KR100653214B1 - Method of depositing thin film using polarity treatment - Google Patents

Abstract

A method for depositing a thin film by using polarization is provided to adjust a degree that a precursor is absorbed on the surface of a semiconductor substrate along a stepped portion according to polarity of the precursor by performing a hydrophilic or hydrophobic polarization treatment on the surface of the semiconductor substrate. After the surface of a semiconductor substrate having a stepped portion is polarized, An absorption layer of a first precursor is formed on the substrate. The absorption layer of the first precursor reacts with a second precursor to deposit a thin film. An Al-containing organic or inorganic compound is used as the first precursor and an O-containing organic or inorganic compound is used as the second precursor so that an Al2O3 thin film is deposited.

Description

Method of depositing thin film using polarity treatment

1 is a cross-sectional view of a DRAM including a typical trench capacitor.

2A to 2D are cross-sectional views illustrating a method of forming a buried plate of a trench capacitor by a conventional thermal diffusion method and forming a color by an oxide film deposition method.

3A to 3C are cross-sectional views illustrating a method of forming a buried plate of a trench capacitor using a conventional gas phase doping and plasma immersion ion implantation method and forming a collar using a LOCOS method.

4A and 4B are cross-sectional views showing another conventional method of manufacturing trench capacitors.

5 is a cross-sectional view showing a problem when forming a trench capacitor collar by a chemical vapor deposition method.

6 is a view of a thin film deposition apparatus capable of performing a thin film deposition method according to the present invention.

7 is a flowchart of a first embodiment of a thin film deposition method according to the present invention.

8 is a view showing a process flow with time in the first embodiment of the present invention.

9A to 9E are cross-sectional views of a process according to a first embodiment of the present invention.

10A and 10B are cross-sectional views of a process according to a second exemplary embodiment of a thin film deposition method according to the present invention.

11 is a flowchart of a third embodiment of a thin film deposition method according to the present invention.

12 is a view showing a process flow over time in a third embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

61 ... semiconductor substrate 66 ... trench 68 ... hydrophobic treatment

69 Hydrophilic treatment 70 First precursor 200 Thin film deposition apparatus

210 ... chamber 211 ... showerhead 212 ... wafer block

212a Heater 213 Pumping baffle 214 Gas curtain block

220 ... source feeder

The present invention relates to a thin film deposition method, and more particularly to a thin film deposition method for adjusting the step coverage.

Single transistor memory cells are used in semiconductor devices such as DRAM. The single transistor memory cell includes a select transistor and a memory capacitor. In the memory capacitor, information is stored in the form of charge, which can be read through the bit line by control of the read transistor via the word line.

In order to be sure that the charge is stored and the information can be distinguished, the memory capacitor must have a high capacitance. As the memory density increases, the area required for a single transistor memory cell is decreasing, and at the same time, the area where the memory capacitor can be formed is narrowing. Accordingly, there is a demand for a method of forming a memory capacitor capable of securing high capacitance even in a small area.

In general, examples of a method for securing sufficient cell capacitance within a limited area include a method of using a high dielectric material as the dielectric film, a method of reducing the thickness of the dielectric film, and a method of increasing the effective area of the lower electrode. Among them, the method of using high dielectric materials requires material and time investment such as introduction of new equipment, verification of reliability and mass production of dielectric film, and lowering of subsequent processes. Therefore, the method of increasing the effective area of the lower electrode is most promising to be applied to the real process because the existing dielectric film can be used continuously and it is relatively easy to implement the process.

One method of increasing the effective area of the lower electrode is to implement a memory capacitor in the trench in the semiconductor substrate. The trench capacitor thus implemented is known to have a flatter surface topography, a smaller number of photolithography processes, and a smaller bit line capacitance as compared to a stacked capacitor formed on a substrate. Therefore, there is an advantage that the cost can be reduced and low power driving.

1 is a cross-sectional view of a DRAM including a typical trench capacitor. Such conventional trench capacitor DRAM cells are disclosed, for example, in trench capacitor DRAM cells with self-aligned buried straps as disclosed in IEDM 93-627. The substrate 100 is doped with a P-type dopant. The trench capacitor 160 includes a deep trench etched into the substrate 100, and the N-type doped polysilicon 161 is filled in the trench. The doped polysilicon 161 functions as the upper electrode (storage electrode) of the capacitor. The N-type doped region 165 surrounds the lower portion of the trench and functions as a lower electrode. Doped region 165 is also referred to as a buried plate. The dielectric film 164 insulates the buried plate 165 and the doped polysilicon 161. The buried N-type well 170 isolates the P-type well 151 from the substrate 100 and serves as a conductive bridge that connects the buried plates 165.

The DRAM cell also includes transistor 110. Transistor 110 includes gate 112 and diffusion regions 113, 114. The diffusion region separated by the channel 117 is formed by implanting an N-type dopant such as phosphorus (P). Node diffusion regions 125, referred to as "node junctions", couple capacitor 160 to transistor 110. The node diffusion region 125 is formed by out diffusion of the dopant from the doped polysilicon 161 filling the trench through a buried strap 162.

Access to the trench capacitors is provided by activating the transistors by providing the appropriate voltages on the gates and bit lines. In general, the gate forms a wordline and the diffusion region 113 is coupled to the bitline 185 in the DRAM cell array via a contact 183. The bit line 185 is insulated from the diffusion region 113 by the interlayer insulating film 189.

Shallow Trench Isolation (STI) 180 is provided to insulate the DRAM from other cells or devices. As shown, a wordline 120 is formed over the trench and insulated by the STI 180.

In addition, an insulating film collar 168 is used to prevent node junction leakage to the buried plate 165. Leakage is undesirable because it reduces the cell's hold time and increases the refresh frequency, which adversely affects performance. The method of forming the insulating film collar 168 includes deposition, local oxidation of silicon (LOCOS), and the like.

Conventional methods of forming the buried plate 165 include thermal diffusion, gas phase doping, plasma immersion ions, which include external diffusion of the dopant into the region of the substrate 100 surrounding the trench bottom. Implants (plasma immersion ion implants) and the like are known.

A method of forming a buried plate of a trench capacitor by a conventional thermal diffusion method and forming a collar by an oxide film deposition method is illustrated in FIGS. 2A to 2D. First, as shown in FIG. 2A, the pad oxide film 2 and the hard mask 4 are formed on the substrate 1. Then, the trench 6 is formed using the hard mask 4.

2B shows a doped insulating film 12, such as arsenosilicate glass (ASG), is formed on the inner wall of the trench 6. Next, the lower portion of the trench 6 is filled with the photoresist 14. As a result, the doped insulating layer 12 on the trench 6 is exposed.

The portion of the doped insulating film 12 on the trench 6 is removed by etching. As a result, the doped insulating layer 12a remains only in the lower portion of the trench 6. Then, a cap oxide film such as TEOS is deposited in the trench 6. The cap oxide film is then recessed to expose the photoresist 14 to form the collar 16. This process is illustrated in Figure 2c.

Referring to FIG. 2D, after removing the photoresist 14 of FIG. 2C, the substrate 1 is subjected to a thermal process, and impurities in the doped insulating layer 12 diffuse into the substrate 1 to thereby diffuse the diffusion region 18. To form. This diffusion region 18 is a buried plate.

Subsequently, the rest of the process for forming the structure shown in FIG. 1 is performed. When the trench capacitor formation process is performed in this manner, there is a disadvantage in that a complex process of seven or more steps is required to form the collar 16 and the buried plate 18. And, ASG is composed of organic precursors such as TEOS and TEAS or TEOA. Such precursors are difficult to apply because they cause undesirable substrate unevenness due to substrate defects. It is also relatively expensive.

Meanwhile, a method of forming a buried plate of a trench capacitor by a conventional gas phase doping and plasma immersion ion implantation method and forming a collar by a LOCOS method is illustrated in FIGS. 3A to 3C.

As shown in FIG. 3A, a pad oxide film 22 and a hard mask 24 are formed on the substrate 21. Then, the trench 26 is formed using the hard mask 24. An insulating film such as a silicon nitride film is formed on the inner wall of the trench 26, and then the lower portion of the trench 26 is filled with the photoresist 34. Next, the insulating film portion over the trench 26 is removed by etching. As a result, the anti-oxidation film 32 made of an insulating film remains below the trench 26, and the upper inner wall of the trench 26 is exposed.

Next, as shown in FIG. 3B, after removing the photoresist 34 of FIG. 3A, the exposed inner wall of the trench 26 is oxidized to form a LOCOS collar 36.

Referring to FIG. 3C, the antioxidant film 32 is removed. At this time, the trench 26 of FIG. 3B may be expanded to have a trench 26a having a wider lower width. Then, the buried plate 38 is formed on the inner wall of the trench 26a by gas phase doping or plasma immersion ion implantation.

This is followed by the rest of the process to form a structure similar to FIG. 1 subsequently. Gas phase doping or plasma immersion ion implantation methods are simpler than thermal diffusion, but considerable effort is required to maintain a uniform doping profile and a desired level of doping concentration in trenches with high aspect ratios. In the formation of the collar 36, even if the LOCOS method, which is a simpler method than the method of FIG.

In the method of manufacturing the trench capacitor, the oxide film collar 56 of the deposition method is formed only on the upper part of the trench 46 and the upper surface of the substrate 41 as shown in FIG. 4A, and as shown in FIG. 4B. In the etching process, the collar 56 is used as an etch mask to etch the lower portion of the trench 46 except for the upper portion and the upper surface of the trench 46, thereby forming a trench 46a having a large surface area. .

In order to implement such a method, since the oxide film should be deposited only on the upper portion of the trench 46 and the upper surface of the substrate 41, the oxide film should be deposited only to a desired depth in the depth direction of the trench 46. However, since the conventional atomic layer deposition (ALD) method conventionally used to form the oxide film color 56 of such a deposition method is a method in which the step coverage is so high that the oxide film is deposited to the bottom of the trench 46, It is very difficult to deposit an oxide film only on the inlet side of the trench 46 and to suppress deposition in the depth direction. In other words, the thin film by the conventional ALD method can not be artificially controlled because the step coverage on the reactor is extremely excellent.

However, if the step coverage ratio is poor, such as chemical vapor deposition (CVD), the overhang of the thin film 56 ′ at the inlet side of the trench 46 is severe as shown in FIG. You will not be able to proceed.

The technical problem to be achieved by the present invention is to provide a thin film deposition method that can adjust the step coverage ratio of the thin film according to the position on the substrate having a step.

According to an aspect of the present invention, there is provided a thin film deposition method comprising: polarizing a surface of a semiconductor substrate having a step, and then (a) forming an adsorption layer of a polar first precursor on the substrate; And (b) reacting the adsorption layer of the first precursor with the second precursor to deposit a thin film.

In the present invention, the polar treatment may be any one of plasma treatment, vapor deposition and wet treatment using a gas. For example, the polar treatment may be a plasma treatment using a gas including at least one of NH ₃ , NF _3, and F ₂ . Instead, the polar treatment may be to deposit at least one of Si ₃ N ₄ and SiF ₄ . Instead, the polar treatment may be a plasma treatment using a gas including at least one of O ₂ , H ₂ O, Ar, and He.

Preferably, an Al ₂ O ₃ thin film is deposited using an organic or inorganic compound containing Al as the first precursor and an organic or inorganic compound containing O as the second precursor. At this time, the second precursor may use any one selected from the group consisting of O ₃ , H ₂ O and a combination thereof.

In the present invention, the polarization treatment and the thin film deposition may proceed in-situ in one reaction chamber. Of course, the polarization treatment may be performed at another place, and then the semiconductor substrate may be introduced into the reaction chamber to perform a thin film deposition process.

In a preferred embodiment, the semiconductor substrate comprises a trench, the polarization treatment is a hydrophobic treatment, and the thin film is deposited on the inlet side of the trench using a hydrophobic precursor as the first precursor. Instead, the polar treatment is a hydrophilic treatment, and a hydrophilic precursor may be used as the first precursor.

Preferably, the cycle consisting of the steps (a) and (b) is repeated until a thin film of a desired thickness is deposited. In addition, between the steps (a) and (b), (p1) purging the residual first precursor and reaction by-products; And after the step (b), (p2) may further comprise the step of purging the residual second precursor and the reaction by-product, even in this case until the thin film of the desired thickness (a) step, (p1) The cycle consisting of the steps (b) and (p2) can be repeated.

While repeating the cycle, the semiconductor substrate surface may further include one or more steps of additional polarization treatment, wherein the polarization treatment and the additional polarization treatment may include hydrophobic treatment after hydrophobic treatment, or hydrophobic treatment after hydrophilic treatment. Alternatively, the hydrophobic treatment and the hydrophilic treatment may be alternated.

The present invention is a method of freely controlling the step coverage ratio of a thin film, the hydrophilic or hydrophobic polarity treatment on the surface of the semiconductor substrate having a step, according to the polarity of the precursor (for example, organometallic source), Therefore, by controlling the degree of adsorption on the surface to control the step coverage ratio of the thin film. According to the present invention, the step coverage ratio of the thin film can be controlled from 100% to 0% according to the position on the substrate. For example, in the deposition of Al ₂ O ₃ thin films for color for the manufacture of trench capacitors, the surface of the substrate is hydrophobized and a hydrophobic precursor is used to provide the desired constant in the depth, ie, depth, direction of the trench formed in the substrate. Al ₂ O ₃ is deposited only by the depth so that the step coverage at this deposited portion is 100% and the step coverage at the lower portion can be 0%.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. The embodiments described below may be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. In the drawings illustrating embodiments of the present invention, like numerals in the drawings refer to like elements.

The apparatus used to perform the thin film deposition method according to the present invention is similar to the ALD system widely used in the past. The structure of the device for this is shown in FIG. 6. Different types of thin films may be formed by using different kinds of reactant gases and precursors while using the present invention. In the following examples, a main example of forming Al ₂ O ₃ thin films is given.

The thin film deposition apparatus 200 of FIG. 6 is for depositing a thin film such as an Al ₂ O ₃ thin film on a semiconductor substrate w such as a silicon wafer seated on the wafer block 212 in the reaction chamber 210.

Here, the thin film deposition apparatus 200 includes a reaction chamber 210 in which thin film deposition is performed, and a source supply device 220 supplying two or more kinds of sources (reactive gas, precursor) and an inert gas to the reaction chamber 210. It includes.

The reaction chamber 210 may include: a shower head 211 installed at an upper portion of the inside thereof, into which a source and an inert gas are injected, a wafer block 212 installed below the shower head 211 and seated on a substrate w; A pumping baffle 213 installed at the outer periphery of the wafer block 212 for smooth and uniform pumping of the source, the inert gas and the reaction byproduct, and a gas curtain block 214 for injecting the inert gas to the outer periphery of the shower head 211. Include.

The source supply device 220 not only supplies two or more kinds of sources and inert gases to the reaction chamber 210, but also enables essential valving in the ALD. In the thin film deposition method according to the present invention, for example, an Al source (eg, TMA) is used as the first precursor, and an O source (eg, O ₃ , H ₂ O, or a combination thereof) is used as the second precursor, and the substrate ( w) to deposit an Al ₂ O ₃ thin film.

The showerhead 211 is divided into several regions so that the sources to be fed do not meet each other. Each region is connected to a flow path that does not meet each other inside the shower head 211 and the injection hole at the bottom. Therefore, the source and the inert gas passing through the flow path inside the shower head 211 do not meet inside the shower head 211 while passing through the shower head 211.

A heater 212a is built in the wafer block 212, and the heater 212a heats the substrate w on which it is seated, for example, in a range of 20 ° C to 700 ° C. The pumping baffle 213 may ensure optimal thickness uniformity and composition of the deposited thin film, that is, Al ₂ O ₃ thin film, and optimize the reaction space. This pumping baffle 213 is preferably separated into two layers to facilitate maintenance of the device, or to facilitate removal / attachment. As such, by configuring the pumping baffle 213 in two layers, the pumping baffle 213 can be operated in consideration of the motility of each source, thereby greatly helping to maintain a constant atomic composition in the deposited thin film.

The gas curtain block 214 injects an inert gas toward the edge of the substrate w to adjust the composition change of the edge of the substrate w, and also the reaction chamber 210, specifically, the inner wall of the pumping baffle 213 is a source. Minimize contamination by

(First embodiment)

FIG. 7 is a flowchart showing a first embodiment of depositing a thin film with an apparatus as shown in FIG. 6 according to the present invention, and the process in which the actual process is performed corresponds to ALD. 8 is a diagram showing the process flow over time in this embodiment. 9A to 9E are cross-sectional views of a process according to the first embodiment.

As in steps s11 and 8 of FIG. 7, first, the surface of the semiconductor substrate having the step is polarized. The polarization treatment may use any one of plasma treatment, vapor deposition, and wet treatment with gas. 9A is a cross-sectional view at this stage.

Referring to Fig. 9A, a trench 66 is formed so that the surface of the semiconductor substrate 61 having a step is polarized, particularly in the present embodiment, hydrophobic. For hydrophobic treatment 68, for example, plasma treatment with a gas comprising at least one of NH ₃ , NF ₃ and F ₂ , or at least one of Si ₃ N ₄ and SiF ₄ is deposited. . As the wet treatment, for example, electrolytic plating or electroless plating may be used.

Then, as in steps s12 and 8 of FIG. 7, a first precursor of polarity is supplied onto the substrate 61, and as shown in FIGS. 9b and 9c, the polarity, in particular the present embodiment, on the substrate 61. In the example, the adsorption layer of the hydrophobic first precursor 70 is formed (step s12). Preferably, the first precursor 70 uses an organic or inorganic compound containing Al, for example, TMA.

As shown in FIG. 9B, when the hydrophobic first precursor 70 arrives inside the trench 66 subjected to the hydrophobic treatment 68, adsorption is not carried out due to the repulsive force. However, even when the hydrophobic treatment 68 is applied, a relatively large amount of the first precursor 70 exists at the inlet side of the trench 66, so that an adsorption layer of the first precursor 70 is formed at the inlet side. . Therefore, when the strength of the hydrophobic treatment 68 is adjusted, the adsorption is partially adsorbed only on the upper surface of the substrate 61 to which the source (the first precursor) is supplied in a large amount and the region adjacent thereto, and thus the reaction gas (the second Even if the precursor is introduced, the deposition can be prevented from being formed below the substrate 61 (that is, inside the trench 66).

After forming the adsorption layer of the first precursor (step s12 of FIG. 7), the purge is carried out as shown in FIG. 8 to purge the residual first precursor and the reaction byproduct (step s13 of FIG. 7). The purge gas may be any one selected from the group consisting of N ₂ , Ar, and He.

Then, as shown in FIG. 8, the second precursor is supplied, and the thin film is deposited by reacting the adsorption layer of the first precursor with the second precursor (step s14 of FIG. 7). Fig. 9D is a cross sectional view at this stage.

Referring to FIG. 9D, a thin film is deposited by the adsorption layer of the first precursor 70 formed on the inlet side of the trench 66 and the second precursor 72, but the first precursor 70 is formed inside the trench 66. Is not adsorbed well, so it is difficult to deposit the thin film. Preferably, as the second precursor, an Al ₂ O ₃ thin film is deposited using an organic or inorganic compound containing O. In FIG. 8, O ₃ and H ₂ O are used as the second precursor.

Subsequently, purge is performed as in FIG. 8 to purge the residual second precursor and the reaction byproduct (step s15 of FIG. 7). Here, the purge gas may be any one selected from the group consisting of N ₂ , Ar, and He. After these steps, it is confirmed whether a thin film of a desired thickness is deposited (step s16 of FIG. 7), and the cycle consisting of steps s12 to s15 is repeated until a thin film of a desired thickness is deposited.

9E, the thin film 76 is deposited only at the inlet side of the trench 66. As shown in FIG. The thin film 76 thus deposited may be used as the color of the trench capacitor.

A carrier gas such as N ₂ , Ar, or He may be used to introduce the first precursor and / or the second precursor into the reaction chamber 210. By adjusting the amount of the transfer gas, the inflow amount of the first precursor and the second precursor introduced into the reaction chamber 210 under the same temperature and the same inflow time can be controlled.

Instead of using the transfer gas, the purge gas may be mixed and introduced when the first precursor and / or the second precursor flow into the reaction chamber 210. In this case, in order to control the inflow amount of the first precursor and the second precursor flowing into the reaction chamber 210, the temperature of the first precursor and the second precursor is lowered to adjust the vapor pressure to the reaction chamber 210 at the same time. The inflow amount is adjusted, or the temperature of the first precursor and the second precursor is fixed, but the inflow time into the reaction chamber 210 is controlled.

On the other hand, polarization of the substrate and thin film deposition may be performed in-situ or ex-situ.

First, in situ is to proceed the polarization process and thin film deposition in one reaction chamber (210). In other words, first, the substrate w is introduced into the reaction chamber 210, and then the surface thereof is polarized, and the polar first precursor is introduced into the reaction chamber 210 to form an adsorption layer. . It is suitable for the case of polar treatment by plasma treatment or thin film deposition.

The ex-situ performs the polarization treatment on the surface of the substrate w at another place, and then introduces the substrate w into the reaction chamber 210, introduces a polar first precursor into the reaction chamber 210, thereby adsorbing the adsorption layer. The process proceeds in the order of formation. It is suitable for the case of polar treatment by wet treatment.

Meanwhile, in the previous embodiment, the polarization treatment and the polarity of the first precursor are both hydrophobic. For example, as in the previous embodiment, the thin film is deposited only on the inlet side of the trench without depositing the thin film inside the trench. In that case, both the polarity treatment and the polarity of the first precursor may be made hydrophilic in the same manner. An example of the hydrophilic polar treatment may be a plasma treatment using a gas including at least one of O ₂ , H ₂ O, Ar, and He.

On the other hand, while repeating the cycle consisting of the step s12 to step s15, the step of further polarizing the surface of the semiconductor substrate may further comprise one or more times, wherein the polarization treatment and the additional polarization treatment, hydrophobic treatment after hydrophobic treatment Or hydrophobic treatment after hydrophilic treatment, or alternating hydrophobic treatment with hydrophilic treatment. When the hydrophobic treatment and the hydrophilic treatment are combined in the deposition step, the surface characteristics of the pattern of the initial deposition and the late deposition are changed over time, and the step coverage of the deposited thin film is also freely controlled.

(2nd Example)

10A and 10B are cross-sectional views of a process according to a second exemplary embodiment of a thin film deposition method according to the present invention. This embodiment is the case opposite to the first embodiment described above, and corresponds to the case where a thin film is to be deposited inside the trench 66.

First, as in FIG. 10A, the surface of the semiconductor substrate 61 on which the trench 66 is formed is polarized, for example, hydrophilic polarized 69. Then, the polar group on the surface disappears and the interfacial energy is lowered. When the hydrophobic first precursor 70 is supplied thereto, as shown in FIG. The first precursor 70 is adsorbed well. Accordingly, when the remaining steps (purge, second precursor adsorption, purge, etc.) are performed, the thin film is well deposited inside the trench 66, and thus the thin film having an extremely high step coverage can be formed.

Of course, similar results can be obtained by hydrophobizing the surface of the semiconductor substrate and using a hydrophilic first precursor. As described above, in the present invention, by combining the surface treatment and the polarity of the precursor, the step coverage can be freely adjusted according to the position on the substrate.

(Third Embodiment)

11 is a flow chart showing a third embodiment of depositing a thin film according to the present invention. The actual process is equivalent to cyclic CVD, which is a similar ALD. 12 is a diagram showing the process flow over time in this example.

This embodiment is almost the same as the first embodiment, and instead, reacts the purge (step s13 in FIG. 7) and the adsorption layer of the first precursor with the second precursor after forming the adsorption layer of the polar first precursor. It does not include the purge (step s15 of FIG. 7) following the step of depositing the thin film.

Although the detailed description of the present invention has been made, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the present invention. The invention is only defined by the scope of the claims.

According to the present invention, a hydrophilic or hydrophobic polarity treatment is performed on a surface of a semiconductor substrate having a step, and according to the polarity of the precursor (for example, an organometallic source), the degree of adsorption on the surface along the step is adjusted. Adjust the step coverage ratio of the thin film.

Thus, in depositing a thin Al ₂ O ₃ thin film for the production of trench capacitors, the hydrophobic treatment of the substrate surface and the use of a hydrophobic first precursor result in a desired constant in the inlet side of the trench formed in the substrate, i.e. in the depth direction. Since Al ₂ O ₃ is deposited only by the depth, it is possible to form a collar with a step coverage ratio of 100% only at the inlet side of the trench, thereby enabling a method for extending the surface area of the trench capacitor.

On the contrary, the hydrophilic treatment of the substrate surface and the use of the hydrophobic first precursor enable the deposition of thin films with excellent step coverage even inside trenches having a high aspect ratio.

In addition, if the hydrophilic treatment and the hydrophobic treatment are properly combined with the progress of the process, the step coverage can be adjusted over time according to the position on the substrate.

Claims (15)

Polarizing the surface of the semiconductor substrate with steps, (a) forming an adsorption layer of a polar first precursor on the substrate; And (b) reacting the adsorption layer of the first precursor with the second precursor to deposit a thin film. The method of claim 1, wherein the polarization treatment comprises any one of plasma treatment, vapor deposition, and wet treatment using a gas. The method of claim 2, wherein the polarization treatment is a plasma treatment using a gas including at least one of NH ₃ , NF _3, and F ₂ . The method of claim 2, wherein the polarization process deposits at least one of Si ₃ N ₄ and SiF ₄ . The method of claim 2, wherein the polarization treatment is a plasma treatment using a gas including at least one of O ₂ , H ₂ O, Ar, and He. The Al ₂ O ₃ thin film according to claim 1, wherein an Al or an organic compound containing Al is used as the first precursor and an organic or inorganic compound containing O is used as the second precursor. Thin film deposition method. The method of claim 6, wherein the second precursor is any one selected from the group consisting of O ₃ , H ₂ O, and a combination thereof. 8. The method of any one of claims 1 to 7, wherein the polarization treatment and the thin film deposition proceed in-situ in one reaction chamber. The thin film according to claim 1, wherein the semiconductor substrate comprises a trench, the polarization treatment is a hydrophobic treatment, and the thin film is deposited on the inlet side of the trench using a hydrophobic precursor as the first precursor. Deposition method. The thin film according to claim 1, wherein the semiconductor substrate comprises a trench, the polarization treatment is a hydrophilic treatment, and the thin film is deposited on the inlet side of the trench using a hydrophilic precursor as the first precursor. Deposition method. 2. The method of claim 1, wherein the cycle consisting of the steps (a) and (b) is repeated until a thin film of a desired thickness is deposited. The method of claim 1, (P) purging the remaining first precursor and reaction byproduct between steps (a) and (b); And After the step (b), (p2) further comprising the step of purging the residual second precursor and the reaction by-products. 13. The thin film deposition method according to claim 12, wherein the cycle consisting of steps (a), (p1), (b) and (p2) is repeated until a thin film of a desired thickness is deposited. 14. The method of any one of claims 11 and 13, further comprising further polarizing the semiconductor substrate surface one or more times while repeating the cycle. The thin film deposition method according to claim 14, wherein the polarity treatment and the additional polarization treatment are hydrophilic treatment after hydrophobic treatment, hydrophobic treatment after hydrophilic treatment, or alternating hydrophobic treatment and hydrophilic treatment.

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