KR101702869B1 - Atomic layer etching apparatus - Google Patents

Abstract

An atomic layer etching apparatus for etching a thin film by using an atomic layer etching method is disclosed. The atomic layer etching apparatus includes a process chamber, a substrate support part provided within the process chamber and having a plurality of substrates placed along a circumferential direction, and a gas injection part provided on the substrate support part and having a plurality of injection parts for individually and continuously supplying a plurality of etching gases to the substrate. So, an etching process can be performed without causing electrical and physical damage.

Description

[0001] ATOMIC LAYER ETCHING APPARATUS [0002]

The present invention relates to an atomic layer etch apparatus capable of etching an atomic layer thickness of a thin film without electrical and physical damage.

As an etching apparatus for implementing a nanometer class semiconductor device, a high density plasma etching apparatus and a reactive ion etching apparatus are mainly used. However, in such an etching apparatus, a large amount of ions exist for performing the etching process, and these ions impinge on the semiconductor substrate or a specific material layer on the semiconductor substrate with energy of several hundreds of eV, Causing damage. For example, as a physical impairment, the surface of a crystalline substrate or a specific material layer that is impinging upon such ions may be converted to an amorphous layer, and only a portion of the material layer in which some of the incident ions are adsorbed or impinged may be selectively The chemical composition of the surface layer to be desorbed and etched may be changed, and the atomic bonds of the surface layer may be broken by the collision, resulting in a dangling bond. Such dangling bonds may cause electrical damage as well as physical damage to the material. In addition, the dangling bonds may cause charge damage of the gate insulating film or notching of the polysilicon due to charging of the photoresist Causing electrical damage. In addition to such physical and electrical damage, surface contamination by process gas such as contamination by chamber materials or generation of C-F polymer when CF-based process gas is used may occur.

The physical and electrical damage caused by such ions in a nanometer class semiconductor device lowers the reliability of the device and further lowers the productivity. Therefore, it can be applied in response to the trend of high integration of the semiconductor device and the decrease of the design rule. The development of a new concept of semiconductor etching equipment and etching method is required.

According to embodiments of the present invention, there is provided a method of etching a semiconductor device and a large-area neutral beam etching apparatus capable of performing an etching process without using electrical and physical damage by using a neutral beam generated through the construction of a simple apparatus have.

Another object of the present invention is to provide an intrinsic etching method of a semiconductor device capable of improving anisotropic etching through a simple device structure and an etching method for rotating a substrate supporting part capable of improving throughput.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an atomic layer etching apparatus comprising: a process chamber; a substrate support disposed inside the process chamber and having a plurality of substrates placed along a circumferential direction; And a gas injection unit provided on the substrate support unit and provided with a plurality of injection units for continuously providing and continuously supplying a plurality of etching gases to the substrate.

According to one aspect of the present invention, the gas jetting unit includes a first jetting section for supplying a process gas adsorbed to a thin film formed on the substrate, a second jetting section for separating the thin film on which the process gas is adsorbed, And a third injection unit for providing a purge gas for removing the sprayed and unreacted process gas and etching byproducts. In addition, at least one of the first to third injection units may be provided. For example, the first to third injectors may have a fan shape. In addition, a top exhaust unit for exhausting exhaust gas from the substrate may be provided between the first to third injection units.

According to one aspect of the present invention, in order to convert an inert gas into a plasma state, an inductively coupled plasma (ICP), an electron cyclotron resonance plasma (ECRP), a helicon plasma Helicon Plasma) may be provided.

Various embodiments of the present invention may have one or more of the following effects.

As described above, according to the embodiments of the present invention, the reactive radicals are adsorbed on the thin film to be etched, and atomic layer etching can be performed by simultaneously removing the thin film surface material and the reactive radicals to be etched using the neutral beam . Thus, it is possible to etch various thin films which can not be performed by the conventional atomic layer etching method.

In addition, the RMS roughness of the surface of the thin film to be etched similar to that of the surface before the etching can be obtained.

In addition, the atomic layer etch satisfies a self-limited mechanism that allows precise control of intrinsic etch depth and etch depth, so that the etch rate can be precisely controlled at the atomic scale without precise control. In addition, productivity can be improved by using a substrate susceptor rotation method other than the conventional pulse method.

1 is a schematic view of an atomic layer etching apparatus according to an embodiment of the present invention.
2 is a plan view of the gas injection part in the atomic layer etching apparatus of FIG.
3 is a view for explaining an atomic layer etching method according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

Hereinafter, an atomic layer etching apparatus 10 according to embodiments of the present invention and an atomic layer etching method using the same will be described in detail with reference to FIGS. 1 to 6. FIG. 1 is a schematic diagram of an atomic layer etching apparatus 10 according to an embodiment of the present invention, and FIG. 2 is a plan view of a gas injection unit in the atomic layer etching apparatus 10 of FIG. And FIG. 3 is a view for explaining an atomic layer etching method according to an embodiment of the present invention.

Referring to the drawings, an atomic layer etching apparatus 10 includes a process chamber 11, a substrate support 12 on which a plurality of substrates 1 are mounted, a plurality of gases for etching the substrates 1 And a gas jetting unit 13 for providing the gas.

For reference, the substrate 1 to be etched in the present embodiments may be a silicon wafer for a semiconductor device. However, the present invention is not limited thereto. The substrate 1 may be a transparent substrate including a glass used for a flat panel display device such as a liquid crystal display (LCD) or a plasma display panel (PDP) Lt; / RTI >

The process chamber 11 accommodates the plurality of substrates 1 and provides a space in which the atomic layer etching process is performed.

The substrate supporter 12 is configured so that a plurality of substrates 1 are seated and rotated. Specifically, the upper surface of the substrate supporting portion 12 is flatly formed, and a plurality of substrates 1 are arranged at regular intervals along the circumferential direction. For example, six substrates 1 can be seated on the substrate support 12 at even intervals. As the substrate support 12 rotates, the substrate 1 sequentially passes through the regions where the process gas, the purge gas P, the ions I and the purge gas P are provided, . Here, the present invention is not limited to the drawings, and the number of the substrates 1 to be mounted on the substrate supporting portion 12 can be substantially varied.

The gas jetting section 13 is provided on the substrate supporting section 12 or on the upper side of the process chamber 11 to form the upper surface of the process chamber 11. Further, the gas jetting section 13 provides the substrate 1 with a plurality of gases for etching.

Here, the process gas (E), the purge gas (P), and the ions (I) are used as the gas for the etching process. Specifically, the gas for the etching process includes a process gas E adsorbed to the thin film to be etched to be removed, a residual process gas E inside the process chamber 11, and a purge gas P) is used. In order to separate the etch by-products adsorbed on the thin film to be etched, the ions (I) are irradiated. The ions (I) generated when the inert gas is activated by the plasma are used. As shown in Table 1, the process gas E can be variously selected depending on the kind of the thin film to be etched. As the purge gas P, an inert gas such as Ar, N2, or He is used, An inert gas activated by a plasma is used.

Thin film to be etched Process gas Mixing ratio Photoresist O2
O2 + CF4 100%
80% + 20% Polyimide
(polyimide) O2
O2 + CF4 100%
80% + 20% Polyurethane
(polyurethane) O2
O2 + CF4 100%
80% + 20% Single crystal silicon
(single crystal silicon) CF4
CF4 + O2
SF6
SF6 + O2 100%
(80 to 92%) + (20 to 8%)
100%
(80 to 90%) + (20 to 10%) Silicon oxide
(SiO2) CF4
CF4 + O2
C2F6
CF3H
C3F8 100%
(80 to 92%) + (20 to 8%)
100%
100%
100% Silicon nitride
(silicon nitride, Si3N4) CF4
CF4 + O2
SF6
CF3H
NF3 100%
(80 to 92%) + (20 to 8%)
100%
100%
100% Epoxy
(epoxy bleedout) Ar
Ar + O2
Ar + H2 100%
(90 to 70%) + (10 to 30%)
(90 to 70%) + (10 to 30%) Tungsten (W) CF4 + O2 (70 to 92%) + (30 to 8%) Gallium arsenide (GaAs) CH4 100%

Table 1 shows the usable process gas (E) and the process gas (E) mixture ratio for various etch target films. Referring to Table 1, atomic layer etching of various thin films such as photoresist and polyimide as well as single crystal silicon or silicon oxide (silicon oxide) is possible using atomic layer etching.

Here, the gas jetting section 13 is divided into a plurality of jetting sections 131, 132, 133 and 134 into which the process gas E, the purge gases P1 and P2 and the ions I are injected, respectively. In each of the plurality of jetting sections 131, 132, 133 and 134, the respective gases are continuously injected, and as the substrate supporting section 12 rotates, the gas is injected from the jetting sections 131, 132, 133, The substrate 1 is etched in an atomic layer. The gas injecting section 13 supplies gas in the order of the process gas E, the purge gases P1 and P2, the ions I and the purge gases P1 and P2 along the rotation direction of the substrate 1 The sprayers 131, 132, 133, and 134 are disposed.

For example, as shown in Fig. 2, the gas jetting section 13 is provided with eight jetting sections 131, 132, 133 and 134, and includes a process gas (E) jetting section 131, (I) splitter 133 and a purge gas P2 splitter 134 along the circumferential direction of the sprayer 132, the ion (I) splitter 133, and the purge gas P2 splitter 134, respectively. Thus, when the substrate support 12 rotates once, the substrate 1 is provided with gas twice for the etching process, and two etching cycles are performed. However, the present invention is not limited to this, and the gas jetting section 13 may be constituted by four regions, or may be constituted by more than sixteen regions.

Here, each of the jetting sections 131, 132, 133, and 134 may be a shower head having a fan shape and formed with a plurality of holes. However, the present invention is not limited to the drawings, and the jetting portions 131, 132, 133, and 134 may have various forms other than the shape of the shower head. Although the gas jetting unit 13 has eight jetting units 131, 132, 133, and 134 of the same size, the jetting units 131, 132, 133, and 134 may have different sizes It is possible.

Between the injection portions 131, 132, 133, and 134, a top exhaust portion 135 for exhausting exhaust gas including residual gas, reaction byproducts, and the like is provided.

The top exhaust portion 135 is provided between the jetting portions 131, 132, 133, and 134, and a plurality of holes may be arranged along the diametrical direction of the gas jetting portion 13. [ The top exhaust 135 may have a shape surrounding the jetting portion 131 of the process gas E and the jetting portion 133 of the ion I. However, the present invention is not limited to the drawings, and the shape of the top exhaust portion 135 may be substantially varied.

In order to conduct ion (I) irradiation, an inactive gas must be converted into a plasma state. For this purpose, an inductively coupled plasma (ICP), an electron cyclotron resonance plasma (ECRP) Helicon Plasma) may be used.

For atomic layer etching, power is applied to the substrate support portion 12 and the gas injection portion 13. The power supply unit 14 may include a first power supply unit 141 that applies a high frequency power to the gas injection unit 13 and a second power supply unit 142 that applies a high frequency power to the substrate support unit 12.

Hereinafter, the atomic layer etching apparatus will be described.

Referring to FIG. 3, the atomic layer etch process comprises four stages of providing and purifying the process gas (E) to expel etch byproducts in one cycle.

First, the substance of the process gas (E) is adsorbed on the thin film to be etched by providing the process gas (E). The gas molecules of the process gas (E) are uniformly adsorbed on the surface of the thin film to be etched to a monolayer (ML) thickness. Here, the process gas E is determined depending on the kind of the thin film to be etched.

Next, the purge gas (P1, P2) is provided to discharge the residual process gas (E). As the purge gases P1 and P2, inert gas such as Ar, N2, or He is used. When the purge gases P1 and P2 are injected, the remaining process gas E does not react with the thin film and discharges the process gas E to the outside of the process chamber 11. Only the molecules of the process gas (E) do.

Next, by providing the ions (I), a part of the thin film to be etched on which the process gas (E) is adsorbed is separated, and a substantial etching process is performed. These separated parts are called 'etching by-products'. Here, by providing the ion (I) particles having specific energy into the process chamber 11, only the molecules of the thin film adsorbed by the process gas E are separated from the thin film surface. That is, in the process of providing the ions (I), etching is performed by the thickness of the monolayer.

Then, one cycle of the atomic layer etching process is completed by supplying the purge gas (P1, P2) and discharging the etching byproduct. The etched etching by-products and unreacted ion (I) particles are discharged to the outside of the process chamber 11 by the purge gases P1 and P2 by irradiating the ions I, and the thin film is etched as much as the single- do.

In the atomic layer etching process, as shown in FIG. 3, since etching is performed only to a monolayer when one cycle is performed, etching can be performed to a desired thickness by repeatedly performing a plurality of cycles. In addition, the etch depth can be precisely controlled by adjusting the number of repetitions of the cycle because the etch is performed at the thickness of the monolayer every cycle, and the control of the etching speed and depth can be accurately and quickly controlled at the atomic scale. In addition, the surface of the thin film after etching is completed has an RMS roughness similar to that before etching.

According to these embodiments, the reactive radicals are adsorbed to the target thin film, and atomic layer etching can be performed by simultaneously removing the thin film surface material and reactive radicals to be etched using the neutral beam of ions. Thus, it is possible to etch various thin films which can not be performed by the conventional atomic layer etching method. In addition, the RMS roughness of the surface of the thin film to be etched similar to that of the surface before the etching can be obtained.

In addition, the atomic layer etching satisfies a self-limiting mechanism that allows precise control of intact etching depth and etch depth, so that the etching rate can be precisely controlled at the atomic scale without precise control. In addition, since the conventional substrate supporting part 12 is rotated, not the pulse method, and gas is continuously supplied to the gas jetting part 13, the productivity can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

1: substrate
10: atomic layer etching apparatus
11: Process chamber
12:
13:
131, 132, 133, 134:
135:
14, 141, 142:

Claims (6)

A process chamber;
A substrate support disposed within the process chamber and having a plurality of substrates mounted along a circumferential direction; And
A gas spraying unit provided on the substrate supporting unit and provided with a plurality of spraying units for continuously providing and continuously supplying a plurality of etching gases to the substrate;
Lt; / RTI >
The gas-
A first jet part for providing a process gas adsorbed on a thin film formed on the substrate;
A second jetting section for separating the thin film adsorbed by the process gas to provide ions for etching the monatomic layer thickness; And
A third jetting section for providing a purge gas for removing unreacted process gas and etching by-products;
And an atomic layer etch device.
delete The method according to claim 1,
Wherein at least one of the first to third injection portions is provided.
The method according to claim 1,
Wherein the first to third injectors have a fan shape.
The method according to claim 1,
And a top exhaust part for exhausting exhaust gas from the substrate is provided between the first to third injection parts.
The method according to claim 1,
In order to make the inert gas into a plasma state, the second spray part may be formed of an inductively coupled plasma (ICP), an electron cyclotron resonance plasma (ECRP), or a helicon plasma An atomic layer etch device comprising a plasma generator.

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