KR20140131474A - A preparation method of nickel sulfide film - Google Patents

Abstract

The present invention relates to a method for manufacturing a nickel sulfide thin film using atomic layer deposition comprising: step (a) of inserting a substrate into a deposition chamber; step (b) of absorbing a nickel precursor represented by the below chemical formula 1 by the atomic layer deposition on the substrate; step (c) of removing the rest of a byproduct except for the absorbed nickel precursor; step (d) of forming a nickel sulfide thin film on the substrate by an exchange reaction with the nickel precursor absorbed on the substrate by inserting sulfur into the deposition chamber; and step (e) of removing the rest of a byproduct except for the nickel sulfide thin film. [Chemical formula 1] When the nickel sulfide thin film is manufactured by the method for manufacturing the nickel sulfide thin film using the atomic layer deposition, a uniform metal layer is formed while the thickness of the metal layer is easily controlled, and the temperature of forming the metal layer on the substrate is relatively lowered.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a nickel sulfide thin film,

The present invention relates to a method for producing a nickel sulphide thin film, and more particularly, to a method for preparing a nickel sulphide thin film using a nickel precursor and hydrogen sulfide.

As electronic devices including semiconductors and magnetic storage devices are becoming finer and smaller, it becomes increasingly important to form a metal or metal thin film having a uniform thickness. Especially, recently, electrodes and solar cell absorbers And the importance of it is increasing day by day.

For example, nickel (Ni) metal has lower resistivity (10 ~ 18 μΩ · cm) than titanium silicide film used as an ohmic contact layer in conventional semiconductor processes and is superior in thermal stability to the ohmic contact layer in next- It is widely known that the potential application fields are widely used in the present and the future. In particular, it is expected that nickel sulfide will be widely used for manufacturing electrodes for secondary batteries and absorbers for solar cells.

As described above, in order to form a metal thin film on a substrate, a vapor deposition method such as PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition) has been used. However, in the vapor deposition method such as PVD and CVD, There is a problem that a metal layer can not be easily deposited on a complicated pattern or an organic film due to a high deposition temperature condition for deposition, low step coverage of the deposited metal layer, and difficulty in controlling the thickness.

In order to overcome such a problem, for example, Korean Patent Laid-Open Publication No. 10-2010-0071463 has conducted a lot of studies on the use of ALD as a deposition method of many metals including nickel, The deposition for the formation of the thin film of the film can not be sufficiently realized.

KR 10-2010-0071463 A

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a method of forming a metal layer by forming a metal layer with ease by controlling the thickness of the metal layer using atomic layer deposition, To a method for forming a nickel sulphide thin film.

In order to achieve the above object,

The present invention provides a method of manufacturing a semiconductor device, comprising: a) introducing a substrate into a deposition chamber; b) adsorbing a nickel precursor represented by the following formula (1) on the substrate by atomic layer deposition; c) removing other by-products, excluding the adsorbed nickel precursor; d) introducing a sulfur source into the deposition chamber to conduct an exchange reaction with the nickel precursor adsorbed on the substrate to form a nickel sulphide thin film on the substrate; And e) removing the by-products except for the nickel sulphide thin film. The present invention also provides a method for manufacturing a nickel sulphide thin film using atomic layer deposition.

[Chemical Formula 1]

(m is an integer ranging from 1 to 3, and R1, R2, R3 and R4 are independently C1-C4 linear or branched alkyl groups)

When a nickel sulphide thin film is manufactured by the method of manufacturing a nickel sulphide thin film using the atomic layer deposition method of the present invention, it is easy to control the thickness of the metal layer, forming a uniform metal layer, It is possible to prevent chemical vapor deposition (CVD) from occurring during the atomic layer deposition, and it is possible to prevent an electrode of an electronic device such as a secondary battery, an ultra thin film solar cell, Can be used in the production of next-generation energy devices such as electrodes of sensitive solar cells.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph of thickness growth versus feed time of Ni (dmamb) ₂ of Example 1. Fig.
2 is a graph of thickness growth versus feed time of H ₂ S of Example 1. FIG.
3 is a graph of thickness growth with increasing ALD process cycles of Example 2. FIG.
4 is a table showing the AFM photograph and the thickness according to the increase of the ALD process cycle in the second embodiment.
5 is an EDS analysis spectrum of the nickel sulfide thin film produced according to Example 3. Fig.
6 is an SEM photograph of the nickel sulfide thin film produced according to Example 3. Fig.

The present invention provides a method of manufacturing a semiconductor device, comprising: a) introducing a substrate into a deposition chamber; b) adsorbing a nickel precursor represented by the following formula (1) on the substrate by atomic layer deposition; c) removing other by-products, excluding the adsorbed nickel precursor; d) introducing a sulfur source into the deposition chamber to conduct an exchange reaction with the nickel precursor adsorbed on the substrate to form a nickel sulphide thin film on the substrate; And e) removing the by-products except for the nickel sulphide thin film. The present invention also relates to a method for manufacturing a nickel sulphide thin film using atomic layer deposition.

[Chemical Formula 1]

M is an integer ranging from 1 to 3; R1, R2, R3 and R4 are independently C1-C4 linear or branched alkyl groups, preferably m is 1 or 2;

In the method for forming a nickel sulphide thin film according to the atomic layer deposition method of the present invention, the nickel precursor and the sulfur source represented by Formula 1 are alternately supplied and adsorbed on the substrate while maintaining the temperature of the substrate constant, Exhaust or an inert gas such as argon is sent to the deposition chamber to remove unreacted residues and by-products to deposit the thin film.

The process for forming a nickel sulphide thin film according to the present invention comprises

A step of introducing the substrate into the deposition chamber, an adsorption step of the nickel precursor, a first purification step, an adsorption step of the sulfur source, and a second purification step, wherein the adsorption step of the nickel precursor, the first purification step, And the second purification step constitute one cycle. To obtain the desired thickness of the nickel sulfide thin film, the above four steps may be repeatedly performed until reaching the target thickness by one cycle.

Specifically, the method for producing a nickel sulphide thin film according to the present invention includes the following manufacturing steps.

a) introducing the substrate into the deposition chamber;

b) adsorbing the nickel precursor represented by Formula 1 on the substrate by atomic layer deposition;

c) removing other by-products, excluding the adsorbed nickel precursor;

d) introducing a sulfur source into the deposition chamber to conduct an exchange reaction with the nickel precursor adsorbed on the substrate to form a nickel sulphide thin film on the substrate; And

e) removing the remaining by-products except the nickel sulphide thin film.

In the step a), the substrate introduced into the deposition chamber is a substrate on which the nickel sulphide thin film according to the present invention is formed. The substrate is selected from the group consisting of silicon (Si), germanium (Ge), silicon carbide (Si) wafer, a germanium (Ge) wafer, a silicon carbide (SiC) wafer, glass, polyethylene terephthalate (PET), polyimide (PI) and the like.

In the step b), the nickel amino alkoxide of Formula 1 adsorbed on the substrate is stable and stable, and is suitable for use as a precursor for atomic layer deposition. The nickel amino alkoxide represented by the above formula (1) is preferably a compound represented by the following formula (2).

(2)

The nickel amino alkoxide of Formula 1 supplied to the deposition chamber is stored in a vessel outside the deposition chamber, and an inert gas such as argon is used as a carrier gas to supply the deposition chamber.

The nickel amino alkoxide of Formula 1 is preferably supplied to the surface of the substrate at a rate of 4 seconds or more per one cycle, more specifically 4 seconds or more and 6 seconds or less. If the supply time is less than 4 seconds, the nickel amino alkoxide of the above formula (1) can not be sufficiently adsorbed. Even if the supply time is excessively longer than 6 seconds, the amount of adsorbed on the substrate is saturated and does not increase any more, and the process time becomes long, which is inefficient. The reaction time of one cycle may be controlled by adjusting the amount of the nickel amino alkoxide or the sulfur source of Formula 1 supplied into the deposition chamber per unit time.

In step b), the nickel amino alkoxide of formula 1 is firstly adsorbed. In step c), an inert gas, such as argon gas, is sent to the chamber or vacuum purified to remove the unreacted compound of formula 1 Nickel amino alkoxide and reaction by-products are removed by venting through an exhaust pump.

After purification in step c), step d) supplies a source of sulfur into the deposition chamber to cause sulfur to adsorb on the surface of the substrate on which the nickel amino alkoxide of formula 1 is adsorbed. As the sulfur source, sulfur or hydrogen sulfide is preferable, and hydrogen sulfide is most preferable. It is preferable that the sulfur source is supplied for at least 1 second, more specifically at least 1 second and at most 3 seconds per cycle, because if the supply time is less than 1 second, the sulfur source is not sufficiently adsorbed . In addition, even if the supply time of the sulfur source exceeds 3 seconds, the amount of adsorbed on the substrate is saturated, and the process time is not increased any more, resulting in inefficiency. In the step d) for adsorbing the sulfur, either a method of simply supplying the sulfur source or a method of generating the plasma with the supply of the sulfur source can be selected.

Subsequently, when the step d) is completed, the second purification step of the step e) proceeds. The second purge step exhausts the inert gas through the exhaust pump by sending the inert gas to the chamber or by vacuum cleaning to remove unreacted sulfur source and reaction byproducts.

In the steps a) to e) of the production method according to the present invention, the temperature of the substrate is maintained at 80 to 400 占 폚, more preferably at 80 to 200 占 폚, and even more preferably at 80 to 100 占 폚, A thin film can be formed. When the temperature of the substrate is lower than 80 ° C, the reaction between the nickel precursor adsorbed on the substrate and sulfur may not be performed well, so that the nickel sulphide thin film may not be formed well. If the temperature of the substrate is excessively higher , The physical properties of the substrate may change, or the CVD process may be performed instead of the ALD process, which is undesirable.

The present invention may be better understood by the following examples, which are for the purpose of illustrating the invention and are not intended to limit the scope of protection defined by the appended claims.

Example

Atomic layer  Formation of nickel sulphide thin film by deposition method

≪ Example 1 >

The silicon substrate on which the nickel oxide thin film was to be deposited was sequentially washed with acetone, ethanol, and deionized water, and then mounted in an atomic layer deposition reactor. The reactor was evacuated with an exhaust pump. The temperature of the substrate was adjusted to 100 ° C and the vapor pressure was kept constant by opening the valve of the nickel precursor supply pipe with bis (dimethylamino-2-methyl-2-butoxy) nickel (II) [Ni (dmamb) ₂ ] . Hydrogen sulphide was used as a sulfur source.

The deposition chamber, the nickel precursor supply pipe, and the nickel precursor vessel were maintained at a constant temperature of 90 ° C. and the deposition reaction was carried out in the order of nickel precursor supply, argon purification, hydrogen sulfide supply, and argon dialing. At this time, the flow rate of the purge gas argon was 200 sccm, the purge time was 40 seconds, and the working pressure of the reactor was adjusted to 1 Torr.

FIG. 1 shows the growth time of the thin films obtained by increasing the supply time of Ni (dmamb) ₂ by maintaining the temperature of the substrate at 100 ° C. by ellipsometry and plotting the growth rate with respect to the supply time. As shown in FIG. 1, the supply time of Ni (dmamb) ₂ exceeds 4 seconds, and the surface reaction saturates and the growth rate becomes almost constant. This is the most characteristic property of atomic layer deposition. FIG. 2 shows the thicknesses of the thin films obtained by increasing the supply time of H ₂ S similarly to Ni (dmamb) ₂ . As shown in FIG. 2, it was confirmed that the supply time of Ni (dmamb) ₂ exceeded 1 second, and the surface reaction saturates and the growth rate became almost constant.

≪ Example 2 >

Under the same conditions as in Example 1, the supply time of Ni (dmamb) ₂ and hydrogen sulfide was set to 4 seconds and 1 second, respectively, and the thickness of the thin film was measured by increasing the cycles of the ALD process to 8, 12, 3 is shown. FIG. 4 shows graphs and thicknesses obtained by AFM image and line profiling of the nickel sulphide thin film when the cycle of the ALD process is repeated 12 times, 25 times, and 50 times. As a result, since the thickness of the thin film depends primarily on the ALD period, it can be clearly seen from FIGS. 3 and 4 that the thin film manufacturing process exhibits true ALD characteristics.

≪ Example 3 >

The ALD process cycle was repeated 200 times under the same conditions as in Example 2. The surface of the formed thin nitride film was cleaned by argon ion sputtering for 5 minutes to remove carbon contamination on the surface, The spectrum is shown in Fig.

In this spectrum, we can observe characteristic optoelectronic peaks of nickel and oxygen, silicon and sulfur. The ratio of nickel to sulfur was measured to be about 1: 0.93. Through this, it was found that the nickel sulphide thin film was well formed.

Further, the side and the surface of the formed nitride film were photographed by SEM and are shown in Figs. 6 (a) and 6 (b), respectively.

Claims (11)

a) introducing the substrate into the deposition chamber;
b) adsorbing a nickel precursor represented by the following formula (1) on the substrate by atomic layer deposition;
c) removing other by-products, excluding the adsorbed nickel precursor;
d) introducing a sulfur source into the deposition chamber to conduct an exchange reaction with the nickel precursor adsorbed on the substrate to form a nickel sulphide thin film on the substrate; And
e) removing the by-products except for the nickel sulphide thin film;
Wherein the method comprises the steps of:
[Chemical Formula 1]

(m is an integer ranging from 1 to 3, and R1, R2, R3 and R4 are independently C1-C4 linear or branched alkyl groups) The method according to claim 1,
Wherein m is 1 or 2 in Formula (1). The method of claim 2,
Wherein the nickel amino alkoxide is a compound represented by the following formula (2).
(2)

The method according to claim 1,
Wherein the sulfur source is selected from sulfur or hydrogen sulphide. The method of claim 4,
Wherein the sulfur source is hydrogen sulfide. The method according to claim 1,
Wherein the substrate comprises at least one selected from silicon (Si), germanium (Ge), silicon carbide (SiC), glass, and organic polymers. The method according to claim 1,
Wherein the temperature of the substrate is maintained in the range of 80 to 400 占 폚. The method of claim 7,
Wherein the temperature of the substrate is maintained in the range of 80 to 200 占 폚. The method of claim 8,
Wherein the temperature of the substrate is maintained in a range of 80 to 100 占 폚. The method according to claim 1,
Wherein the step (b) comprises supplying the nickel precursor at a period of not less than 4 seconds and not more than 6 seconds,
Wherein the step (d) comprises supplying the sulfur source at a period of not less than 1 second and not more than 3 seconds. The method according to claim 1,
and b) to e) are repeatedly carried out.

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