Systems and methods for depositing high-density and high-tensile-stress films

Abstract

Exemplary methods for semiconductor processing may include infusing a silicon-containing precursor, a nitrogen-containing precursor, and diatomic hydrogen into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The method may further include forming a plasma containing the silicon-containing precursor, the nitrogen-containing precursor, and diatomic hydrogen. The plasma may be formed at a frequency above 15 MHz. The method may further include depositing a silicon nitride material onto the substrate.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 17 / 009,002, filed September 1, 2020, entitled “Systems and methods for depositing high density and high tensile stress films,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This technology relates to deposition processes and chambers. More specifically, this technology relates to a method for producing high-density and high-tensile-stress films at low temperatures. Background Technology

[0004] Integrated circuits are made possible by processes that create complex patterned material layers on substrate surfaces. Producing patterned materials on substrates requires controlled methods for material formation and removal. Plasma-enhanced deposition can produce films with certain properties that can affect device performance. These properties can be tuned or enhanced by modifying deposition conditions such as the chemical composition and frequency of the plasma.

[0005] Therefore, there is a need for improved systems and methods for producing high-quality devices and structures. This technology addresses these and other needs. Summary of the Invention

[0006] Exemplary methods for semiconductor processing may include infusing a silicon-containing precursor, a nitrogen-containing precursor, and diatomic hydrogen into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The method may further include forming a plasma containing the silicon-containing precursor, the nitrogen-containing precursor, and diatomic hydrogen. The plasma may be formed at a frequency above 15 MHz. The method may further include depositing a silicon nitride material onto the substrate.

[0007] In some embodiments, the silicon nitride material may have a density higher than or approximately 2.85 g / cm³. 3 The density of silicon nitride materials can be characterized by a stress greater than or approximately 400 MPa. Silicon nitride materials can be characterized by a refractive index greater than or approximately 1.75. Silicon nitride materials may contain less than or approximately 10% hydrogen.

[0008] Diatomic hydrogen atoms larger than or approximately 100 sccm can flow into the processing area of ​​a semiconductor processing chamber. Diatomic hydrogen atoms smaller than or approximately 5000 sccm can flow into the processing area of ​​a semiconductor processing chamber.

[0009] Plasma can be formed at temperatures below or around 550°C. The frequency can be above or around 27 MHz.

[0010] Some embodiments may cover a method including infusing a silicon-containing precursor, a nitrogen-containing precursor, and diatomic hydrogen into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The method may further include forming a plasma containing the silicon-containing precursor, the nitrogen-containing precursor, and diatomic hydrogen, wherein the plasma does not contain any material having nitrogen-hydrogen bonds. Furthermore, the method may also include depositing a silicon nitride material onto the substrate. The silicon nitride material may have a density greater than or approximately 2.85 g / cm³. 3 The density can be characterized, and silicon nitride materials can be characterized by stresses of 400 MPa or higher.

[0011] In some embodiments, the silicon nitride material may be characterized by a refractive index greater than or about 1.75. The silicon nitride material may include less than or about 10% hydrogen.

[0012] Diatomic hydrogen atoms larger than or approximately 100 sccm can flow into the processing area of ​​a semiconductor processing chamber. Diatomic hydrogen atoms smaller than or approximately 5000 sccm can flow into the processing area of ​​a semiconductor processing chamber.

[0013] Plasma can be formed at temperatures below or approximately 550°C. Plasma can be formed at frequencies above 15 MHz. The frequency can be higher than or approximately 27 MHz.

[0014] Some embodiments of this technology may cover a method of infusing a silicon-containing precursor, a nitrogen-containing precursor, and diatomic hydrogen into a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region of the semiconductor processing chamber. The method may further include forming a plasma containing the silicon-containing precursor, the nitrogen-containing precursor, and diatomic hydrogen. Furthermore, the method may also include depositing silicon nitride material on the substrate. Diatomic hydrogen at concentrations greater than or approximately 100 sccm may infuse into the processing region of the semiconductor processing chamber, and diatomic hydrogen at concentrations less than or approximately 5000 sccm may infuse into the processing region of the semiconductor processing chamber.

[0015] In some embodiments, the silicon nitride material may have a density higher than or approximately 2.85 g / cm³. 3 Density characterization. Silicon nitride materials can be characterized by stresses higher than or approximately 400 MPa.

[0016] Such techniques offer numerous advantages over conventional systems and techniques. For example, incorporating diatomic hydrogen with silicon- and nitrogen-containing precursors during high-frequency plasma deposition can provide silicon nitride films with improved properties. For instance, both the density and stress of the silicon nitride film can be increased. Furthermore, the amount of hydrogen doping in the silicon nitride film can be reduced. Additionally, silicon nitride films can be formed at low temperatures, thereby reducing the thermal budget and preventing damage to other layers. These and other embodiments, along with their many advantages and features, will be described in more detail below in conjunction with the accompanying drawings. Attached Figure Description

[0017] A further understanding of the nature and advantages of the disclosed technology can be achieved by referring to the remainder of the specification and the accompanying drawings.

[0018] Figure 1 A top plan view of an exemplary processing system according to some embodiments of the present technology is shown.

[0019] Figure 2 A schematic cross-sectional view of an exemplary plasma system according to some embodiments of the present technology is shown.

[0020] Figure 3 The operation of an exemplary method of semiconductor processing according to some embodiments of the present technology is shown.

[0021] Figures 4A-4D Examples illustrating growth mechanisms in some deposition processes.

[0022] Figure 4E-4G Examples illustrating the growth mechanism according to some embodiments of the present technology.

[0023] Figures 5A-5F This section describes various deposition and film parameters as a function of the flow rate of diatomic hydrogen, according to some embodiments of the present technology.

[0024] Several of the accompanying drawings are included as schematic diagrams. It should be understood that the drawings are for illustrative purposes and should not be considered to be to scale unless specifically stated otherwise. Furthermore, as schematic diagrams, the drawings are provided to aid understanding and may not include all aspects or information compared to a realistic representation, and may include exaggerated material for illustrative purposes.

[0025] In the accompanying drawings, similar parts and / or features may have the same reference numerals. Furthermore, various parts of the same type may be distinguished by adding a letter after the reference numeral to differentiate them. If only the first reference numeral is used in the description, the description applies to any of the similar parts having the same first reference numeral, regardless of the letter used. Detailed Implementation

[0026] Plasma-enhanced deposition processes can excite one or more component precursors to promote film formation on a substrate. Any number of material films can be produced to create semiconductor structures, including conductive and dielectric films, as well as films that facilitate material transfer and removal. For example, in memory production such as DRAM, film deposition can be performed to create cell structures. To reduce thermal budgets and prevent damage to already deposited materials, low-temperature deposition processes are desirable. For example, temperatures during film deposition can be less than or about 550°C, less than or about 450°C, or even lower.

[0027] Silicon nitride films can be used as hard molds, where high density, high tensile stress, and high quality can improve the handling of certain structures in production. High-density films may have greater resistance to more etching chemicals and may have higher etch selectivity relative to the material above or below the film to form a variety of patterns. Because silicon nitride films that can typically be formed on wafers are characterized by compressive stress due to the characteristics of the structure and the materials used during formation, silicon nitride films characterized by tensile stress can produce more neutral stress or flatter curvature, which can prevent breakage, delamination, or other processing effects. However, many conventional low-temperature deposition processes have a trade-off between the density and stress of silicon nitride films, making it impossible to achieve both high density and high tensile stress simultaneously. For example, low-temperature physical vapor deposition (PVD) processes can achieve 3 g / cm³. 3 While the density is high, the stress generated by the strong ion bombardment from the sputtering process can be more compressive. Adjusting the stress of the PVD process (such as by changing the precursor distribution or power) can lead to a decrease in density. Furthermore, conventional low-temperature plasma-enhanced chemical vapor deposition (PECVD) processes using SiH4 and NH3 as reactive precursors and typically employing a plasma frequency of 13.56 MHz cannot produce silicon nitride films characterized by both high density and high stress. This is likely at least in part due to the intrafilm hydrogen content of these films exceeding 10%, which can degrade film quality due to porosity formation that may occur during subsequent degassing. Hydrogen doping can also reduce film stress by decreasing the more tetrahedral network formed when hydrogen doping is reduced. Dissociated ammonia can comprise radicals of nitrogen-hydrogen bonds, which may be more likely to be incorporated into the film and could further increase hydrogen doping. Additionally, NH bonds within the deposited film can adversely reduce both density and film stress.

[0028] This technique overcomes these problems by utilizing a high-frequency plasma deposition process formed from a mixture of SiH4, N2, and H2. Some conventional PECVD processes use N2 instead of NH3 as the nitrogen source for forming silicon nitride films. Due to the high electron impact dissociation of N2 (24.3 eV), N2 dissociates weakly in plasma, meaning it may not be completely dissociated in a 13.56 MHz plasma. Therefore, the resulting silicon nitride films tend to have a high hydrogen content because it is difficult to break the bonds between the two nitrogen atoms to form silicon-nitrogen bonds. At higher plasma frequencies, the N2 dissociation process can become more efficient. However, because the silicon-hydrogen bonds in SiH4 cannot be completely removed, the film still has a high hydrogen content. Therefore, this technique increases the frequency to dissociate N2 and can also include H2 gas as a plasma precursor, which advantageously generates a chemical annealing atmosphere that promotes the desorption of nitrogen-hydrogen bonds. As discussed in further detail below, while the goal may be to reduce hydrogen doping in the film, counterintuitively, incorporating H2 gas along with the deposition precursor can reduce the number of nitrogen-hydrogen bonds formed in the silicon nitride film, increase film density, and increase film stress compared to conventional cryogenic deposition techniques. Incorporating H2 gas can also reduce the hydrogen content within the film and improve film quality. When the nitrogen-hydrogen bonds within the film are reduced due to hydrogen doping in the plasma precursor, more volatile hydrogen residues can be extracted from the film and expelled from the processing chamber during deposition.

[0029] While the remainder of this disclosure will conventionally identify specific deposition processes utilizing the disclosed techniques, it will be readily understood that the systems and methods are equally applicable to other deposition and cleaning chambers, and processes that may occur within said chambers. Therefore, this technology should not be considered limited to use with these specific deposition processes or chambers. Before describing additional details of embodiments according to this technology, this disclosure will discuss one possible system and chamber that can be used to perform deposition processes according to embodiments of this technology.

[0030] Figure 1A top plan view of one embodiment of a processing system 100 for deposition, etching, baking, and curing chambers according to an embodiment is shown. In the figure, a pair of front-opening standard chambers 102 provide substrates of various sizes, which are received by a robotic arm 104 and placed into a low-pressure holding region 106, and then placed into one of the substrate processing chambers 108a-f located in series portions 109a-c. A second robotic arm 110 is used to transport substrate wafers from the holding region 106 to and from the substrate processing chambers 108a-f. Each substrate processing chamber 108a-f can be configured to perform a variety of substrate processing operations, including forming stacks of semiconductor materials as described herein, as well as plasma-enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, pre-cleaning, degassing, orientation, and other substrate processes, including annealing, ashing, etc.

[0031] The substrate processing chambers 108a-f may include one or more system components for depositing, annealing, curing, and / or etching dielectric films or other films on the substrate. In one configuration, two pairs of processing chambers (e.g., 108c-d and 108e-f) may be used to deposit dielectric material on the substrate, while a third pair of processing chambers (e.g., 108a-b) may be used to etch the deposited dielectric. In another configuration, all three pairs of processing chambers (e.g., 108a-f) may be configured to deposit a stack of alternating dielectric films on the substrate. Any one or more of the processes described may be performed in chambers separate from the manufacturing systems shown in the different embodiments. It is understood that system 100 takes into account additional configurations for chambers used for the deposition, etching, annealing, and curing of dielectric films.

[0032] Figure 2 A schematic cross-sectional view of an exemplary plasma system 200 according to some embodiments of the present technology is shown. The plasma system 200 may be shown as a pair of processing chambers 108 that can be mounted in one or more of the series portions 109 described above, and according to embodiments of the present technology, the pair of processing chambers 108 may include cover stack members, which will be further explained below. The plasma system 200 generally includes a chamber body 202 having sidewalls 212, a bottom wall 216, and an inner sidewall 201 defining a pair of processing regions 220A and 220B. Each of the processing regions 220A-220B may be similarly configured and may include the same components.

[0033] For example, its components may also be included in processing region 220B within processing region 220A, and may include a base 228 disposed in the processing region via a channel 222 formed in the bottom wall 216 of the plasma system 200. The base 228 may provide a heater suitable for supporting a substrate 229 on an exposed surface (such as a body portion) of the base. The base 228 may include a heating element 232 (e.g., a resistance heating element) that heats and controls the substrate temperature to the desired process temperature. The base 228 may also be heated by a remote heating element, such as a lamp assembly or any other heating device.

[0034] The body of base 228 is coupled to rod 226 via flange 233. Rod 226 electrically couples base 228 to a power outlet or power supply box 203. Power supply box 203 may include a drive system that controls the raising, lowering, and moving of base 228 within processing area 220B. Rod 226 may also include an electrical power interface to provide electrical power to base 228. Power supply box 203 may also include interfaces for electrical power and temperature indicators, such as thermocouple interfaces. Rod 226 may include a base assembly 238 adapted for detachable coupling to power supply box 203. A circumferential ring 235 is shown above power supply box 203. In some embodiments, circumferential ring 235 may be a shoulder adapted as a mechanical stop or ground, configured to provide a mechanical interface between base assembly 238 and upper surface of power supply box 203.

[0035] The rod 230 may be included by a channel 224 formed in the bottom wall 216 of the processing area 220B and may be used to position a substrate lifting rod 261 passing through the main body of the base 228. The substrate lifting rod 261 may selectively separate the substrate 229 from the base to facilitate substrate 229 exchange by a robot that feeds the substrate 229 into and out of the processing area 220B through a substrate transfer port 260.

[0036] A chamber cover 204 may be coupled to a top portion of a chamber body 202. The cover 204 may accommodate one or more precursor distribution systems 208 coupled to it. The precursor distribution system 208 may include a precursor inlet channel 240 that can deliver reactants and cleaning precursors into a processing region 220B via a dual-channel nozzle 218. The dual-channel nozzle 218 may include an annular base plate 248 having a partition plate 244 disposed intermediate to a panel 246. A radio frequency (“RF”) source 265 may be coupled to the dual-channel nozzle 218, providing power to the dual-channel nozzle 218 to facilitate the generation of a plasma region between the panel 246 and the base 228 of the dual-channel nozzle 218. In some embodiments, the RF source may be coupled to other portions of the chamber body 202, such as the base 228, to facilitate plasma generation. A dielectric isolator 258 may be disposed between the cover 204 and the dual-channel nozzle 218 to prevent RF power from being conducted to the cover 204. A shielding ring 206 may be disposed around the base 228 and engage with the base 228. The dual-channel nozzle 218 may have a spacing greater than or approximately 200 mils, greater than or approximately 300 mils, greater than or approximately 400 mils, greater than or approximately 500 mils, greater than or approximately 600 mils, or greater. Alternatively or additionally, the dual-channel nozzle 218 may have a spacing less than or approximately 1200 mils, less than or approximately 1100 mils, less than or approximately 1000 mils, less than or approximately 900 mils, less than or approximately 800 mils, less than or approximately 700 mils, or smaller.

[0037] Optional cooling channels 247 may be formed in the annular base plate 248 of the precursor distribution system 208 to cool the annular base plate 248 during operation. Heat transfer fluids such as water, glycol, or gases may circulate through the cooling channels 247, maintaining the base plate 248 at a predefined temperature. A liner assembly 227 may be disposed within the processing zone 220B, near the sidewalls 201, 212 of the chamber body 202, to prevent the sidewalls 201, 212 from being exposed to the processing environment within the processing zone 220B. The liner assembly 227 may include a circumferential pumping chamber 225, which may be coupled to a pumping system 264 configured to discharge gases and byproducts from the processing zone 220B and control the pressure within the processing zone 220B. Multiple discharge ports 231 may be formed on the liner assembly 227. The discharge port 231 can be configured to allow gas to flow from the treatment area 220B to the circumferential pumping chamber 225 in a manner that promotes treatment within the system 200.

[0038] Figure 3The operation of an exemplary method 300 for semiconductor processing according to some embodiments of the present technology is illustrated. The method can be performed in various processing chambers, including the processing system 200 described above, and any other chamber in which plasma deposition can be performed. Method 300 may include several optional operations that may or may not be specifically associated with some embodiments of the method according to the present technology. Method 300 can be used to deposit a silicon nitride film on a substrate (such as substrate 229).

[0039] Method 300 may include processing methods that may include operations for forming a material film or other deposition operations at high frequencies, such as producing DRAM memory or other materials that can be formed to have higher density and / or higher stress compared to conventional processes. The method may include optional operations prior to initiating method 300, or the method may include additional operations. For example, method 300 may include operations performed before the start of the method, including additional deposition, removal, or processing operations. In some embodiments, method 300 may include, at operation 305, the introduction of a plurality of precursors into a processing chamber, operation 305 delivering the precursors into a processing region of the chamber that can accommodate a substrate, such as region 220. The precursors may be delivered using diatomic hydrogen. Additionally, carrier gases such as argon and / or helium may also be used to deliver the precursors.

[0040] In some embodiments, the precursor may include a silicon-containing precursor (such as silane) and a nitrogen-containing precursor (such as diatomic nitrogen). While any silicon-containing precursor may be used in embodiments of this technology, the use of silane allows for better control of the amount of hydrogen in the processing area and reduces hydrogen incorporation within the deposited film. The precursor may or may not include additional precursors, such as a carrier gas and / or one or more oxygen-containing precursors for depositing the oxide layer. The precursor may also include hydrogen. As discussed further in detail below, including diatomic hydrogen and the precursor can reduce the number of nitrogen-hydrogen bonds formed in the silicon nitride film, increase the film density, and increase the film stress compared to conventional cryogenic deposition techniques. Furthermore, in some embodiments, the processing precursor may explicitly exclude any precursors including nitrogen-hydrogen bonds that, as previously described, may affect film properties. Therefore, in some embodiments, the gas phase material may be free of any nitrogen-hydrogen bonds.

[0041] At operation 310, a plasma of precursors and diatomic hydrogen can be generated within the processing region, such as by providing RF power to the panel to generate plasma within processing region 220, although any other processing chamber capable of generating plasma can be used similarly. The plasma can be generated at any of the frequencies previously described, and can be generated at frequencies greater than or about 15 MHz, greater than or about 20 MHz, greater than or about 27 MHz, greater than or about 40 MHz, or higher. Alternatively or additionally, the plasma can be generated at frequencies lower than or about 100 MHz, lower than or about 80 MHz, lower than or about 60 MHz, or lower. By using plasma at higher frequencies, nitrogen dissociation can be increased, and yield can also be increased due to the increased deposition rate.

[0042] At operation 315, materials formed in the plasma can be deposited onto the substrate, producing silicon and nitrogen-containing materials such as silicon nitride. Deposition can be performed at temperatures less than or approximately 550°C, less than or approximately 500°C, less than or approximately 450°C, less than or approximately 400°C, or lower. By using lower temperatures, the thermal budget of the DRAM memory can be kept within limits, and damage to the material already deposited on the substrate can be prevented. Furthermore, deposition can be performed at powers greater than or approximately 25W, greater than or approximately 250W, greater than or approximately 500W, greater than or approximately 750W, greater than or approximately 1000W, greater than or approximately 1250W, or greater. Using higher power increases the deposition rate, suggesting that nitrogen dissociation may be a limiting factor in the process. However, with increasing plasma power, nitrogen dissociation may further increase, and additional nitrogen radicals can be incorporated into the film, which can reduce the formation of a silicon-nitrogen network, as discussed below. Therefore, in some embodiments, the plasma power may be maintained at or below 3000 W, or below 2500 W, or below 2000 W, or below 1500 W, or below 1250 W, or below 1000 W, or below 900 W, or lower. Additionally, the pressure may be maintained at or above 2 Torr, or above 3 Torr, or above 4 Torr, or above 5 Torr, or higher. Alternatively or additionally, the pressure may be maintained at or below 10 Torr, or below 9 Torr, or below 8 Torr, or below 7 Torr, or below 6 Torr, or lower.

[0043] Figures 4A-4D Examples of growth mechanisms in some deposition processes are illustrated. In this example, low-temperature PECVD is used to deposit silicon nitride films with silane and diatomic nitrogen precursors. Figure 4A As shown, no gas-phase reaction occurs between silane and diatomic nitrogen. Conversely, SiN... x H y Deposition is the deposition of SiH from the growth substratem It begins with the chemisorption of free radicals. For example... Figure 4B As shown, when nitrogen radicals land on the reaction surface of the growth substrate, they combine with silicon atoms and release hydrogen atoms. Due to the low energy of silicon-hydrogen bonds, this occurs at almost all silicon-hydrogen bond sites. However, as... Figure 4C As shown, once a silicon-nitrogen bond forms, the released hydrogen radicals reattach to the unpaired electrons of nitrogen, which limits or prevents the formation of stretched silicon-nitrogen bonds, which increase the stress within the film. Numerous nitrogen-hydrogen and silicon-hydrogen bonds remain in the film, which also reduces the density. Figure 4D As shown, the cumulative vapor pressure of nitrogen atoms, through silicon-nitrogen bonds, causes any SiH atoms reaching the surface to... m Free radicals reach saturation. Due to the low bond energy of silicon-nitrogen bonds, the membrane eventually becomes nitrogen-rich, as increased nitrogen bonds can appear at every site, which can further restrict network formation.

[0044] Figure 4E-4G Examples illustrating growth mechanisms comprising nitrogen and hydrogen precursors according to some embodiments of the present technology are provided. In this example, a silicon nitride film is deposited using low-temperature PECVD by adding diatomic hydrogen to a silane and a diatomic nitrogen precursor. The addition of diatomic hydrogen creates a chemical annealing atmosphere that promotes the desorption of nitrogen-hydrogen bonds. Figure 4E As shown, the addition of diatomic hydrogen gas catalyzes the removal of nitrogen-hydrogen bonds through the presence of free H radicals. This is energy-efficient compared to the silicon-hydrogen bond removal process. Figure 4F As shown, one or more unpaired electrons on the nitrogen atom promote the crosslinking of silicon-nitrogen bonds, thereby increasing tensile stress. (As...) Figure 4G As shown, the membrane has a high density because it has fewer nitrogen-hydrogen voids. In such a compact membrane, nitrogen atoms are less likely to fall onto silicon-hydrogen sites, which results in the membrane having more silicon-hydrogen bonds and being silicon-rich.

[0045] Figures 5A-5FVarious deposition and film parameters, as a function of the flow rate of diatomic hydrogen, are described according to some embodiments of the present technology. In this example, a 27 MHz plasma is formed in a PECVD chamber at a temperature of 450 °C. The flow rate of diatomic hydrogen can be greater than or about 100 sccm, greater than or about 1000 sccm, greater than or about 2000 sccm, greater than or about 3000 sccm, greater than or about 4000 sccm, or greater. However, as the hydrogen flow rate continues to increase, as will be explained below, although nitrogen-hydrogen bonding may be limited, which may stabilize the density, the increase in available hydrogen may affect formation and may increase the generation of silicon-silicon bonding within the film, which may reduce film stress. Therefore, in some embodiments, the flow rate of diatomic hydrogen may be less than or about 5000 sccm and may remain less than or about 4000 sccm, less than or about 3000 sccm, less than or about 2000 sccm, or less, depending on the target internal stress within the film. The flow rate of diatomic hydrogen can be adjusted to achieve various deposition and film properties, as discussed in further detail below.

[0046] like Figure 5A As shown, the film deposition rate increases as a function of the diatomic hydrogen flow rate. Furthermore, for each flow rate, the first deposition rate 505 of the film deposited at the higher power of 1250 W is greater than the second deposition rate 510 of the film deposited at the lower power of 750 W. In this example, the deposition rate can be greater than or approximately [missing information]. / minute, greater than or approximately / minute, greater than or approximately / minute, greater than or approximately / minute, greater than or approximately / minute, greater than or approximately / minute, greater than or approximately / minute, or more.

[0047] like Figure 5B As shown, the membrane stress exhibits peak values ​​that vary with power. For example, the first stress 515 of a membrane deposited at a higher power of 1250 W has a higher peak flow rate than the second stress 520 of a membrane deposited at a lower power of 750 W. This is because the higher power generates more nitrogen radicals, which are incorporated into the membrane during the deposition process. Furthermore, the peak value of the first stress 515 of the membrane deposited at the higher power may be lower than the peak value of the second stress 520 of the membrane deposited at the lower power. In this example, the stress can be greater than or approximately 300 MPa, greater than or approximately 400 MPa, greater than or approximately 500 MPa, greater than or approximately 600 MPa, greater than or approximately 700 MPa, greater than or approximately 800 MPa, greater than or approximately 900 MPa, or greater.

[0048] like Figure 5C As shown, the membrane density exhibits a distribution that varies with power. For example, the first density 525 of the membrane deposited at a higher power of 1250 W increases as a function of flow rate before leveling off. On the other hand, the second density 530 of the membrane deposited at a lower power of 750 W increases more rapidly as a function of flow rate, reaching a peak, and then gradually decreases. In this example, the density can be greater than or approximately 2.50 g / cm³. 3 Greater than or approximately 2.55 g / cm³ 3 Greater than or approximately 2.60 g / cm³ 3 Greater than or approximately 2.65 g / cm³ 3 Greater than or approximately 2.70 g / cm³ 3 Greater than or approximately 2.75 g / cm³ 3 Greater than or approximately 2.80 g / cm³ 3 Greater than or approximately 2.85 g / cm³ 3 Greater than or approximately 2.90 g / cm³ 3 Or even larger.

[0049] like Figure 5D As shown, the refractive index of the film increases as a function of the diatomic hydrogen flow rate. This indicates that a lower nitrogen-hydrogen bond density results in a more Si-rich film, which may lead to an increase in refractive index. Furthermore, for each flow rate, the first refractive index 605 of the film deposited at the higher power of 1250 W is lower than the second refractive index 610 of the film deposited at the lower power of 750 W. In this example, the refractive index can be greater than or approximately 1.75, greater than or approximately 1.80, greater than or approximately 1.85, greater than or approximately 1.90, greater than or approximately 1.95, greater than or approximately 2.00, greater than or approximately 2.05, greater than or approximately 2.10, greater than or approximately 2.15, greater than or approximately 2.20, or greater.

[0050] like Figure 5E As shown, the ratio of silicon-hydrogen bond density to silicon-nitrogen bond density increases as a function of the diatomic hydrogen flow rate. Furthermore, for each flow rate, the first ratio 535 of silicon-hydrogen bond density to silicon-nitrogen bond density of the film deposited at the higher power of 1250 W is lower than the second ratio 540 of silicon-hydrogen bond density to silicon-nitrogen bond density of the film deposited at the lower power of 750 W. In this example, the ratio of silicon-hydrogen bond density to silicon-nitrogen bond density can be greater than or about 0.0%, greater than or about 0.4%, greater than or about 0.8%, greater than or about 1.2%, or greater.

[0051] like Figure 5FAs shown, the ratio of nitrogen-hydrogen bond density to silicon-nitrogen bond density decreases as a function of the diatomic hydrogen flow rate. Furthermore, for each flow rate, the first ratio 555 of the nitrogen-hydrogen bond density to silicon-nitrogen bond density of the film deposited at the higher power of 1250 W is lower than the second ratio 560 of the nitrogen-hydrogen bond density to silicon-nitrogen bond density of the film deposited at the lower power of 750 W. In this example, the ratio of nitrogen-hydrogen bond density to silicon-nitrogen bond density may be less than or approximately 25%, less than or approximately 20%, less than or approximately 15%, less than or approximately 10%, less than or approximately 5%, or lower.

[0052] like Figure 5E and Figure 5F As shown, when a small amount of diatomic hydrogen is added, the nitrogen-hydrogen bond density decreases sharply, while the silicon-hydrogen bond density increases moderately. This increases both the density and stress of the film. The lower nitrogen-hydrogen bond density results in a more silicon-rich film, which can be achieved through… Figure 5D This is demonstrated by the corresponding increase in refractive index shown in the diagram. Furthermore, as... Figure 5B and Figure 5C As shown, both the first density 525 and the second density 530 reach saturation levels generally above a certain flow rate level, where the certain flow rate level corresponds to... Figure 5F The nitrogen-hydrogen bond density is sufficiently reduced, while the first stress 515 and the second stress become more compressible above this flow rate level. In this region, the silicon-silicon bonds effectively release tensile stress.

[0053] As discussed above, SiH4 can be used as a silicon precursor. The flow rate of the silane can be greater than or about 10 sccm, greater than or about 100 sccm, greater than or about 200 sccm, greater than or about 300 sccm, greater than or about 400 sccm, or greater. Alternatively or additionally, the flow rate of the silane can be less than or about 1000 sccm, less than or about 900 sccm, less than or about 800 sccm, less than or about 700 sccm, or less. Furthermore, as discussed above, N2 can be used as a nitrogen precursor. The flow rate of N2 can be greater than or about 1000 sccm, greater than or about 2000 sccm, greater than or about 3000 sccm, greater than or about 4000 sccm, greater than or about 5000 sccm, or greater. Alternatively or additionally, the flow rate of N2 may be less than or about 10,000 sccm, less than or about 9,000 sccm, less than or about 8,000 sccm, less than or about 7,000 sccm, or even less.

[0054] Some of the methods discussed above can be used for deposition processes without using NH3 as a precursor and may explicitly exclude ammonia. In other examples, NH3 can be used as a nitrogen precursor. The flow rate of NH3 can be greater than or about 1000 sccm, greater than or about 2000 sccm, greater than or about 3000 sccm, greater than or about 4000 sccm, greater than or about 5000 sccm, or greater. Alternatively or additionally, the flow rate of NH3 can be less than or about 10,000 sccm, less than or about 9000 sccm, less than or about 8000 sccm, less than or about 7000 sccm, or less.

[0055] In addition, as discussed above, carrier gases such as argon and / or helium can be used to transport the precursor. The flow rate of argon can be greater than or about 0 sccm, greater than or about 1000 sccm, greater than or about 2000 sccm, greater than or about 3000 sccm, greater than or about 4000 sccm, or greater. Alternatively or additionally, the flow rate of argon can be less than or about 10,000 sccm, less than or about 9000 sccm, less than or about 8000 sccm, less than or about 7000 sccm, or less. Similarly, the flow rate of helium can be greater than or about 0 sccm, greater than or about 1000 sccm, greater than or about 2000 sccm, greater than or about 3000 sccm, greater than or about 4000 sccm, or greater. Alternatively or additionally, the flow rate of helium may be less than or about 10,000 sccm, less than or about 9,000 sccm, less than or about 8,000 sccm, less than or about 7,000 sccm, or even less.

[0056] The methods described above can also be used to reduce the amount of hydrogen formed in silicon nitride films. Conventional low-temperature PECVD processes typically produce films with hydrogen doping levels exceeding 10%, which can degrade film quality due to subsequent porosity formation. In contrast, the methods described above can include diatomic hydrogen with silicon-containing and nitrogen-containing precursors, which can counterintuitively reduce the amount of hydrogen in the film to below or approximately 10%, below or approximately 9%, below or approximately 8%, below or approximately 7%, or even lower. This can improve film quality and facilitate subsequent removal with nitride-specific etchants.

[0057] In the foregoing description, numerous details have been set forth for illustrative purposes to provide an understanding of various embodiments of the present technology. However, it will be apparent to those skilled in the art that certain embodiments may be implemented without some of these details or with additional details.

[0058] Several embodiments have been disclosed, and those skilled in the art will recognize that various modifications, alternative structures, and equivalents can be used without departing from the spirit of the embodiments. Furthermore, numerous well-known processes and elements have not been described in order to avoid unnecessarily obscuring the scope of the art. Therefore, the above description should not be construed as limiting the scope of the art.

[0059] Where a range of values ​​is provided, it should be understood that, unless the context expressly specifies otherwise, the smallest fraction of each intermediate value between the upper and lower limits of this range, up to the lower limit unit, is also specifically disclosed. Any smaller range between any stated or unstated intermediate value within the stated range and any other stated or intermediate value within this stated range is included. The upper and lower limits of these smaller ranges may be independently included or excluded from the range, and each range in which any one, neither, or both of the limit values ​​are included is also included in this technique, subject to any specifically excluded limit value in the stated range. Where the stated range includes one or both of the limit values, the range excluding any or both of these included limit values ​​is also included.

[0060] Unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” used herein and in the appended claims include plural references. Thus, for example, “a material” may refer to a plurality of such materials, while “the precursor” may refer to one or more precursors and their equivalents known to those skilled in the art, and so on.

[0061] Furthermore, when used in this specification and the appended claims, the terms “comprise(s)”, “comprising”, “contain(s)”, “containing”, “include(s)”, and “including” are intended to indicate the presence of the stated feature, integer, component, or operation, but do not exclude the presence or addition of one or more other features, integers, components, operations, behaviors, or groups.

Claims

1. A method comprising: Multiple precursors are introduced into the processing region of a semiconductor processing chamber, wherein the multiple precursors include SiH4 precursor, N2 precursor and diatomic hydrogen, wherein a substrate is housed in the processing region of the semiconductor processing chamber. A plasma is formed to form the SiH4 precursor, the N2 precursor, and the diatomic hydrogen, wherein the plasma is formed at a frequency of 15 MHz or higher; and Silicon nitride material is deposited on the substrate. The ratio of silicon-hydrogen bond density to silicon-nitrogen bond density increases as a function of the flow rate of the diatomic hydrogen, and the ratio of nitrogen-hydrogen bond density to silicon-nitrogen bond density decreases as a function of the flow rate of the diatomic hydrogen.

2. The method of claim 1, wherein the silicon nitride material has a content of 2.85 g / cm³ or higher. 3 Density characterization.

3. The method of claim 1, wherein the silicon nitride material is characterized by a stress of 400 MPa or higher.

4. The method of claim 1, wherein the silicon nitride material is characterized by a refractive index greater than or equal to 1.

75.

5. The method of claim 1, wherein the silicon nitride material comprises less than or equal to 10% hydrogen.

6. The method of claim 1, wherein a diatomic hydrogen mass of 100 sccm or greater flows into the processing region of the semiconductor processing chamber.

7. The method of claim 6, wherein less than or equal to 5000 sccm of the diatomic hydrogen flows into the processing region of the semiconductor processing chamber.

8. The method of claim 1, wherein the plasma is formed at a temperature of 550°C or lower.

9. The method of claim 1, wherein the frequency is greater than or equal to 27 MHz.

10. A method comprising: Multiple precursors are introduced into the processing region of a semiconductor processing chamber, wherein the multiple precursors include SiH4 precursor, N2 precursor and diatomic hydrogen, wherein a substrate is housed in the processing region of the semiconductor processing chamber. A plasma is formed containing the SiH4 precursor, the N2 precursor, and the diatomic hydrogen. as well as Silicon nitride material is deposited on the substrate, wherein: The silicon nitride material has a density of 2.85 g / cm³ or higher. 3 Density characterization, The silicon nitride material is characterized by a stress of 400 MPa or higher. The plasma is formed at frequencies above 15 MHz. The ratio of silicon-hydrogen bond density to silicon-nitrogen bond density increases as a function of the flow rate of the diatomic hydrogen atoms, and The ratio of nitrogen-hydrogen bond density to silicon-nitrogen bond density decreases as a function of the flow rate of the diatomic hydrogen.

11. The method of claim 10, wherein the silicon nitride material is characterized by a refractive index greater than or equal to 1.

75.

12. The method of claim 10, wherein the silicon nitride material comprises less than or equal to 10% hydrogen.

13. The method of claim 10, wherein a diatomic hydrogen mass of 100 sccm or greater flows into the processing region of the semiconductor processing chamber.

14. The method of claim 13, wherein less than or equal to 5000 sccm of the diatomic hydrogen flows into the processing region of the semiconductor processing chamber.

15. The method of claim 10, wherein the plasma is formed at a temperature of 550°C or lower.

16. The method of claim 10, wherein the frequency is greater than or equal to 27 MHz.

17. A method comprising: Multiple precursors are introduced into the processing region of a semiconductor processing chamber, wherein the multiple precursors include SiH4 precursor, N2 precursor and diatomic hydrogen, wherein a substrate is housed in the processing region of the semiconductor processing chamber. Plasma containing the SiH4 precursor, the N2 precursor, and the diatomic hydrogen is formed at frequencies above 15 MHz; as well as Silicon nitride material is deposited on the substrate, wherein: A concentration of diatomic hydrogen of 100 sccm or greater flows into the processing region of the semiconductor processing chamber. The diatomic hydrogen atoms, at concentrations less than or equal to 5000 sccm, flow into the processing region of the semiconductor processing chamber. The ratio of silicon-hydrogen bond density to silicon-nitrogen bond density increases as a function of the flow rate of the diatomic hydrogen atoms, and The ratio of nitrogen-hydrogen bond density to silicon-nitrogen bond density decreases as a function of the flow rate of the diatomic hydrogen.

18. The method of claim 17, wherein the silicon nitride material has a content of 2.85 g / cm³ or higher. 3 Density characterization.

19. The method of claim 17, wherein the silicon nitride material is characterized by a stress of 400 MPa or higher.

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