KR20100082915A - Method for fabricating cigs thin layer by ald - Google Patents

Abstract

PURPOSE: A method for manufacturing a CIGS thin film by an atomic layer depositing method is provided to easily manufacture a thin film with high quality and large area by successively supplying precursors like copper, indium, gallium, and selenium to a chamber with a pulse type. CONSTITUTION: A substrate(S) is positioned inside a reactive chamber(10) and maintains the substrate with a specific reaction temperature. A copper precursor compound is supplied and reacted to the reactive chamber. A pursing process is performed to remove non-reactive materials and byproducts. An indium precursor compound is supplied and reacted to a reactive chamber. A gallium precursor compound is supplied and reacted to the reactive chamber. The pursing process is performed to remove the non-reactive materials and the byproducts. A selenium precursor is supplied and reacted to the reactive chamber. The pursing is performed to remove the non-reactive materials and byproducts.

Description

CIS thin film manufacturing method by atomic layer deposition method {METHOD FOR FABRICATING CIGS THIN LAYER BY ALD}

The present invention relates to a CIGS thin film manufacturing method for producing a CIGS thin film by an atomic layer deposition method while supplying each precursor sequentially in the form of a pulse inside the chamber.

In general, the group I-III-VI group ₂ (I: Ag, Cu; III: Al, Ga, In; VI: S, Se, Te) compound semiconductor has a chalcopyrite structure at room temperature atmospheric pressure, It is applied in a wide range of fields because it shows various physical properties according to different member elements.

These Ⅰ-Ⅲ-Ⅵ ₂ group compound semiconductor was first synthesized by the like 1953 Hahn, is used and the application possibilities such as presented later, light-emitting diodes, as well as an infrared detector, a nonlinear optical device and a solar cell as a semiconductor or the like by Goodman.

Among them, CuInSe ₂ (hereinafter referred to as “CIS”) or CuIn ₁ because the energy band spacing is about 1 to 2.5 eV at room temperature and the linear light absorption coefficient is about 10 to 100 times larger than other semiconductors. _-x Ga _x Se ₂ (hereinafter referred to as "CIGS") compound semiconductors are frequently used.

In particular, thin film solar cells using CIGS thin films can be manufactured with a thickness of 10 μm or less unlike conventional solar cells using silicon crystals, and have stable characteristics even when used for a long time. As it shows the energy conversion efficiency of, it is known that it is highly commercialized as a low-cost, high-efficiency thin-film solar cell that can replace the silicon crystalline solar cell.

However, CIGS thin film solar cells having such excellent characteristics have not been widely used because they are difficult to manufacture high quality thin films in an economical manner. Conventionally, as a method for manufacturing a CIGS thin film, a physical vapor deposition method in which each element is simultaneously evaporated and deposited on a substrate in a vacuum atmosphere is used. However, the physical vapor deposition method is not only difficult to mass-produce, but also has a problem of poor film quality.

The technical problem to be solved by the present invention is to provide a CIGS thin film manufacturing method capable of forming a large-area thin film with excellent film quality, low manufacturing cost by supplying each precursor in a sequential pulse form to produce a CIGS thin film by atomic layer deposition method To provide.

In the method for manufacturing a CIGS thin film according to the present invention for achieving the above technical problem, in the method for producing a CIGS thin film on a substrate using an atomic layer deposition method, 1) to position the substrate inside the reaction chamber, Maintaining at a specific reaction temperature; 2) supplying and reacting a copper precursor compound into the reaction chamber; 3) a first purging step to remove unreacted material and byproducts; 4) supplying and reacting the indium precursor compound into the reaction chamber; 5) a second purging step to remove unreacted material and by-products; 6) supplying and reacting a gallium precursor compound into the reaction chamber; 7) third purging step to remove unreacted material and by-products; 8) supplying and reacting the selenium precursor compound into the reaction chamber; 9) a fourth purging step of removing unreacted material and by-products.

In steps 2), 4), 6), and 8) of the present invention, the copper, indium, gallium, and selenium precursor compounds are sequentially supplied and purged, respectively, but the order of supplying these precursors is changeable and double It is possible for one or more precursors to be supplied repeatedly.

And in steps 2), 4), 6), and 8), the copper, indium, gallium, and selenium precursor compounds are preferably supplied into the reaction chamber in a vaporized state for 0.1 to 200 seconds, respectively. .

In addition, in steps 3), 5), 7), and 9), it is preferable to inject N2 or Ar gas, which is an inert gas, at a flow rate of 1 sccm to 1000 slm for about 0.1 to 200 seconds and discharge the same to a pump.

In the present invention, the copper precursor compound is Bis (acetylacetonato) copper, Bis (2,2,6,6-tetramethylheptandionato) copper, Bis (hexafluoroacetylacetonato) copper, (vinyltrimethylsilyl) (hexafluoroacetylacetonato) copper, (vonyltrimethylsilyl) (acetylacetonato) copper, (Vinyltrimethylsilyl) (2,2,6,6-tetramethylheptandionato) copper, (Vinyltriethylsilyl)-(acetylacetonato) copper, (Vinyltriethylsilyl)-(2,2,6,6-teramethylheptandionato) copper, (Vinyltriethylsilyl)-(hexafluoroacetylacetonato It is characterized in that any one or a mixture of two or more selected from the group consisting of) copper.

On the other hand, the indium precursor compound is characterized by having the structure of formula (1) below.

<Formula 1>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.)

Specifically, the indium precursor compound is selected from trimethylindium, triethylindium, Triisopropylindium, Tributylindium, Tritertiarybutylindium, Triethoxyindium, Triethoxyindium, Triisopropoxyindium, Dimethylisopropoxyindium, Diethylisopropoxyindium, Dimethylethylindium, Diethylmethylindium, Dimethylisopropylindium, Diindium ethyltitidium, which is selected from the group consisting of two or more of diethylisopropylindium; Can be configured.

In addition, the gallium precursor compound is characterized by having the structure of formula (2) below.

<Formula 2>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.)

Specifically, the gallium precursor compound is trimethylgallium, Triethylgallium, Triisopropylgallium, Tributylgallium, Tritertiarybutylgallium, Triethoxygallium, Triethoxygallium, Triisopropoxygallium, Dimethylisopropoxygallium, Diethylisopropoxygallium, Dimethylethylgallium, Diethylmethylgallium, Dimethylisopropylgallium, or a group consisting of two or more of diethylisopropylgallium, Can be configured.

And the selenium precursor compound is characterized by having the structure of formula (3) or formula (4) below.

<Formula 3>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.)

<Formula 4>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.)

Specifically, the selenium precursor may be composed of any one or two or more selected from the group consisting of Dimethylselenide, Diethylselenide, Diisoprylselenide, Ditertiarybutylselenide, Dimethyldiselenide, Diethylselenide, Diisopropyldiselenide, Ditertiarybutyldiselenide, Tertiarybutylisopropylselenide, Tertiarybutylselenol.

In the present invention, the copper precursor, the indium precursor, or the gallium precursor is preferably supplied while maintaining the canister temperature at -40 to 200 ° C and the supply line temperature at room temperature to 400 ° C, so that the precursor can be efficiently supplied to the reaction chamber.

Meanwhile, the selenium precursor is preferably supplied while maintaining the canister temperature at -60 to 200 ° C and the supply line temperature at room temperature to 400 ° C.

And while maintaining the temperature of the substrate at room temperature ~ 600 ℃ during the process of the present invention, it is preferable to induce efficient thin film deposition.

In the present invention, when supplying the copper, indium, gallium, selenium precursor compound to the chamber, to assist the reaction hydrogen (H ₂ ), ammonia (NH ₃ ), oxygen (O ₂ ), ozone (O ₃ ), nitrous oxide (N2O) and the like can be supplied to the chamber simultaneously or sequentially as a reaction gas.

In the first, 2, 3, 4 purging step in the present invention, any one selected from the group consisting of helium (He), hydrogen (H ₂ ), nitrogen (N ₂ ), argon (Ar), ammonia (NH ₃ ) Injecting one purge gas into the reaction chamber and sucking and removing gas present in the reaction chamber by using a vacuum pump provided in the reaction chamber effectively discharges unreacted gas and reaction by-products to obtain excellent membrane quality. It is preferable because it can.

According to the present invention, a precursor of copper, indium, gallium, selenium, and the like is sequentially supplied to the chamber using an atomic layer deposition method to manufacture a CIGS thin film, so that the film quality is excellent and a large area thin film can be easily manufactured. It is effective in mass production.

Hereinafter, with reference to the accompanying drawings will be described in detail a specific embodiment of the present invention.

In the CIGS thin film manufacturing method according to the present embodiment, a general atomic layer deposition apparatus as shown in FIG. 1 may be used. The atomic layer deposition apparatus includes a reaction chamber 10 capable of maintaining an interior in a vacuum state, and a substrate chuck 20 on which a substrate S is mounted is provided below the reaction chamber 10. .

The substrate S is loaded into the reaction chamber 10 through a gate (not shown) provided on one side of the reaction chamber 10, placed on the substrate chuck 20, and then fixed. After the substrate S is loaded into the reaction chamber 10, the gate is sealed, and the inside of the reaction chamber 10 is decompressed, and the pressure inside the reaction chamber is preferably maintained at 0.01 mtorr to atmospheric pressure.

In addition, the upper portion of the reaction chamber 10 is provided with a shower head 30 through which a process gas and a purging gas can be supplied, and the shower head 30 has a myriad of minute holes having a diameter of about 0.5 to 1 mm. . Therefore, the process gas and the purging gas may be uniformly supplied to the entire substrate through the shower head 30.

As shown in FIG. 1, the shower head 30 is connected to a plurality of canisters 40, 50, 60, and 70 disposed outside, and has a structure capable of receiving process gas from each canister. Have

In this state, the process gas, that is, the copper precursor, the indium precursor, the gallium precursor, and the selenium precursor are sequentially supplied through the shower head 30 while the substrate S is mounted in the reaction chamber 10. Atomic layer deposition methods produce CIGS thin films quickly and efficiently.

Here, the sequential supply in the form of a pulse means that the copper precursor compound is supplied into the reaction chamber for a predetermined short time by a carrier gas to react with the substrate, and then the purging gas is supplied into the chamber to purge at least once. The copper precursor compound thin film is repeatedly grown on the substrate, and then the indium precursor compound, like the copper precursor compound, is supplied into the reaction chamber for a short time by a carrier gas to react with the substrate, and then the purging gas is supplied into the chamber. The process of purging is repeated one or more times to make the indium compound react on the copper compound thin film, and the gallium precursor and the selenium precursor also proceed in the same manner.

In other words, it refers to an intermittent supply of supplying and shutting off for a short time, rather than supplying a single process gas continuously, while removing unreacted gas and reaction by-products while the process gas is not supplied and no longer reacting. The purging process is repeated so as not to proceed.

At this time, the purging gas is preferably any one selected from the group consisting of helium (He), hydrogen (H ₂ ), nitrogen (N ₂ ), argon (Ar), ammonia (NH ₃ ). In the purging method, a purging gas is injected into the reaction chamber 10, and the gas present in the reaction chamber is sucked and removed by using a vacuum pump (not shown) provided in the reaction chamber 10. The method is preferred because it can be most efficiently purged into the reaction chamber.

Meanwhile, in the case of the indium precursor compound and the gallium precursor compound, they may be sequentially supplied, but a mixture of both may be simultaneously supplied in a ratio of indium and gallium in the CIGS thin film to be manufactured.

In the present embodiment, the copper precursor canister 40 that supplies the copper precursor is preferably maintained at a temperature of about -40 to 200 ° C. in order to supply an appropriate copper precursor. In addition, the temperature of the supply line 44 through which the copper precursor leaving the canister 40 passes to reach the showerhead 30 is preferably maintained at a temperature higher than room temperature to about 400 ° C.

The copper precursor is preferably supplied into the chamber by a carrier gas supplied by the first carrier gas source 42, as shown in FIG. 1, rather than into the chamber alone. (Ar), helium (He), nitrogen (N ₂ ) gas, etc. are preferable.

In addition, the copper precursor may be supplied by being mixed with a gas such as hydrogen (H ₂ ), ammonia (NH ₃ ), nitrogen dioxide (NO ₂ ), oxygen (O ₂ ), and after the copper precursor is supplied, the aforementioned gases are carried. It may be supplied into the chamber together with the gas or alone.

Meanwhile, in the present embodiment, as a copper precursor, Bis (acetylacetonato) copper, Bis (2,2,6,6-tetramethylheptandionato) copper, Bis (hexafluoroacetylacetonato) copper, (vinyltrimethylsilyl) (hexafluoroacetylacetonato) copper, (vonyltrimethylsilyl) (acetylacetonato) copper , (Vinyltrimethylsilyl) (2,2,6,6-tetramethylheptandionato) copper, (Vinyltriethylsilyl)-(acetylacetonato) copper, (Vinyltriethylsilyl)-(2,2,6,6-teramethylheptandionato) copper, (Vinyltriethylsilyl)-(hexafluoroacetylacetonato) Any one or a mixture of two or more selected from the group consisting of copper may be used.

Next, the canister 50 for supplying the indium precursor may also maintain the temperature of the canister at about −40 to 200 ° C. for the efficient supply of the indium precursor like the copper precursor described above. In addition, the temperature of the supply line 54 is also slightly higher than the temperature of the canister, it is preferable to maintain at about room temperature ~ 400 ℃. In addition, like the copper precursor, the indium precursor is preferably carried by a carrier gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) gas.

In the present embodiment, it is preferable to use a compound having the structure of Formula 1 below as an indium precursor.

<Formula 1>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.)

Such indium precursor, specifically, trimethylindium, Triethylindium, Triisopropylindium, Tributylindium, Tritertiarybutylindium, Triethoxyindium, Triethoxyindium, Triisopropoxyindium, Dimethylisopropoxyindium, Diethylisopropoxyindium, Dimethylethylindium, Diethylmethylindium, Dimethylisopropylindium, Diin methylpropyltidium or any one selected from the group of diethylisopropylindium, This can be used.

Next, the canister 60 for supplying the gallium precursor is also preferably maintained at the temperature of the canister at about -40 to 200 ° C for the efficient supply of the gallium precursor, similar to the copper precursor described above. In addition, it is preferable that the temperature of the supply line 64 is also slightly higher than the temperature of the canister, and maintained at about room temperature to 400 ° C. Also, like the copper precursor, the gallium precursor is preferably carried by a carrier gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) gas.

In the present embodiment, it is preferable to use a compound having the structure of Formula 2 below as a gallium precursor.

<Formula 2>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.)

Specifically gallium precursor, trimethylgallium, Triethylgallium, Triisopropylgallium, Tributylgallium, Tritertiarybutylgallium, Triethoxygallium, Triethoxygallium, Triisopropoxygallium, Dimethylisopropoxygallium, Diethylisopropoxygallium, Dimethylethylgallium, Diethylmethylgallium, Dimethylisopropylgallium, Diethylisopropylgalaryl group, which is made of two or more diethylisopropylgallium, etc. Can be.

Next, the canister 70 for supplying the selenium precursor is also preferably maintained at a temperature of about −60 to 200 ° C. for the efficient supply of the selenium precursor, similar to the copper precursor described above. In addition, it is preferable that the temperature of the supply line 74 is also slightly higher than the temperature of the canister, and maintained at about room temperature to 400 ° C. In addition, like the copper precursor, the selenium precursor is preferably carried by a carrier gas such as argon (Ar), helium (He), or nitrogen (N ₂ ) gas.

The selenium precursor according to the present embodiment is preferably a compound having the structure of Formula 3 or Formula 4 below.

<Formula 3>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.)

<Formula 4>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.)

Specifically, the selenium precursor may be any one or two or more selected from the group consisting of Dimethylselenide, Diethylselenide, Diisoprylselenide, Ditertiarybutylselenide, Dimethyldiselenide, Diethylselenide, Diisopropyldiselenide, Ditertiarybutyldiselenide, Tertiarybutylisopropylselenide, Tertiarybutylselenol, and the like.

1 is a cross-sectional view showing an example of an atomic layer deposition apparatus according to an embodiment of the present invention.

Claims (15)

In the method for producing a CIGS thin film on a substrate using an atomic layer deposition method, 1) placing a substrate inside the reaction chamber and maintaining the substrate at a specific reaction temperature; 2) supplying and reacting a copper precursor compound into the reaction chamber; 3) a first purging step to remove unreacted material and byproducts; 4) supplying and reacting the indium precursor compound into the reaction chamber; 5) a second purging step to remove unreacted material and by-products; 6) supplying and reacting a gallium precursor compound into the reaction chamber; 7) third purging step to remove unreacted material and by-products; 8) supplying and reacting the selenium precursor compound into the reaction chamber; 9) a fourth purging step of removing unreacted materials and by-products. The method of claim 1, wherein in steps 2), 4), 6), and 8), And supplying the copper, indium, gallium, and selenium precursor compounds in a vaporized state into the reaction chamber for 0.1 to 200 seconds, respectively. The method of claim 1, wherein in steps 3), 5), 7), and 9), A method of producing a CIGS thin film, characterized in that the inert gas N2 or Ar gas is injected for about 0.1 to 200 seconds at a flow rate of 1 sccm to 1000 slm and discharged to a pump. The method of claim 1, wherein the copper precursor compound, Bis (acetylacetonato) copper, Bis (2,2,6,6-tetramethylheptandionato) copper, Bis (hexafluoroacetylacetonato) copper, (vinyltrimethylsilyl) (hexafluoroacetylacetonato) copper, (vonyltrimethylsilyl) (acetylacetonato) copper, (Vinyltrimethylsilyl) (2,2, 6,6-tetramethylheptandionato) copper, (Vinyltriethylsilyl)-(acetylacetonato) copper, (Vinyltriethylsilyl)-(2,2,6,6-teramethylheptandionato) copper, (Vinyltriethylsilyl)-(hexafluoroacetylacetonato) copper Or a mixture of two or more CIGS thin films. The method of claim 1, wherein the indium precursor compound, CIGS thin film manufacturing method characterized by having a structure of the formula (1) below. <Formula 1>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.) The method of claim 5, wherein the indium precursor compound, Trimethylindium, Triethylindium, Triisopropylindium, Tributylindium, Tritertiarybutylindium, Triethoxyindium, Triethoxyindium, Triisopropoxyindium, Dimethylisopropoxyindium, Diethylisopropoxyindium, Dimethylethylindium, Diethylmethylindium, Dimethylisopropylindium, Diethylisopropylindium, Dimethyltertiary group is selected from the group consisting of two or more compounds selected from the group . The method of claim 1, wherein the gallium precursor compound, CIGS thin film manufacturing method characterized by having a structure of the formula (2) below. <Formula 2>

In Formula 1, R1, R2, and R3 are methyl, ethyl, buthyl, tert-buthyl, iso-buthyl, sec-buthyl, methoxy, ethoxy, propoxy, iso-propoxy, buthoxy, tert-buthoxy, iso-buthoxy, sec is a functional group of -buthoxy.) The method of claim 7, wherein the gallium precursor compound, Trimethylgallium, Triethylgallium, Triisopropylgallium, Tributylgallium, Tritertiarybutylgallium, Triethoxygallium, Triethoxygallium, Triisopropoxygallium, Dimethylisopropoxygallium, Diethylisopropoxygallium, Dimethylethylgallium, Diethylmethylgallium, Dimethylisopropylgallium, Diethyltertiyl is made of a mixture of two or more compounds made of CImethylgaltigalyl group, which is made of a mixture of two or more of the methyl methyl . The method of claim 1, wherein the selenium precursor compound, CIGS thin film manufacturing method characterized by having a structure of the formula (3) below. <Formula 3>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.) The method of claim 1, wherein the selenium precursor compound, CIGS thin film manufacturing method characterized by having a structure of the formula (4) below. <Formula 4>

(In Formula 3, R1, R2 is any one of H, metyl, ethyl, propyl, iso-propyl, butyl, tert-butyl, sec-butyl.) The method of claim 1, wherein the selenium precursor, Dimethylselenide, Diethylselenide, Diisoprylselenide, Ditertiarybutylselenide, Dimethyldiselenide, Diethylselenide, Diisopropyldiselenide, Ditertiarybutyldiselenide, Tertiarybutylisopropylselenide, Tertiarybutylselenol, characterized in that the CIGS thin film manufacturing method characterized in that the mixture. The method of claim 1, The copper precursor or indium precursor or gallium precursor, CIGS thin film manufacturing method characterized in that the supply while maintaining the canister temperature -40 ~ 200 ℃, supply line temperature at room temperature ~ 400 ℃. The method of claim 1, wherein the selenium precursor, CIGS thin film manufacturing method characterized in that the supply while maintaining the canister temperature -60 ~ 200 ℃, supply line temperature at room temperature ~ 400 ℃. The method of claim 1, CIGS thin film manufacturing method characterized in that the temperature of the substrate is maintained at room temperature ~ 600 ℃. The method of claim 1, wherein in the first, second and third purging steps, A purging gas selected from the group consisting of helium (He), hydrogen (H ₂ ), nitrogen (N ₂ ), argon (Ar), and ammonia (NH ₃ ) is injected into the reaction chamber, and the reaction chamber is injected into the reaction chamber. CIGS thin film manufacturing method, characterized in that for removing the gas present in the reaction chamber by using a vacuum pump provided.

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