FILM DEPOSITION METHOD OF Zr-BASED FILM
CVD and ALD methods using a Zr source and active hydrogen enable the formation of Zr-based films with uniform thickness on complex surfaces, addressing the limitations of PVD in forming Zr films on miniaturized and three-dimensional structures.
Patent Information
- Application Number
- JP2023190984
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-11-08
- Publication Date
- 2025-05-20
AI Technical Summary
Existing physical vapor deposition (PVD) methods struggle to form Zr films of uniform thickness on highly miniaturized or three-dimensional surfaces, as well as on surfaces with unevenness or pores in the semiconductor and catalyst fields.
A method involving chemical vapor deposition (CVD) or atomic layer deposition (ALD) is employed, using a Zr source and active hydrogen to form Zr-based films with high Zr concentration, achieving uniform thickness on three-dimensional surfaces, where active hydrogen is generated through plasma irradiation or application of activation energy.
Zr-based films with high Zr concentration and uniform thickness are successfully formed on complex surfaces, including three-dimensional areas, using CVD or ALD methods.
Smart Images
Figure 2025078427000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention is a technology relating to Zr-based films. [Background technology]
[0002] Zr is used in the semiconductor field, the catalyst field, and various other fields, and the fields in which Zr-based films are used will continue to expand.
[0003] Zr-based films have been formed by physical vapor deposition (PVD) such as sputtering or evaporation. RSCAdv., 2022,12,14235-14245 (Non-Patent Document 1) proposes a technique for forming a Zr film by sputtering. The Zr film is used in a resistance change memory.
[0004] Physical vapor deposition (PVD) methods such as the sputtering method have not been able to form a Zr film of uniform thickness on the surfaces of highly miniaturized or three-dimensional (stereoscopic) areas in the semiconductor field.
[0005] Even in catalysts, it is not possible to form a Zr film of uniform thickness on the surface of a carrier that has unevenness or pores. It is not possible to form a Zr film of uniform thickness on the powder surface. [Prior art documents] [Non-patent literature]
[0006] [Non-Patent Document 1] RSCAdv., 2022,12,14235-14245 Summary of the Invention [Problem to be solved by the invention]
[0007] Since there are problems with forming Zr films using the PVD method, would it be possible to use chemical vapor deposition (CVD) or atomic layer deposition (ALD) instead?
[0008] However, until now, there has been no news of Zr film formation technology using CVD or ALD methods.
[0009] Therefore, the problem to be solved by the present invention is to provide a technique for forming a Zr-based film having a high Zr concentration by a CVD method or an ALD method, in particular, to provide a technique for forming a Zr-based film having a high Zr concentration with a uniform thickness on the surface of a three-dimensional (stereoscopic) portion. [Means for solving the problem]
[0010] The present invention relates to A method for forming a Zr-based film, comprising the steps of: A Zr source and active hydrogen are supplied into the deposition chamber to deposit a Zr-based film on the substrate. A method for forming Zr-based films is proposed.
[0011] The present invention relates to A method for forming a Zr-based film having a C concentration of less than 1% in elemental ratio, a N concentration of less than 1% in elemental ratio, and an O concentration of 20% or less in elemental ratio, A Zr source and active hydrogen are supplied into the deposition chamber to deposit a Zr-based film on the substrate. A method for forming Zr-based films is proposed.
[0012] The present invention proposes a method for forming the Zr-based film, preferably a method for forming the Zr-based film on the substrate by a reaction between the Zr source and the active hydrogen.
[0013] The present invention proposes a method for forming the Zr-based film, in which the active hydrogen is preferably obtained by plasma irradiation.
[0014] The present invention proposes a method for forming the Zr-based film, in which the active hydrogen is preferably obtained by applying activation energy to hydrogen.
[0015] The present invention proposes a method for forming a Zr-based film, preferably a method for forming a Zr-based film, in which the activation energy is radiation.
[0016] The present invention proposes a method for forming the Zr-based film, which is, for example, an atomic layer deposition method.
[0017] The present invention proposes a method for forming the Zr-based film, which is, for example, a chemical vapor deposition method.
[0018] The present invention proposes a method for forming the Zr-based film, preferably, in which the Zr source is aminozirconium.
[0019] The present invention relates to a method for forming a Zr-based film, wherein the amino zirconium is Zr(NR 1 R 2 ) 4 [R 1 and R 2 may be the same or different. 1 ,R 2 is H or a hydrocarbon group having 1 to 10 carbon atoms.].
[0020] The present invention proposes a method for forming the Zr-based film, in which the Zr source is a zirconium halide.
[0021] The present invention proposes a method for forming a Zr-based film, in which the temperature of the substrate is preferably 200 to 300°C.
[0022] The present invention proposes a method for forming a Zr-based film, in which the supply ratio of the Zr source to active hydrogen is preferably such that one or more active hydrogen molecules are provided per molecule of the compound that is the Zr source. Effect of the Invention
[0023] Zr-based films with high Zr concentrations could be formed by CVD or ALD. In particular, even in three-dimensional (stereoscopic) areas, a Zr-based film of uniform thickness could be formed on the surface. [Brief description of the drawings]
[0024] [Figure 1] Schematic diagram of the reaction between aminozirconium and hydrogen radicals during film formation [Diagram 2] Schematic diagram of the film forming device [Diagram 3] Cross-sectional SEM image of Zr thin film [Figure 4] Composition analysis results of Zr thin film by EDX DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Embodiments of the present invention are described below.
[0026] The present invention is a method for forming (depositing) a Zr-based film. In particular, it is a method for forming a Zr-based film (the C concentration in the film is less than 1% in elemental ratio, the N concentration is less than 1% in elemental ratio, and the O concentration is 20% or less in elemental ratio). The film forming (deposition) method is a method in which a Zr source and active hydrogen are supplied into a film forming chamber to form a Zr-based film on a substrate. For example, it is a method in which a Zr source and active hydrogen for forming a Zr-based film are supplied onto a substrate in a film forming chamber (a film forming chamber that can be evacuated) to form a Zr-based film on a substrate. The method includes, for example, a step of supplying the Zr source and active hydrogen. For example, a Zr source and hydrogen (the supplied hydrogen may be active hydrogen) are supplied into the film forming chamber. If the hydrogen is not active hydrogen, the hydrogen is irradiated with radiation. As a result, the hydrogen is modified into active hydrogen. The Zr source reacts with the active hydrogen. This reactant is exposed to the surface of the substrate and is deposited on the substrate surface. This deposition process is shown in Figure 1. Figure 1 shows an example in which the Zr source is amino zirconium. Amino zirconium and active hydrogen (e.g., hydrogen radical ( * H)) reacts with amines (HNR 1 R 2) is released from the amino zirconium. Zr becomes a radical. This is deposited on the substrate. The amino group of the Zr compound deposited on the substrate surface and the hydrogen radical ( * H) reacts with amines (HNR 1 R 2 The amine is released from the amino zirconium. The film formation chamber is evacuated to a vacuum, so the released amine is discharged outside the chamber. The amine release reaction from aminated zirconium is 2 The reaction with Zr did not occur. The need for hydrogen radicals was also confirmed by molecular chemistry calculations. The Zr source was ZrX 4 (The above X is a group that reacts with active hydrogen and leaves Zr. X 4 The X's may all be the same or different.) From Figure 1, one molecule of ZrX 4 It will be understood that it is preferable to supply one or more active hydrogens to the film formation chamber. It will be understood that it is preferable to supply two or more active hydrogens. It will be understood that it is preferable to supply three or more active hydrogens. It will be understood that it is preferable to supply four or more active hydrogens. The Zr source supplied to the film formation chamber has a partial pressure of preferably 0.01 to 10 Pa. The hydrogen supplied to the film formation chamber has a partial pressure of preferably 0.01 to 100 Pa. The supplies may be simultaneous or different. The Zr source is for forming a Zr-based film. The Zr source is preferably amino zirconium. The amino zirconium is, for example, Zr(NR 1 R 2 ) 4 [R 1 and R 2 may be the same or different. 1 ,R 2 R is H or a hydrocarbon group having 1 to 10 carbon atoms. 1 ,R 2At least one of the above is a hydrocarbon group. Examples of the hydrocarbon group include methyl group (Me), ethyl group (Et), n-propyl group (nPr), isopropyl group (iPr), n-butyl group (nBu), isobutyl group (iBu), sec-butyl group (sBu), tert-butyl group (tBu), and tert-amyl group (tAm). Among the above, preferred hydrocarbon groups are those having 4 or less carbon atoms. Amines with too many carbon atoms can be easily converted to hydrogen radicals ( * H) was difficult to cause separation. Particularly preferred were methyl groups (Me) and ethyl groups (Et). The Zr source may also be, for example, zirconium halide. For example, ZrCl 4 The active hydrogen is H 2 The active hydrogen is obtained when activation energy is applied to the active hydrogen. The activation energy is radiation (e.g., X-rays, electron beams, electromagnetic waves, or light). The active hydrogen is preferably active hydrogen (e.g., hydrogen radicals or hydrogen atoms (H)) produced by plasma irradiation. The film formation (deposition) method is, for example, plasma-assisted atomic layer deposition or plasma-assisted chemical vapor deposition. Here, plasma use means that hydrogen is modified into active hydrogen. Therefore, in addition to plasma-enhanced ALD (PEALD), plasma-enhanced CVD (PECVD), and plasma-photon-assisted CVD (PPECVD), ALD and CVD in which radiation (X-rays, electron beams, electromagnetic waves, or light) is applied to convert hydrogen into active hydrogen are also included. ALD and CVD similar to these are also included. The temperature of the substrate is preferably 200 to 300°C.
[0027] The following description is more specific. The following description is merely a preferred exemplary embodiment. The present invention is not limited thereto. Various modifications are also included without departing from the spirit and scope of the present invention defined in the claims.
[0028] [Example 1] FIG. 2 is a schematic cross-sectional view of a film forming apparatus. Reference numeral 11 denotes a housing of the film forming apparatus. Reference numeral 12 denotes a heater for heating a substrate 13. The substrate 13 is, for example, a silicon wafer. The substrate 13 is heated to 300° C. by the heater 12. Reference numeral 14 denotes a Zr source (tetrakismethylethylaminozirconium (Zr(NMeEt) 4 This is a pipe for introducing a film-forming raw material such as Zr) into the film-forming apparatus 11. The introduction flow rate of the Zr source was, for example, 7 sccm. The Zr source was N 2 It is transported by gas. 2 The gas flow rate was 40 sccm. 15 is a pipe for evacuating the inside of the film forming apparatus 11. A vacuum pump (not shown) is connected to the pipe 15. 16 is a pipe for introducing a plasma gas. For example, Ar and H 2 The flow rate of Ar gas is, for example, 70 sccm. 2 The flow rate of the gas was, for example, 10 sccm. 17 is a coil. 18 is a high-frequency power source. When a current flows through the coil 17, an electromagnetic wave is induced in the coil 17. This causes the introduced hydrogen gas to become plasma. Active hydrogen (hydrogen radicals ( * That is, active hydrogen (hydrogen radicals ( * The vacuum pump connected to the pipe 15 was operated to reduce the pressure inside the film forming apparatus 11, and the pressure inside the apparatus was adjusted to 63 Pa. The high-frequency power source 18, to which a power of 50 W was applied, outputted a high-frequency wave of 13.67 MHz. This produced plasma. The introduced H 2 Active hydrogen (hydrogen radical ( * H) was generated. And the hydrogen radical ( * H) and Zr(NMeEt) 4 The reaction took place (see FIG. 1). A Zr-based film having a thickness of 200 nm was formed on the surface of the substrate 13. The reaction took 15 minutes.
[0029] The composition of the Zr-based film obtained by the above-mentioned film formation method was measured by X-ray photoelectron spectroscopy (XPS). The element ratio was 80% Zr and 20% O. No C or N was detected. This (no C or N was detected) is due to the hydrogen radical ( * H) by Zr(NMeEt) 4 This will allow one to understand that the NMeEt group has been removed.
[0030] [Example 2] In Example 1, a silicon wafer (having a trench-type pattern) 13 was used. The silicon wafer 13 was heated to a temperature of 200° C. Zr(NMeEt) 4 N 2 Introduced as a gas. Zr(NMeEt) 4 The amount of N introduced was 6 sccm. 2 The gas flow rate was 40 sccm. The pressure inside the film forming apparatus 11 was adjusted to 45 Pa. A Zr-based film having a thickness of 50 nm was formed on the surface of the silicon wafer 13. The time required was 5 minutes. A thin metal Co film was formed on the Zr-based film to a thickness of 10 nm by the ALD method.
[0031] The cross section of the thin film sample was observed with a scanning electron microscope (Regulus8230, Hitachi High-Tech) (see Figure 3). Figure 3 shows that the thin film is also deposited on the sidewalls and bottom of the recess. Figure 3(a) is an overall view of the pattern. Figure 3(b) is an enlarged view of the upper corner of the pattern. Figure 3(c) is an enlarged view of the bottom of the pattern.
[0032] Figure 4 shows the X-ray spectrum. This was obtained by observation under an electron microscope and qualitative analysis using an energy dispersive X-ray analyzer. The analysis area is the same as that shown in Figure 3(c). By identifying the peak of the characteristic X-rays, it was confirmed that Zr elements were present within the observation field and that a Zr film had been deposited.
[0033] [Comparative Example 1] The film forming apparatus described in Example 1 was used. In this Comparative Example 1, unlike the above-mentioned Example, hydrogen gas was not supplied. The high frequency power source 18 was not operated. The silicon wafer 13 was heated to 300 to 500°C. Zr(NMeEt) 4 was introduced (0.1 to 10 sccm). 2 A gas (flow rate of 10 to 100 sccm) was used. The pressure inside the film forming apparatus 11 was adjusted to 1 to 1000 Pa. A film (thickness of 1 to 2000 nm) was formed. The time required was 1 to 100 minutes.
[0034] The composition of the obtained Zr-based film was measured by X-ray photoelectron spectroscopy (XPS). The element ratio was 30% Zr, 50% O, and 20% C. No N was detected. In this Comparative Example 1, the proportion of Zr in the thin film was lower than that in the Example 1.
[0035] [Comparative Example 2] The film forming apparatus described in Example 1 was used. The silicon wafer 13 was heated to 300 to 500° C. Zr(NMeEt) 4 was introduced (0.1 to 10 sccm). 2 Gas (flow rate 10-100sccm) was used. H 2 Gas (flow rate 1 to 100 sccm) was supplied. In this comparative example 2, hydrogen gas was supplied, but the high frequency power supply 18 was not operated. In other words, active hydrogen was not generated. The pressure inside the film forming apparatus 11 was adjusted to 1 to 1000 Pa. A film (thickness 1 to 2000 nm) was formed. The time required was 1 to 100 minutes.
[0036] The composition of the obtained Zr-based film was measured by X-ray photoelectron spectroscopy (XPS). The element ratio was 30% Zr, 45% O, 20% C, and 5% N. The Zr ratio in the thin film in this Comparative Example 2 was also lower than that in the Example 1. The presence of C and N in the thin film indicates that Zr(NMeEt) 4 This will make you think about the accumulation of
Claims
1. A method for forming a Zr-based film, comprising the steps of: A Zr source and active hydrogen are supplied into the deposition chamber to deposit a Zr-based film on the substrate. A method for forming a Zr-based film.
2. A Zr-based film is formed on the substrate by the reaction between the Zr source and the active hydrogen. The method for forming a Zr-based film according to claim 1.
3. In the formed Zr-based film, the C concentration is less than 1% in terms of element ratio, the N concentration is less than 1% in terms of element ratio, and the O concentration is 20% or less in terms of element ratio. The method for forming a Zr-based film according to claim 1 or 2.
4. The active hydrogen is obtained by plasma irradiation. The method for forming a Zr-based film according to claim 1 or 2.
5. The active hydrogen is obtained by applying activation energy to hydrogen. The method for forming a Zr-based film according to claim 1 or 2.
6. The activation energy is radiation. The method for forming a Zr-based film according to claim 5.
7. The deposition method is an atomic layer deposition method. The method for forming a Zr-based film according to claim 1 or 2.
8. The film formation method is a chemical vapor deposition method. The method for forming a Zr-based film according to claim 1 or 2.
9. The Zr source is aminozirconium. The method for forming a Zr-based film according to claim 1 or 2.
10. The amino zirconium is Zr(NR １ R ２ ) ４ [R １ and R ２ may be the same as or different from each other. １ , R ２ is H or a hydrocarbon group having 1 to 10 carbon atoms. The method for forming a Zr-based film according to claim 8.
11. The Zr source is a zirconium halide. The method for forming a Zr-based film according to claim 1 or 2.
12. The temperature of the substrate is 200 to 300° C. The method for forming a Zr-based film according to claim 1 or 2.
13. The supply ratio of the Zr source and the active hydrogen is such that one or more active hydrogen molecules are provided per one molecule of the compound which is the Zr source. The method for forming a Zr-based film according to claim 1 or 2.