Precursors and methods for making silicon-containing films

Abstract

Provided herein are certain liquid silicon precursors useful for depositing silicon-containing films, such as films comprising silicon, silicon nitride, silicon oxynitride, silicon dioxide, silicon carbide, carbon-doped silicon nitride, or carbon-doped silicon oxynitride. Also provided are methods of forming such films using vapor deposition techniques.

Description

Technical Field

[0001] Generally, the present invention relates to methods and precursors for depositing silicon-containing films on the surface of microelectronic devices. Background Technology

[0002] In semiconductor manufacturing, chemically inert dielectric materials (e.g., silicon nitride (Si3N4), silicon oxynitride (SiO2)) are used. x N y Thin (e.g., <1000 nm thick) passivation layers of silicon carbide (SiC), silicon carbide (SiCN), silicon carbon oxide (SiCO), and / or silicon dioxide (SiO2) are widely used in microelectronic device structures to serve as structural elements of multilayer devices, such as sidewall spacer elements, diffusion masks, oxide barriers, trench isolation coatings, intermetallic dielectric materials, passivation layers, insulators, and etch stop layers.

[0003] Depositing silicon-containing films via chemical vapor deposition (CVD) is a highly attractive method for forming such films. A particular need arises for CVD processes involving low deposition temperatures (e.g., below approximately 550°C), but this requires the availability of suitable silicon precursor compounds for this purpose. In some cases, higher deposition temperatures may be considered when the thermal budget of the integrated circuit allows. In these cases, temperatures >450°C can be utilized to achieve the desired properties of the dielectric film, specifically where a high-quality silicon dioxide film is required. In cases where extremely high-quality films are required and a high thermal budget is permissible, a high-temperature stable source material is preferred because it enables saturated ALD pulses, thereby providing uniform stepped coverage on high aspect ratio structures.

[0004] Silicon nitride (SiN) has been used as source and drain spacers (S / D spacers) in FinFETs and gate all-around (GAA) structures due to its high wet etch and O2 ashing resistance. Unfortunately, SiN has a high dielectric constant (k) of approximately 7.5. Carbon and nitrogen-doped SiO2 (SiCON) spacers have been developed to reduce the dielectric constant and maintain excellent wet etch and ashing resistance during post-deposition processing. Currently, the best wet etch and ashing resistant SiCON dielectrics have a k value of approximately 4.0. Dielectrics with wet etch and ashing resistance less than 3.5 are required for next-generation devices.

[0005] Furthermore, in the manufacture of microelectronic devices, specifically in processes utilizing low-temperature vapor deposition (LCD) to form silicon nitride, silicon dioxide, and silicon oxynitride films, the industry still requires improved organosilicon precursors and methods for forming silicon-containing films. Specifically, the industry needs liquid silicon precursors that exhibit good thermal stability, high volatility, and reactivity with substrate surfaces during storage and vapor transport. Summary of the Invention

[0006] The present invention generally relates to the formation of silicon-containing films in the manufacture of semiconductor devices, and more specifically to compositions and methods for forming said silicon-containing films (e.g., films comprising silicon, silicon nitride, silicon oxynitride, silicon dioxide, silicon carbide, carbon-doped silicon nitride, or carbon-doped silicon oxynitride) at relatively low temperatures in certain cases.

[0007] Compounds of formula (I) as illustrated herein can be used as precursor compounds in the formation of the various silicon-containing films. Advantageously, the precursors of the present invention can be used to form high-quality nitride films under low-temperature vapor deposition conditions, while also being able to be used to form high-quality and high-growth-rate silica films at relatively high temperatures. This versatility thus demonstrates the flexibility of the precursors of formula (I). In one embodiment, compounds of formula (I) (e.g., bis(dimethylsilyl)dimethylhydrazine) can also provide a higher deposition rate of silica films compared to conventional silicon precursors. Similarly, compounds of formula (I) can be used to prepare silicon nitride films at higher growth rates. (See below) Figure 5 SiN and SiCN films are deposited under similar conditions in the presence of N2 and NH3 co-reactants. Vapor deposition conditions and processes can utilize these precursor compounds to form silicon-containing films, including processes such as chemical vapor deposition (CVD), atomic layer deposition (ALD), plasma-enhanced ALD (PEALD), plasma-enhanced cyclic chemical vapor deposition (PECCVD), flowable chemical vapor deposition (FCVD), plasma-enhanced ALD-like processes, or ALD processes utilizing oxygen-containing reactants, nitrogen-containing reactants, or combinations thereof. Attached Figure Description

[0008] Figure 1 It uses bis(dimethylsilyl)dimethylhydrazine (hereinafter formula (I), wherein each R 1 The plot shows the per-cycle SiO2 growth rate (in angstroms) versus pulse time (in seconds) for methyl groups and ozone as oxidizing co-reactant gases at three temperatures: 500 °C, 550 °C, and 600 °C. For substrate temperatures <600 °C, ALD saturation profiles were observed, indicating saturated ALD behavior at lower temperatures. At 550 °C, [further details are needed]. High SiO2 growth rate.

[0009] Figure 2 It is for passing Figure 1 A graph (depth profile) showing the atomic percentage of a pure SiO2 film deposited using a similar process described in the figure, measured by X-ray photoelectron spectroscopy (XPS), as a function of etching time (in seconds). No N or C was observed after removing the environmental protection layer of the film. The relative Si:O content reflects the composition of the SiO2 film.

[0010] Figure 3 The diagram illustrates the application of a SiN / SiO2 / Si trench structure with an 18:1 aspect ratio. Figure 1 The deposition of SiO2 films with >92% conformal step coverage is achieved by the precursor chemistry and process described herein.

[0011] Figure 4 This compares the wet etching rates of films deposited from bis(dimethylsilyl)dimethylhydrazine (BDMSDMH) and films deposited from bis(tert-butylamino)silane (BTBAS) at various substrate temperatures. Wet etching was performed using a 200:1 HF aqueous solution. In this case, the wet etching rate of the film deposited from the bis(dimethylsilyl)dimethylhydrazine precursor represents an improvement of approximately >60% compared to the film deposited from BTBAS. The wet etching rate is also compared to the wet etching rate of thermal oxides (SiO2).

[0012] Figure 5 The diagram illustrates the growth rate per cycle as a function of silicon pulse duration under N2 plasma exposure for a silicon nitride deposition process using bis(dimethylsilyl)dimethylhydrazine as a precursor at 250 °C and a nitrogen flow rate of 300 sccm at a plasma power of 200 watts, with N2 plasma exposure. The cycle sequence used is (i) precursor, where the pulse length is plotted on the x-axis, (ii) 20-second purge, (iii) 15-second (square) or 20-second (circular) nitrogen plasma, followed by (iv) 20-second purge.

[0013] Figure 6 Diagram illustrating when... Figure 5 The similar reactors and plasma deposition conditions shown use bis(dimethylsilyl)dimethylhydrazine as a precursor with different pulse times, the effect of nitrogen plasma power (200 watts or 300 watts) on the growth rate per cycle, and the plasma exposure time is 15 seconds. Detailed Implementation

[0014] Unless the context clearly indicates otherwise, as used in this specification and the appended claims, the singular forms “a, an” and “the” include a plural of indicators. Unless the context clearly indicates otherwise, as used in this specification and the appended claims, the term “or” is generally used in its meaning as including “and / or”.

[0015] The term "approximately" typically refers to a range of numbers that are considered equivalent to the listed values ​​(e.g., having the same function or result). In many cases, the term "approximately" may include a numerical value rounded to the nearest significant figure.

[0016] Numerical ranges expressed using endpoints include all numerical values ​​belonging to the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0017] In a first aspect, the present invention provides compounds of formula (I):

[0018]

[0019] Each R 1 The atoms are independently selected from hydrogen, C1-C4 alkyl groups, or halogen atoms selected from Cl, Br, and I. In one embodiment, each R 1 It is a methyl group.

[0020] Compounds of formula (I) can be used as precursors for depositing silicon-containing films on the surface of microelectronic devices. In some embodiments, the films also contain nitrogen and / or oxygen and / or carbon.

[0021] Therefore, in a second aspect, the present invention provides a method for depositing a silicon-containing film on the surface of a microelectronic device, comprising introducing at least one compound of formula (I) into the surface in a reaction chamber under vapor deposition conditions.

[0022] Compound (I) can be prepared according to the following reaction scheme:

[0023] Step 1:

[0024]

[0025] In step 1, chlorosilane reacts with dimethylhydrazine to provide a silane-based hydrazine intermediate and a hydrazine hydrochloride byproduct.

[0026] Step 2:

[0027]

[0028] As shown in step 2 above, hydrazide dimethylsilane (or some other hydrazide (R) 1 2-Silanes can react with n-butyllithium or some other reactive alkali metal C1-C6 alkanes that optionally contain a nitrogen atom. Other potential reactants include methyllithium, tert-butyllithium, diisopropylaminolithium, methylpotassium, n-butylpotassium, etc., to obtain novel intermediates (II) as described below:

[0029]

[0030] Each R 1 The halogen atom is independently selected from hydrogen, C1-C4 alkyl, or halogen atoms selected from Cl, Br, and I, and wherein R 2The compound is selected from lithium or potassium, which can then be used in the synthesis of the compound of formula (I). The compound of formula (II) is then reacted with, for example, dichloromethylsilane in this embodiment. Therefore, in a third aspect of the invention, the compound of formula (II) as described above is provided.

[0031] In a fourth aspect of the invention, a process for preparing the compound of formula (I) is thus provided:

[0032]

[0033] Each R 1 The process comprises the following steps: The atom is independently selected from hydrogen, C1-C4 alkyl groups, or halogen atoms selected from Cl, Br, and I.

[0034] A. Make the following compound

[0035]

[0036] With MR 3 The compound contacts, where M is lithium or potassium and R 3 It is optionally a C1-C6 alkyl group containing a nitrogen atom to provide a compound of formula (II):

[0037]

[0038] Each R 1 The halogen atom is independently selected from hydrogen, C1-C4 alkyl, or halogen atoms selected from Cl, Br, and I, and wherein R 2 Selected from lithium or potassium; subsequently

[0039] B. React the compound of formula (II) with the compound of the following formula.

[0040] Where X is a halogen.

[0041] As used herein, the term "silicon-containing film" refers to films such as silicon dioxide, silicon nitride, silicon oxynitride, silicon carbide, silicon carbonitride, silicon oxycarbonitride, low-k thin silicon-containing films, etc.

[0042] In some embodiments, the vapor deposition conditions include reaction conditions referred to as chemical vapor deposition, pulsed chemical vapor deposition, and atomic layer deposition. In the case of pulsed chemical vapor deposition, a series of alternating pulses of precursor compounds and co-reactants can be used, with or without an intermediate (inert gas) purging step, to accumulate the film thickness to the desired endpoint.

[0043] The compound of formula (I) enables the formation of silicon-containing films by low-temperature CVD and / or ALD. The compound exhibits high volatility and chemical reactivity, but is stable with respect to thermal degradation at the temperatures involved in precursor volatilization or evaporation, which allows the resulting precursor vapor to be consistently and repeatedly delivered to the deposition zone or reaction chamber.

[0044] In some embodiments, the pulse duration of the precursor compound described above (i.e., the duration of the precursor exposure to the substrate) is in the range of about 0.1 to 30 seconds. In other embodiments, the pulse duration of the co-reactant is in the range of about 0.1 to about 30 seconds.

[0045] In one embodiment, the vapor deposition conditions include a temperature of about 50°C to about 750°C. In another embodiment, the vapor deposition conditions include a temperature of about 200°C to about 650°C. In yet another embodiment, the vapor deposition includes a temperature of about 500°C to 550°C.

[0046] In one embodiment, the vapor pressure conditions comprise a pressure of about 0.5 to about 1000 Torr.

[0047] The above compounds can be used to form high-purity thin silicon-containing films using any suitable vapor deposition technique (e.g., CVD, digital (pulsed) CVD, ALD, and pulsed plasma deposition (PEALD)). The aforementioned vapor deposition process can be used to form silicon-containing films on microelectronic devices at deposition temperatures of approximately 250°C to approximately 550°C, to form films with thicknesses of approximately 20 angstroms to approximately 2000 angstroms.

[0048] In the process of this invention, the above-mentioned compounds can be reacted with the desired microelectronic device substrate in any suitable manner, such as in a single-wafer CVD, ALD and / or PECVD or PEALD chamber or in a furnace containing multiple wafers.

[0049] Alternatively, the process of the present invention may be implemented as an ALD or similar ALD process. As used herein, the term “ALD or similar ALD” refers to a process such as: (i) sequentially introducing each reactant comprising a silicon precursor compound of formula (I) and an oxidizing and / or reducing gas into a reactor such as a single-wafer ALD reactor, a semi-batch ALD reactor, or a batch furnace ALD reactor; or (ii) sequentially exposing each reactant comprising a silicon precursor compound of formula (I) and an oxidizing and / or reducing gas to a substrate or microelectronic device surface by moving or rotating a substrate to different sections of the reactor, and each section being separated by an inert gas curtain, i.e., a space ALD reactor or a roll-to-roll ALD reactor.

[0050] In one aspect, the present invention relates to a plasma-enhanced atomic layer deposition (PEALD) process, which uses a precursor of formula (I) described herein, together with hydrogen plasma or nitrogen plasma, to deposit a film having a low wet etch rate. Nitrogen plasma can be used together with the precursor compound of formula (I) to form the silicon nitride film used.

[0051] Therefore, in another embodiment, the above-described vapor deposition process may further include a step involving exposing the membrane to a reducing gas. In some embodiments of the invention, the reducing gas comprises a gas selected from H2, hydrazine (N2H4), methylhydrazine, tert-butylhydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, alkylamine, pyridine, and NH3.

[0052] In another embodiment, the vapor deposition process may further include a step involving exposing the precursor to an oxidizing gas (e.g., O2, O3, N2O, water vapor, alcohol, or oxygen plasma) to form a silicon dioxide film. In this embodiment, R... 1 In cases where the oxidizing agent is halogenated, oxidants such as water and alcohols can be used with bases such as pyridine, alkylamines, N,N'-dimethylformamide, and ammonia. In some embodiments, the oxidizing gas further comprises an inert gas, such as argon, helium, nitrogen, or combinations thereof. In another embodiment, the oxidizing gas further comprises nitrogen, nitrous oxide, or ammonia, which can react with the precursor of formula (I) under plasma conditions to form a silicon oxynitride film.

[0053] Generally, the desired membrane produced using the precursor compound of formula (I) can be customized by selecting each compound and reaction conditions, as well as utilizing the reduction or oxidation co-reactant. See, for example, scheme 1 below:

[0054]

[0055] In bis(dimethylsilyl)dimethylhydrazine (formula (I), when each R 1 In the case where the methyl group is present, the resulting SiO2 film exhibits [symbols] at 450°C. It exhibits a high growth rate and extremely rapid surface saturation in oxygen plasma processes.

[0056] In one embodiment, an oxidizing gas (e.g., ozone (O3)) is used in the vapor deposition process to provide a rapidly grown silica film. In one embodiment, the temperature is about 500°C to 600°C. In the case of the ozone process, a concentration of 1.9 to about [missing value] is observed. The growth rate was improved. Furthermore, the wet etching rate of the resulting SiO2 film was superior to that of the comparison film using BTBAS (bis(tert-butylamino)silane) as a silicon precursor.

[0057] In the case of silicon dioxide films, exemplary pulse mechanisms include the following:

[0058] (i) The precursor for injection (I) lasts from 0.1 to 30 seconds, followed by

[0059] (ii) Purge with inert gas for 1 to 30 seconds, then

[0060] (iii) Inject ozone at a flow rate of 50 to 500 sccm (standard cubic centimeters per minute) for approximately 0.1 to 30 seconds, then...

[0061] (iv) Purge with inert gas for 1 to 30 seconds (one cycle). Therefore, steps (i) to (iv) can be repeated until a film of the desired thickness is obtained.

[0062] Therefore, in another embodiment, the present invention provides a method for preparing a silicon dioxide film, wherein the vapor deposition conditions include a temperature of about 150°C to about 650°C and a pulse sequence comprising the following steps:

[0063] (i) The precursor for injection (I) lasts from 0.1 to 30 seconds, followed by

[0064] (ii) Purge with inert gas for 1 to 30 seconds, then

[0065] (iii) Inject ozone at a flow rate of 50 to 500 sccm for approximately 0.1 to 30 seconds, followed by

[0066] (iv) Purge with inert gas for 1 to 30 seconds and repeat steps (i) to (iv) until a film of the desired thickness is obtained.

[0067] In one embodiment, a nitrogen plasma is used in a vapor deposition process to provide a silicon nitride film. In one embodiment, the temperature is about 200°C to 300°C. In the case of bis(dimethylsilyl)dimethylhydrazine, silicon nitride is provided using a nitrogen plasma of N2 with a power of 200 watts to 300 watts and a flow rate of 100 to 300 sccm.

[0068] In the case of silicon nitride films, exemplary pulse mechanisms include the following:

[0069] (i) The precursor for injection (I) lasts from 0.1 to 30 seconds, followed by

[0070] (ii) Purge with inert gas for 1 to 30 seconds, then

[0071] (iii) Nitrogen plasma is injected using N2 at a flow rate of 50 to 500 sccm and a power of approximately 50 watts to 1000 watts for 0.1 to 30 seconds, followed by

[0072] (iv) After plasma exposure, purge with an inert gas for 1 to 30 seconds (one cycle). Steps (i) to (iv) can be repeated until a film of the desired thickness is obtained.

[0073] Therefore, in another embodiment, in the preparation of the silicon nitride film, the vapor deposition conditions include a temperature of about 150°C to about 300°C, a pressure of about 0.1 to about 5 Torr, and a pulse sequence comprising the following steps:

[0074] (i) The precursor for injection (I) lasts from 0.1 to 30 seconds, followed by

[0075] (ii) Purge with inert gas for 1 to 30 seconds, then

[0076] (iii) Nitrogen plasma was injected using N2 at a flow rate of 50 to 500 sccm and a power of approximately 50 to 500 watts for 0.1 to 30 seconds, followed by

[0077] (iv) After plasma exposure, purge with an inert gas for 1 to 30 seconds and repeat steps (i) to (iv) until a film of the desired thickness is obtained.

[0078] When using precursor compounds of formula (I), the incorporation of carbon and nitrogen into the membrane is a natural consequence of the compound's composition, and process conditions can be adjusted to favor the incorporation or exclusion of these elements. Alternatively, if carbon incorporation is desired, carbon in the form of methane, ethane, ethylene, or acetylene can be used, for example, to further introduce carbon into the silicon-containing membrane, thereby producing silicon carbide, silicon carbonitride, or silicon carbide.

[0079] The deposition methods disclosed herein may involve one or more purge gases. The purge gas used to purge unconsumed reactants and / or reaction byproducts is an inert gas that does not react with the precursors. Exemplary purge gases include (but are not limited to) argon, nitrogen, helium, neon, hydrogen, and mixtures thereof. In some embodiments, a purge gas (e.g., Ar) is supplied to the reactor at a flow rate in the range of about 10 to about 2000 sccm for about 0.1 to 1000 seconds, thereby purging unreacted material and any byproducts that may remain in the reactor. Note that the gas (e.g., nitrogen) is inert and acts as a purge gas when not activated by plasma, but becomes a co-reactant when activated by plasma.

[0080] The corresponding steps of supplying silicon precursor compounds, oxidizing gases, reducing gases and / or other precursors, source gases and / or reagents can be implemented by changing the sequence of their supply and / or changing the stoichiometric composition of the resulting dielectric film.

[0081] Energy is supplied to at least one of the silicon precursor compound of formula (I) and an oxidizing gas, a reducing gas, or a combination thereof to induce a reaction and form a silicon-containing film on a microelectronic device substrate. The energy can be provided by, but is not limited to, thermal energy, pulsed thermal energy, plasma, pulsed plasma, helical wave plasma, high-density plasma, inductively coupled plasma, X-rays, electron beams, photons, remote plasma methods, and combinations thereof. In some embodiments, a secondary RF frequency source can be used to modify the plasma characteristics at the substrate surface. In other embodiments, a DC bias can be maintained between the plasma and the substrate. In embodiments where plasma deposition is involved, the plasma generation process can include a direct plasma generation process in which plasma is generated directly in a reactor, or a remote plasma generation process in which plasma is generated “remotely” in the reaction zone and the substrate and supplied to the reactor.

[0082] As used herein, the term "microelectronic device" refers to semiconductor substrates (including 3D NAND structures), flat panel displays, and microelectromechanical systems (MEMS) manufactured for microelectronic, integrated circuit, or computer chip applications. It should be understood that the term "microelectronic device" is not intended to limit or include in any way any substrate containing negative-channel metal-oxide-semiconductor (nMOS) and / or positive-channel metal-oxide-semiconductor (pMOS) transistors that will ultimately become a microelectronic device or microelectronic assembly. The microelectronic device comprises at least one substrate, which may be selected from, for example, silicon, SiO2, Si3N4, OSG, FSG, silicon carbide, hydrogenated silicon carbide, silicon nitride, hydrogenated silicon nitride, silicon carbonitride, hydrogenated silicon carbonitride, boron nitride, antireflective coating, photoresist, germanium, germanium-containing, boron-containing, Ga / As, flexible substrates, and porous inorganic materials, metals (e.g., copper, aluminum, cobalt, tungsten, molybdenum, ruthenium, and iridium), and diffusion barrier layers (e.g., but not limited to TiN, Ti(C)N, TaN, Ta(C)N, Ta, WN, WC, MoC, or MoN). The film is compatible with various subsequent processing steps (e.g., chemical mechanical planarization (CMP) and anisotropic etching processes).

[0083] The present invention can be further illustrated by the following examples of certain embodiments thereof, but it should be understood that, unless otherwise specifically indicated, these examples are included for illustrative purposes only and are not intended to limit the scope of the invention.

[0084] Example

[0085] Example 1 – Synthesis of dimethylhydrazine-dimethylsilane

[0086] A solution of dichlorodimethylsilane (70 g, 0.74 mol) in n-pentane (70 g, 0.97 mol) was added dropwise to an ice-cold solution of N,N'-dimethylhydrazine (88.93 g, 1.48 mol) in n-pentane (350 g, 4.85 mol) and stirred below -10 °C. After the addition of the dichlorodimethylsilane solution, the reaction mixture was stirred at room temperature for 5 hours. The resulting white slurry was filtered and washed with n-pentane (125 g). After removal of volatiles, the crude product was purified by simple distillation at 240 Torr at 50 °C to obtain the title compound (62.50 g, 71.4%) as a colorless liquid.

[0087] Example 2 – Synthesis of bis(dimethylsilyl)dimethylhydrazine

[0088] A solution of n-butyllithium in n-hexane (203 mL, 2.5 mol) was added dropwise to a solution of dimethylhydrazine-dimethylsilane (60 g, 0.507 mol) in n-hexane (210 g, 2.44 mol) at -20 °C. After adding the n-butyllithium solution, the reaction mixture was stirred at room temperature for 2 hours and then cooled to -10 °C. A solution of dichlorodimethylsilane in n-hexane was added dropwise to this reaction mixture, followed by stirring at room temperature for 5 hours. The resulting white slurry was filtered and washed with n-hexane (90 g). After removing volatiles, the crude product was purified by simple distillation at 80 °C and 80 Torr to obtain a final product as a colorless liquid (78.71 g, 63.5%).

[0089] Example 3 – Deposition of Silica Film

[0090] Silica films were deposited using bis(dimethylsilyl)dimethylhydrazine vapor as a silicon precursor. Bis(dimethylsilyl)dimethylhydrazine was placed in a bubbler at room temperature. A silicon oxide film was deposited on a silicon wafer using an ozone co-reactant at a wafer temperature of 500 to 600 °C in a dual-shower ALD reactor. The reactor pressure was controlled between 0.5 and 1.5 Torr. The silica film was formed using the following pulse sequence: 28 seconds of silicon precursor pulse, 20 seconds of Ar purge, 25 seconds of ozone pulse, and 20 seconds of Ar purge. This sequence was repeated 160 cycles to obtain the desired result. The film thickness. The deposition rate at 550°C is approximately... The membrane was saturated and free of carbon and chlorine impurities. This was obtained using a 0.2% HF dilution solution. The wet etching rate of the film.

[0091] Example 4 – Deposition of Silicon Nitride Films

[0092] Silicon nitride films were deposited using bis(dimethylsilyl)dimethylhydrazine as the silicon source precursor material. The BDMSDMH bubbler was maintained at room temperature (approximately 23°C), and the reactor pressure was controlled between 0.5 and 1.5 Torr. The silicon nitride films were formed using the following pulse sequence: 28 seconds of silicon precursor pulse, 20 seconds of Ar purging, 15 or 20 seconds of direct nitrogen plasma at 200 or 300 W pulsed at a frequency of 13.56 MHz, and 20 seconds of Ar purging. This sequence was repeated 170 cycles to obtain the desired silicon nitride film. The film thickness. This process takes approximately [amount] at 300°C. The membrane is saturated and free of carbon and chlorine impurities.

[0093] The present invention has been described in detail with particular reference to certain embodiments thereof, but it should be understood that various changes and modifications may be made within the spirit and scope of the invention.

[0094] Therefore, having described several illustrative embodiments of this disclosure, those skilled in the art will readily understand that other embodiments can be made and used within the scope of the appended claims. Many advantages of this disclosure have been set forth in the foregoing description. However, it should be understood that this disclosure is illustrative in many respects only. Changes may be made in detail, specifically in the shape, size, and arrangement of the parts, without departing from the scope of this disclosure. The scope of this disclosure is, of course, defined by the language expressed in the appended claims.

Claims

1. A compound of formula (I), (I)， Each R 1 Independently, it is a C1-C4 alkyl group, and The compound mentioned is not .

2. The compound according to claim 1, wherein each R 1 It is an ethyl group.

3. A method for preparing a compound of formula (I), (I)， Each R 1 Independently, they are C1-C4 alkyl groups, and the compounds described therein are not... The method includes the following steps: A. Make the following compound ， With MR 3 The compound contacts, where M is lithium or potassium and R 3 It is optionally a C1-C6 alkyl group containing a nitrogen atom to provide a compound of formula (II): (II), Each R 1 Independently, it is a C1-C4 alkyl group, and wherein R 2 Selected from lithium or potassium; subsequently B. React the compound of formula (II) with the compound of the following formula. , where X is a halogen.

4. A compound of formula (II), (II), Each R 1 It is independently a C4 alkyl or ethyl, and wherein R 2 Selected from lithium or potassium.

5. The compound according to claim 4, wherein R 2 It is lithium.

6. The compound according to claim 4, wherein R 2 It's potassium.

7. A method for depositing a silicon-containing film on the surface of a microelectronic device, comprising guiding at least one compound of formula (I) into the surface in a reaction chamber under vapor deposition conditions. (I)， Each R 1 Independently, they are C1-C4 alkyl groups, and the compounds described therein are not... .

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