Selective atomic layer deposition method for sequential double passivation
By employing a sequential double passivation selective atomic layer deposition method, and utilizing a combination of silicon inhibitors and polymer passivation layers, the problem of lateral thin film expansion was solved, enabling precise deposition and performance enhancement of dielectric thin films in semiconductor devices.
Patent Information
- Application Number
- CN202511402718.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2026-01-27
AI Technical Summary
In semiconductor manufacturing, the lateral expansion of thin film materials in existing technologies leads to a decline in device performance. Unintended lateral expansion introduces interface defects and bridging paths, affecting circuit signal transmission and energy density performance.
A selective atomic layer deposition method with sequential dual passivation is adopted. A first passivation layer is formed by depositing a silicon inhibitor in the dielectric material region, and a second passivation layer of polymer is deposited in the metal material region. The upper surface of the second passivation layer is higher than that of the first passivation layer, forming a steep transition to block the lateral expansion of the dielectric film.
This improves the deposition selectivity of dielectric films in dielectric material regions, avoids undesirable deposition, achieves precise confinement of films on patterned substrates, and enhances device performance and process stability.
Smart Images
Figure CN121419656A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of atomic layer deposition technology, and in particular to a selective atomic layer deposition method with sequential double passivation. Background Technology
[0002] In the semiconductor manufacturing field, traditional processes such as photolithography, deposition, and etching remain the core means of constructing nanoscale devices. As device feature sizes continue to shrink towards sub-10 nanometer nodes, selective atomic layer deposition (SID) is becoming increasingly prominent due to its advantages in precise material control. SID enables the directional growth of thin films in specific substrate regions, significantly reducing the traditional photolithography patterning steps, improving process accuracy while reducing material waste.
[0003] Ideally, thin film materials should be grown strictly vertically within a predetermined region. However, in actual processes, unexpected lateral expansion often occurs. Lateral expansion leads to a decrease in device performance, process stability, and manufacturing yield. When thin film materials expand laterally onto the metal surface outside the growth region, they may introduce additional interface defects or bridging paths into the device structure, resulting in a significant increase in leakage current. This directly affects the integrity of circuit signal transmission and the energy density performance of the energy storage unit. Summary of the Invention
[0004] Therefore, it is necessary to provide a selective atomic layer deposition method that can restrict the lateral expansion of thin films by sequential double passivation.
[0005] One aspect of the present invention provides a selective atomic layer deposition method with sequential dual passivation, comprising the following steps:
[0006] S1. A substrate is provided, the surface of which includes a dielectric material region and a metal material region disposed adjacent to each other;
[0007] S2. Deposit a first passivation layer on the dielectric material region of the substrate, wherein the material of the first passivation layer includes a silicon inhibitor;
[0008] S3. Deposit a second passivation layer on the metal material region of the substrate provided with the first passivation layer, the second passivation layer comprising a polymer; the upper surface of the second passivation layer is higher than the upper surface of the first passivation layer;
[0009] S4. A dielectric material thin film is formed on the surface of the first passivation layer obtained in S3.
[0010] The aforementioned sequential dual passivation selective atomic layer deposition method forms a first passivation layer by spontaneously adsorbing an ordered monolayer of silicon inhibitor on the dielectric material region. This first passivation layer in the dielectric material region prevents undesired polymer deposition. By locking the dielectric material region with the silicon inhibitor and combining it with polymer coverage of the metal material region, the sequential dual passivation selective atomic layer deposition method is achieved. Utilizing this sequential dual passivation process, a high-coverage and sufficiently thick polymer second passivation layer effectively prevents undesired dielectric film deposition in the metal material region, avoiding the problem of poor selectivity associated with a single inhibitor. This improves the selectivity of dielectric film deposition in the dielectric material region, enabling precise regional definition of the dielectric film on the patterned substrate. Furthermore, by controlling the upper surface of the second passivation layer to be higher than the upper surface of the first passivation layer, creating a steep transition between the second and first passivation layers, the lateral expansion of the dielectric film can be controlled.
[0011] In one embodiment, the silicon inhibitor comprises an amino-containing organosilane.
[0012] In one embodiment, the silicon inhibitor comprises at least one of N-(trimethylsilyl)dimethylamine, N,N-diethyl-1,1,1-trimethylsilylamine, triisopropyldimethylaminosilane, 3-aminopropyltrimethylsilane, dimethyl(dimethylamino)silane, and allyl(diisopropylamino)dimethylsilane.
[0013] In one embodiment, step S2, depositing a first passivation layer on the dielectric material region of the substrate, includes the following steps:
[0014] S21. The silicon inhibitor is introduced into the reaction chamber, where it is selectively adsorbed onto the dielectric material region, thereby forming the first passivation layer.
[0015] S22. Repeat step S21 until the thickness of the first passivation layer reaches the target value.
[0016] In one embodiment, the single-pass injection time of the silicon inhibitor is 0.1s-0.2s, the pressure in the reaction chamber is 30Pa-50Pa, and the temperature in the reaction chamber is 120℃-200℃.
[0017] In one embodiment, the monomers for preparing the polymer include a diamine monomer containing two amino groups and a dianhydride monomer containing two acetyl groups.
[0018] In one embodiment, the diamine monomer includes at least one selected from 1,6-hexanediamine, 1,4-cyclohexanediamine, methylcyclohexanediamine, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodicyclohexylmethane.
[0019] The dianhydride monomer includes at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, 4,4'-oxophthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, and 4,4'-terephthalic anhydride.
[0020] In one embodiment, step S3, depositing a polymer on a substrate having the first passivation layer, wherein the polymer is deposited on the metal material region to form a second passivation layer, further includes the following steps:
[0021] S31. The dianhydride monomer and the diamine monomer are alternately introduced into the reaction chamber, so that the dianhydride monomer and the diamine monomer react in the metal material region to form a second passivation layer.
[0022] S32. Repeat step S31 until the thickness of the second passivation layer reaches the target value.
[0023] In one embodiment, the single-pass time for the dianhydride monomer and the diamine monomer is 4s-6s, the pressure in the reaction chamber is 5Pa-15Pa, and the temperature in the reaction chamber is 200℃-300℃.
[0024] In one embodiment, the thickness of the first passivation layer is 0.5nm-2.5nm, the thickness of the second passivation layer is 1nm-15nm, the thickness of the first passivation layer is less than the thickness of the second passivation layer, and the height difference between the upper surface of the second passivation layer and the upper surface of the first passivation layer is 1nm-9nm. Attached Figure Description
[0025] Figure 1 This is a flowchart illustrating the sequential dual passivation selective atomic layer deposition method of Examples 1-3 of this application;
[0026] Figure 2 This is a schematic diagram illustrating the operation of the sequential dual passivation selective atomic layer deposition method in Examples 1-3 of this application;
[0027] Figure 3 This is a comparison diagram of the dielectric film thickness in different regions of Embodiment 1 and Comparative Example 1 of this application;
[0028] Figure 4 This is a transmission electron microscope (TEM) image of the dielectric thin film obtained in Example 1 of this application;
[0029] Figure 5 The X-ray photoelectron spectrum of the dielectric thin film obtained in Example 1 of this application is shown, where a is the X-ray photoelectron spectrum of the copper 3s orbital and b is the X-ray photoelectron spectrum of the aluminum 2p orbital.
[0030] Figure 6 These are comparison diagrams showing the reaction chamber temperature and the thickness of the second passivation layer during polymer deposition in Examples 1-7 of this application.
[0031] Figure 7 A comparison diagram of the dielectric film thickness in different regions of the dielectric film obtained in Comparative Example 3 of this application;
[0032] Figure 8 This is a comparison chart showing the effect of polymer cycle number in different regions on the thickness of the second passivation layer and the water contact angle in Examples 9-13 of this application;
[0033] Figure 9 These are Auger electron spectra of different regions of the dielectric thin film obtained in Example 8 of this application.
[0034] Explanation of reference numerals in the attached figures:
[0035] 10. Substrate; 11. Dielectric material region; 12. Metal material region; 13. First passivation layer; 14. Second passivation layer; 15. Barrier region. Detailed Implementation
[0036] To facilitate understanding of the present invention, a more complete description will be given below with reference to relevant embodiments. Preferred embodiments of the invention are shown below. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the disclosure of the invention will be achieved.
[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0038] In the field of thin film deposition technology, controlling the reactivity of precursors to achieve selective deposition is one of the mainstream strategies. This strategy can achieve high-precision deposition in specific regions by precisely controlling the chemical interaction between precursor molecules and the substrate. However, this places high demands on the chemical composition and surface state of the substrate; at the same time, the differences in reaction kinetics, adsorption modes, and active site recognition characteristics of different precursor molecules pose multidimensional challenges to the optimization of process parameters, greatly increasing the difficulty of process control and the resistance to widespread adoption in large-scale integrated manufacturing.
[0039] As a supplementary mechanism, depositing polymer molecules to form a suppression layer in non-growth regions has become another important approach. Forming a suppression layer with polymer molecules can effectively improve deposition selectivity and suppress lateral film expansion. However, there are certain limitations. The polymer-deposited suppression layer must completely cover the non-growth regions, and some of the polymer-formed suppression layer inevitably deposits in the growth regions, thus interfering with the uniformity of the subsequent dielectric film and ultimately affecting the electrical performance and long-term reliability of the device.
[0040] Therefore, this application proposes a method for region-selective atomic layer deposition using a sequential dual passivation mechanism.
[0041] Please refer to Figures 1-2 A selective atomic layer deposition method with sequential dual passivation includes the following steps:
[0042] S1. A substrate 10 is provided. The surface of the substrate 10 includes a dielectric material region 11 and a metal material region 12 disposed adjacently. The dielectric material region 11 and the metal material region 12 are separated by a barrier region 15. The substrate 10 includes a patterned substrate, the dielectric material region 11 includes a SiO2 region, the metal material region 12 includes a Cu region, and the barrier region 15 includes a TaN region.
[0043] S2. A first passivation layer 13 is deposited on the dielectric material region 11 of the substrate 10, wherein the material of the first passivation layer 13 includes a silicon inhibitor.
[0044] S3. Deposit a second passivation layer on the metal material region of the substrate having the first passivation layer, the second passivation layer comprising a polymer; the upper surface of the second passivation layer is higher than the upper surface of the first passivation layer, wherein the second passivation layer comprises a polyimide layer;
[0045] S4. A dielectric material film is formed on the surface of the first passivation layer obtained in S3, wherein the dielectric material film includes aluminum oxide.
[0046] The aforementioned sequential dual passivation selective atomic layer deposition method forms a first passivation layer 13 by spontaneously adsorbing an ordered monolayer of silicon inhibitor on the dielectric material region 11. This first passivation layer 13 prevents unwanted polymer deposition in the dielectric material region 11. By locking the dielectric material region 11 with the silicon inhibitor and combining it with polymer coverage of the metal material region 12, the sequential dual passivation selective atomic layer deposition method is achieved. Utilizing the sequential dual passivation process, a high-coverage and certain-thickness polymer second passivation layer 14 effectively prevents unwanted dielectric film deposition in the metal material region 12, avoiding the problem of poor selectivity with a single inhibitor. This improves the selectivity of dielectric film deposition in different regions, achieving precise regional definition of the dielectric film on the patterned substrate 10. The dense second passivation layer 14 and the steep transition to the first passivation layer 13 control the lateral expansion of the dielectric film.
[0047] In one embodiment, the silicon inhibitor comprises an amino-containing organosilane.
[0048] In one embodiment, the silicon inhibitor includes at least one of N-(trimethylsilyl)dimethylamine, N,N-diethyl-1,1,1-trimethylsilylamine, triisopropyldimethylaminosilane, 3-aminopropyltrimethylsilane, dimethyl(dimethylamino)silane, and allyl(diisopropylamino)dimethylsilane.
[0049] Optionally, the silicon inhibitor includes N-(trimethylsilyl)dimethylamine.
[0050] In one embodiment, step S2, depositing a first passivation layer on the dielectric material region of the substrate, includes the following steps:
[0051] S21. The silicon inhibitor is introduced into the reaction chamber, where it is selectively adsorbed onto the dielectric material region, thereby forming the first passivation layer.
[0052] S22. Repeat step S21 until the thickness of the first passivation layer reaches the target value.
[0053] In one embodiment, step S21 is repeated 5 to 60 times; as an example, the number of times step S21 is repeated is 5, 10, 20, 30, 40, 50, or 60 times, or within the range of any two of the above values.
[0054] Optionally, repeat step S21 10 to 50 times.
[0055] In one embodiment, the single-pass time for the silicon inhibitor is 0.1s-0.2s, the pressure in the reaction chamber is 30Pa-50Pa, and the temperature in the reaction chamber is 120℃-200℃.
[0056] Optionally, the single-pass time for the silicon inhibitor is 0.1 s, the pressure in the reaction chamber is 40 Pa, and the temperature in the reaction chamber is 150 °C.
[0057] In one embodiment, an inert gas is introduced to purge the unadsorbed silicon inhibitor for 20 seconds.
[0058] In the aforementioned sequential dual passivation selective atomic layer deposition method, the ordered monolayer formed by the spontaneous adsorption of silicon inhibitor on the dielectric material region 11 can form specific chemical bonds (e.g., Si-O-Si bonds) with the active sites of the dielectric material region 11, thereby forming the first passivation layer 13. The metal material region 12 lacks active sites capable of forming specific chemical bonds with the silicon inhibitor; therefore, the silicon inhibitor will not deposit on the metal material region 12. The first passivation layer 13 formed by the silicon inhibitor only in the dielectric material region 11 can prevent the subsequent deposition of the second passivation layer 14 in the dielectric material region 11, thereby improving the coverage effect of the second passivation layer 14 on the metal material region 12.
[0059] In one embodiment, the polymer comprises polyimide.
[0060] In one embodiment, the monomers for preparing the polymer include a diamine monomer containing two amino groups and a dianhydride monomer containing two acetyl groups.
[0061] In one embodiment, the diamine monomer includes at least one selected from 1,6-hexanediamine, 1,4-cyclohexanediamine, methylcyclohexanediamine, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodicyclohexylmethane.
[0062] In one embodiment, the dianhydride monomer includes at least one selected from pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, 4,4'-oxophthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, and 4,4'-terephthalic anhydride.
[0063] Optionally, the diamine monomer includes 1,6-hexanediamine, and the dianhydride monomer includes pyromellitic dianhydride.
[0064] In one embodiment, step S3 involves depositing a polymer on a substrate having a first passivation layer 13, with the polymer deposited on the metal region 12 to form a second passivation layer 14. The step also includes the following steps:
[0065] S31. The dianhydride monomer and the diamine monomer are alternately introduced into the reaction chamber, so that the dianhydride monomer and the diamine monomer react in the metal material region 12, thereby forming the second passivation layer 14.
[0066] S32. Repeat step S31 until the thickness of the second passivation layer 14 reaches the target value.
[0067] In one embodiment, step S31 is repeated 20 to 250 times; as an example, the number of times step S31 is repeated is 20, 50, 100, 150, 200, or 250 times, or within the range of any two of the above values.
[0068] Optionally, repeat step S31 50 to 200 times.
[0069] In one embodiment, the single-pass time for the dianhydride monomer and the diamine monomer is 4s-6s, the pressure in the reaction chamber is 5Pa-15Pa, and the temperature in the reaction chamber is 200℃-300℃.
[0070] Optionally, the single-pass time for 1,6-hexanediamine and pyromellitic dianhydride is 5 s, the pressure in the reaction chamber is 10 Pa, and the temperature in the reaction chamber is 250 °C.
[0071] In one embodiment, the dianhydride monomer and the diamine monomer are introduced into the reaction chamber and then heated.
[0072] Optionally, the temperature of the dianhydride monomer is 150℃-180℃, and the temperature of the diamine monomer is 30℃-50℃.
[0073] Furthermore, the temperature for 1,6-hexanediamine is 165°C, and the temperature for pyromellitic dianhydride is 40°C.
[0074] In one embodiment, the inert gas is used to purge unadsorbed dianhydride monomers for 20 seconds; the inert gas is also used to purge unadsorbed diamine monomers for 20 seconds.
[0075] The above-described sequential double passivation selective atomic layer deposition method, by depositing a second passivation layer 14 on the surface of the metal material region 12, prevents the dielectric film from being deposited undesirably in the metal material region 12; it improves the suppression efficiency of the metal material region 12 and avoids the problem of poor selectivity of a single inhibitor. It has good process compatibility and adaptability and can be widely applied to atomic layer deposition processes of various complex structures and material systems.
[0076] In one embodiment, the thickness of the second passivation layer 14 is 1 nm to 15 nm, and the thickness of the first passivation layer 13 is less than the thickness of the second passivation layer 14. Further, the height difference between the upper surface of the second passivation layer 14 and the upper surface of the first passivation layer 13 is 1 nm to 9 nm, and for example, it can be 1 nm, 2 nm, 5 nm, 7 nm, 8 nm, 9 nm, or any two of the above values.
[0077] Optionally, the thickness of the first passivation layer 13 is 1nm-2nm; optionally, the thickness of the second passivation layer 14 is 2nm-10nm, and the height difference between the upper surface of the second passivation layer 14 and the upper surface of the first passivation layer 13 is 5nm-9nm.
[0078] In the above-described sequential double passivation selective atomic layer deposition method, there is a certain height difference between the first passivation layer 13 and the second passivation layer 14, resulting in a steep boundary between them. The second passivation layer 14 can prevent the dielectric film from "climbing" to the metal material region 12 and can confine the subsequently deposited dielectric film to the dielectric material region 11.
[0079] In one embodiment, after step S1 and before step S2, the process further includes pretreatment of the substrate 10 and preparation of the reaction chamber, including the following steps:
[0080] S11 and substrate 10 are ultrasonically cleaned in acetone and ethanol for 10 min each, and then dried by blowing with nitrogen gas to remove surface organic matter and particulate impurities. The substrate 10 obtained by the above treatment is placed in the reaction chamber and stabilized in an inert gas environment to increase the vacuum degree in the reaction chamber to below 5 Pa.
[0081] In one embodiment, the dielectric material film comprises an oxide.
[0082] Optionally, the oxide includes at least one of silicon oxide, zirconium oxide, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, yttrium oxide, lanthanum oxide, and gallium oxide.
[0083] Furthermore, oxides include aluminum oxide.
[0084] In one embodiment, aluminum-based precursors are used to deposit aluminum oxide, including at least one of trimethylaluminum, dimethylaluminum chloride, aluminum trichloride, aluminum dimethylisopropoxide, tri(tert-butyl)aluminum, tri(isopropanol)aluminum, triethylaluminum, and dimethylaluminum isopropoxide.
[0085] Alternatively, isopropyl dimethylaluminum oxide can be used to deposit alumina.
[0086] In one embodiment, forming a dielectric material film on the surface of the first passivation layer 13 further includes the following steps:
[0087] S41. Isopropyl dimethylaluminum oxide and H2O are alternately introduced into the reaction chamber, and isopropyl dimethylaluminum oxide is adsorbed onto the dielectric material region, thereby forming a dielectric film.
[0088] After introducing isopropyl dimethylaluminum oxide, inert gas is used to purge the unadsorbed isopropyl dimethylaluminum oxide. After introducing H2O, inert gas is used to purge the unadsorbed H2O.
[0089] Repeat step S41 until the dielectric film thickness reaches the target value.
[0090] In one embodiment, step S41 is repeated 80 to 120 times; as an example, the number of times step S41 is repeated is 80, 100, or 120 times, or within the range of any two of the above values.
[0091] In one embodiment, the single-pass introduction time of isopropyl dimethylaluminum oxide and H2O is 0.5 s, and the pressure in the reaction chamber is 10 Pa.
[0092] In one embodiment, the inert gas was used to purge unadsorbed dimethylaluminum isopropylidene for 10 seconds; the inert gas was used to purge unadsorbed H2O for 20 seconds.
[0093] The following are specific examples.
[0094] Example 1
[0095] Please see Figure 2 The sequential dual passivation selective atomic layer deposition method includes the following steps:
[0096] S1. A patterned substrate is provided, the surface of which includes adjacent SiO2 regions and Cu regions. The patterned substrate is ultrasonically cleaned in acetone and ethanol for 10 min each, and then purged and dried with nitrogen gas to remove surface organic matter and particulate impurities. The patterned substrate obtained by the above treatment is placed in a reaction chamber and stabilized in an inert gas environment to increase the vacuum degree in the reaction chamber to below 5 Pa.
[0097] S2. Deposit a silicon inhibitor layer on the SiO2 region. Specific steps include: introducing N-(trimethylsilyl)dimethylamine into the reaction chamber for 0.1 s at a time; maintaining a pressure of 40 Pa and a temperature of 150 °C within the reaction chamber after introduction; selectively adsorbing N-(trimethylsilyl)dimethylamine onto the SiO2 region; then purging unadsorbed N-(trimethylsilyl)dimethylamine with inert gas for 20 s. This process constitutes one cycle; repeating this cycle multiple times until the SiO2 region thickness reaches 1 nm-2 nm.
[0098] S3. Deposit a polyimide layer on a substrate with a silicon inhibitor layer. Specific steps include: heating 1,6-hexanediamine to 165°C; the single-pass 1,6-hexanediamine introduction time is 5s; after introduction, the pressure in the reaction chamber is 10Pa, and the temperature in the reaction chamber is 250°C; 1,6-hexanediamine is adsorbed in the Cu region; then, an inert gas is introduced for 20s to purge any unadsorbed 1,6-hexanediamine. Heating pyromellitic dianhydride to 40°C; the single-pass pyromellitic dianhydride introduction time is 5s; after introduction, the pressure in the reaction chamber is 10Pa, and the temperature in the reaction chamber is 250°C; the pyromellitic dianhydride is adsorbed in the Cu region and reacts with 1,6-hexanediamine to obtain polyimide, further forming a polyimide layer; then, an inert gas is introduced for 20s to purge any unadsorbed pyromellitic dianhydride. The above process involves alternately introducing 1,6-hexanediamine and pyromellitic dianhydride into the reaction chamber. The 1,6-hexanediamine and pyromellitic dianhydride react to form a polyimide layer, constituting one cycle. This process is repeated multiple times to form a 10 nm thick polyimide layer in the Cu region.
[0099] S4. Form a dielectric material film on the surface of the silicon inhibitor layer obtained in S3. Specific steps include: alternately introducing isopropyl dimethylaluminum oxide and H2O into the reaction chamber. The single introduction time of isopropyl dimethylaluminum oxide is 0.5 s. After the introduction of isopropyl dimethylaluminum oxide, the pressure in the reaction chamber is 10 Pa. The isopropyl dimethylaluminum oxide is adsorbed onto the SiO2 region passivated by the silicon inhibitor layer. Then, an inert gas is introduced for 10 s to purge the unadsorbed isopropyl dimethylaluminum oxide. The single introduction time of H2O is 0.5 s. After the introduction of H2O, the pressure in the reaction chamber is 10 Pa. H2O oxidizes the isopropyl dimethylaluminum oxide, forming an alumina dielectric film in the SiO2 region. This operation constitutes one cycle, which is repeated multiple times until the thickness of the alumina dielectric film reaches 6 nm.
[0100] Example 2
[0101] The preparation method of Example 2 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 200°C.
[0102] Example 3
[0103] The preparation method of Example 3 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 210°C.
[0104] Example 4
[0105] The preparation method of Example 4 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 220°C.
[0106] Example 5
[0107] The preparation method of Example 5 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 230°C.
[0108] Example 6
[0109] The preparation method of Example 6 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 240°C.
[0110] Example 7
[0111] The preparation method of Example 7 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S3 is 260°C.
[0112] Example 8
[0113] The preparation method of Example 8 is basically the same as that of Example 1, except that the temperature of the reaction chamber in step S31 is 180°C.
[0114] Example 9
[0115] The preparation method of Example 9 is basically the same as that of Example 1, except that in step S3, the number of cycles of 1,6-hexanediamine and pyromellitic dianhydride is adjusted to 50 times, and the thickness of the polyimide layer is adjusted to 10±1nm by controlling the number of cycles.
[0116] Example 10
[0117] The preparation method of Example 10 is basically the same as that of Example 1, except that in step S31, the number of cycles of 1,6-hexanediamine and pyromellitic dianhydride is adjusted to 100 times, and the thickness of the polyimide layer is adjusted to 15±1nm by controlling the number of cycles.
[0118] Example 11
[0119] The preparation method of Example 11 is basically the same as that of Example 1, except that in step S31, the number of cycles of 1,6-hexanediamine and pyromellitic dianhydride is adjusted to 150 times, and the thickness of the polyimide layer is adjusted to 20±1nm by controlling the number of cycles.
[0120] Example 12
[0121] The preparation method of Example 12 is basically the same as that of Example 1, except that in step S31, the number of cycles of 1,6-hexanediamine and pyromellitic dianhydride is adjusted to 200 times, and the thickness of the polyimide layer is adjusted to 25±1nm by controlling the number of cycles.
[0122] Example 13
[0123] The preparation method of Example 13 is basically the same as that of Example 1, except that in step S31, the number of cycles of 1,6-hexanediamine and pyromellitic dianhydride is adjusted to 250 times, and the thickness of the polyimide layer is adjusted to 35±1nm by controlling the number of cycles.
[0124] Comparative Example 1
[0125] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that step S2 is omitted, i.e., the silicon inhibitor layer is not deposited, and the polymer is deposited directly after the patterned substrate is pretreated.
[0126] Comparative Example 2
[0127] The preparation method of Comparative Example 2 differs from that of Example 1 in that the patterned substrate obtained after pretreatment is immersed in an ethanol solution of 50 mol / L 1-octadecyl mercaptan for 48 h, so that 1-octadecyl mercaptan spontaneously forms a passivation film in the Cu region. The 1-octadecyl mercaptan passivation film is obtained by growth in the immersion liquid environment rather than by deposition.
[0128] Comparative Example 3
[0129] The preparation method of Comparative Example 3 is basically the same as that of Example 1, except that steps S2 and S3 are omitted, that is, the silicon inhibitor layer and polyimide layer are not deposited, and the dielectric film is deposited directly after the patterned substrate is pretreated.
[0130] Performance testing
[0131] The dielectric film, first passivation layer 13, and second passivation layer 14 of each embodiment and comparative example were subjected to performance tests.
[0132] (1) Observe the morphology of dielectric thin films using transmission electron microscopy (TEM);
[0133] (2) X-ray photoelectron spectroscopy (XPS) was used to test the elemental information and chemical state of the dielectric thin film and the outermost surface of the passivated substrate 10;
[0134] (3) The thickness of the dielectric film, the first passivation layer 13 and the second passivation layer 14 is measured by an ellipsometry.
[0135] (4) Water contact angle test: Droplets are dropped onto the substrate 10 and the surface of the obtained dielectric film. The shape image of the droplets is obtained through a microscope and camera. Then, digital image processing and algorithms are used to calculate the contact angle of the droplets in the image.
[0136] (5) X-ray photoelectron spectroscopy (XPS) is used to measure the quantitative information of the component content of the dielectric film, the first passivation layer 13, and the second passivation layer 14, thereby calculating the selectivity of the dielectric film. The selectivity is based on the dielectric film content of the dielectric material region 11 and the metal material region 12 measured by XPS. The specific calculation formula is as follows.
[0137]
[0138] Where, θ GA It is the content of characteristic elements of the dielectric thin film deposited in region 11 of the dielectric material, θ NGA It refers to the content of characteristic elements of dielectric thin films in the metal material region.
[0139] From Example 1, Comparative Example 1 and Figures 3-5 As can be seen, in Example 1, the surface of the SiO2 region is covered with a silicon suppression layer, which prevents the deposition of the polyimide layer in the SiO2 region and promotes the selective deposition of the polyimide polymer in the Cu region. In Comparative Example 1, due to the lack of protection from the silicon suppression layer, a polyimide layer with a thickness of approximately 0.45 nm is deposited on the surface of the SiO2 region, indicating that the passivation of the SiO2 region is incomplete, resulting in the polyimide layer covering the SiO2 region. TEM characterization shows that the Al2O3 film is precisely deposited in the SiO2 region, and the Al2O3 film only partially covers the edge of the TaN region, without... The presence of the selective atomic layer deposition method with sequential double passivation that penetrates beyond the TaN region into the Cu region demonstrates that this application can effectively suppress the lateral expansion of the tantalum nitride dielectric film and has great potential to solve the problems of short circuits and parasitic capacitance in semiconductor devices. XPS confirmed that only Cu characteristic peaks were present on the surface of the Cu region, indicating the absence of Al. However, Al2O3 peaks were detected on the surface of the SiO2 region, indicating that after the deposition of silicon inhibitors, the alumina dielectric film was precisely grown in the SiO2 region, meeting the requirement of zero cross-contamination of heterogeneous substrates in semiconductor devices.
[0140] Examples 1-8 and Figure 6 , Figure 9 It can be seen that the polyimide layer thickness first increases and then decreases with increasing reaction chamber temperature; among them, the polyimide layer thickness in the SiO2 region is the lowest (<2nm) and the dielectric film selectivity is the highest (0.71) at 250℃. This proves that the preferred temperature process parameters should be controlled at 250±5℃. The preferred temperature promotes the stability of the polyimide layer on the Cu region surface and further prevents undesirable deposition of the dielectric film on the SiO2 region surface.
[0141] Comparative Example 3 and Figure 7 It can be seen that Al2O3 dielectric films grow on the surfaces of both SiO2 and Cu regions, and Al2O3 dielectric films do not exhibit selectivity.
[0142] Examples 9-13 and Figure 8 It can be seen that the polyimide layer is only in the Cu region, and the thickness of the polyimide layer increases significantly with the number of cycles in step S3; in contrast, the thickness of the silicon suppression layer hardly changes with the number of cycles in step S2, confirming that the silicon suppression layer protects the SiO2 region from being covered by the polyimide layer.
[0143] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0144] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A selective atomic layer deposition method with sequential dual passivation, characterized in that, Includes the following steps S1-S4: S1. A substrate is provided, the surface of which includes a dielectric material region and a metal material region disposed adjacent to each other; S2. Deposit a first passivation layer on the dielectric material region of the substrate, wherein the material of the first passivation layer includes a silicon inhibitor; S3. Deposit a second passivation layer on the metal material region of the substrate provided with the first passivation layer, the second passivation layer comprising a polymer; the upper surface of the second passivation layer is higher than the upper surface of the first passivation layer; S4. A dielectric material thin film is formed on the surface of the first passivation layer obtained in S3.
2. The selective atomic layer deposition method with sequential dual passivation as described in claim 1, characterized in that, The silicon inhibitors include organosilanes containing amino groups.
3. The selective atomic layer deposition method with sequential dual passivation as described in claim 2, characterized in that, The silicon inhibitor includes at least one of N-(trimethylsilyl)dimethylamine, N,N-diethyl-1,1,1-trimethylsilylamine, triisopropyldimethylaminosilane, 3-aminopropyltrimethylsilane, dimethyl(dimethylamino)silane, and allyl(diisopropylamino)dimethylsilane.
4. The selective atomic layer deposition method with sequential dual passivation as described in claim 1, characterized in that, In step S2, a first passivation layer is deposited on the dielectric material region of the substrate, including the following steps: S21. The silicon inhibitor is introduced into the reaction chamber, where it is selectively adsorbed onto the dielectric material region, thereby forming the first passivation layer. S22. Repeat step S21 until the thickness of the first passivation layer reaches the target value.
5. The selective atomic layer deposition method with sequential dual passivation as described in claim 4, characterized in that, The single-pass injection time of the silicon inhibitor is 0.1s-0.2s, the pressure in the reaction chamber is 30Pa-50Pa, and the temperature in the reaction chamber is 120℃-200℃.
6. The selective atomic layer deposition method with sequential dual passivation as described in any one of claims 1-5, characterized in that, The monomers used to prepare the polymer include a diamine monomer containing two amino groups and a dianhydride monomer containing two acetyl groups.
7. The selective atomic layer deposition method with sequential dual passivation as described in claim 6, characterized in that, The diamine monomer includes at least one of 1,6-hexanediamine, 1,4-cyclohexanediamine, methylcyclohexanediamine, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodicyclohexylmethane. The dianhydride monomer includes at least one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, 4,4'-oxophthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic anhydride, and 4,4'-terephthalic anhydride.
8. The selective atomic layer deposition method with sequential dual passivation as described in claim 7, characterized in that, In step S3, a polymer is deposited on the substrate having the first passivation layer, and the polymer is deposited on the metal material region to form a second passivation layer. The step also includes the following steps: S31. The dianhydride monomer and the diamine monomer are alternately introduced into the reaction chamber, so that the dianhydride monomer and the diamine monomer react in the metal material region to form a second passivation layer. S32. Repeat step S31 until the thickness of the second passivation layer reaches the target value.
9. The selective atomic layer deposition method with sequential dual passivation as described in claim 8, characterized in that, The single-pass time for introducing the diamine monomer and the dianhydride monomer is 4s-6s, the pressure in the reaction chamber is 5Pa-15Pa, and the temperature in the reaction chamber is 200℃-300℃.
10. The selective atomic layer deposition method with sequential dual passivation as described in any one of claims 1-5, characterized in that, The thickness of the first passivation layer is 0.5nm-2.5nm, the thickness of the second passivation layer is 1nm-15nm, the thickness of the first passivation layer is less than the thickness of the second passivation layer, and the height difference between the upper surface of the second passivation layer and the upper surface of the first passivation layer is 1nm-9nm.