr, temperature can be used at room temperature (25) ~ 150C range Do.

Since the trimming process using such a gas is a gas phase reaction, the selectivity between silicon and oxide film can be increased.

In addition, the above processes can be carried out in each chamber on a single sheet, thus improving wafer-to-wafer uniformity.

Semiconductor device manufacturing method that can achieve high etching selectivity

Referring to FIG. 12, according to the semiconductor device manufacturing method according to the exemplary embodiment of the present invention, first, a titanium nitride (TiN) film is formed on a substrate (step S210).

Thereafter, a titanium nitride (TiN) film is patterned (step S220). The patterned titanium nitride film may be applied to, for example, forming a contact hole or a capacitor of a semiconductor device for connecting the upper conductive layer and the lower conductive layer.

Thereafter, a silicon film is formed on the substrate on which the patterned titanium nitride (TiN) is formed (step S230). The silicon film may include, for example, amorphous silicon or polysilicon. Such a silicon film can be formed, for example, for forming an active layer or a diode of a switching element.

Thereafter, optionally, the silicon oxide film naturally formed on the silicon film may be removed (step S240). For example, when the silicon substrate is exposed to oxygen, an unintended silicon oxide film may be formed on the silicon film, and it is necessary to remove this silicon oxide film. To this end, hydrogen fluoride (HF) gas and ammonia (NH ₃ ) gas are supplied to the silicon oxide film.

In this case, a by-product [(NH ₄ ) ₂ SiF ₆ (s)] generated by reacting the silicon oxide film, the hydrogen fluoride (HF) gas, and the ammonia (NH ₃ ) gas may be generated. Therefore, these by-products ((NH ₄ ) ₂ SiF ₆ (s)) can be removed by heating. Lamps can be used, for example, to heat these byproducts ((NH ₄ ) ₂ SiF ₆ (s)).

Thereafter, the silicon film is etched using chlorine trifluoride (ClF ₃ ) gas (step S250). The etched silicon film may be formed of an active layer or a diode of a switching device. On the other hand, during the etching of the silicon film, when the titanium nitride (TiN) is exposed, the substrate is maintained in the range of -76 to 70. When lower than -76, for example, chlorine trifluoride (ClF ₃ ) gas may be liquefied in a vacuum in the chamber, and when higher than 70, the titanium nitride pattern may be etched. Therefore, it is preferable to keep the substrate within the range of -76 to 70 in the process of etching the silicon film.

In order to keep the substrate within the range of -76 to 70, a substrate support such as a susceptor for supporting the substrate may be used. Alternatively, the substrate may be transferred to a cooling chamber before the silicon film is formed to transfer the substrate to the temperature. Can be lowered to a range. In this case, the cooling chamber maintains the temperature of the substrate at a temperature lower than the temperature in consideration of the temperature rise in the etching process of the silicon film.

As such, when the substrate is held in the range of −76 to 70 during silicon etching, the titanium nitride (TiN) pattern may be etched to etch the amorphous silicon film or the polysilicon film without causing any damage.

Hereinafter, the semiconductor manufacturing method according to the present embodiment will be described in more detail with reference to FIGS. 13 to 19.

Referring to FIG. 13, for example, a contact pad CP may be formed on a surface of the substrate S, and an insulating film 201 may be formed thereon. The insulating film 201 may constitute an interlayer insulating film for isolation between unit elements or for interlayer separation in a multilayer wiring structure. In addition, the insulating layer 201 may form a contact hole to expose the contact pad CP.

Meanwhile, the substrate S is not limited to the illustrated shape. That is, a plurality of films may be formed between the substrate S and the insulating film 201, and many films may be formed under the contact pad CP.

Referring to FIG. 14, a titanium nitride film 202 is formed on the substrate S shown in FIG. 13. As described above, the substrate S may be a substrate including a plurality of films. For example, the titanium nitride film 202 may be formed by a thermal chemical vapor deposition (CVD) process using titanium chloride (TiCl ₄ ) and ammonia (NH ₃ ).

In more detail, for example, first, the substrate S is preheated, and then purged using nitrogen (N ₂ ) gas or the like. Next, using titanium chloride (TiCl ₄ ) and ammonia (NH ₃ ) as the reaction gas, a titanium nitride film 202 is formed on the substrate S at a predetermined thickness. Then, purged with nitrogen (N ₂ ) gas or the like to release the unreacted gas, and then unreacted Ti-Cl bond remaining in the titanium nitride film 202 formed by additional injection of ammonia (NH ₃ ) gas. Is nitrided and impurities such as chlorine (Cl) that may remain in the titanium nitride film 202 are released to the outside.

Meanwhile, the titanium nitride film 202 may be formed of a titanium nitride base film (not shown) and one or more conductive capping films (not shown) formed thereon in order to increase specific resistance. In this case, the titanium nitride base film (not shown) may be formed by the method described above, and the conductive capping film (not shown) may be formed by atomic layer deposition (ALD).

Referring to FIG. 15, such a titanium nitride film is patterned to form, for example, a barrier film 202a. This barrier film 202a prevents the diffusion of the metal, such as aluminum (Al), that constitutes the contact plug (205 in FIG. 19) to be formed later into the insulating film.

On the other hand, an electrode film (not shown) for forming the electrode of the capacitor may be formed.

Referring to FIG. 16, a silicon film 203 is formed on the substrate S on which the barrier film 202a is formed. For example, the silicon film 203 may be formed of amorphous silicon or polysilicon. The silicon film 203 may be formed using a conventional chemical vapor deposition (CVD) method.

Meanwhile, the silicon film 203 may be easily oxidized to generate a silicon oxide film (not shown) on the surface. If the silicon oxide film is thus produced, it must be removed. This is because the silicon oxide film and the silicon film have a high etching ratio in the process of etching the silicon film used in the semiconductor manufacturing method according to the present invention. That is, since the silicon film is easily etched, while the silicon oxide film is not easily etched, when the silicon oxide film is formed on the silicon film when etching to pattern the silicon film, it is not easily etched.

Referring to FIG. 17, in order to remove the silicon oxide film 204, the silicon oxide film 204 is supplied by supplying hydrogen fluoride (HF) gas (G1) and ammonia (NH ₃ ) gas (G1) to the silicon oxide film 204. ) Can be removed. Since this process is substantially the same as the description corresponding to FIG. 9, the detailed description is omitted.

Referring to FIG. 18, the silicon film is etched except for a portion that requires the presence of the silicon film to form an active layer or a diode of the switching device.

Therefore, when etching the silicon film (203 in FIG. 17), a condition in which the silicon oxide film 204 and the titanium nitride pattern 202a and silicon have a high selectivity is required.

Therefore, in this embodiment, the chlorine trifluoride (ClF ₃ ) gas G2 is supplied to the silicon film (203 in FIG. 17) from which the silicon oxide film (204 in FIG. 17) has been removed, thereby providing the silicon film ( 203). In the case of gaseous etching such as etching using chlorine trifluoride (ClF ₃ ) gas, there is no reaction mechanism that depends on the concentration of hydrogen and carbon as in liquid etching, and thus may have a high etching ratio regardless of the type of oxide film. .

The reaction mechanism at this time is as follows.

4ClF ₃ + 3Si-> 2Cl ₂ (g) + 3SiF ₄ (g)

In addition, before supplying the chlorine trifluoride (ClF ₃ ) gas, the chlorine trifluoride (ClF ₃ ) gas may be diluted, wherein the chlorine trifluoride (ClF ₃ ) gas to the nitrogen (N ₂ ) gas Can be diluted. For example, the chlorine trifluoride (ClF ₃ ) gas may be 1 to 3000 sccm, and the nitrogen (N ₂ ) gas may be supplied at 100 to 3000 sccm to perform etching. For example, the process of etching the silicon film 203 of FIG. 17 may be performed under a pressure of 300 m torr to 20 torr.

At this time, when the titanium nitride (TiN) is exposed, the substrate (S) is maintained in the range of -76 to 70. If lower than -76, for example, chlorine trifluoride (ClF ₃ ) gas may be liquefied in a vacuum in the chamber, and if higher than 70, the titanium nitride pattern may be etched. Therefore, it is preferable to keep the substrate within the range of -76 to 70 in the process of etching the silicon film.

Referring to FIG. 20, when the temperature of the substrate is maintained at 40 and the etching process described above is performed, there is almost no change in the thickness of the titanium nitride film even during etching of amorphous silicon and polysilicon 5000. That is, titanium nitride is not etched.

Referring to FIG. 21, when the temperature is maintained at 60 and the etching process described above is performed, there is little change in color (yellow) of the titanium nitride film, and there is almost no change in sheet resistance of the titanium nitride film before and after etching. You can see that.

In other words, the figure on the left shows a situation in which the silicon etching process is immediately performed, and the figure on the right shows an oxide removal process and the silicon etching process. The upper figure is the figure before the process progression, and the lower figure is the figure after the process progression.

When the silicon etching process was performed immediately, the sheet resistance was 28.28 / sq for the first sample before the etching process, 28.49 / sq for the first measurement after etching, 29.28 / sq for the second measurement, and 28.90 / for the third measurement. measured in sq, the second sample was 25.96 / sq before the etching process, 26.54 / sq for the first measurement after the etching, 26.57 / sq for the second measurement, and 29.05 / sq for the third measurement. You can see almost nothing.

In the case of performing the oxide film removal process and then performing the silicon etching process, the sheet resistance was 29.02 / sq in the first sample before the etching process, 30.64 / sq in the first measurement after etching, 29.35 / sq in the second measurement, 31.88 / sq at the 3rd measurement, the second sample was 26.07 / sq before the etching process, 27.60 / sq at the 1st measurement after etching, 27.95 / sq at the 2nd measurement, 27.40 at the 3rd measurement Measured as / sq, we see little change.

Referring to FIG. 22, when the temperature is maintained at 80 and the etching process described above is performed, it can be seen that the color (yellow) change of the titanium nitride film is obvious, and the change in the sheet resistance of the titanium nitride film before and after etching is increased. Can be.

When the silicon etching process was performed immediately, the sheet resistance was 28.97 / sq in the first sample before the etching process, and it was impossible to measure in the first measurement after etching, 36.05 / sq in the second measurement, and 37.55 in the third measurement. / sq was measured, the second sample was 42.70 / sq before the etching process, the measurement was impossible at the first measurement after etching, the 53.83 / sq at the second measurement, and the measurement was impossible at the third measurement. You can see a very big one.

In the case of performing the oxide film removal process and then performing the silicon etching process, the sheet resistance was 31.16 / sq before the first sample, and the measurement was impossible at the first measurement after etching, and 27.09k / at the second measurement. sq, measured at 8.544 k / sq in the third measurement, the second sample was 26.44 / sq before the etching process, and measurement was not possible.

On the other hand, in order to keep the substrate S in the range of -76 to 70, a substrate support such as a susceptor for supporting the substrate may be used, or alternatively, before the silicon film is formed, it is transferred to a cooling chamber. The substrate S can be lowered to the temperature range. In this case, the cooling chamber maintains the temperature of the substrate S at a temperature lower than the temperature in consideration of the temperature rise in the etching process of the silicon film.

As such, when the substrate is held within the range of −76 to 70 during silicon etching, the titanium nitride (TiN) pattern may be etched to etch the amorphous silicon film or the polysilicon film without applying a daisy.

Referring to FIG. 19, a highly conductive metal film (not shown) is formed on the substrate S on which the barrier film 202a is formed and patterned to form a contact plug 205. For example, the contact plug 205 may be formed of aluminum (Al).

In the above, the case where the shape of the titanium nitride pattern is the form shown in FIG. 15 has been described as an example. Hereinafter, the same process may be applied to the various forms of FIGS. 23, 25, and 27.

FIG. 23 is a cross-sectional view of a titanium nitride pattern formed by patterning a titanium nitride film formed only on a lower portion of an inside of a hole, and a silicon layer formed on an upper portion thereof, and FIG. 24 illustrates a silicon layer being etched in FIG. 23. It is a cross section. FIG. 25 is a cross-sectional view of a titanium nitride pattern formed by patterning a titanium nitride film formed on a lower side of a hole and a side surface of an inside of a hole, and a silicon layer formed on an upper portion thereof. FIG. It is a cross-sectional view showing the appearance. FIG. 27 is a cross-sectional view illustrating a titanium nitride pattern formed by patterning a titanium nitride film, a silicon nitride film formed on a lower side of a hole, and a silicon layer formed on a side of the hole, and FIG. 28. 27 is a cross-sectional view showing the silicon layer is etched.

First, referring to FIGS. 23, 25, and 27, the silicon oxide film (not shown) naturally formed on the silicon film 301 formed inside the hole of the insulating film 302 is removed. This process can proceed by supplying hydrogen fluoride gas and ammonia gas as described above. Thereafter, in the same chamber, chlorine trifluoride (ClF ₃ ) is supplied to etch the silicon film 301, as shown in FIGS. 24, 26, and 28, respectively.

In this case, as shown in FIG. 23, the titanium nitride pattern 301 is formed only on the lower inner side of the hole of the insulating film 302, or as shown in FIG. 27, the titanium nitride pattern 301 is formed of the insulating film 302. If the silicon nitride film 304 is formed on the inner side of the hole, the silicon nitride film 304 is formed in the lower side of the hole, and maintained within the range of 70 to 80 until the titanium nitride pattern 301 is exposed in the etching process of the formed silicon film 301. After that, when the titanium nitride pattern 301 is exposed, as described above, the titanium nitride pattern 301 is maintained in the range of -76 to 70.

However, as shown in FIG. 25, when the titanium nitride pattern 301 is exposed from the initial etching of the silicon film 303, the titanium nitride pattern 301 is etched only when the titanium nitride pattern 301 is exposed within the range of -76 to 70 from the beginning. Can be prevented.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims

Forming a silicon layer on the substrate;

Forming a photoresist film on the silicon layer;

Exposing the photoresist film;

Developing the exposed photoresist film;

Forming a pattern on the silicon layer using the developed photoresist film as a mask;

Removing the photoresist film;

Forming an insulating film; And

A semiconductor device manufacturing method comprising the step of trimming the pattern formed on the silicon substrate.
The method of claim 1, wherein after forming the insulating film,

And removing a portion of the insulating film to expose the pattern.
The method of claim 2,

The insulating film is a silicon oxide film,

Removing a portion of the insulating film,

And supplying hydrogen fluoride (HF) gas and ammonia (NH 3 ) gas to the insulating film.
The method of claim 3,

Removing a portion of the insulating film,

And removing by-products generated by the reaction between the insulating film, the hydrogen fluoride (HF) gas, and the ammonia (NH 3 ) gas.
The method of claim 4, wherein

Removing the by-products is a semiconductor device manufacturing method, characterized in that by the heating (heating) method using a lamp.
The method of claim 5,

Removing the by-products by the heating method, and transferring the substrate to a cooling chamber to cool the semiconductor device.
The method of claim 1,

The trimming step,

And supplying chlorine trifluoride (ClF 3 ) gas to the substrate on which the insulating film is partially removed.
The method of claim 7, wherein

The chlorine trifluoride (ClF 3) prior to the gas supply, the chlorine trifluoride (ClF 3) method of manufacturing a semiconductor device the step of diluting the gas, characterized in that it further comprises.
The method of claim 8,

The chlorine trifluoride (ClF 3 ) is diluted by nitrogen (N 2 ) gas,

The chlorine trifluoride (ClF 3 ) gas is 1 to 30 sccm, the nitrogen (N 2 ) gas is a semiconductor device manufacturing method, characterized in that for supplying at 100 to 1000 sccm.
The method of claim 9,

The trimming step,

A method of manufacturing a semiconductor device, characterized in that proceeds under a pressure of 300m torr to 8 torr.
The method of claim 1,

Removing the insulating film and then continuing the trimming without breaking the vacuum.
Forming a titanium nitride (TiN) film on the substrate;

Patterning a titanium nitride (TiN) film;

Forming a silicon film on a substrate on which patterned titanium nitride (TiN) is formed; And

Etching the silicon film using chlorine trifluoride (ClF 3 ) gas,

In the etching of the silicon film, when the titanium nitride (TiN) is exposed, the substrate is maintained in the range of -76 to 70, characterized in that the semiconductor device manufacturing method.
The method of claim 12, wherein in the etching of the silicon film,

If the titanium nitride is not exposed, the substrate is a semiconductor device manufacturing method, characterized in that maintained in the range of 70 to 80.
The method of claim 12, prior to etching the silicon film,

And transferring the substrate to a cooling chamber to lower the temperature of the substrate in the cooling chamber.
The method of claim 12, after the forming of the silicon film,

And removing the silicon oxide film formed naturally on the silicon film.
The method of claim 15, wherein removing the silicon oxide film comprises:

And supplying hydrogen fluoride (HF) gas and ammonia (NH 3 ) gas to the silicon oxide film.
The method of claim 16, wherein removing the silicon oxide layer comprises:

And removing by-products generated by the reaction between the silicon oxide film, the hydrogen fluoride (HF) gas, and the ammonia (NH 3 ) gas by a heating method using a lamp. Manufacturing method.