KR20220070795A - Selectivity material and method of selective formation of thin film using selectivity material - Google Patents

Abstract

The objective of the present invention is to provide a method for forming a thin film that can be selected according to an area. According to an embodiment of the present invention, an area-selective thin film formation method using a selectivity imparting agent comprises: a selectivity imparting agent supplying step of supplying the selectivity imparting agent to the inside of a chamber in which a substrate is placed and adsorbing the selectivity imparting agent to a non-growth area of the substrate; a step of purging the interior of the chamber; a precursor supply step of supplying a precursor to the inside of the chamber and adsorbing it to a growth area of the substrate; a step of purging the interior of the chamber; and a thin film forming step of supplying a reactant to the inside of the chamber to react with the adsorbed precursor to form a thin film.

Description

Area-selective thin film formation method using a selectivity imparting agent {SELECTIVITY MATERIAL AND METHOD OF SELECTIVE FORMATION OF THIN FILM USING SELECTIVITY MATERIAL

The present invention relates to a method for forming a thin film, and more particularly, to a method for forming a region-selective thin film using a selectivity imparting agent.

The patterning of the semiconductor device is fabricated using an arrangement of various material layers and a lithography or etching process. However, over the past few decades, device miniaturization has accelerated and the size of a required pattern has been reduced to the nanometer (nm) level, which greatly increases cost and time for nanopattern formation. In addition, various studies on a selective deposition process capable of obtaining a self-aligned structure without the need to perform a subsequent process are being conducted.

However, it is difficult to achieve the desired selectivity due to insufficient inhibition or subsequent film formation on the unwanted surface. Accordingly, the present invention seeks to overcome the limitations of the prior art and provide an improved method for the selective deposition of thin film materials using an ALD deposition process.

Korean Patent Publication No. 2007-0015958 (2007.02.06.)

An object of the present invention is to provide a method for forming a thin film that can be selected according to an area.

Further objects of the present invention will become more apparent from the following detailed description.

According to an embodiment of the present invention, a method for forming a region-selective thin film includes: supplying a selectivity-imparting agent into a chamber in which a substrate is placed, and adsorbing the selectivity-imparting agent to a non-growth region of the substrate; purging the interior of the chamber; a precursor supply step of supplying a precursor to the inside of the chamber and adsorbing it to the growth region of the substrate; purging the interior of the chamber; and supplying a reactant into the chamber to react with the adsorbed precursor to form a thin film.

The method may include, prior to the step of supplying the selectivity imparting agent, contacting a wet compound with the substrate; rinsing the surface of the substrate with DI water; And it may further include the step of drying the surface of the substrate.

The wet compound is selected from the group consisting of a composition comprising a mixture of H2O2 (28% aq), NH4OH (28-30%) and H2O, HF, Peroxide, RCA clean chemical SC-1/SC-2, H2SO4/H2O2 There may be more than one.

The growth region may be one or more thin films selected from the group consisting of SiO2, metal oxide, copper, cobalt, tungsten, amorphous silicon, polysilicon, monocrystalline silicon, germanium, and amorphous germanium hydride.

The non-growth region may be a silicon nitride layer.

The silicon nitride layer may be at least one selected from among SiN, SiCN, C-doped SiN, and SiON.

The selectivity imparting agent may be represented by the following <Formula 1>.

<Formula 1>

In <Formula 1>, R1 is selected from an alkyl group having 1 to 8 carbon atoms, an aryl group, and carboxylate, and R2 is selected from hydrogen, a halogen element, and an alkyl group having 1 to 8 carbon atoms.

The selectivity imparting agent may be represented by the following <Formula 2>.

<Formula 2>

In <Formula 2>, R is selected from hydrogen, a halogen element, an alkyl group having 1 to 8 carbon atoms, an alkyl group substituted with a halogen having 1 to 8 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

The reactant may be any one of O3, O2, and H2O.

The precursor may be a compound containing Si.

According to an embodiment of the present invention, in a state in which the selectivity imparting agent is adsorbed to the non-growth region, the subsequently supplied precursor is prevented from being adsorbed to the non-growth region, thereby preventing the formation of a thin film in the non-growth region. can In addition, through this, a self-aligned structure can be obtained without a subsequent process.

1 is a flowchart schematically illustrating a method for forming a thin film according to an embodiment of the present invention.
FIG. 2 is a graph schematically illustrating a supply cycle according to FIG. 1 .
FIG. 3 is a diagram schematically illustrating a process of forming a thin film according to FIG. 1 .
4 is a graph showing the thickness of a thin film according to an embodiment and a comparative example of the present invention.
5 is a table showing GPC according to an embodiment and a comparative example of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings 1 to 5. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These examples are provided to explain the present invention in more detail to those of ordinary skill in the art to which the present invention pertains. Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a clearer description.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

As used throughout this specification, the terms "about," "substantially," and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to enhance the understanding of this application. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure.

Throughout this specification, the term "alkyl" or "alkyl group" refers to 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 5 carbon atoms, 1 to 3 carbon atoms, straight or branched alkyl groups having from 3 to 8 carbon atoms, or from 3 to 5 carbon atoms. For example, the alkyl group includes a methyl group, an ethyl group, an n-propyl group ( ⁿ Pr), an iso-propyl group ( ⁱ Pr), an n-butyl group ( ⁿ Bu), a tert-butyl group ( ^t Bu), an iso- Butyl group ( ⁱ Bu), sec-butyl group ( ^s Bu), n-pentyl group, tert-pentyl group, iso-pentyl group, sec-pentyl group, neopentyl group, 3-pentyl group, hexyl group, isohexyl group Sil group, heptyl group, 4,4-dimethylpentyl group, octyl group, 2,2,4-trimethylpentyl group, nonyl group, decyl group, undecyl group, dodecyl group, and isomers thereof, etc., but are limited thereto. it may not be

Throughout this specification, the term “film” may include, but is not limited to, “membrane” or “thin film”.

In the conventional process, a film is deposited on a non-growth region, for example, an undesired region, and thus electrical characteristics and device characteristics may be deteriorated. However, the selectivity-imparting agent described below is adsorbed to the silicon nitride layer at a higher density than the silicon oxide layer, and the selectivity-imparting agent blocks the adsorption of a precursor to be injected later to form a seed layer only on the silicon oxide layer.

1 is a flowchart schematically illustrating a method for forming a thin film according to an embodiment of the present invention, and FIG. 2 is a graph schematically illustrating a supply cycle according to FIG. 1 . FIG. 3 is a diagram schematically illustrating a process of forming a thin film according to FIG. 1 .

The substrate is loaded into the process chamber, and the following ALD process conditions are adjusted. The ALD process conditions may include a temperature of a substrate or a process chamber, a chamber pressure, and a gas flow rate, and the temperature is 10 to 900°C.

First, the substrate is exposed to a wet compound prior to the selectivity imparting agent. The wet compound is one selected from the group consisting of H2O2 (28% aq), NH4OH (28-30%) and a composition comprising H2O, HF, Peroxide, RCA clean chemical SC-1/SC-2, H2SO4/H2O2 mixture may be more than Thereafter, the substrate is rinsed with DI water or the like and dried.

Next, the substrate is exposed to the selectivity-imparting agent supplied to the interior of the chamber, and the selectivity-imparting agent is adsorbed to the surface of the non-growth region of the substrate. The non-growth region may be a silicon nitride layer, and may be at least one selected from among SiN, SiCN, C-doped SiN, and SiON. In addition, the substrate has a growth region, and the growth region may be one or more thin films selected from the group consisting of SiO2, metal oxide, copper, cobalt, tungsten, amorphous silicon, polysilicon, monocrystalline silicon, germanium and amorphous germanium hydride. The selectivity imparting agent is adsorbed at a high density on the surface of the non-growth region, and prevents adsorption of the precursor in a subsequent process.

The selectivity imparting agent may be represented by the following <Formula 1>.

<Formula 1>

In <Formula 1>, R1 is selected from an alkyl group having 1 to 8 carbon atoms, an aryl group, and carboxylate, and R2 is selected from hydrogen, a halogen element, and an alkyl group having 1 to 8 carbon atoms.

The selectivity imparting agent may be represented by the following <Formula 2>.

<Formula 2>

In <Formula 2>, R is selected from hydrogen, a halogen element, an alkyl group having 1 to 8 carbon atoms, an alkyl group substituted with a halogen having 1 to 8 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify the non-adsorbed selectivity-imparting agent or by-product.

Thereafter, the substrate is exposed to the precursor supplied into the chamber, and the precursor is adsorbed to the surface of the growth region and not adsorbed to the surface of the non-growth region due to the selectivity imparting agent. The precursor may be a compound containing Si.

Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify unadsorbed precursors or by-products.

Thereafter, the substrate is exposed to the reactant supplied into the chamber, and a thin film is formed on the surface of the substrate. The reactant material reacts with the precursor layer to form a thin film, and the reactant material may be O3, O2, or H2O gas, and an oxide layer may be formed through the reactant material.

Thereafter, a purge gas (eg, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify unreacted materials or by-products.

- Example 1

Pretreatment was performed on SiN and SiO substrates using 1.12 wt% of DHF as a wet compound. The heating mantle set temperature was 100℃, and after 12 hours of dipping, it was rinsed with isopropyl alcohol and DI water. N2 blowing was performed so that no solution remained on the substrate surface.

After the above-described selectivity imparting agent, propionaldehyde, was supplied on the growth region substrate (SiO) and the non-growth region substrate (SiN), respectively, a silicon oxide layer was formed. A silicon oxide film was formed through the ALD process, the ALD process temperature was 160° C., and O3 gas was used as the reaction material.

The silicon oxide film formation process through the ALD process is as follows, and the following process was performed as one cycle (refer to FIGS. 1 to 3).

1) Adsorbed to the substrate by supplying a selectivity-imparting agent in the reaction chamber

2) Removal of non-adsorbed selectivity-imparting agents or by-products by supplying Ar gas into the reaction chamber

3) Using Ar as a carrier gas, the silicon precursor DIPAS (Diisopropylamino Silane) is supplied to the reaction chamber and the silicon precursor is adsorbed on the substrate

4) Removal of unadsorbed silicon precursors or by-products by supplying Ar gas into the reaction chamber

5) O3 gas is supplied to the reaction chamber to form a silicon oxide film

6) Removal of unreacted substances or by-products by supplying Ar gas into the reaction chamber

- Comparative Example 1

A silicon oxide layer was respectively formed on the growth region substrate (SiO) and the non-growth region substrate (SiN) without using the wet compound/selectivity imparting agent described above. A silicon oxide film was formed through the ALD process, the ALD process temperature was 160° C., and O3 gas was used as the reaction material.

The silicon oxide film formation process through the ALD process is as follows, and the following process was performed as one cycle.

1) Using Ar as a carrier gas, the silicon precursor DIPAS is supplied to the reaction chamber and the silicon precursor is adsorbed on the substrate

2) Removal of unadsorbed silicon precursors or by-products by supplying Ar gas into the reaction chamber

3) O3 gas is supplied to the reaction chamber to form a silicon oxide film

4) Removal of unreacted substances or by-products by supplying Ar gas into the reaction chamber

- Comparative Example 2

Pretreatment was performed on SiN and SiO substrates using 1.12 wt% of DHF as a wet compound. The heating mantle set temperature was 100℃, and after 12 hours of dipping, it was rinsed with isopropyl alcohol and DI water. N2 blowing was performed so that no solution remained on the substrate surface. Thereafter, a silicon oxide layer was respectively formed on the growth region substrate (SiO) and the non-growth region substrate (SiN) in the same manner as in Comparative Example 1 without using a selectivity imparting agent.

4 is a graph showing the thickness of a thin film according to an embodiment and a comparative example of the present invention, and FIG. 5 is a table showing a GPC according to an embodiment and a comparative example of the present invention. The SiO thickness (A) in Comparative Example 1 was SiN substrate: SiO substrate = 69.97: 60.44, and the SiO thickness (A) in Comparative Example 2 was SiN substrate: SiO substrate = 62.48: 62.47, whereas in Example 1, SiN substrate : SiO substrate = 6.36: 58.42, the selectivity increased.

The thickness decreased by 6.48% on the SiO substrate, while the thickness decreased by 89.8% on the SiN substrate, confirming that the selectivity increased. Such a result can be interpreted that the selectivity imparting agent adsorbed to the SiN substrate and suppressed the deposition of the silicon precursor.

The reason the selectivity imparting agent has selectivity in Example 1 is that it is structurally compatible with the SiN substrate to enhance the adsorption force, which is interpreted as delaying the nuclear growth of the thin film on the SiN substrate, and the desired selectivity as a result of other complex causes can get

Although the present invention has been described in detail through examples above, other types of embodiments are also possible. Therefore, the spirit and scope of the claims set forth below are not limited to the embodiments.

Claims (10)

supplying the selectivity-imparting agent to the inside of the chamber in which the substrate is placed, and adsorbing the selectivity-imparting agent to the non-growth region of the substrate;
purging the interior of the chamber;
a precursor supply step of supplying a precursor to the inside of the chamber and adsorbing it to the growth region of the substrate;
purging the interior of the chamber; and
and a thin film forming step of supplying a reactant into the chamber to react with the adsorbed precursor to form a thin film. According to claim 1,
The method is
prior to the step of supplying the selectivity imparting agent, the method further comprising the step of contacting a wet compound to the substrate. 3. The method of claim 2,
The wet compound is
At least one selected from the group consisting of H2O2 (28% aq), NH4OH (28-30%) and a composition comprising a mixture of H2O, HF, Peroxide, RCA clean chemical SC-1/SC-2, H2SO4/H2O2, area selective A method of forming a thin film. According to claim 1,
The growth region is at least one thin film selected from the group consisting of SiO2, metal oxide, copper, cobalt, tungsten, amorphous silicon, polysilicon, monocrystalline silicon, germanium and amorphous germanium hydride. According to claim 1,
wherein the non-growth region is a silicon nitride film. 6. The method of claim 5,
The silicon nitride film is at least one selected from SiN, SiCN, C-doped SiN, and SiON. According to claim 1,
The method for forming a region-selective thin film, wherein the selectivity imparting agent is represented by the following <Formula 1>.
<Formula 1>

In <Formula 1>, R1 is selected from an alkyl group having 1 to 8 carbon atoms, an aryl group, and carboxylate, and R2 is selected from hydrogen, a halogen element, and an alkyl group having 1 to 8 carbon atoms. According to claim 1,
The method for forming a region-selective thin film, wherein the selectivity imparting agent is represented by the following <Formula 2>.
<Formula 2>

In <Formula 2>, R is selected from hydrogen, a halogen element, an alkyl group having 1 to 8 carbon atoms, an alkyl group substituted with a halogen having 1 to 8 carbon atoms, and an aryl group having 6 to 10 carbon atoms. According to claim 1,
The reactive material is any one of O3, O2, and H2O. According to claim 1,
The precursor is a compound containing Si, a method for forming a region-selective thin film.

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