KR20230063041A - Method for depositing thin film on wafer - Google Patents

Abstract

The present invention relates to a method for depositing a thin film, and more specifically, to a method for depositing a thin film capable of preventing an increase in the thickness of an ultrafine thin film and a change in physical properties due to the generation of particles by introducing a pulsed plasma purge process. The method for depositing a thin film according to an embodiment is a method for depositing a thin film using a substrate processing apparatus that applies RF power to a chamber and generates plasma in the chamber to form a thin film on a substrate, in which the method comprises: a step of preparing a substrate in the chamber; a thin film formation step of generating a first plasma in the chamber and supplying a source gas to form a thin film layer on the substrate; and a pulsed plasma purge step of generating a second plasma having a preset duty ratio in the chamber and supplying an inert gas to remove a residual source gas in the chamber.

Description

Thin film deposition method {Method for depositing thin film on wafer}

The present invention relates to a thin film deposition method, and more particularly, to a thin film deposition method capable of preventing an increase in the thickness of an ultrafine thin film and a change in physical properties due to particle generation by introducing a pulsed plasma purge process.

In accordance with the integration of electronic devices, development of thin film manufacturing process technology for manufacturing ultra-thin films of several to several tens of angstroms using EUV is actively progressing. In particular, plasma enhanced chemical vapor deposition (PECVD) is a method of depositing a thin film by chemical reaction of source gases by generating plasma in a reaction chamber. The PECVD method is widely used because it is characterized in that low-temperature deposition is possible because source gases are energized by plasma.

More specifically, in the PECVD method, plasma is generated in the chamber by applying a high voltage to the chamber. Then, the source gases are injected, and the source gas is changed into an ion state, that is, a plasma state by the plasma already generated in the chamber. When the wafer seated in the chamber is heated to a preset temperature, a chemical reaction occurs between the surface of the object and the material to be deposited. Materials bonded to the surface of the object by a chemical reaction, that is, materials other than deposited materials are discharged to the outside.

However, when depositing a thin film by the PECVD method, the source gas may remain in an unreacted state in the chamber. Since the remaining source gas may react chemically to form particles, in order to remove it, continuous wave plasma is applied for a short period of time in a low-power region together with an inert gas to control particle formation.

In addition, the conventional process as described above has a problem in that the residual gas reacts with the thin film by plasma and the thickness of the thin film increases, making it difficult to realize a thin film of several to several tens of angstroms (Å).

In addition, in the purge step of forming a thin film on the wafer and then removing the residual source gas, there is a problem that particles adhere to the wafer surface and deteriorate the physical properties of the semiconductor device, so that the particle does not cause a change in the thickness of the thin film. It is necessary to study a thin film deposition method that can prevent deterioration of physical properties because it is not attached to the surface.

According to an embodiment, it is intended to provide a thin film deposition method capable of preventing an increase in thickness of a thin film and a change in physical properties due to generation of particles by preventing source gas from remaining in an unreacted state.

A thin film deposition method according to an embodiment is a thin film deposition method using a substrate processing apparatus for applying RF power to a chamber and generating a plasma inside the chamber to form a thin film on a substrate, comprising preparing a substrate into the chamber. step; a thin film forming step of generating a first plasma in the chamber and supplying a source gas to form a thin film layer on the substrate; and a pulsed plasma purging step of generating second plasma having a preset duty ratio inside the chamber and supplying an inert gas to remove remaining source gas inside the chamber.

According to one embodiment, the thin film layer may be a carbon hard mask layer.

According to an embodiment, the thin film forming step may form the first plasma by applying RF power of 50 to 150 W, and the pulsed plasma purging step may apply RF power of 10 to 50 W to form the second plasma. can form

The first plasma may be a pulsed plasma and may have a different duty ratio from that of the second plasma.

The second plasma may be pulsed plasma having a duty ratio of 5 to 50%.

The first plasma may be a pulsed plasma formed by supplying power of 2,000 to 10,000 Hz, and the second plasma may be a pulsed plasma formed by supplying a power of 10 to 2,000 Hz.

According to one embodiment, the substrate processing apparatus includes a chamber providing a substrate processing space; a power supply unit for generating continuous wave plasma or pulsed plasma in the chamber by applying at least one RF power source; a gas supply unit supplying a source gas for forming a thin film layer into the substrate processing space; and a control unit controlling driving of the power supply unit and the gas supply unit.

The thin film deposition method according to the embodiment can remove unreacted source gas and particles inside the chamber without changing the thickness of the thin film and the contact angle of the thin film by introducing a pulsed plasma purge process, so it can be applied to realize an ultra-fine thin film. .

1 is a reference diagram for explaining power modulation of continuous wave plasma and pulsed plasma in a thin film deposition method according to an embodiment.
2 (a) and (b) are timing diagrams for explaining a thin film deposition method according to an embodiment, respectively.
3 is a conceptual diagram schematically illustrating an example of a substrate processing apparatus used in a thin film deposition method according to an embodiment.
Figure 4 is a result of analyzing the contact angle of the thin film formed on the specimen treated by the method according to the Reference Example, Comparative Example and Example, respectively.
Figure 5 is a result of analyzing the thickness of the thin film formed on the specimen treated by the method according to the Reference Example, Comparative Example and Example, respectively.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, since the description of the present invention is only an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, since the embodiment can be changed in various ways and can have various forms, it should be understood that the scope of the present invention includes equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only such effects, the scope of the present invention should not be construed as being limited thereto.

The meaning of terms described in the present invention should be understood as follows.

Terms such as "first" and "second" are used to distinguish one component from another, and the scope of rights should not be limited by these terms. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element. It should be understood that when an element is referred to as “connected” to another element, it may be directly connected to the other element, but other elements may exist in the middle. On the other hand, when an element is referred to as being “directly connected” to another element, it should be understood that no intervening elements exist. Meanwhile, other expressions describing the relationship between components, such as “between” and “immediately between” or “adjacent to” and “directly adjacent to” should be interpreted similarly.

Singular expressions should be understood to include plural expressions unless the context clearly dictates otherwise, and terms such as “comprise” or “having” refer to a described feature, number, step, operation, component, part, or It should be understood that it is intended to indicate that a combination exists, and does not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless defined otherwise. Terms defined in commonly used dictionaries should be interpreted as consistent with meanings in the context of related art, and cannot be interpreted as having ideal or excessively formal meanings unless explicitly defined in the present invention.

In many existing processes, a method of controlling particle generation by supplying an inert gas and applying power in a purge step is used. However, in this case, there is a problem in that the thickness increases by reacting with the remaining source gas supplied in the deposition process.

Most of them are different for each material, but in particular, in the case of silicon carbide (SiC), it was confirmed that 4 Å increases despite applying a low power of 30 W in the purge step. In a process technology that requires an ultra thin film of several to several tens of angstroms (Å) level, a thickness increase of 4 Å due to plasma purge needs to be controlled with a very large numerical change in the entire process thickness.

In addition, even in the case of the surface, since the physical impact is applied by the inert gas, the contact angle of the surface may be changed to cause a decrease in bonding strength with other materials. In particular, the adhesion of the carbon hard mask layer to the photoresist is very important, and the most important factor determining adhesion is the contact angle. The contact angle change due to the plasma purge affects the bonding with the photoresist, which can lead to pattern defects.

According to the inventors of the present invention, in the conventional plasma purging step, if pulsed plasma purging is performed by applying the frequency and duty value of the plasma, a higher potential difference can be realized compared to the existing technology, and a low electron density and low electron temperature can be achieved in the plasma off section. It is possible to implement, and the reaction energy is lowered so that it does not react with residual gas, thereby preventing an increase in thickness, enabling particle control, and preventing a change in contact angle due to the physical treatment effect of an inert gas. A thin film deposition method according to the example was completed.

Hereinafter, a semiconductor manufacturing method according to an embodiment will be described in detail.

A semiconductor manufacturing method according to an embodiment is a thin film deposition method using a substrate processing apparatus that generates a plasma in a chamber to form a thin film on a substrate, comprising: preparing a substrate into the chamber; a thin film forming step of generating a first plasma in a chamber and supplying a source gas to form a thin film layer on the substrate; and a pulsed plasma purging step of generating second plasma having a preset duty ratio inside the chamber and supplying an inert gas to remove remaining source gas inside the chamber.

First, the substrate preparation step is a step of preparing a substrate into the chamber.

The substrate may be made of various known materials used for manufacturing semiconductor devices. The substrate may be a result of a semiconductor substrate on which a predetermined device is formed, or may be a bare wafer.

Specifically, the substrate may be crystalline silicon, silicon oxide, silicon oxynitride, silicon nitride, strained silicon, silicon germanium, tungsten, titanium nitride, doped or undoped polysilicon, doped or undoped silicon wafer, patterned or from materials including unpatterned wafers, silicon on insulator (SOI), carbon doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, low k dielectrics, or mixtures thereof. that can be used

In addition, the substrate may have a layer to be etched, and the layer to be etched may be formed of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon silicide (SiC) film, or a derivative film thereof.

Next, in the thin film forming step, a first plasma may be generated in the chamber and a source gas may be supplied to form a thin film layer on the substrate.

In this step, a source gas and an inert gas may be simultaneously supplied, and a thin film layer may be deposited using a plasma enhanced chemical vapor deposition (PECVD) method. The inert gas may include at least one gas selected from helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). In particular, the inert gas may include argon (Ar) gas.

The source gas may be appropriately selected according to the type of thin film to be formed. Specifically, the thin film layer may be a hard mask layer, and the thin film layer may be formed by supplying a variety of conventional source gases used to form a hard mask layer. The source gas contains any one of alkylsilanes such as trimethylsilane (3MS) and tetramethylsilane (4MS), hydrocarbons such as ethylene, siliconoxynitride (SiON), and siliconnitride (Si ₃ N ₄ ). can include

In particular, the thin film layer may be a carbon hard mask layer formed using an alkylsilane such as trimethylsilane (3MS) or tetramethylsilane (4MS). The carbon hard mask layer is processed through a pulsed plasma purging step to be described later, so that a contact angle change is not caused and bonding strength is not reduced, so that a semiconductor device having desirable characteristics can be implemented.

In the thin film deposition method according to the embodiment, the first plasma may be continuous wave plasma, and in this step, the continuous wave plasma may be generated inside the chamber as the first plasma and a source gas may be supplied to form the thin film layer. there is.

Alternatively, the first plasma may be a pulsed plasma, and a thin film layer may be formed by generating the pulsed plasma as the first plasma inside the chamber and supplying a source gas to form the thin film. The first plasma may form a pulsed plasma having a different duty ratio from that of the second plasma. Details of the pulsed plasma used in the thin film forming step will be described in detail below.

The thin film layer may have a thickness of 5 to 100 Å, and thus, in the case of an ultra-thin thin film having a thickness of 1 to 10 Å, a change in thickness may have a great effect on physical properties, according to the embodiment When the thin film deposition method is applied, it can be easily applied because the thickness change does not occur. In particular, the thin film layer may have a thickness of 5 to 30 Å.

Meanwhile, the pulsed plasma purging step is a step of forming a thin film layer on a substrate, generating a second plasma having a preset duty ratio inside the chamber, and supplying an inert gas to remove residual source gas inside the chamber. .

In this step, a purge process may be performed by supplying an inert gas. The inert gas may include at least one gas selected from helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). In particular, the inert gas may include argon (Ar) gas.

In this step, the second plasma having a preset duty ratio may be formed by a simple method of turning on/off the power of the plasma. The second plasma may adjust the processing efficiency of the purge process by a pulse frequency, a duty ratio, and power modulation.

Specifically, the pulse frequency means a rate at which pulse power is repeated at regular time intervals.

The duty ratio, that is, the pulse operating ratio means a ratio between an on cycle and an off cycle of the pulsed plasma. For example, the duty ratio of 30% means that the on cycle of the pulsed plasma is 30% and the off cycle is 70% when one cycle of the pulse is 100%. Since this duty ratio can be adjusted by the ratio of on time and off time, the degree of charge offset, reactivity, etc. can be adjusted according to the degree of change.

As shown in FIG. 1, the power modulation is a continuous wave plasma (CW) method in which a plasma source is continuously applied, and a bias pulse method (bias pulse method) in which a pulse is applied to a substrate while maintaining the plasma source as a continuous wave. , the source pulse method in which pulses are applied to the plasma source while the substrate electrode is maintained in a continuous wave (CW), and the synchronous pulse method in which pulses (with or without a phase difference) are applied to both the plasma and the substrate. branches can be broadly classified.

More specifically, in the thin film deposition method according to the embodiment, the thin film forming step and the pulsed plasma purge step may be respectively performed by adjusting pulse frequency, duty ratio, and power modulation.

First, in the thin film formation step, the charge density is increased to increase the deposition rate, and in the purge step, the charge density is lowered to enable effective control of residual gas.

For example, in the thin film forming step, it can be performed by applying 50 to 500 W (watt) of RF power, and in the pulsed plasma purge step, 10 to 50 W of RF power is applied so that uniform pulses are regularly generated, and It may be performed by generating a low density second plasma having a lower density compared to the first plasma. The RF power source may generate plasma of HF power.

In addition, the thin film forming step and the pulsed plasma purging step may be performed by supplying high-frequency power of 10 to 1 × 10 ⁶ Hz to generate pulsed plasma, respectively, and pulsed plasma of different frequencies may be generated. In particular, the first plasma may be a pulsed plasma having a frequency of 2,000 to 10,000 Hz, and the second plasma may be a pulsed plasma having a frequency of 10 to 2,000 Hz.

In the pulsed plasma purging step, pulsed plasma can be formed with a duty ratio of 5 to 50%, and the lower the duty ratio, the longer the off period, thereby improving the particle control efficiency. However, if the off period is too long There is a possibility that the efficiency may be reduced, so it can be adjusted appropriately. In particular, in the pulsed plasma purging step, pulsed plasma may be formed with a duty ratio of 5 to 15%.

Also, the thin film forming step may be performed by forming first plasma having the same or different duty ratio as the pulsed plasma purging step. In particular, process simplification may be achieved by forming the first plasma and the second plasma with the same duty ratio.

In addition, in the thin film deposition method according to the embodiment, in the purge step, a potential difference according to pulse on/off is generated using a source pulse method, and particles can be removed as a source due to the generation of the potential difference. This is because the second plasma is a pulsed plasma, and the pulsed plasma has a lower electron temperature in the plasma off period compared to the continuous wave plasma, so that the reactivity with the unreacted residual source gas is lowered, so that the thickness does not increase. Also, in the off period, electron density is reduced due to low potential and low temperature, so that the surface of the thin film layer is not damaged, so that notching, bowing, etc. do not occur, and the contact angle does not change.

Therefore, in the thin film deposition method according to the embodiment, as shown in FIG. 2 (a), in step t1, which is a thin film forming step, a source gas and an inert gas are supplied, and a continuous wave plasma is formed as a first plasma in the chamber, A thin film layer can be formed. In step t2, which is a purge step, an inert gas may be supplied, and a pulsed plasma may be formed as a second plasma in the chamber to perform a purge process.

In particular, in the thin film deposition method according to the embodiment, as shown in FIG. 2 (b), in step t1, which is a thin film forming step, a source gas and an inert gas are supplied, and a pulsed plasma is formed as a first plasma inside the chamber Thus, a thin film layer can be formed. In step t2, which is the purge step, the purge process may be performed by supplying an inert gas and forming a pulsed plasma into the chamber as the second plasma, and the first plasma may have a higher frequency than the second plasma.

In addition, the thin film deposition method according to the embodiment may further include a gas purging step after performing the pulsed plasma purging step.

The gas purging step can be performed by supplying a purge gas, supplying the purge gas to the chamber in a state where generation of pulsed plasma is stopped, and removing particles and unreacted source gas by a strong flow of the purge gas, The gas purging step may include a pumping process for removing gas from the inside of the chamber.

Meanwhile, in the thin film deposition method according to the embodiment, one or more RF power sources may be applied to the chamber, and plasma may be generated in the chamber to form a thin film on the substrate.

Describing the substrate processing apparatus 10 in detail, the substrate processing apparatus 10 includes a chamber 100 providing a substrate processing space; a power supply unit 200 for generating continuous wave plasma or pulsed plasma in the chamber 100 by applying at least one RF power; a gas supply unit 300 supplying a source gas for substrate processing into the substrate processing space; and a control unit 400 controlling driving of the power supply unit 200 and the gas supply unit 300 may be used.

Specifically, the chamber 100 provides an environment in which a thin film layer made of a desired material can be formed on the substrate W using a plasma CVD method while maintaining the substrate W therein. The chamber 100 may include a main body 110 with an open top and a cover 120 configured to close the top of the main body. The inner space of the chamber 100 may be a space where processing of the substrate W, such as a deposition process, is performed. A gate G through which the substrate W is carried in and out may be provided at a designated location on the side of the main body 110 . A through hole into which a support shaft of the susceptor 130 on which a substrate is seated is inserted may be formed on the bottom surface of the main body.

The susceptor 130 has a flat plate shape as a whole so that at least one substrate W is seated on its upper surface, and may be installed in a horizontal direction facing the gas supply unit 300 . The support shaft 140 is vertically coupled to the rear surface of the susceptor 130 and is connected to an external driving unit (not shown) through a through hole at the bottom of the chamber 100 to lift and/or rotate the susceptor 130. It can be configured as a list. In one embodiment, the susceptor 130 may act as an electrode (second electrode).

A heater H is provided inside the susceptor 130 to adjust the temperature of the substrate seated thereon. The heater H may be configured to generate heat by connecting a power supply unit 150 supplying power to one side thereof.

Since the inside of the chamber 100 should generally be formed in a vacuum atmosphere, an exhaust port may be formed at a designated location of the main body, for example, on the bottom surface. The exhaust port may be connected to an external pump 160 . The inside of the chamber can be made into a vacuum state through the exhaust port, and the gas generated after the process can be discharged.

The power supply unit 200 may be configured to provide power having a preset frequency band as a plasma power source in order to form a thin film layer and perform a purge step in the thin film forming step. The power supply 200 may form continuous wave plasma or may form pulsed plasma by turning on/off the power. To this end, the power supply unit 200 may include a plurality of power application members that apply RF power having different frequencies and apply the RF power after performing bump modulation. The power supply member may supply RF power for applying a bias, or may supply RF power for applying plasma to a plasma source. Also, RF power may be supplied to apply pulses to both the plasma and the substrate.

The gas supply unit 300 may include a gas supply means installed on the main body to face the susceptor 130 . The gas supply unit 300 is provided with one or more gas storage tanks 310 to inject various process gases into the chamber 100 . The gas supply unit may be selected from various types of gas supply devices such as a showerhead type, an injector type, and a nozzle type. The gas supply unit of the gas supply unit 300 may act as an electrode (first electrode).

The gas supply unit 300 may include a gas storage tank 310, a valve V and a gas supply line L. The gas storage tank 310 is a source gas. Each of the inert gases may be stored, and each gas may be supplied to the chamber 100 by being connected to a gas supply line (L).

The valve (V) is installed between the gas storage tank 310 and the gas supply line (L) to control the supply of each gas to the chamber 100 and to be installed on each gas supply line (L). can

The control unit 400 can control the RF power supplied from the power supply unit 200 to have a preset duty ratio and a preset frequency by on/off control according to preset control parameters. there is. Therefore, it can be understood that the frequency of the RF power determines the number of switching times of the RF power for a given time period, and the duty ratio is an on/off ratio of the RF power during the time during which the RF power is being applied.

The substrate processing apparatus 10 having the above structure generates continuous wave plasma and pulsed plasma in the chamber 100, respectively, and drives the thin film deposition step and the purge step to be performed.

On the other hand, in the past, a purge process was performed using continuous wave plasma, but in the case of such a process, there is a problem in that the thickness of the thin film increases by the number of Å by reacting with the remaining reaction gas when the plasma purge is used. In particular, in the case of the carbon hard mask process, the thickness of the target thin film is often very thin, less than 10 Å, and in the case of such a thin film, the increase in the thickness of the thin film can have a great effect on the line width (critical dimension, CD) deviation.

To prevent this, the present invention proposes a plasma purge process using pulsed plasma. When using the pulsed plasma purge, a high potential difference can be realized, and a low electron density and low electron temperature can be realized in the plasma off section.

In addition, a higher potential difference than before enables efficient particle control despite a short time, and a low electron density and electron temperature prevent additional reaction with unreacted source gas in the deposition process, thereby preventing an increase in the thickness of the thin film layer. .

In addition, the treatment effect by the inert gas is also prevented due to the low electron density so that the change in the contact angle of the thin film layer is not caused.

According to a preferred embodiment, in the thin film forming step, RF power of 100 W is applied, and RF power having a duty ratio of 70% and a frequency of 50 kHz is applied to generate a pulsed plasma inside the chamber, and trimethylsilane A carbon hard mask layer having a thickness of 5 to 20 Å may be formed by supplying a mixed gas including a source gas and an argon gas. In the pulsed plasma purge step, RF power of 30W is applied, RF power having a duty ratio of 10% and a frequency of 50 Hz is applied to generate pulsed plasma in the chamber, and containing argon gas. A purge process may be performed by supplying an inert gas.

Hereinafter, the present invention will be described in more detail by way of examples.

The presented examples are only specific examples of the present invention, and are not intended to limit the scope of the present invention.

<Example>

The substrate on which the layer to be etched was formed was placed in a chamber of a PECVD apparatus. Source gas and argon gas containing trimethylsilane are supplied, RF power of 100 W is applied, and RF power having a duty ratio of 10% and a frequency of 50,000 Hz is applied to generate pulsed plasma inside the chamber, , a carbon hardmask layer was formed on the substrate.

An inert gas is supplied to the substrate on which the carbon hard mask layer is formed, RF power of 30 W is applied, and RF power having a duty ratio of 10% and a frequency of 50 Hz is applied to generate pulsed plasma inside the chamber. A purge process was performed. A gas purge process of supplying pulsed plasma, supplying purge gas, and pumping was additionally performed, and then pumping was performed to discharge gas into the chamber. Accordingly, a substrate sample (pursed plasma purge) was prepared by performing a purge process using pulsed plasma.

<Comparative example>

A substrate sample (CW plasma purge) was prepared by processing in the same manner as in Example, except that the purge process was performed using continuous wave plasma.

<Reference example>

A substrate sample (No plasma purge) was prepared by processing in the same manner as in Example, except for performing only the gas purge process.

<Experimental example>

(1) Analysis of the effect on the surface

Surface changes of the prepared substrate samples were confirmed, and the results are shown in FIG. 2 . The surface change was confirmed by measuring the contact angle.

As shown in Figure 2, the contact angle of the substrate specimen of the reference example was confirmed to be 91.4 °, and the contact angle of the substrate specimen treated by the method according to the embodiment was confirmed to be 89.6 °, confirming that the change in contact angle was insignificant. , The contact angle of the substrate specimen treated by the method according to the comparative example was confirmed to be 79.8 °, confirming that the contact angle change was large. In particular, the contact angle measurement resolution is approximately 3 ° level, considering that the contact angle difference between the embodiment and the reference example is within 3 °, it is predicted that the contact angle will hardly change.

Through the above results, it was confirmed that the continuous plasma treatment may change the surface of the thin film and reduce the bonding strength with the photoresist. On the other hand, when the pulsed plasma is introduced, the contact angle change is insignificant, so the bonding strength does not decrease. It was judged to be

(2) Analysis of the effect on the thickness of the thin film

Changes in the thickness of the prepared substrate samples were confirmed, and the results are shown in Table 1.

thickness Tolerance Example 12.5 Å 1.8 Å comparative example 16.4 Å 1.8 Å reference example 12.4 Å 1.8 Å

As shown in Table 1, it was confirmed that the thickness change hardly occurred in the case of the substrate sample treated by the method according to the example compared to the reference example, whereas in the case of the substrate sample of the comparative example, the purge process by continuous plasma It was confirmed that the thickness increased by 4 Å due to the reaction of the remaining gas.

Through the above results, when the thickness of the thin film is several tens of angstroms, the reaction of the remaining raw material gas occurs by continuous plasma supply, so that the purge process using pulsed plasma can reduce the effect on the CD deviation. It is judged to be a preferable method. It became.

(3) Analysis of the effect on particle generation

In addition, large particle sizes exceeding 0.042 to 42 nm are formed by performing a general purge process (5 repetitions in total, #1 to #5) and a pulsed plasma purge process (5 repetitions in total, #6 to #10), respectively. It was confirmed whether or not, and the results are shown in Table 2 below.

SP5, >42 nm Reference example (Ref) Example #One #2 #3 #4 #5 #6 #7 #8 #9 #10 0.042 - 0.05 0 0 0 0 0 0 0 0 0 0 0.05-0.06 0 0 One One One 0 2 0 0 0 0.06-0.07 0 0 0 0 0 0 0 0 0 0 0.07-0.085 0 0 0 One 0 0 0 0 0 0 0.085-0.099 0 0 0 One 0 0 0 0 0 0 0.099-0.13 0 0 0 0 0 0 0 0 0 0 0.13-0.17 0 0 0 3 One 0 0 0 0 0 0.17-0.2 0 0 0 0 0 0 0 0 0 0 0.2-0.55 0 0 0 0 0 0 0 0 0 0 0.2-0.81 0 0 One 0 0 0 0 0 0 0 Saturated 0 0 One 2 One 0 0 0 0 0 Total 0 0 3 8 3 0 2 0 0 0 Avg Avg. 3.1ea Avg. 0.6ea

As shown in Table 2, in the case of the reference example, it was confirmed that an average of 3.1 particles were generated during the purge process, whereas when the pulse plasma purge process was performed, it was confirmed that an average of 0.6 particles were formed. Through the above results, it was confirmed that when the pulse plasma purge process is performed, particles having a large indenter size are not generated, and thus deterioration in physical properties of the semiconductor device can be prevented.

Although the present invention has been described in detail with preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. do.

10: substrate processing device
100: chamber 200: power supply
300: gas supply unit 400: control unit

Claims (9)

A thin film deposition method using a substrate processing apparatus for applying RF power to a chamber and generating a plasma in the chamber to form a thin film on a substrate, comprising:
preparing a substrate into the chamber;
a thin film forming step of generating a first plasma in the chamber and supplying a source gas to form a thin film layer on the substrate; and
and a pulsed plasma purging step of generating a second plasma having a preset duty ratio inside the chamber and supplying an inert gas to remove residual source gas inside the chamber. According to claim 1,
The thin film deposition method of claim 1, wherein the thin film layer is a carbon hard mask layer. According to claim 1,
The thin film forming step is a thin film deposition method for applying an RF power of 50 to 150W. According to claim 1,
The first plasma is a pulsed plasma having a different duty ratio than the second plasma. According to claim 1,
The pulsed plasma purging step is a thin film deposition method for applying an RF power of 10 to 50W. According to claim 1,
The second plasma has a duty ratio of 5 to 50%. According to claim 1,
The first plasma is a thin film deposition method that is a pulsed plasma formed by supplying power of 2,000 to 10,000 Hz. According to claim 1,
The second plasma is a pulsed plasma formed by supplying power of 10 to 2,000 Hz. According to claim 1,
The substrate processing apparatus includes a chamber providing a substrate processing space; a power supply unit for generating continuous wave plasma or pulsed plasma in the chamber by applying at least one RF power source; a gas supply unit supplying a source gas for forming a thin film layer into the substrate processing space; and a control unit controlling driving of the power supply unit and the gas supply unit.

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