Deposition of silicon nitride with enhanced selectivity

Abstract

The use of selective deposition of silicon nitride can eliminate traditional patterning steps by allowing silicon nitride to be deposited only in selected desired areas. Using a silicon iodide precursor alternating with a thermal nitrogen source in ALD or pulsed CVD mode, silicon nitride can be preferentially deposited on surfaces such as silicon nitride, silicon dioxide, germanium oxide, SiCO, SiOF, silicon carbide, silicon oxynitride and low-k substrates, with little to no deposition on exposed surfaces such as titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide and strontium oxide.

Description

Technical Field

[0001] Priority Claim This invention claims the priority of U.S. Provisional Application No. 63 / 289,714, filed on December 15, 2021, which is incorporated herein by reference.

[0002] This invention relates to a method for the selective deposition of silicon nitride on a specific surface of a microelectronic device.

Background Art

[0003] Silicon nitride is commonly used in the fabrication of integrated circuits. For example, it is often used as an insulating material in the manufacture of various microelectronic devices such as memory cells, logic devices, memory arrays, etc. Conventionally, a silicon nitride film is deposited over the entire substrate surface, but the deposition may only be required in specific regions. As a result, additional lithography steps and etching steps are utilized to remove the unwanted regions. As a means to reduce the overall cost of fabrication, it is highly desirable to reduce the number of lithography steps and etching steps involved. Furthermore, when silicon nitride is selectively deposited only where it is needed, lithography errors do not affect the definition of the coating region. Therefore, it would be desirable to achieve such a highly selective silicon nitride deposition.

Summary of the Invention

[0004] The use of selective deposition of silicon nitride can eliminate conventional patterning steps by allowing silicon nitride to be deposited only in selected, desired regions. By using silicon iodide precursors alternately with a thermal nitrogen source in ALD or pulsed CVD mode, silicon nitride can be preferentially deposited on surfaces such as silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF, and low-k substrates, with little to no deposition on other exposed surfaces such as titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, and strontium oxide.

[0005] Furthermore, by both (i) pre-treating these surfaces with ammonia plasma and (ii) periodically directly treating the substrate within the reaction zone with an additional regime of ammonia plasma, selectivity can be maintained throughout the silicon nitride bulk deposition, and the refractive index of the resulting film can also be improved. [Brief explanation of the drawing]

[0006] [Figure 1] (Comparative Example) This is a plot of silicon nitride thickness in angstroms against the number of cycles for a known method in which ammonia plasma is directly applied to a substrate in a reaction zone, followed by the deposition of silicon tetraiodide and ammonia thermal atomic layers. From this plot, it can be observed that initially, this method is selective for deposition on the silicon dioxide surface, but this selectivity begins to decrease after about 100 angstroms (10 nm). [Figure 2]The results achieved by an embodiment of the present invention are shown, in which silicon tetraiodide / ammonia atomic layer deposition (silicon tetraiodide / ammonia ALD) is performed while adding a direct ammonia plasma step after each of the 200 cycles of silicon tetraiodide / ammonia ALD. In other words, in this method, ammonia direct plasma is applied, followed by 200 cycles of silicon tetraiodide / ammonia ALD, followed by another application of ammonia direct plasma, followed by another 200 cycles of silicon tetraiodide / ammonia ALD, and so on. [Figure 3] This demonstrates the associated improvement in the refractive index of deposited silicon nitride using various junctions for reapplying ammonia direct plasma to the substrate within the reaction zone. [Figure 4a] This illustrates the practical challenges faced when selective deposition of silicon nitride is desired. In Figure 4a, the desired result is to deposit silicon nitride within the well while minimizing deposition on the aluminum oxide sidewall, thus resulting in "filling". [Figure 4b] This illustrates another practical challenge faced when selective deposition of silicon nitride is desired. Figure 4b shows the opposite challenge, namely, depositing silicon nitride on the silicon dioxide sidewall without depositing it on the aluminum oxide bottom. [Modes for carrying out the invention]

[0007] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” refer to multiple subjects unless the context clearly indicates otherwise. As used herein and in the appended claims, the term “or” is generally used to mean “and / or” unless the context clearly indicates otherwise.

[0008] The term "approximately" generally refers to a range of numbers that are considered equivalent to (for example, have the same function or result as) a given value. Often, the term "approximately" can include numbers rounded to the nearest significant digit.

[0009] A numerical range expressed using endpoints includes all numbers contained within that range (for example, 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0010] In a first aspect, the present invention relates to a method for depositing silicon nitride on a microelectronic device substrate having a plurality of surfaces of different compositions, a. Under deposition conditions, at a temperature of approximately 150°C to approximately 400°C and a pressure of less than approximately 15 Torre, pulsed silicon tetraiodide or disilicon hexaiodide and a nitrogen-containing co-reactant are brought into contact with the substrate, thereby defining the pulse cycle. Includes, b. The substrate has been (i) pre-treated with ammonia plasma, (ii) The substrate is then periodically further treated with ammonia plasma. Provide a method.

[0011] The present invention provides a method for the selective deposition of silicon nitride layers onto various microelectronic device substrates. Generally speaking, the present invention enables the selective deposition of silicon nitride films on microelectronic device substrates having silicon, silicon oxide, and / or silicon nitride surfaces, over and in the presence of surfaces composed of high-k dielectrics, metals, and metal nitrides. As described above, step b(ii) includes periodic treatment with ammonia plasma. "Periodic" means that no ammonia plasma treatment is performed after each pulse cycle of silicon tetraiodide (SiI4) or disilicon hexaiodide (Si2I6) and nitrogen-containing co-reactants.

[0012] In certain embodiments, the deposition of the present invention is atomic layer deposition (ALD). For the purposes of this specification, ALD is referred to as a chemical deposition mode in which various reactants and co-reactants are separated in space or time so that the substrate is alternatively exposed to one reactant separately from co-reactants. In other embodiments, the deposition of the present invention is spatial ALD in which film growth is achieved by exposing the substrate to locations containing different precursors. In other embodiments, the deposition conditions include pulsed chemical deposition (Pulsed CVD) conditions, in which a first reactant, such as silicon tetraiodide or silicon hexaiodide, is successively introduced into a reaction zone containing a microelectronic device substrate, along with pulsed exposure of the substrate to ammonia, with each pulse set defining a cycle by initial pretreatment of the substrate with ammonia plasma. Further pulses of ammonia plasma are introduced into the reaction zone after a selected number of cycles. In both ALD and pulsed CVD regimes, this periodic introduction of ammonia plasma into the reaction zone occurs after two or more cycles of silicon tetraiodide (or silicon hexaiodide) and ammonia pulses. In certain embodiments, the ammonia plasma is introduced periodically after 3, 5, 10, 50, 100, 150, 200, or 1000 such cycles, or after any such pulse cycle within the range of 3 to 1000 cycles. In other words, the ammonia plasma is introduced at least once after the initial surface treatment and can be introduced multiple times at regular or irregular intervals within the range of 3 to 1000 cycles. As shown in the experimental results below, substrate pretreatment with ammonia plasma resulted in highly selective deposition of silicon nitride, although this selectivity began to dissipate after achieving a silicon nitride film thickness of approximately 10 nm (100 Å). Advantageously, treatment with ammonia plasma after each 200 cycles (in the ALD example herein) significantly improved selectivity.

[0013] In the embodiment of the present invention, the appropriate temperature is about 150°C to about 400°C and the pressure is less than about 15 Torre. In other embodiments, the temperature is about 175°C to about 350°C, or about 200°C to about 250°C. Selective deposition is achieved when the silicon nitride film deposits on a portion of the exposed surface at a somewhat manufacturable rate, while other surfaces receive an amount of silicon nitride that is negligible or easily removed.

[0014] In certain embodiments, one of the microelectronic device surfaces on which silicon nitride deposition is desired (i.e., the "first" surface) includes a silicon nitride surface. In other embodiments, such a first surface is selected from oxides such as silicon dioxide, germanium oxide, SiOC, SiFO, silicon carbide, silicon oxynitride, and low-k substrates. In some embodiments, the dielectric is a porous material. In some embodiments, the porous dielectric includes pores that are connected to each other, while in other embodiments, the pores are not connected to each other. In some embodiments, the dielectric includes a low-k material defined as an insulator having a dielectric value of less than about 4.0. In some embodiments, the dielectric value of the low-k material is less than about 3.5, less than about 3.0, less than about 2.5, or less than about 2.3. In some embodiments, the first surface includes a Si-O bond.

[0015] In certain embodiments, the microelectronic device also has a substrate or surface (i.e., a "second" surface) on which silicon nitride deposition is not desired. In one embodiment, this second surface is aluminum oxide. In other embodiments, this second surface is selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, strontium oxide, and combinations thereof.

[0016] In certain embodiments, the device substrate comprises at least one silicon dioxide surface and at least one aluminum oxide surface, thereby allowing silicon nitride to be selectively deposited on the aluminum oxide surface.

[0017] In certain embodiments, the device substrate comprises at least one silicon dioxide surface and at least one zirconium dioxide surface, wherein silicon nitride is selectively deposited on the at least one zirconium dioxide surface.

[0018] In certain embodiments, the device substrate comprises at least one silicon dioxide surface and at least one aluminum oxide surface, the device surface being pretreated with an ammonia plasma and subsequently periodically treated with the ammonia plasma described herein, thereby selectively depositing silicon nitride on the at least one silicon dioxide surface.

[0019] In certain embodiments, the device substrate comprises at least one silicon dioxide surface and at least one hafnium oxide surface, the device surface being pretreated with an ammonia plasma, thereby selectively depositing silicon nitride on the at least one silicon dioxide surface, and subsequently being periodically treated with the ammonia plasma described herein.

[0020] In certain embodiments, the device substrate comprises at least one silicon dioxide surface and at least one zirconium dioxide surface, the device surface being pretreated with an ammonia plasma, thereby selectively depositing silicon nitride on the at least one silicon dioxide surface, and subsequently being periodically treated with the ammonia plasma described herein.

[0021] In such embodiments, the terms "selectively deposit" or "selectivity" are intended to reflect preferential deposition of silicon nitride on one surface over another. A numerical definition is given by Gladfelter as the difference in coverage between two surfaces normalized to the sum of the coverages of the same two surfaces [Chem. Mater. 5, 1372 (1993)]. In practice, the selectivity of the method generally depends on the film thickness. The present invention enables a selectivity greater than about 89% at a thickness of 97 Å. In other embodiments, preferential deposition of silicon nitride on one surface over another occurs at a rate greater than 99% at a thickness exceeding 190 Å.

[0022] This methodology uses silicon tetraiodide (SiI4) or disilicon hexaiodide (Si2I6) as a "silicon" precursor and utilizes and employs a nitrogen-containing material as a co-reactant or another precursor. The nitrogen-containing material can be organic (e.g., t-butylhydrazine, methylhydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, alkylamine or pyridine) or inorganic (e.g., ammonia or hydrazine). In some embodiments, a mixture of nitrogen-containing materials may be utilized as a precursor for ALD, and in other embodiments, only one nitrogen-containing material may be utilized as a precursor for ALD (e.g., only ammonia, or only t-butylhydrazine). As used herein, the term "nitrogen-containing material" can be utilized to refer to a pure (e.g., completely ammonia or completely t-butylhydrazine) precursor material or a precursor containing the "nitrogen-containing material" as part of a mixture of nitrogen-containing materials. In certain embodiments, materials containing silicon and nitrogen can be formed using the deposition of the present invention. Such materials may contain silicon nitride, consist essentially of it, or consist of it, and / or may have other components.

[0023] In one embodiment, a microelectronic device having surfaces or substrates of different compositions is pretreated with ammonia plasma, and then silicon nitride of about 0.3 to about 5.0 nanometers is selectively deposited on the silicon dioxide surface via nitrogen compounds such as silicon tetraiodide and ammonia by periodically introducing ammonia plasma after a selected number of cycles or pulses. However, deposition is not achieved or limited deposition is achieved on some metal oxide surfaces (e.g., Al2O3, HfO2, and ZrO2).

[0024] In atomic layer deposition, the sequential processing steps are generally referred to as "pulses" or cycles. Thus, the ALD process is based on the controlled self-limiting surface reactions of precursor chemical substances. The present invention can be implemented with just separate pulses of the precursor and co-reactant for a fully saturated reaction or, if more manufacturable. Gas phase reactions are substantially avoided by alternately sequentially contacting the substrate with the precursors. This can be done by moving the substrate from areas of different reactants and co-reactants or by alternating the gas flow over a stationary substrate. In either case, the gas phase reactants are separated from each other both temporally and on the substrate surface, for example, by removing excess reactants and / or reactant by-products from the reaction chamber between reaction pulses. In some embodiments, one or more substrate surfaces are alternately sequentially contacted with two or more gas phase precursors or reactants. Contacting the substrate surface with a gas phase reactant means that the reactant vapor is in contact with the substrate surface for a limited period of time. In other words, it can be understood that the substrate surface is exposed to each gas phase reactant for a limited period of time.

[0025] In short, a substrate including at least a first surface and a second distinct surface is heated to a suitable deposition temperature in the range of 150°C to 400°C at a low pressure, generally less than about 0.5 to 15 Torre. In other embodiments, the temperature is about 175°C to 350°C or 200°C to 250°C. The deposition temperature is generally below the thermal decomposition temperature of the reactants but is maintained at a temperature high enough to avoid condensation of the reactants and provide the activation energy for the desired "selective" surface reaction.

[0026] The surface of the substrate comes into contact with the first reactant in the gas phase. In certain embodiments, pulses of the first reactant in the gas phase are supplied to the reaction space containing the substrate. In other embodiments, the substrate is moved into the reaction space containing the first reactant in the gas phase. The conditions are generally selected so that about one or less single layer of the first reactant is adsorbed self-limitingly onto the substrate surface. A suitable contact time can be readily determined by those skilled in the art based on specific conditions, substrate, and reactor configuration. Excess first reactant and reaction byproducts, if present, are removed from the substrate surface, for example by purging with an inert gas, or by removing the substrate from the presence of the first reactant.

[0027] Purge refers to the removal of gas-phase precursors and / or gas-phase by-products from the substrate surface, for example, by evacuating the chamber with a vacuum pump and / or by replacing the gas in the reactor with an inert gas such as argon or nitrogen. In certain embodiments, the purge time is approximately 0.05 to 20 seconds, approximately 1 to 10 seconds, or approximately 1 to 3 seconds. However, other purge times can be used as needed, such as when highly conformal step coverage is required for structures with very high aspect ratios or other structures with complex surface morphologies.

[0028] The surface of the substrate comes into contact with a second gaseous reactant in the gas phase. In certain embodiments, pulses of the second gaseous reactant are delivered to the reaction space containing the substrate. In other embodiments, the substrate is moved into the reaction space containing the second gaseous reactant in the gas phase. Excess second reactant and gaseous byproducts of the surface reaction, if present, are removed from the substrate surface. The contact and removal steps are repeated until a thin film of the desired thickness is selectively formed on the first surface of the substrate, with each cycle leaving approximately one or fewer molecular monolayers. Additional steps may be included to form more complex materials, such as ternary materials, by sequentially and alternately contacting the surface of the substrate with other reactants.

[0029] Each step in each cycle is generally self-limiting. An excess of reactant precursors is supplied at each step to saturate the susceptible structural surface. Surface saturation ensures reactant occupation of all available reaction sites (which are constrained, for example, by physical size or "steric hindrance"), thus ensuring excellent step coverage. Typically, fewer than one molecular layer of material is deposited in each cycle, but in some embodiments, more than one molecular layer is deposited during the cycle.

[0030] Removing excess reactants may include draining a portion of the contents of the reaction space and / or purging the reaction space with helium, nitrogen, or another inert gas. In certain embodiments, purging may include turning off the flow of reactive gases while continuing to flow an inert carrier gas through the reaction space. In another embodiment, the purging step may use a vacuum step to remove excess reactants from the surface.

[0031] With respect to ammonia plasma, the method may include a direct plasma generation method in which the plasma is generated directly within the reactor, or alternatively, a remote plasma generation method in which the plasma is generated "remotely" from the reaction zone and substrate and supplied into the reactor. In this regard, an energy source such as a radio frequency (RF) source can provide sufficient power to the deposition chamber to ionize the ammonia gas introduced as a pretreatment step and subsequently introduced periodically. In the ammonia plasma treatment step, the applied power is greater than 200 W, and in certain embodiments, greater than about 250 W, greater than about 275 W, greater than about 300 W, greater than about 325 W, or even greater than about 350 W. For example, the applied power may be in the range of about 250 to about 500 W, about 300 to about 475 W, about 350 to about 450 W, or about 375 to about 425 W. During the ammonia plasma treatment step, the applied power may be optionally varied, such as by increasing the power over the treatment period.

[0032] Exemplary flow rates of the ammonia plasma are at least 50 sccm, at least about 100 sccm, at least about 150 sccm, or at least about 175 sccm. In more specific embodiments, the flow rate of the reducing gas is in the range of about 100 to about 400 sccm, about 150 to about 300 sccm, or about 175 to about 275 sccm. The amount of ammonia plasma flowing into the chamber can be optionally expressed in relation to the amount of ammonia plasma relative to the total amount of gas (ammonia plasma and inert gas) flowing into the chamber during the ammonia plasma treatment step. For example, the amount of ammonia plasma may be in the range of about 10% to about 50%, about 15% to about 40%, or about 20% to about 35% of the total amount of gas flowing into the chamber during the ammonia plasma treatment step.

[0033] Reactors that can be used in the method of the present invention include ALD reactors, as well as CVD reactors equipped with suitable apparatus and means for supplying the reactants in a "pulsed" manner. According to certain embodiments, showerhead reactors can be used. Examples of suitable reactors that can be used include commercially available equipment, as well as home-built reactors, which are known to those skilled in the art of CVD and / or ALD.

[0034] As used herein, the term “microelectronic device” refers to semiconductor substrates, including 3D NAND structures, logic devices, DRAM, power devices, flat panel displays, and microelectromechanical systems (MEMS), manufactured for use in microelectronic components, integrated circuits, or computer chip applications. It should be understood that the term “microelectronic device” is not intended to be limiting in any way.

[0035] To the extent that the method of the present invention enables highly selective deposition of silicon nitride, the resulting microelectronic device substrate is thus advantageous by minimizing the amount of silicon nitride deposited on undesirable surfaces. Accordingly, in a further embodiment, the present invention provides a microelectronic device having a plurality of surfaces of different compositions, comprising at least one first surface including at least one surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF and low-k substrates, and one surface including at least one second surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide and strontium oxide.

[0036] In one embodiment, the present invention provides a microelectronic device having a plurality of surfaces of different compositions, comprising at least one first surface including at least one surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF, and a low-k substrate, and one second surface including at least one surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, and strontium oxide, wherein the first surface has a silicon nitride film deposited thereon having a thickness of at least 200 Å, and the second surface has a silicon nitride film deposited thereon having a thickness of about 3 Å or less.

[0037] In another embodiment, the present invention provides a microelectronic device having a plurality of surfaces of different compositions, comprising at least one surface containing silicon dioxide and at least one surface containing aluminum oxide, wherein the silicon dioxide-containing surface has a silicon nitride film deposited thereon having a thickness of at least 200 Å, and the aluminum oxide-containing surface has a silicon nitride film deposited thereon having a thickness of about 3 Å or less.

[0038] The present invention can be further illustrated by the following examples of its particular embodiments, but it will be understood that these examples are included for illustrative purposes only and are not intended to limit the scope of the invention unless otherwise specified. [Examples]

[0039] [Example 1] In this example, silicon nitride was selectively deposited on the first surface of the substrate, onto second, third, and fourth different surfaces of the substrate. The first surface of the substrate contained natural silicon oxide. The second surface of the substrate contained Al2O3 deposited by ALD. The third surface of the substrate contained HfO2 deposited by ALD. The fourth surface of the substrate contained ZrO2 deposited by ALD. Before the deposition of silicon nitride, the substrate was subjected to an ammonia plasma treatment method.

[0040] Silicon nitride films were selectively deposited by an ALD (Advanced Liquid Deposition) method using silicon tetraiodide (SiI4) as the first precursor and ammonia as the second precursor. Silicon tetraiodide was contained in a ProE-Vap ampoule and heated to 100°C. An N2 carrier gas flowed over the surface of solid silicon tetraiodide, carrying silicon tetraiodide vapor into a heated chamber containing the substrate at a temperature of 200°C and a reaction chamber pressure of 1.5 Torre. Each deposition cycle consisted of a 10-second silicon tetraiodide vapor pulse, a 3-second inert N2 purge, a 10-second ammonia pulse, and a 3-second inert N2 purge. Referring to Figure 1, samples were deposited using the ALD method consisting of 100–600 deposition cycles, and the thickness of the material deposited on the first plasma-treated natural silicon oxide surface was measured and compared to the thickness of the material deposited on the second, third, and fourth plasma-treated Al2O3, HfO2, and ZrO2 surfaces. Figure 1 shows that silicon nitride deposition on plasma-treated natural silicon oxide surfaces exhibited significantly higher selectivity (over 95%) compared to plasma-treated Al2O3 surfaces up to 400 cycles. However, plasma-treated HfO2 and ZrO2 surfaces showed the same 95% selectivity only up to 300 cycles.

[0041] [Example 2] In this example, silicon nitride was selectively deposited on the first surface of a substrate, on second, third, and fourth different surfaces of the substrate. The first surface of the substrate contained natural silicon oxide. The second surface of the substrate contained Al2O3 deposited by ALD. The third surface of the substrate contained HfO2 deposited by ALD. The fourth surface of the substrate contained ZrO2 deposited by ALD. Before silicon nitride deposition, the substrate was subjected to an ammonia plasma treatment method. The ammonia plasma treatment method was reapplied to all surfaces of the substrate every 200 deposition cycles. Referring to Figure 2, samples were deposited using the ALD method consisting of 200 to 800 deposition cycles, and the thickness of the material deposited on the first plasma-treated natural silicon oxide surface was measured and compared with the thickness of the material deposited on the second, third, and fourth plasma-treated Al2O3, HfO2, and ZrO2 surfaces. Figure 2 shows that silicon nitride deposition on a plasma-treated natural silicon oxide surface exhibited significantly higher selectivity (over 95%) compared to a plasma-treated Al2O3 surface up to 800 cycles. However, plasma-treated HfO2 and ZrO2 surfaces showed the same 95% selectivity only up to 600 and 400 cycles, respectively. Comparing Figure 1 and Figure 2, reapplying the ammonia plasma treatment method significantly improves the selectivity between natural silicon oxide and all three other surfaces.

[0042] [Example 3] In this example, the refractive index (RI) of silicon nitride deposited using the methods described in Examples 1 and 2 was measured using spectroscopic ellipsometry. The reapplication frequency of different ammonia plasma treatments was varied from every 200 cycles to every 50 cycles. Comparing the RI of the bulk silicon nitride film with that of the film without reapplication, reapplication every 50 cycles significantly improved the RI of the deposited silicon nitride film.

[0043] manner In a first aspect, the present invention relates to a method for depositing a silicon nitride film on a microelectronic device substrate having multiple surfaces of different compositions, a. Under deposition conditions, at a temperature of approximately 150°C to approximately 400°C and a pressure of less than approximately 15 Torre, pulsed silicon tetraiodide or disilicon hexaiodide and a nitrogen-containing co-reactant are brought into contact with the substrate, thereby defining the pulse cycle. Includes, b. The substrate has been (i) pre-treated with ammonia plasma, (ii) The substrate is then periodically further treated with ammonia plasma. Provide a method.

[0044] In a second aspect, the present invention provides a method according to the first aspect, wherein the substrate is further treated with ammonium plasma at least once within a range of every 10 pulse cycles to every 1000 pulse cycles.

[0045] In a third aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 15 pulse cycles.

[0046] In a fourth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 20 pulse cycles.

[0047] In a fifth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 25 pulse cycles.

[0048] In a sixth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 30 pulse cycles.

[0049] In a seventh aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 35 pulse cycles.

[0050] In an eighth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 40 pulse cycles.

[0051] In a ninth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated with ammonia plasma every 45 pulse cycles.

[0052] In a tenth aspect, the present invention provides a method according to the first or second aspect, wherein the substrate is further treated at least once with ammonia plasma in the range of every 50 pulse cycles to every 200 pulse cycles.

[0053] In an eleventh aspect, the present invention provides a method according to any of the first to tenth aspects, wherein silicon nitride is deposited on a surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiFO, and low-k substrates.

[0054] In a twelfth aspect, the present invention provides a method, according to any one of the first to tenth aspects, wherein a silicon nitride film is deposited on a surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiFO and low-k substrates, with about 85 to about 99% selectivity, rather than on a surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, strontium oxide and combinations thereof.

[0055] In a thirteenth aspect, the present invention provides a method according to any one of the first to tenth aspects, wherein the device substrate comprises at least one surface composed of silicon dioxide and at least one surface containing aluminum oxide, and the method provides a silicon nitride film deposited on the silicon dioxide surface, wherein silicon nitride is preferentially deposited on the silicon dioxide with about 99% selectivity, and the silicon nitride film has a thickness of about 200 Å.

[0056] In a fourteenth aspect, the present invention provides a method according to any one of the first to tenth aspects, wherein the device substrate comprises at least one surface composed of silicon dioxide and at least one surface containing aluminum oxide, and the method provides a silicon nitride film deposited on the silicon dioxide surface, wherein silicon nitride is preferentially deposited on the silicon dioxide with about 99% selectivity, and the silicon nitride film has a thickness of at least about 50 Å.

[0057] In a fourteenth aspect, the present invention provides a microelectronic device having a plurality of surfaces of different compositions, comprising at least one first surface including at least one surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF, and a low-k substrate, and one second surface including at least one surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, and strontium oxide, wherein the first surface has a silicon nitride film deposited thereon having a thickness of about 200 Å, and the second surface has a silicon nitride film deposited thereon having a thickness of about 3 Å or less.

[0058] In a 15th aspect, the present invention provides a microelectronic device having a plurality of surfaces of different compositions, comprising at least one surface containing silicon dioxide and at least one surface containing aluminum oxide, wherein the silicon dioxide-containing surface has a silicon nitride film deposited thereon having a thickness of about 200 Å, and the aluminum oxide-containing surface has a silicon nitride film deposited thereon having a thickness of about 3 Å or less.

[0059] Having described several exemplary embodiments of this disclosure, those skilled in the art will readily understand that further embodiments can be created and used within the scope of the appended claims. Many of the advantages of this disclosure, which are covered herein, are described above. However, it will be understood that this disclosure is in many respects only illustrative. The scope of this disclosure is, naturally, defined in the language in which the appended claims are expressed.

Claims

1. A method for depositing a silicon nitride film on a microelectronic device substrate having multiple surfaces of different compositions, a. Under deposition conditions, at a temperature of 150°C to 400°C and a pressure of less than 2000 Pa, pulsed silicon tetraiodide or disilicon hexaiodide and a nitrogen-containing co-reactant are brought into contact with the substrate, thereby defining the pulse cycle. Includes, b. (i) The substrate is pre-treated with ammonia plasma, (ii) The substrate is then periodically further treated with ammonia plasma. method.

2. The method according to claim 1, wherein the substrate is further treated at least once with ammonia plasma within a range of every 50 pulse cycles to every 200 pulse cycles.

3. The method according to claim 1, wherein the silicon nitride film is deposited with a selectivity of more than 85% on a surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF, and low-k substrates, rather than on a surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, strontium oxide, and combinations thereof.

4. The method according to claim 1, wherein the device substrate comprises at least one surface composed of silicon dioxide and at least one surface containing aluminum oxide, and the method involves preferentially depositing silicon nitride on the silicon dioxide with a selectivity of more than 95% in a silicon nitride film deposited on the silicon dioxide surface, and the silicon nitride film has a thickness of at least 50 Å.

5. A microelectronic device having multiple surfaces of different compositions, wherein the microelectronic device comprises at least one first surface including at least one surface selected from silicon nitride, silicon dioxide, germanium oxide, SiCO, SiC, SiON, SiOF, and a low-k substrate, and one second surface including at least one surface selected from titanium nitride, tantalum nitride, aluminum nitride, hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, lanthanum oxide, yttrium oxide, magnesium oxide, calcium oxide, and strontium oxide, wherein a silicon nitride film having a thickness of at least 200 Å is deposited on the first surface, and a silicon nitride film having a thickness of 3 Å or less is deposited on the second surface.

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