KR20030063635A - Method for depositing thin film using magnetic field - Google Patents

Abstract

PURPOSE: A method for depositing a magnetic atomic layer deposition(ALD) thin film is provided to more rapidly deposit a thin film having high purity, an excellent electrical characteristic and good step coverage even at a low temperature as compared with a chemical vapor deposition(CVD) method by applying only a magnetic field or both the magnetic field and plasma altogether. CONSTITUTION: A wafer transferred through a wafer transfer hole is positioned in a reactor block. A wafer block in which the wafer is settled is installed in the reactor block. A shower head sprays the first and second reaction gases on the wafer. An exhaust unit exhausts the gas inside the reactor block to the outside. A magnetic field generating apparatus applies a magnetic field to the surface of the wafer block. The wafer is placed on the wafer block(S1). A magnetic field is formed on the wafer(S3). The first reaction gas mixed with inert gas is sprayed on the wafer(S4). The first reaction gas is purged from a reaction receptacle(S5). The second reaction gas mixed with inert gas is sprayed on the wafer(S6). The second reaction gas is purged from the reaction receptacle.

Description

Method for depositing thin film using magnetic field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film deposition method for depositing a thin film, and more particularly, to a magnetic ALD thin film deposition method capable of depositing a higher purity thin film at a lower temperature in manufacturing a semiconductor wafer or a flat panel display device. .

The ALD (Atom Layer Deposition) thin film deposition method is mainly used as a method for manufacturing a high-density chip because the thin film can be deposited at a lower temperature than the CVD thin film deposition method.

2A to 2D are diagrams illustrating a state in which reactant gas particles react on a wafer, and FIG. 2A is a diagram illustrating a reaction state of a first reactant gas and a wafer in a first reactant gas feeding step, and FIG. 2B. 2 is a view showing a purge state of the first reaction gas, FIG. 2C is a view showing a reaction state of the first reaction gas adsorbed on the wafer and the second reaction gas injected in the second reaction gas feeding step, FIG. 2D illustrates a purge state of the remaining gases after one atomic layer of the thin film is formed.

Preheating the substrate or wafer (hereinafter referred to as wafer) to deposit a thin film is performed. The preheating step is a step ⓐ-ⓑ shown in FIG. 1, in which the wafer is preheated to a lower temperature than the CVD inside the reaction vessel. In this step, an inert gas is constantly introduced into the reaction vessel into the purge gas.

Step ⓑ-ⓒ is a step of feeding the first reaction gas ABn to the reaction vessel. Here, A and B meant the specific element, n was set to 2. In this step, as shown in FIG. 2A, the first reaction gas (ABn) particles are adsorbed onto the wafer.

Ⓒ- ⓓ step is a purge step, and as shown in FIG. 2B, the remaining first reaction gas which is not adsorbed on the wafer w is purged.

Feed the second reaction gas into the reaction vessel in step ⓓ-ⓔ. C and D mean a specific element here, and m was set to 3. In this step, as shown in FIG. 2C, the second reaction gas CDm injected onto the wafer w is substituted with the first reaction gas ABn already adsorbed on the wafer w (in a circle). On the wafer, an atomic layer of the thin film AC is formed. The thin film AC forming one atomic layer is shown in FIG. 2D.

Ⓔ-ⓕ step is purging the second reaction gas (CDm) from the reaction vessel. In this step, the second reaction gas (CDm) and the reaction by-product (BD) and the like which are not used for forming the thin film are discharged to the outside of the reaction vessel. And practically, thin film AC formation continues to this stage.

Thereafter, the thin film having a desired thickness may be deposited on the wafer w by repeating the ⓑ-ⓕ step for several cycles several times. At this time, the substitution reaction between the first reaction gas and the second reaction gas is made by the thermal decomposition energy in the reaction vessel.

However, in the ALD thin film deposition method as described above, since the substitution reaction of the first and second reaction gases is performed only by pyrolysis energy, the thin film deposition rate is lower than that of the CVD method which performs thin film deposition at a relatively high temperature. I had no choice but to. Therefore, research and development is in full swing to obtain a high film deposition rate while maintaining the advantages of low temperature processing capability, which is an advantage of the ALD method.

The present invention has been made in view of the above-described trend, and an object of the present invention is to provide a magnetic ALD thin film deposition method capable of rapidly depositing a thin film that realizes high purity and excellent electrical properties and step coverage at a lower temperature than CVD. It is done.

1 is a graph illustrating a conventional ALD thin film deposition method.

2A to 2D are diagrams illustrating a state in which reactant gas particles react on a wafer, and FIG. 2A is a diagram illustrating a reaction state of a first reactant gas and a wafer in a first reactant gas feeding step, and FIG. 2B. 2 is a view showing a purge state of the first reaction gas, FIG. 2C is a view showing a reaction state of the first reaction gas adsorbed on the wafer and the second reaction gas injected in the second reaction gas feeding step, FIG. 2D illustrates a purge state of the remaining gases after one atomic layer of the thin film is formed.

Figure 3 is a block diagram of a first embodiment of a reaction vessel for performing the ALD thin film deposition method according to the present invention.

FIG. 4 is a view showing an extract of the magnetic field generating device and the wafer block in the reaction container of FIG. 3.

FIG. 5 is a graph illustrating an ALD thin film deposition method using the reaction vessel of FIG. 3.

6 is a diagram illustrating a reaction state of a first reaction gas adsorbed on a wafer and a second reaction gas injected in a state where a magnetic field is applied.

FIG. 7 is a flow diagram sequentially illustrating the ALD thin film deposition method of FIGS. 3 to 6.

Figure 8 is a block diagram of a second embodiment of a reaction vessel for performing the ALD thin film deposition method according to the present invention.

9 is a diagram illustrating a reaction state of a first reaction gas adsorbed on a wafer and a second reaction gas injected in a state where a magnetic field and plasma are applied.

FIG. 10 is a flow diagram sequentially illustrating an ALD thin film deposition method using the reaction vessel of FIG. 8.

11 is a view showing a state in which the horizontal magnetic field is rotated as a whole on the wafer.

12 is a configuration diagram of a third embodiment of a reaction vessel for performing the ALD thin film deposition method according to the present invention.

FIG. 13 is a graph illustrating an ALD thin film deposition method using the reaction vessel of FIG. 8.

<Description of Signs of Major Parts of Drawings>

10 ... transfer module 20 ... reactor block

21 ... feed hole 30, 130 ... wafer block

35 ... Wafer Block Support 40 ... Top Plate

50 ... shower head 51. 52 ... 1st, 2nd injection hole

51a, 51b ... first and second reaction gas supply lines

60, 160 ... magnetic field generator

61 ... rotating frame 63 ... magnet

65 ... rotary drive 71 ... RF power

73 ... RF Matching Box 75 ... Capacitor

77 ... RF pole plate 150 ... Gas distributor

B ... magnetic field P ... plasma

H ... heater

In order to achieve the above object, the magnetic ALD thin film deposition method according to the present invention,

A reactor block 20 in which the wafer w transferred through the wafer transfer hole 21 is located, a wafer block 30 installed in the reactor block 20 and seated on the wafer w, and supplied A shower head 50 for injecting a first reaction gas and a supplied second reaction gas toward the wafer, an exhaust unit for exhausting gas inside the reactor block 20 to the outside, and the wafer block 30 As using the ALD reaction vessel including a magnetic field generating device 60 for applying a magnetic field on the surface,

A wafer seating step (S1) for seating the wafer (w) onto the wafer block (30); A magnetic field forming step (S3) of forming a magnetic field on the wafer (w) surface; A first reaction gas feeding step S4 of injecting the first reaction gas mixed with an inert gas to the wafer w and a first reaction gas purge step of purging the first reaction gas from the reaction vessel S5. ), A second reaction gas feeding step (S6) for injecting the second reaction gas mixed with an inert gas to the wafer (w), and a second reaction gas purge for purging the second reaction gas from the reaction vessel. Reaction gas feeding and purge repeating step (S8) to repeat the step (S7); characterized in that it comprises a. In this case, plasma may be formed on the wafer during at least one of the first reaction gas feeding step and the second reaction gas feeding step.

In the present invention, the magnitude of the substitution reaction activation energy between the first reaction gas and the second reaction gas is adjusted on the wafer surface by changing the intensity of the magnetic field.

In the present invention, when the total cycle required for thin film deposition is deposited by dividing A + B cycles, the strength of the magnetic field applied during the A cycle is referred to as a, and the strength of the magnetic field applied during the B cycle is referred to as b. The intensity of a> b makes the purity of the thin film in contact with the underlying film better.

In the present invention, the flow amount of the inert gas injected from the showerhead is always constant during the deposition of the thin film.

In the present invention, after the thin film deposition is completed, further comprising a heat treatment step (S9) for injecting an inert gas and reaction gas to heat treatment the thin film while applying a magnetic field on the wafer surface.

In the present invention, the applied magnetic field has a uniform distribution on the wafer surface.

In the present invention, as the magnetic field generating device 60 rotates around the reaction vessel, the direction of the magnetic field formed on the surface of the wafer w is rotated.

In order to achieve the above object, the magnetic ALD thin film deposition method according to the present invention, the wafer block on which the wafer w is seated 130, the first reaction gas supplied and the second reaction gas supplied respectively An ALD reaction including a gas distributor 150 for ejecting to the side of the wafer, an exhaust unit for exhausting the introduced gas to the outside, and a magnetic field generator 160 for applying a magnetic field onto the surface of the wafer block 130 In using a container,

A wafer seating step of mounting a wafer (w) onto the wafer block 130; A magnetic field forming step of forming a magnetic field on a surface of the wafer (w); A first reaction gas feeding step of injecting the first reaction gas mixed with an inert gas to the wafer w, a first reaction gas purge step of purging the first reaction gas from the reaction vessel, an inert gas and Reaction gas feeding and purging which repeats the second reaction gas feeding step of injecting the mixed second reaction gas to the wafer w and the second reaction gas purging step of purging the second reaction gas from the reaction vessel. Iterative step; characterized in that it comprises a.

In the present invention, plasma is formed on the wafer during at least one of the first reaction gas feeding step and the second reaction gas feeding step.

In the present invention, when the total cycle required for thin film deposition is deposited by dividing A + B cycles, the strength of the magnetic field applied during the A cycle is referred to as a, and the strength of the magnetic field applied during the B cycle is referred to as b. The intensity of a> b makes the purity of the thin film in contact with the underlying film better.

In the present invention, the flow rate of the inert gas flowing into the reaction vessel is always constant during the deposition of the thin film.

In the present invention, after the thin film deposition is completed, further comprises a heat treatment step (S9) for injecting an inert gas and reaction gas to heat treatment the thin film while applying a magnetic field on the wafer surface.

In the present invention, by rotating the magnetic field generating device 160 located above the reaction vessel, the direction of the magnetic field formed horizontally on the wafer surface is rotated.

Hereinafter, preferred embodiments of the magnetic ALD thin film deposition method according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram of a first embodiment of a reaction vessel for carrying out a magnetic ALD thin film deposition method according to the present invention, Figure 4 is a view showing an extract of the magnetic field generating device and the wafer block in the reaction vessel of FIG. to be. 5 is a diagram illustrating a method of depositing a magnetic ALD thin film by the reaction vessel of FIG. 3, and FIG. 6 is a second reaction injected with a first reaction gas adsorbed onto a wafer while a magnetic field is applied. FIG. 7 is a flow diagram illustrating a reaction state of a gas, and FIG. 7 is a flow diagram sequentially illustrating the magnetic ALD thin film deposition method of FIGS. 3 to 6.

As shown in the drawing, the reaction vessel includes a reactor block 20 having a transfer hole 21 into which a wafer w supplied through the transfer module 10 is introduced, and a reactor w installed in the reactor block 20. ) Is mounted on the wafer block 30, the top plate 40 coupled to cover the reactor block 20, and the first reaction gas and the second reaction gas supplied and coupled to the lower end of the top plate 40. To exhaust the gas inside the shower head 50 and the reactor block 20 having the first injection hole 51 and the second injection hole 52 formed at regular intervals so as to spray the gas toward the wafer. And a magnetic field generating device 60 for applying a magnetic field onto the surface of the wafer block 30. At this time, the first injection hole 51 and the second injection hole 52 are formed in the wafer direction at regular intervals.

The magnetic field generating device 60 includes a rotating frame 61 positioned on the outer circumferential side of the reactor block 20, at least two magnets 63 installed on the rotating frame 61, and a rotating frame 61. It has a rotation drive part 65 for rotating. In this case, the magnets may be implemented as a permanent magnet or an electromagnet. 4 shows the positional relationship between the magnets 63 of the magnetic field generating device 60 and the wafer block 30, and shows a positional relationship of the magnetic field so that the magnetic field can be evenly distributed on the surface of the wafer block 30. The spacing of the magnets at 61 is not constant. In addition, the directions of the magnetic field B applied on the wafer surface by the magnets 63 have a uniform distribution while forming a constant one direction, and when the rotating frame 61 is rotated by the rotation driving unit 65. As shown in FIG. 11, the direction of the magnetic field on the wafer w can be changed continuously and simultaneously (B ′ → B). And, the magnets must be installed at a certain height on the side of the reaction vessel so that the magnetic field generated by the magnets can be applied on the wafer surface.

The wafer block 30 may be lifted and lowered to a position corresponding to the transfer hole 21 by a lifting device (not shown) connected to the wafer block support 35, and to a process position where the wafer can be received from the transfer module. Before the process proceeds, the wafer w is raised to the position where the process efficiency is the best.

In addition, a plurality of heaters H are installed in the reactor block 20 and the wafer block 30, and the heater H in the wafer block supplies pyrolysis energy for the substitution reaction between the first reaction gas and the second reaction gas. The other heaters keep the temperature of the inner surface of the reaction vessel at an appropriate level while minimizing the deposition of thin film deposition by-products on the surface of the reaction vessel in powder form.

The thin film deposition method using the reaction vessel of the above structure will be described.

First, a wafer step S1 of moving the wafer w introduced from the transfer hole 21 onto the wafer block 30 to be seated is performed. The wafer w is transferred onto the wafer block 30 by a robot (not shown).

Next, the lifting device lifts the wafer block 30 to perform a transfer step S2 of moving the wafer w to a process position corresponding to the transfer hole 21.

Next, the magnetic field generating device 60 is operated to perform a magnetic field forming step S3 of forming a magnetic field on the wafer w surface. This magnetic field forming step (S3) begins at step ⓐ′-ⓑ ′ shown in FIG. 5. That is, in step ⓐ'-ⓑ ', not only the wafer w in the reaction vessel is preheated by the inside of the wafer block, but also the magnetic field generating device 60 generates a magnetic field, as shown in FIG. Magnetic field (B) is formed in the. At this time, when the magnet 63 of the magnetic field generating device is a permanent magnet, the magnetic field is naturally applied to the wafer w by lifting the wafer w to the process position in the transfer step S2. In this step, an inert gas flows into the reaction vessel as a purge gas.

Meanwhile, in this step, which is a preheating step of the wafer w, the first and second reaction gases are introduced into the reaction vessel until the wafer w is seated on the wafer block 30 and then raised to a temperature necessary for the thin film forming process and stabilized. Do not feed. Because, when the reaction gas is injected before the ⓑ 'step, since the thin film is deposited at a lower temperature than the proper temperature, the purity and characteristics of the ALD thin film layer formed at this time are deteriorated.

Next, a first reaction gas feeding step S4 of injecting the first reaction gas ABn mixed with the inert gas to the wafer w through the first injection hole 51 is performed. This is ⓑ'-ⓒ 'step, in which the first reaction gas ABn particles fed into the reaction vessel are adsorbed onto the wafer w surface. Here, A and B meant a specific element, n was set to 2.

Next, by stopping the feeding of the first reaction gas, the first reaction gas purge step to purge the first reaction gas that has already flowed into the reaction vessel and has not been adsorbed to the wafer (w) by the inert gas ( S5) is performed. The first reaction gas purge step S5 is performed in step ⓒ'-ⓓ '.

Next, a second reaction gas feeding step S6 of injecting the second reaction gas CDm mixed with the inert gas to the wafer w through the second injection hole 52 is performed. This is a step ⓓ'-ⓔ ', in which the second reaction gas CDm fed into the reaction vessel is replaced with the first reaction gas ABn already adsorbed on the wafer w (see FIG. 6, circled). )do. In the present embodiment, C, D means a specific element, m is 3.

In this step, the magnetic field B allows a substitution reaction to occur more preferably between the first reaction gas ABn and the second reaction gas CDm already adsorbed on the wafer w surface. Since the substitution reaction is performed by exchanging electrons between molecules, the exchange of electrons can be further activated by the magnetic field B as well as the thermal decomposition energy. The magnetic field B further activates the substitution reaction by increasing the momentum of the electrons, thereby increasing the saturation surface reaction rate for forming monoatomic layers evenly on the wafer w. As a result, the feeding and purge times can be reduced without increasing the wafer temperature by the magnetic field B, and the same thin film purity can be obtained. This can be seen by comparing FIG. 5 with FIG. 1, which shows that the cycle time can be reduced by using the magnetic field B as compared with the conventional magnetic ALD thin film deposition method (FIG. 1). Through this process, a higher purity thin film AC can be rapidly deposited on the wafer.

Next, by stopping the feeding of the second reaction gas, the second reaction gas purge step S7 which causes the second reaction gas which has already flowed into the reaction vessel and has not been adsorbed onto the wafer w is purged by the inert gas. Perform. This second reaction gas purge step (S7) is to be carried out in the ⓔ '-ⓕ' step. In this step, the second reaction gas CDm and the reaction byproduct BD which are not used to form the thin film are discharged out of the reaction vessel. And the thin film AC is actually formed up to this stage.

As described above, when one step of ⓑ '-ⓕ' is formed, one thin film layer is formed on the wafer w, and a thin film having a desired thickness may be formed by repeating the cycle several dozen times. One cycle to form a thin film is a step ⓑ '-ⓕ' step, which is summarized as follows. The first step ⓑ '~ ⓒ' is the first reaction gas feeding step (S4), the second step ⓒ '~ ⓓ' is the first reaction gas purge step (S5), and the third step ⓓ '~ ⓔ' is Feeding step (S6) of the second reaction gas, ⓔ '~ ⓕ' step is the purge step (S7) of the second reaction gas.

Next, a single monolayer layer thin film is formed by performing the above four steps in one cycle, and the reaction gas feeding and purge repetition step S8 of depositing a thin film having a desired thickness by repeating the cycle is performed.

Next, after the thin film having a desired thickness is formed, a so-called heat treatment step (S9) of spraying reaction gases such as H ₂ , NH ₃ , and N ₂ onto the inert gas and the wafer is performed. The heat treatment step is to improve the formed thin film purity, in other words, to further reduce the impurity content in the thin film.

The efficiency of the heat treatment step, that is, the efficiency for reducing the impurity concentration to improve the quality of the thin film, is generally higher at higher substrate temperatures. However, the higher the wafer temperature, the greater the likelihood of damage to the wafer due to high temperatures. Therefore, in order to reduce the impurity concentration to improve the quality of the thin film and reduce the possibility of damage to the wafer, the heat treatment is performed with the magnetic field B applied at a lower temperature. By using the magnetic field it is possible to reduce the content of impurities in the thin film and improve the quality of the thin film.

As described above, in the present invention, the magnitude of the substitution reaction activation energy between the first reaction gas and the second reaction gas is increased by additionally applying the magnetic field B in addition to the pyrolysis energy and changing the intensity of the magnetic field. Adjust

On the other hand, in order to deposit a thin film of a desired thickness, the cycle (ⓑ'-ⓕ 'step) should be repeated several times. For example, in order to form a thin film of 100 μs, assuming that the above cycles should be repeated about 30 times, five cycles out of the total cycles are called A cycles. When 25 cycles are referred to as B cycles, the strength of the magnetic field applied at this time can be referred to as b. In this case, by making a> b, the purity of the thin film in contact with the underlying film can be further improved.

In addition, in the thin film deposition step, it is preferable to keep the flow rate of the inert gas fed into the reaction vessel at all times to keep the process pressure in the reaction vessel constant.

Until now, the magnetic field generated by the magnetic field generating device in the first embodiment can be rotated on the wafer surface, but a thin film can be formed even if the magnetic field is not rotated.

FIG. 8 is a configuration diagram of a second embodiment of a reaction vessel for performing a magnetic ALD thin film deposition method according to the present invention, and FIG. 9 is a view showing the injection of a first reaction gas adsorbed onto a wafer in a state where a magnetic field and plasma are applied. FIG. 10 is a flow diagram illustrating a method of depositing a magnetic ALD thin film by the reaction vessel of FIG. 8 in sequence, and FIG. 11 illustrates a state in which a horizontal magnetic field is rotated as a whole on a wafer. Figure is shown. Here, the same reference numerals as in FIGS. 3 to 6 are the same members having the same function.

The reaction vessel carrying out the second embodiment is different from the first embodiment in that plasma is formed on the wafer during at least one of the first reaction gas feeding step and the second reaction gas feeding step. In this embodiment, for the sake of explanation, the plasma is formed during the second reaction gas feeding step as an example.

Electrical energy for forming the plasma P is applied between the wafer block 30 and the shower head 50. That is, the plasma P formed by the electrical energy is applied when the thin film having the desired purity is not obtained even by the pyrolysis energy and the magnetic field as in the first embodiment so that the thin film deposition can be performed. By forming the plasma P, the substitution reaction between the first reaction gas and the second reaction gas is activated.

In the plasma P, electrical energy generated by the RF power source 71 is applied to the RF electrode plate 77 in the wafer block through the RF matching box 73 and the condenser 75, thereby showering with the wafer block 30. It is formed between the head (50). The plasma P is collected by the magnetic field toward the center of the wafer, thereby increasing the plasma density at the center of the wafer. At this time, when plasma energy is delivered to the gas lines 51a and 52a through which the first and second reaction gases flow, unwanted effects are generated, so that plasma energy is not transmitted to the gas lines 51a and 52a. It is important to do. Therefore, the showerhead 50 is preferably composed of a first showerhead plate made of an insulator such as quartz, and a second showerhead plate made of a material such as aluminum that is grounded at a portion in contact with the top plate 40. Do. In addition, the portion surrounding the outside of the shower head is preferably made of quartz, ceramic material, etc. to prevent unwanted effects caused by plasma. In this way, the showerhead plate and the reaction vessel wall are electrically insulated, and the plasma cloud (cloud) formed on the top of the wafer can be more limited on the wafer.

The thin film deposition method using the reaction vessel of the above structure is substantially similar to that in the first embodiment. The difference is that the plasma P is formed and dissipated at the same cycle as the cycle described above during the thin film deposition process. At this time, the formation and disappearance of the plasma (P) is made during at least one reaction gas supply time, in the present embodiment, as shown in Figure 13, during the purge step (S5 ') of the first reaction gas (©' '~ Ⓓ') or immediately before the feeding of the second reaction gas (S6 '), and the plasma P is formed during the purge step (S7') of the second reaction gas (ⓔ &quot; -ⓕ &quot;). It is destroyed. As such, the plasma P is formed until immediately before and after the second reaction gas is fed so that the second reaction gas is consumed as much as possible on the wafer surface for thin film formation. The pulse application of the plasma P is performed until the thin film formation is completed.

The second reaction gas injected when the plasma is synchronized may typically be hydrogen (H 2) gas. In this case, the first reaction gas may be a metal organic compound, and the purpose of excluding plasma formation during the injection of the metal organic compound is to prevent decomposition of the metal organic compound raw material in the gas state. This minimizes the occurrence of footage and poor deposition of thin films.

In order for the plasma P formed on the wafer to be uniform, the applied magnetic field must have a uniform directionality on the surface of the wafer w. In addition, the stable maintenance of the process pressure is very important in terms of the thickness and uniformity of the thin film, the stability of the formed plasma, and the process stability. To this end, the flow rate of the inert gas flowing into the reaction vessel is always constant. As in the first embodiment, after the thin film is deposited to a desired thickness, the thin film may be subjected to the heat treatment step S9 by spraying an inert gas and a reactive gas while applying a magnetic field on the wafer surface.

When plasma P is formed on the wafer, a large number of ionized gas molecules and clouds of electrons are formed in the space. When the plasma cloud (cloud) is concentrated and uniformly concentrated on the wafer, the uniformity of thin film deposition can be expected, and the increase in the density of the plasma cloud is caused by the application of a magnetic field. The magnetic field application is to transfer the E x B force to the ions, thereby causing the cycloidal motion shown in FIG. 9 to increase the density of the plasma cloud. Therefore, the collision probability, that is, the reactivity between the reactants on the wafer becomes high, resulting in denser thin film deposition.

On the other hand, the nonuniformity of the plasma P density formed on the wafer is due to the E x B force. The E x B force induces cycloidal motion of ions and contributes to the increase of plasma density, but the density of electrons is caused by the drift motion of numerous electrons in the plasma cloud in a direction orthogonal to the magnetic flux line applied on the wafer. Makes it uneven on the substrate. This means that the plasma density uniformity on the substrate becomes worse, resulting in poor film deposition uniformity.

In order to overcome this problem, as shown in FIG. 4, the directions of the magnetic field B formed on the wafer should all have a uniform distribution while forming a constant one direction. 63) through proper placement. Then, the horizontal magnetic field must be rotated to prevent electrons from continuing to drift in either direction, and thus, the rotation frame 61 must be rotated by the rotation driving unit 65. In this way, the magnets rotate as a whole, and as shown in FIG. 11, the horizontal magnetic field B rotates slowly in one direction.

Since the first embodiment to be described below does not use plasma unlike the second embodiment, there is no problem of imbalance in plasma density due to a magnetic field. Therefore, the rotation of the magnetic field is not essential in the first embodiment, but the rotation of the magnetic field is essential in the second embodiment.

12 is a configuration diagram of a third embodiment of a reaction vessel for performing the magnetic ALD thin film deposition method according to the present invention, Figure 13 is a diagram showing a magnetic ALD thin film deposition method by the reaction vessel of FIG. Here, the same reference numerals as in FIGS. 3 to 11 are the same members having the same function.

The reaction vessel of the third embodiment is a flow type, and is a gas distributor for injecting the wafer block 130 on which the wafer w is seated, the first reaction gas supplied and the second reaction gas supplied to the side of the wafer, respectively. 150, an exhaust unit for exhausting the introduced gas to the outside, and a magnetic field generating device 160 for applying a magnetic field on the surface of the wafer block 130. That is, the difference from the reaction vessels of the first and second embodiments is that the reaction gases are injected from the side of the wafer w, and an electromagnet or permanent magnet capable of forming a horizontal magnetic field on the wafer w is placed on the reaction vessel. It is located. Although the magnetic field generating device is located above the reaction vessel, essentially the purpose of the construction is the same as the reaction vessel in the first and second embodiments, and the horizontal magnetic field B is arranged to have a uniform orientation and uniform distribution on the wafer. To form and rotate. The structure of electromagnets and permanent magnets wound by coils having constant directionality is already well known in the field of PVD devices, and thus detailed descriptions thereof will be omitted.

The thin film deposition method using the reaction vessel of the third embodiment is almost similar to the thin film deposition method in the first and second embodiments. That is, by applying the plasma, the substitution reaction between the first reaction gas and the second reaction gas is activated.

In addition, assuming that the above cycles should be repeated about 30 times in order to deposit a thin film having a desired thickness, for example, 100 μs, five cycles of the total cycles are called A cycles. If the intensity of the applied magnetic field is a, the remaining 25 cycles may be referred to as B cycles, and the strength of the applied magnetic field may be referred to as b. In this case, by making a> b, the purity of the thin film in contact with the underlying film can be further improved.

On the other hand, the magnetic field on the surface of the wafer (w) should be formed horizontally, the magnetic field is rotated on the wafer surface by rotating the magnetic field generating device 160 located on the reaction vessel.

In addition, in the thin film deposition step, it is preferable to keep the flow rate of the inert gas fed into the reaction vessel at all times to keep the process pressure in the reaction vessel constant.

Further, as in the first and second embodiments, after the thin film is deposited to a desired thickness, the heat treatment step of the thin film may be further performed by spraying an inert gas and a reactive gas while applying a magnetic field on the wafer surface. As the reaction gas used in the heat treatment step, H ₂ , NH ₃ , N _2, or the like may be used.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

As described above, according to the magnetic ALD thin film deposition method according to the present invention, by applying the magnetic field alone or the magnetic field and the plasma at the same time, it is possible to deposit a thin film that realizes high purity and excellent electrical properties and step coverage at a lower temperature than CVD. There is an effect.

Claims (14)

A reactor block 20 in which the wafer w transferred through the wafer transfer hole 21 is located, a wafer block 30 installed in the reactor block 20 and seated on the wafer w, and supplied A shower head 50 for injecting a first reaction gas and a supplied second reaction gas toward the wafer, an exhaust unit for exhausting gas inside the reactor block 20 to the outside, and the wafer block 30 As using the ALD reaction vessel including a magnetic field generating device 60 for applying a magnetic field on the surface, A wafer seating step (S1) for seating the wafer (w) onto the wafer block (30); A magnetic field forming step (S3) of forming a magnetic field on the wafer (w) surface; A first reaction gas feeding step S4 of injecting the first reaction gas mixed with an inert gas to the wafer w and a first reaction gas purge step of purging the first reaction gas from the reaction vessel S5. ), A second reaction gas feeding step (S6) for injecting the second reaction gas mixed with an inert gas to the wafer (w), and a second reaction gas purge for purging the second reaction gas from the reaction vessel. Reactive gas feeding and purge repeating step (S8) to repeat the step (S7); magnetic ALD thin film deposition method comprising a. The method of claim 1, And forming a plasma on the wafer during at least one of the first reactive gas feeding step and the second reactive gas feeding step. The method according to claim 1 or 2, And controlling the magnitude of the substitution reaction activation energy between the first reaction gas and the second reaction gas on the wafer surface by changing the intensity of the magnetic field. The method according to claim 1 or 2, In the case of dividing the total cycle required for thin film deposition into A + B cycles, the intensity of the magnetic field applied in the A cycle is a and the strength of the magnetic field applied in the B cycle is b. Magnetic ALD thin film deposition method to improve the purity of the thin film in contact with the underlying film The method according to claim 1 or 2, The flow rate of the inert gas injected from the shower head is always constant during the deposition of the thin film ALD thin film deposition method. The method according to claim 1 or 2, After the thin film deposition is completed, the magnetic ALD thin film deposition method further comprises a heat treatment step (S9) of injecting an inert gas and a reaction gas while applying a magnetic field on the wafer surface to heat-treat the thin film. The method of claim 2, A method for depositing a magnetic ALD thin film, wherein the applied magnetic field has a uniform distribution on the wafer surface. The method of claim 2, And the magnetic field generating device (60) rotates around the reaction vessel so that the direction of the magnetic field formed on the surface of the wafer (w) is rotated. The wafer block 130 on which the wafer w is seated, the gas distributor 150 which injects the supplied first reaction gas and the supplied second reaction gas to the side of the wafer, and exhausts the introduced gas to the outside. By using an ALD reaction vessel including an exhaust unit (not shown) and a magnetic field generating device 160 for applying a magnetic field on the surface of the wafer block 130, A wafer seating step of mounting a wafer (w) onto the wafer block 130; A magnetic field forming step of forming a magnetic field on a surface of the wafer (w); A first reaction gas feeding step of injecting the first reaction gas mixed with an inert gas to the wafer w, a first reaction gas purge step of purging the first reaction gas from the reaction vessel, an inert gas and Reaction gas feeding and purging which repeats the second reaction gas feeding step of injecting the mixed second reaction gas to the wafer w and the second reaction gas purging step of purging the second reaction gas from the reaction vessel. Repeating step; magnetic ALD thin film deposition method comprising a. The method of claim 9, And forming a plasma on the wafer during at least one of the first reactive gas feeding step and the second reactive gas feeding step. The method of claim 9 or 10, In the case of dividing the total cycle required for thin film deposition into A + B cycles, the intensity of the magnetic field applied in the A cycle is a and the strength of the magnetic field applied in the B cycle is b. Magnetic ALD thin film deposition method to improve the purity of the thin film in contact with the underlying film The method of claim 9 or 10, The flow rate of the inert gas flowing into the reaction vessel is always constant during the deposition of the thin film ALD thin film deposition method. The method of claim 9 or 10, After the thin film deposition is completed, the magnetic ALD thin film deposition method further comprises a heat treatment step (S9) of injecting an inert gas and a reaction gas while applying a magnetic field on the wafer surface to heat-treat the thin film. The method of claim 9 or 10, Magnetic field ALD thin film deposition method characterized in that the direction of the magnetic field formed horizontally on the wafer surface is rotated by the rotation of the magnetic field generating device (160) located on the reaction vessel.