Multilayer Deposition and Treatment of Silicon Nitride Film

Abstract

An exemplary processing method may include forming a first deposition plasma of a precursor containing silicon and nitrogen. The method may include depositing a first portion of a silicon nitride material on a semiconductor substrate using the first deposition plasma. A first processing plasma of a precursor containing helium and nitrogen may be formed, and the first portion of the silicon nitride material may be processed using the first processing plasma. A second deposition plasma may deposit a second portion of the silicon nitride material, and the second processing plasma may process the second portion of the silicon nitride material. The helium-to-nitrogen flow ratio of the first processing plasma may be less than the He / N2 flow ratio of the second processing plasma. A first power level from a plasma power source forming the first processing plasma may be lower than a second power level forming the second processing plasma.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims the priority of U.S. Patent Application No. 16 / 935,423, entitled "MULTI - LAYER DEPOSITION AND TREATMENT OF SILICON NITRIDE FILMS", filed on July 22, 2020, and the entire disclosure thereof is incorporated herein by reference in its entirety.

[0002] Technical Field

[0002] This technology relates to semiconductor processing. Specifically, this technology relates to a method for forming and treating a material including a silicon nitride film.

Background Art

[0003]

[0003] Integrated circuits can be fabricated by a process that creates a complexly patterned material layer on a substrate surface. To create a patterned material on the substrate, a controlled method of forming and removing the exposed material is required. As device miniaturization and complexity progress, material formation can affect subsequent processes. For example, in a barrier layer formation process, a material can be formed or deposited to form a barrier layer in a trench or other feature formed on a semiconductor substrate. Such barrier formation processes can be difficult because the features can be characterized by reduced critical dimensions, lower thermal budgets, higher sensitivity to contaminants, and higher sensitivity to stress. For example, the processing of the deposited barrier layer may require high-temperature thermal annealing that exceeds the thermal budget of the devices formed on or within the semiconductor substrate. In an additional example, the deposited barrier layer may require high-power plasma processing that generates voids and particles in and around the features formed in the semiconductor substrate. Thermal annealing, plasma processing, and other types of plasma processing can also change the spatial dimensions of the material during deposition, thereby stressing adjacent substrate features. On the other hand, insufficient processing of the material during deposition can result in a moisture-permeable barrier layer with low hermeticity. This can affect the performance of the device and subsequent processing steps.

[0004]

[0004] Accordingly, there is a need for improved systems and methods that can be used to create high-quality devices and structures. These needs and other needs are addressed by the present technology.

Summary of the Invention

[0005]

[0005] Using this technology, a barrier film having high airtightness and mechanical strength can be formed while avoiding unnecessary voids, particles, and high stress generated by conventional barrier film formation methods. This technology includes exemplary processing methods for depositing and treating continuous portions of a barrier material such as a silicon nitride material to form a barrier film. An early portion of the barrier material can be treated with a processing plasma having higher energy formed from a processing gas mixture having a higher flow rate ratio of helium to nitrogen gas than a later portion of the barrier material. The early treatment rich in helium having higher energy produces a treated portion of the barrier material having higher density and airtightness than subsequent treated portions of the barrier material. When the barrier material includes silicon nitride, the early treated portion also has more Si-N bonds and fewer Si-H bonds compared to an equal portion of the silicon nitride barrier material to be treated later.

[0006]

[0006] An exemplary processing method of this technology produces a barrier film constructed from continuously deposited and treated portions of a barrier material. The early deposited and treated portions of the barrier material in the barrier film have higher density, airtightness, and stress than the later deposited and treated portions. This gives high airtightness to the barrier film near the interface with the semiconductor substrate, and the reduction of the overall stress generated by the barrier film can affect the surrounding substrate and substrate features. For example, subsequent layers deposited with the opposite type of stress (e.g., a subsequent layer deposited using tensile stress to balance a lower layer having compressive stress) can neutralize the overall stress. In some embodiments, the later deposited portion of the barrier material can be deposited larger (e.g., thicker) and more rapidly than the early portion of the barrier material to shorten the overall production time for completing the barrier film. In further embodiments, the later deposited and larger portion can fill the openings (e.g., pinholes) of the early deposited portion. The lower energy and lower helium to nitrogen flow rate ratio used during the processing steps of such later deposited portions of the barrier material minimize the generation of voids and particles in such portions.

[0007]

[0007] An exemplary processing method includes forming a barrier film containing silicon nitride. Such a processing method can include a number of deposition and processing cycles, each including a deposition step and a processing step for forming a processed portion of the silicon nitride barrier material. The deposition step can include forming a deposition plasma of one or more deposition precursors including a silicon-containing precursor and a nitrogen-containing precursor. In some cases, the silicon-containing precursor and the nitrogen-containing precursor are the same precursor (e.g., an aminosilane precursor). In additional cases, the silicon-containing precursor and the nitrogen-containing precursor are different precursors that are mixed (e.g., silane and ammonia). The method may further include depositing a portion of the silicon nitride barrier material on a semiconductor substrate using the plasma emissions of the one or more deposition precursors.

[0008]

[0008] The processing step following each deposition step can include forming a processing plasma of a processing mixed gas including helium gas and nitrogen gas. The processing plasma can be formed by exciting (i.e., generating plasma) the processing mixed gas using a plasma output source set to a certain output level. An early portion of the deposited silicon nitride material can be processed with a processing plasma formed with a processing mixed gas having a higher helium-to-nitrogen flow rate that is excited by a plasma output source set to a higher output level than the portion of the silicon nitride material that is subsequently deposited and processed.

[0009]

[0009] After a plurality of deposition and processing cycles are performed, a barrier film containing silicon nitride can be completed. The number of deposition and processing cycles performed to complete the barrier film can include, among other ranges, at least 2 cycles, at least 3 cycles, at least 4 cycles, at least 5 cycles, at least 10 cycles, at least 20 cycles, at least 30 cycles, at least 40 cycles, at least 50 cycles, at least 60 cycles, at least 70 cycles, at least 80 cycles, at least 90 cycles, or at least 100 cycles.

[0010]

[0010] Such a technique can bring about a number of advantages over conventional systems and techniques. For example, by implementing the processing steps according to embodiments of the present technology, the formation of voids and particles caused by the formation of the barrier layer can be restricted or controlled. These embodiments and other embodiments will be described in more detail below in conjunction with the following description and the accompanying drawings, along with many of their advantages and features.

Brief Description of the Drawings

[0011]

[0011] The nature and advantages of the disclosed technology can be further understood by referring to the remainder of this specification and the drawings.

[0012]

Figure 1

[0012] FIG. is a top view of an exemplary processing system according to some embodiments of the present technology.

Figure 2

[0013] FIG. is a schematic cross-sectional view of an exemplary processing chamber according to some embodiments of the present technology.

Figure 3

[0014] FIG. shows exemplary steps in a processing method according to some embodiments of the present technology.

Figure 4

[0015] FIG. shows exemplary steps in a processing method according to additional embodiments of the present technology.

Figure 5

[0016] A and B are schematic cross-sectional views of a substrate during processing according to some embodiments of the present technology.

[0013]

[0017] Some of the drawings are included as schematic diagrams. It should be understood that the drawings are for illustrative purposes only and should not be considered to be to scale unless expressly stated to be so. Further, as schematic diagrams, the drawings are provided to aid understanding and may not include all aspects or information compared to a realistic depiction, and may include materials emphasized for illustrative purposes.

[0014]

[0018] In the accompanying drawings, similar components and / or features may have the same reference numerals. Further, various components of the same type can be distinguished according to the reference numerals by letters that distinguish between similar components. When only a first reference numeral is used herein, the description is applicable to any one of the similar components having the same first reference numeral, regardless of the letters.

DETAILED DESCRIPTION OF THE INVENTION

[0015]

[0019] The present technology includes a method and a system for forming a barrier film on a semiconductor substrate. Embodiments of this method and system include a method and a system for forming a barrier film containing silicon nitride on a semiconductor substrate. The silicon nitride-containing material includes cases where it is used as a barrier material, such as a charge trap material, an encapsulation material, a dielectric barrier material, and an etch stop material, among other functions, in the manufacture of semiconductor devices, and can be used in many structures and processes. Such a silicon nitride barrier film can be permanently or temporarily incorporated into semiconductor device structures including, among other types of semiconductor devices, dynamic random access memory (DRAM) devices, static random access memory (SRAM) devices, and phase change random access memory (PRAM) devices.

[0016]

[0020] Conventional processing methods for forming a silicon nitride barrier film utilize low-temperature, plasma-enhanced chemical vapor deposition (PECVD) to form a silicon nitride barrier material (e.g., SiNH) with a high hydrogen content that aids in the formation of a conformal layer on a semiconductor substrate that may have one or more features. The silicon nitride material initially formed on the semiconductor substrate is then processed to remove a portion of the hydrogen and form a barrier film with improved hermeticity. The processing steps include high-temperature thermal annealing and high-energy plasma treatment, both of which form processing defects in the semiconductor device structure being formed. Such defects include thermal breakdown of the material and structure when the high-temperature annealing exceeds the heat budget of semiconductor device formation. Also included in the defects are the formation of voids, particles, and high stress when many Si-H bonds in the silicon nitride material during deposition are rapidly broken by the high-energy plasma treatment. These defects and other defects occur regularly in conventional processing methods for forming a silicon nitride barrier film with high hermeticity in a single deposition and processing cycle. Defects are also seen in conventional processing methods that deposit and process continuous layers of the silicon nitride barrier film under relatively constant processing conditions between cycles. As feature sizes are scaled down and substrate features become more complex, defects resulting from conventional processing methods for forming a silicon nitride barrier film are increasing the failure rate of devices.

[0017]

[0021] The present technology includes a processing method and system for reducing or eliminating these defects by forming a silicon nitride barrier film on two or more parts having decreasing airtightness. In some embodiments, the first portion of the deposited and processed barrier film is characterized by high airtightness, and at least the second portion is characterized by lower airtightness than that. However, as the plasma output increases and the helium concentration rises, the generation of bubbles due to the treatment can increase. In further embodiments, the silicon nitride barrier film formed on the substrate is characterized in that the portion of the film closest to the substrate has the highest airtightness, and the portion of the film farthest from the substrate has the lowest airtightness. This seems to be related, at least in part, to the lower processing power and the reduced helium in the processing precursor. In still further embodiments, the silicon nitride barrier film can be characterized by an airtightness gradient from the highest airtightness where the film is closest to the substrate to the lowest airtightness where the film is farthest from the substrate.

[0018]

[0022] Embodiments of the present technology include depositing and processing successive portions of a silicon nitride-containing material to form a silicon nitride layer (e.g., a SiN barrier film) having two or more levels of decreasing hermeticity. In some embodiments, successive portions of the silicon nitride-containing material may also be characterized by reducing the number of voids created by the formation of hydrogen and / or helium bubbles during deposition and processing. Successive portions of the silicon nitride-containing material may be deposited and processed using a different set of processing conditions between portions. These processing conditions may include, among other processing conditions, the helium-to-nitrogen flow rate ratio of the processing gas mixture forming the processing plasma, the output level used to form the processing plasma, and the deposition rate of the deposited portion of the silicon nitride-containing material. Embodiments of the present technology include processing an initial portion of the deposited silicon nitride-containing material at a higher plasma output and a higher helium-to-nitrogen flow rate ratio to remove more hydrogen and increase the hermeticity of the material. Thereafter, the deposited portion of the silicon nitride-containing material is processed at a lower plasma output and a lower helium-to-nitrogen flow rate ratio to reduce the formation of voids due to dissociated hydrogen and helium in the material being processed. These subsequent processes may leave a higher hydrogen content that reduces the hermeticity of the material. After describing a general aspect of a chamber according to some embodiments of the present technology in which the plasma processing steps described below may be implemented, a specific methodology will be described. The present technology is not intended to be limited to the specific membranes, chambers, or processes described, and it should be understood that the techniques described can be used to improve a number of barrier film formation processes and can be applied to various processing chambers and processes.

[0019]

[0023] FIG. 1 is a top view of one embodiment of a processing system 100 of a deposition chamber, an etching chamber, a baking chamber, and a curing chamber according to an embodiment. In the figure, a pair of front-opening unified pods (FOUPs) 102 are received by a robot arm 104 and supply substrates of various sizes disposed in a low-pressure holding area 106, and the substrates are then positioned in one of the substrate processing chambers 108a-f located in the tandem section 109a-c. A second robot arm 110 can be used to transfer substrate wafers from the holding area 106 to and from the substrate processing chambers 108a-f. Each of the substrate processing chambers 108a-f can be equipped to perform many substrate processing steps including the formation of stacks of semiconductor materials described herein, in addition to other substrate processes including plasma enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, pre-cleaning, degassing, orientation, and annealing, ashing, etc.

[0020]

[0024] The substrate processing chambers 108a-f can include one or more system components for depositing, annealing, curing, densifying, and / or etching a dielectric film, a barrier film, or other film on a substrate. In one configuration, two pairs of processing chambers, for example, 108c-d and 108e-f, can be used to deposit material on a substrate, and a third pair of processing chambers, for example, 108a-b, can be used to etch the deposited dielectric. In another configuration, all three pairs of chambers, for example 108a-f, can be configured to deposit a stack of alternating films (e.g., dielectric films, barrier films, etc.) on a substrate. Any one or more of the processes described may be performed in a chamber separated from the manufacturing system shown in different embodiments. It will be understood that additional configurations of deposition, etching, annealing, curing, and densifying chambers for dielectric films are contemplated by the system 100.

[0021]

[0025] FIG. 2 is a schematic cross-sectional view of an exemplary plasma system 200 according to some embodiments of the present technology. The plasma system 200 illustrates a pair of processing chambers 108 that can be mounted on one or more of the tandem units 109 described above, and may include components or assemblies specifically configured to perform processes according to embodiments of the present technology. The plasma system 200 generally may include a chamber body 202 having sidewalls 212, a bottom wall 216, and internal sidewalls 201 that define a pair of processing regions 220A and 220B. Each of the processing regions 220A-220B can be similarly configured and may include the same components.

[0022]

[0026] For example, the processing region 220B, whose components may also be included in the processing region 220A, may include a pedestal 228 disposed within the processing region through a passage 222 formed in the bottom wall 216 of the plasma system 200. The pedestal 228 can provide a heater adapted to support a substrate 229 on an exposed surface of the pedestal, such as a body portion. The pedestal 228 can include a heating element 232, such as a resistive heating element, and can heat and control the substrate temperature to a desired process temperature. The pedestal 228 may be heated by a remote heating element, such as a lamp assembly or any other heating device.

[0023]

[0027] The body of the pedestal 228 can be connected to the stem 226 by a flange 233. The stem 226 can electrically connect the pedestal 228 to a power outlet or a power box 203. The power box 203 can include a drive system that controls the raising and movement of the pedestal 228 within the processing area 220B. The stem 226 can also include a power interface that provides power to the pedestal 228. The power box 203 can also include interfaces for power meters and thermometers, such as a thermocouple interface. The stem 226 may include a base assembly 238 adapted to be removably connected to the power box 203. A peripheral ring 235 is shown above the power box 203. In some embodiments, the peripheral ring 235 can be a shoulder adapted as a mechanical stop or land configured to provide a mechanical interface between the base assembly 238 and the upper surface of the power box 203.

[0024]

[0028] The rod 230 can be included through a passage 224 formed in the bottom wall 216 of the processing area 220B and can be used to position a substrate lift pin 261 disposed through the body of the pedestal 228. The substrate lift pin 261 can selectively space the substrate 229 from the pedestal to facilitate the exchange of the substrate 229 using a robot utilized to convey substrates into and out of the processing area 220B through a substrate transfer port 260.

[0025]

[0029] The chamber lid 204 can be connected to the upper part of the chamber body 202. The lid 204 can house one or more precursor distribution systems 208 connected thereto. The precursor distribution system 208 may include a precursor inlet passage 240 capable of delivering reactants and cleaning precursors to the processing region 220B through the gas delivery assembly 218. The gas delivery assembly 218 may include a gas box 248 having a shielding plate 244 disposed intermediate to the faceplate 246. A radio frequency (“RF”) source 265 can be connected to the gas delivery assembly 218, which can supply power to the gas delivery assembly 218 to facilitate generating a plasma region between the faceplate 246 of the gas delivery assembly 218 and the pedestal 228, which can be a processing region of the chamber. In some embodiments, the RF source may be connected to other parts of the chamber body 202, such as the pedestal 228, to facilitate plasma generation. A dielectric isolator 258 may be disposed between the lid 204 and the gas delivery assembly 218 to prevent RF power from being transmitted to the lid 204. The shadow ring 206 can be disposed at the outer edge of the pedestal 228 that engages the pedestal 228.

[0026]

[0030] To cool the gas box 248 in the process, optional cooling channels 247 may be formed in the gas box 248 of the gas distribution system 208. A heat transfer fluid such as water, ethylene glycol, or gas may circulate through the cooling channels 247 so that the gas box 248 can be maintained at a predetermined temperature. To prevent the exposure of the side walls 201, 212 to the processing environment within the processing region 220B, a liner assembly 227 may be disposed within the processing region 220B proximate to the side walls 201, 212 of the chamber body 202. The liner assembly 227 may include a circumferential pumping cavity 225 that can be connected to a pumping system 264 configured to discharge gas and by-products from the processing region 220B and to control the pressure within the processing region 220B. A plurality of exhaust ports 231 may be formed in the liner assembly 227. The exhaust ports 231 may be configured such that gas can flow from the processing region 220B to the circumferential pumping cavity 225 in a manner that facilitates processing within the system 200.

[0027]

[0031] Figure 3 shows exemplary steps in a processing method 300 according to some embodiments of the present technology. This method can be implemented in various processing chambers including the plasma system 200 described above. Method 300 may include one or more steps including front-end processing, deposition, etching, polishing, cleaning, or any other optional steps that may be performed prior to the steps of the method described, before the start of the steps of the method described. The method can include a plurality of optional steps shown in the figures, which may or may not be associated with the method according to the present technology. For example, many of the steps are described to provide a broader range of semiconductor processes, which may not be important for this technology or may be implemented by alternative methodologies as further described below.

[0028]

[0032] Method 300 can include optional steps for developing a semiconductor structure to a particular manufacturing process. In some embodiments, method 300 can be implemented on a base structure, but in some embodiments, the method may be implemented after other material formation or removal. For example, any number of deposition, masking, or removal steps can be implemented to generate any transistors, memories, or other structural aspects on a substrate. In some embodiments, one or more structures formed on the substrate can be characterized by a thermal budget of about 500 °C or less, about 450 °C or less, about 400 °C or less, about 350 °C or less, about 300 °C or less, about 250 °C or less, about 200 °C or less, about 150 °C or less, or lower. Thus, method 300 and any subsequent steps can be implemented at a temperature below the structural thermal budget. The substrate can be disposed on a substrate support, which can be positioned within the processing region of a semiconductor processing chamber. The step of generating the lower structure can be implemented in the same chamber in which aspects of method 300 can be implemented, and one or more steps can be implemented in one or more chambers on a platform similar to or other than the chamber in which the steps of method 300 can be implemented.

[0029]

[0033] In some embodiments, method 300 may include forming a silicon nitride barrier film on a substrate. The method may include forming a deposition plasma in a processing region in which the substrate is housed in step 305. Forming the deposition plasma may include providing one or more deposition precursors including a silicon-containing precursor. In some cases, the silicon-containing precursor also includes one or more nitrogens (e.g., aminosilanes such as trisilylamine), and the silicon precursor supplies both silicon and nitrogen groups to the deposited portion of the silicon nitride barrier material. In additional cases, the silicon-containing precursor may not include nitrogen groups (e.g., silanes such as SiH4), and one or more nitrogen-containing precursors (e.g., ammonia) may be combined with the silicon-containing precursor that does not contain nitrogen to form the deposition precursor. The one or more deposition precursors may be delivered with a carrier gas including an inert precursor such as, for example, helium, argon, and / or nitrogen (N2). Also, when nitrogen is used as the carrier gas for the deposition precursor, it may be incorporated into the silicon nitride-containing material during deposition to at least some extent.

[0030]

[0034] In some embodiments, the flow rate of the silicon-containing precursor (e.g., TSA) supplying the deposition plasma may range from 10 standard cubic centimeters per minute (sccm) to 100 sccm. When an additional deposition precursor (e.g., NH3) is provided to the deposition plasma, it may be provided at a flow rate ranging from 50 sccm to 150 sccm. When a carrier precursor (e.g., N2) is supplied to the deposition plasma, it may be provided at a flow rate ranging from 0.2 standard liters per minute (slm) to 4 slm. The deposition plasma may be formed in a processing region of a semiconductor processing apparatus chamber. A portion around the processing region may include the surface of the semiconductor substrate exposed to the deposition plasma and the faceplate of the semiconductor processing chamber. In some embodiments, the distance between the substrate and the faceplate may range from 200 mils to 500 mils.

[0031]

[0035] The formation of the deposition plasma in Project 305 may include exciting a deposition precursor using a source of radio frequency (RF) power. In some embodiments, the amount of RF power supplied to the deposition precursor may range from 60 watts (W) to 200 watts. In some embodiments, the plasma formation process may include pulsing the plasma output during plasma generation. The plasma may be generated, in one non-limiting example, at a plasma generation frequency such as 13.56 MHz. The plasma output can be a pulsed frequency that can be about 10 kHz or less, and can be pulsed at a pulsed frequency of about 9 kHz or less, about 8 kHz or less, about 7 kHz or less, about 6 kHz or less, about 5 kHz or less, about 4 kHz or less, about 3 kHz or less, about 2 kHz or less, about 1 kHz or less, or even lower. The duty cycle of the pulsed frequency can provide a certain amount of "off" time for plasma generation.

[0032]

[0036] During the plasma "off" period, deposition may not be performed. Although the ions generated immediately before disappear quickly, radical nuclides may still be in contact with the substrate and can transfer energy to the barrier film to be formed. This activates and breaks the bonds within the barrier film, which can then cause the formation of gas species removed from the deposited film. At high duty cycles, there may not be enough time for this effect to be obtained before the resumption of deposition. Thus, in some embodiments, the duty cycle can be maintained at about 50% or less, and can be maintained at about 45% or less, about 40% or less, about 35% or less, about 30% or less, about 25% or less, about 20% or less, about 15% or less, about 10% or less, about 5% or less, or even lower. Any of these techniques, alone or in combination, can reduce the incorporation of hydrogen in the silicon nitride material during deposition.

[0033]

[0037] In process 310, the deposition plasma may be generated from a deposition precursor introduced into the processing region, and a portion of the silicon nitride material can be deposited on the substrate. That portion of the silicon nitride material can be deposited on the semiconductor substrate while the semiconductor substrate is housed in the processing region of the semiconductor processing chamber. The semiconductor substrate may define one or more features within the semiconductor substrate. That portion of the silicon nitride material can be deposited on one or more of the features of the semiconductor substrate and on portions of the substrate that are not etched or otherwise shaped by the substrate features. The processing region may be at least partially defined between a faceplate and a substrate support on which the semiconductor substrate is placed.

[0034]

[0038] In some embodiments, the deposition of the portion of the silicon nitride material may be on a semiconductor substrate having a heat budget of about 550 °C or less, about 500 °C or less, about 450 °C or less, about 400 °C or less, about 350 °C or less, about 300 °C or less, about 250 °C or less, about 200 °C or less, or about 150 °C or less, or lower. Thus, the silicon nitride material can be deposited at any of these temperatures to accommodate underlying materials, and in some embodiments, one or more steps, including all steps of method 300, can be performed at any of these temperatures, and the substrate being processed can be maintained at any of these temperatures throughout the processing. In some embodiments, the deposition temperature of the silicon nitride material on the substrate can be in the range of 200 °C to 300 °C (e.g., a deposition temperature range of 250 °C to 280 °C). The processing pressure during the deposition of the silicon nitride-containing material can be, in some embodiments, about 30 mTorr or more and can be between about 30 mTorr and about 20 mTorr.

[0035]

[0039] The portion of the silicon nitride-containing material can be deposited using a deposition precursor containing silicon, nitrogen, and hydrogen atoms. As a result, the portion during the deposition of the silicon nitride material can be characterized by a first amount of incorporated hydrogen. This first amount of incorporated hydrogen can be about 3 at.% or more, about 5 at.% or more, about 7 at.% or more, about 10 at.% or more, or more.

[0036]

[0040] The portion during the deposition of the silicon nitride material can be further processed by a processing process that can enhance the density and airtightness of the material. The processing process can be carried out in the same chamber as the deposition, or the substrate may be transferred from the first processing chamber to the second processing chamber. In some embodiments, the second chamber may be on the same tool as described above, and the transfer can be carried out while maintaining the vacuum conditions of the substrate. The processing process can be configured to reduce the amount of hydrogen incorporated into the silicon nitride material during deposition by transferring additional energy to the material during deposition and breaking the bonds of hydrogen groups to other atoms such as silicon atoms, nitrogen atoms, and carbon atoms. Thereby, the amount of hydrogen in the material during deposition can be reduced from a first amount to a second, lower amount of hydrogen in the material after the processing step. The second hydrogen incorporation amount can be about 2 at.% or less, about 1.5 at.% or less, about 1.0 at.% or less, about 0.5 at.% or less, or even less.

[0037]

[0041] In step 315, the treatment of the silicon nitride-containing material during deposition may include the formation of a treatment plasma. The formation of the treatment plasma can include providing one or more treatment precursors such as a mixed gas of helium and nitrogen (N2). Plasma can be generated from the treatment precursors introduced into the treatment region, and helium and nitrogen ions (N + , N2 +) can contact a silicon nitride material on which plasma emissions such as are deposited. At least a part of the impact energy of the plasma emissions contacting the deposited silicon nitride material can exceed the threshold energy for breaking the bonds of hydrogen groups embedded in the silicon nitride material. At least a part of the separated hydrogen groups may be reformed as nuclides removed from the silicon nitride material. For example, at least a part of the separated hydrogen groups can be reformed as hydrogen molecules (H2) removed from the silicon nitride material. In some cases, the waste water of the treatment plasma breaks the bonds between silicon and hydrogen and replaces the replaced hydrogen groups with nitrogen groups that form new silicon-nitrogen bonds in the silicon nitride material. Both the decrease in the number of silicon-hydrogen bonds and the increase in the number of silicon-nitrogen bonds densify the silicon nitride material in step 320.

[0038]

[0042] In some embodiments, in step 315, forming the treatment plasma includes providing a treatment precursor as a mixed gas of helium and nitrogen (N2). The flow rate ratio of helium gas to nitrogen gas (He:N2) may vary between treatment cycles. For example, the helium gas to nitrogen gas flow rate ratio (i.e., He:N2 flow rate ratio) for an early treatment step following the previous deposition of a portion of the silicon nitride material may be higher than the He:N2 flow rate ratio for a later (e.g., subsequent) treatment process following the subsequent deposition of a portion of the silicon nitride material. In some embodiments, the He:N2 flow rate ratio may be gradually decreased in each treatment plasma step implemented in the multilayer deposition of the silicon nitride-containing barrier film. In additional embodiments, the He:N2 flow rate ratio may be gradually decreased in each treatment step until it reaches the lower limit of the He:N2 ratio that remains the same for consecutive treatment plasma steps until the formation of the silicon nitride-containing barrier film is completed. In some embodiments, the He:N2 flow rate ratio can be in the range of 0.1 to 10.

[0039]

[0043] For example, from the initial flow rate ratio of helium to nitrogen, in the continuous treatment process, the helium flow rate can be continuously decreased while the nitrogen flow rate can be continuously increased. For example, in each successive treatment, the helium flow rate can be decreased by about 300 sccm or more, and the helium flow rate can be decreased by about 400 sccm or more, about 500 sccm or more, about 600 sccm or more, about 700 sccm or more, about 800 sccm or more, about 900 sccm or more, about 1000 sccm or more, about 1100 sccm or more, about 1200 sccm or more, about 1300 sccm or more, about 1400 sccm or more, about 1500 sccm or more, or even more. Similarly, in each successive treatment, the nitrogen flow rate can be increased by about 500 sccm or more, and the nitrogen flow rate can be increased by about 600 sccm or more, about 700 sccm or more, about 800 sccm or more, about 900 sccm or more, about 1000 sccm or more, about 1100 sccm or more, about 1200 sccm or more, about 1300 sccm or more, about 1400 sccm or more, about 1500 sccm or more, or even more.

[0040]

[0044] In some embodiments, a higher flow rate ratio of helium gas to nitrogen gas, which can be run in combination with a higher output level to form a processing plasma, can produce a processed silicon nitride-containing material with higher hermeticity because a large amount of high-energy helium dissociates more hydrogen in the deposited material. The liberated helium and hydrogen can form bubbles in the material and increase the number of voids in the processed material. In some embodiments, the amount of bubbles can be reduced or eliminated by depositing portions of the silicon nitride-containing material that are too thin to form a large number of bubbles (e.g., no bubbles are formed). Additional portions of the silicon nitride-containing material can be processed at a lower flow rate ratio of helium gas to nitrogen gas and, in some embodiments, at a lower output level of the processing plasma, to form processed portions with less dissociated hydrogen, lower hermeticity, and fewer voids. In some embodiments, these additional portions of the silicon nitride-containing material can be formed with a greater thickness and higher deposition rate than the initial portions. The final silicon nitride layer can be characterized by a decreasing hermeticity from the initial portion to the final portion of the deposited and processed material and, in some embodiments, by a decreasing number of voids.

[0041]

[0045] The formation of the processing plasma may also include exciting the processing precursor using an RF power source. In some embodiments, the RF power may be continuously supplied to the processing precursor in a power range of 10 W to 1000 W. Additional RF power ranges include, among other ranges, 100 W to 800 W, 200 W to 700 W, and 300 W to 600 W. The plasma can be generated, in one non-limiting example, at a plasma generation frequency such as 13.56 MHz. In some embodiments, the RF output level used to form the early processing plasma for processing an early portion of the silicon nitride material during deposition can be made greater than the RF output level used to form the late (e.g., subsequent) processing plasma for processing a late portion of the silicon nitride material during deposition. For example, the RF output level used to form the early processing plasma can be 600 W, and the RF output level used to form the late processing plasma can be 500 W.

[0042]

[0046] After the deposition and processing cycles are performed multiple times, the formation of the silicon nitride-containing barrier film is completed in step 325. In some embodiments, the film can be formed with at least two deposition and processing cycles, in which case the thickness of the first portion of the deposited silicon nitride material is less than the thickness of the second and subsequent portions of the deposited silicon nitride material. For example, the first portion of the silicon nitride material deposited on the substrate can have a film thickness of less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, less than 5%, or less than that of the film.

[0043]

[0047] As described above, in some embodiments, the first portion of the silicon nitride-containing barrier film can have a higher gas tightness than the second portion of the barrier film and, if included, subsequent portions. The first portion of the barrier film, which can be the portion closest to the substrate on which the barrier film is formed, can have a gas tightness that is about 10% or more higher than that of the second portion of the barrier film or subsequent portions, about 15% or more higher than that of the second portion of the barrier film, about 20% or more higher than that of the second portion of the barrier film, about 25% or more higher than that of the second portion of the barrier film, about 30% or more higher than that of the second portion of the barrier film, about 40% or more higher than that of the second portion of the barrier film, about 50% or more higher than that of the second portion of the barrier film, or significantly higher than that. In additional embodiments, the first portion of the silicon nitride-containing barrier film can have an equal or greater number of voids as the second portion of the barrier film and, if included, subsequent portions.

[0044]

[0048] For example, the first portion of the silicon nitride-containing barrier film can have about 5% or more voids than the second portion of the barrier film, about 10% or more voids than the second portion of the barrier film, about 15% or more voids than the second portion of the barrier film, about 20% or more voids than the second portion of the barrier film, about 25% or more voids than the second portion of the barrier film, about 50% or more voids than the second portion of the barrier film, or more voids. Additionally, each subsequent film layer can be characterized by a reduction in void formation, as described above. For example, each subsequent layer can be characterized by having about 5% or more voids than the immediately preceding continuous layers, and can be characterized by a linear reduction in voids in that it can be characterized by a reduction in voids or bubbles at any of the ratios described above for voids or gas tightness.

[0045]

[0049] To limit the waiting time, the plasma treatment process can be carried out in the deposition chamber, and other energy treatments can be carried out in a chamber on the same tool as the deposition chamber. By utilizing one or more aspects of the present technology, compared with the prior art, the incorporation of hydrogen in the silicon nitride film can be reduced, and the number of voids and particles can be decreased. In addition, the described process can be carried out at a lower temperature than many prior arts and can accommodate structures that may be restricted by the heat balance.

[0046]

[0050] FIG. 4 shows exemplary steps in a processing method 400 according to some embodiments of the present technology. This method can be carried out in various processing chambers including the plasma system 200 described above. Similar to the method 300 described above, the method 400 can include one or more steps prior to the start of the described method steps and one or more steps following the described method steps. The method 400 can include the deposition 405 of an initial portion of a silicon nitride-containing material on a substrate. This initial portion can take the form of a relatively thin layer (e.g., 2 - 5 nm thick) of the silicon nitride material. In some embodiments, the method 400 can further include a processing step for the initial portion during the deposition of the silicon nitride-containing material. The optional processing step (not shown) may include exposing the initial portion of the silicon nitride-containing material to a low-energy processing plasma (e.g., 200 watts or less) that can redistribute the initial portion of the material on the substrate without substantially breaking the Si-H bonds in the material. The low-energy processing plasma can be formed from a processing gas mixture containing helium and nitrogen gas. The processing gas mixture can have a higher helium-to-nitrogen flow rate ratio than the flow rate ratio of the subsequent processing gas mixture used in the method 400. As described above, the low-energy processing plasma does not generate a large amount of plasma emissions with enough energy to break the Si-H bonds in the initially deposited silicon nitride-containing material. As a result, the low-energy processing plasma has enough energy to redistribute a portion of the initial material during deposition, but does not significantly change the amount of hydrogen in the material, increase its density, or enhance its hermeticity.

[0047]

[0051] Following the deposition of an initial portion of the silicon nitride-containing material on the substrate and any optional processing, method 400 includes two or more deposition and processing cycles to build the processed portion of the silicon nitride-containing material into a silicon nitride-containing barrier film. The first of these deposition and processing cycles includes the deposition 410 of the next portion of the silicon nitride-containing material on the initial portion of the silicon nitride-containing material. The deposition step 410 can include forming a deposition plasma and depositing the next portion of the material containing silicon and nitrogen from the plasma effluent. The next portion of the silicon nitride-containing material during deposition can be processed 415 with a processing plasma. In contrast to the preceding low-energy processing plasma, the processing plasma in the processing step 415 has sufficient energy to change the composition of the silicon nitride-containing material during deposition. In some embodiments, the processing plasma in the processing step 415 is supplied at the highest output level of the processing plasma in the deposition and processing cycles implemented in method 400 (e.g., an output level in the range of 600 watts to 1000 watts). In some embodiments, the processing gas mixture forming the processing plasma in the processing step 415 can have a higher helium-to-nitrogen flow rate than any subsequent processing step implemented in method 400. In each successive processing step formed after each additional deposition step, the plasma output can be further reduced to reduce the bubbles in the film layer by layer. For example, each successive processing step can further reduce the plasma output by about 40 W or more, and can be reduced by about 50 W or more, about 60 W or more, about 70 W or more, about 80 W or more, or even more. As a result, the processing of the final layer can be performed with a plasma output of about 500 W or less, and can be performed with an output of about 480 W or less, about 460 W or less, about 440 W or less, about 420 W or less, about 400 W or less, about 380 W or less, about 360 W or less, about 340 W or less, about 320 W or less, or even less.

[0048]

[0052] Method 400 is one embodiment of the present technology, which further includes at least a second deposition and treatment cycle following the deposition and treatment of the next portion of the silicon nitride-containing material. The second deposition and treatment cycle includes the deposition 420 of an additional portion of the silicon nitride-containing material. The additional portion of the silicon nitride-containing material can be deposited on top of the processed next portion of the silicon nitride-containing material. The deposition step 420 may include forming a deposition plasma from one or more deposition precursors and depositing an additional portion of the material containing silicon and nitrogen from the plasma emissions. In some embodiments, the deposition rate and / or deposition amount of the additional portion of the material containing silicon and nitrogen can be made greater than the deposition rate and / or deposition amount of the next portion of the material containing silicon and nitrogen that preceded it. In some of these embodiments, the flow rate of the deposition precursor supplying the deposition plasma can be made greater than the flow rate of the deposition precursor supplying the deposition plasma that formed the immediately preceding portion of the silicon nitride-containing material. Embodiments may include an increased flow rate of a silicon-containing precursor (e.g., TSA, silane), and may further include an increased flow rate of a nitrogen-containing precursor (e.g., NH3) if the nitrogen-containing precursor is included in the deposition precursor. For example, each successive deposition may include a similar or increased flow rate compared to the deposition step immediately preceding the plurality of cycles. For example, in each successive deposition, the flow rate of ammonia or another nitrogen-containing precursor can be increased by about 10 sccm or more. The additional portion during the deposition of the silicon nitride-containing material can be treated with a treatment plasma 425. The treatment plasma may be formed from a plasma output source set to a plasma output level lower than the output level used to form the treatment plasma that treated the preceding next portion of the silicon nitride material.

[0049]

[0053] Embodiments of method 400 may further include the completion 430 of a silicon nitride-containing barrier film. In the embodiments shown in method 400, the silicon nitride-containing barrier film was completed after the deposition of an initial portion of the silicon nitride-containing material and at least two deposition and treatment cycles following optional treatment. The completed silicon nitride nitride barrier film may include the portion closest to the substrate that is the most airtight, the most dense, and has a relatively low hydrogen concentration compared to any portion of the barrier film. Also, the completed silicon nitride nitride barrier film may include the portion farthest from the substrate that has the highest hydrogen concentration and the lowest stress compared to any portion of the barrier film.

[0050]

[0054] Figures 5A and 5B are exemplary schematic cross-sectional views of a substrate during processing according to some embodiments of the present technology. This cross-sectional view shows a portion of the structure 500 after different steps described in processing methods 300 and 400 according to some embodiments of the present technology. The processing chamber 200 can be utilized for processing methods 300 and 400 that may include the formation and processing of silicon nitride materials for semiconductor structures in some embodiments of the present technology. It should be understood that the chambers described are not to be considered limiting, and any chamber configured to perform the steps as described can be used as well. Methods 300 and 400 can include a number of optional steps that may or may not be specifically associated with some embodiments of the methods according to the present technology. For example, many of the steps are described to provide a broader scope of structure formation and may not be important to the technology or can be implemented by alternative methodologies as would be readily understood. Methods 300 and 400 can illustrate the steps schematically shown in Figures 5A and 5B. It should be understood that the figures only show partial schematics and the substrate can include any number of additional materials and features with various characteristics and aspects as illustrated.

[0051]

[0055] The substrate on which multiple processes have been performed may be the substrate 505 of the structure 500, which shows a partial view of the substrate on which semiconductor processing can be performed above. It should be understood that the structure 500 may show only some of the topmost layers during processing for the purpose of explaining aspects of the present technology. The substrate 505 can include materials in which one or more features 510 can be formed. The substrate 505 can be any number of materials used in semiconductor processing. The substrate material can be silicon, germanium, a dielectric material including silicon oxide or silicon nitride, a metal material, or any number of combinations of these materials, and can also be the material formed on the substrate 505 or the structure 500. According to the present technology, the feature 510 can be characterized by any shape or configuration. In some embodiments, the feature can be or can include a trench structure or an aperture formed within the substrate 505.

[0052]

[0056] The feature 510 can be characterized by any shape or size, but in some embodiments, the feature 510 can be characterized by a higher aspect ratio, that is, the ratio of the depth of the feature to the width across the feature. For example, in some embodiments, the feature 510 can be characterized by an aspect ratio of about 5:1 or more, and can be characterized by an aspect ratio of about 10:1 or more, about 15:1 or more, about 20:1 or more, about 25:1 or more, about 30:1 or more, about 40:1 or more, about 50:1 or more, or greater. In addition, the feature can be characterized by a narrow width or diameter across the feature, including between two sidewalls, for example, a dimension of about 20 nm or less, and can be characterized by a width across the feature of about 15 nm or less, about 12 nm or less, about 10 nm or less, about 9 nm or less, about 8 nm or less, about 7 nm or less, about 6 nm or less, about 5 nm or less, or less.

[0053]

[0057] In some embodiments, methods 300 and 400 may include optional processing steps, such as pre-treatment, that may be performed to prepare 405 the surface of the substrate for deposition. After the preparation is complete, methods 300 and 400 may include delivering one or more precursors to a processing region of a semiconductor processing chamber that houses structure 500. The precursors can include one or more precursors containing silicon and nitrogen, and one or more diluents or carrier gases, such as an inert gas or other gas delivered with the precursor containing silicon and nitrogen. In step 310, the plasma may be formed of a deposition precursor that includes a precursor containing silicon and nitrogen. The deposition plasma can be formed within the processing region, which enables a silicon nitride deposition material to be deposited on the substrate. For example, in some embodiments, a capacitively coupled plasma can be formed within the processing region by applying a plasma output to a faceplate as described above. The formed deposition plasma may be formed by applying a plasma output to a faceplate or showerhead, and in some embodiments, other power supplies may not be engaged.

[0054]

[0058] As shown in FIG. 5A, the silicon nitride material 515 can be deposited 405 on the substrate and can be deposited within trench or feature 510. As shown, the deposition material 515 can be deposited at the bottom of the feature.

[0055]

[0059] As shown in FIG. 5B, following a certain deposition amount, a processing step can be performed to densify the silicon nitride material, enhance the airtightness of the silicon nitride material, and reduce the hydrogen content of the silicon nitride material. This process can be carried out in the same chamber as the deposition. In some embodiments, the flow of the precursor containing silicon and nitrogen can be stopped, and the processing region can be purged. Following the purge, the processing precursor can be introduced into the processing region of the processing chamber. A processing plasma can be formed, which may be a capacitively coupled plasma formed within the processing region. The processing step can provide a reduced hydrogen uptake, for example, a hydrogen uptake of about 40 at.% or less, in the processed silicon nitride material 520, and can provide a hydrogen uptake of about 35 at.% or less, about 30 at.% or less, about 25 at.% or less, about 20 at.% or less, about 15 at.% or less, about 10 at.% or less, about 5 at.% or less, or less than that.

[0056]

[0060] The deposition of the silicon nitride material during deposition can be formed to be several nanometers or more by performing the deposition process described above. However, the thickness of the processed silicon nitride material can be controlled to a thickness of about 100 Å or less, and can be about 90 Å or less, about 80 Å or less, about 70 Å or less, about 60 Å or less, about 50 Å or less, about 40 Å or less, about 30 Å or less, about 20 Å or less, about 10 Å or less, or even smaller. By controlling the thickness of each part of the silicon nitride material during deposition, the problem of penetration of the processing plasma common in conventional processes can be solved. As shown in FIG. 4C, the material 415 deposited on the substrate and within the feature can be converted into the processed silicon nitride material 420 throughout the depth of the material. Then the deposition and processing steps can be repeated to continue generating a complete barrier film on and / or within the substrate features.

[0057]

[0061] In the above description, for the purpose of explanation, numerous details have been presented 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 can be practiced without some of these details or with additional details.

[0058]

[0062] Although several embodiments have been disclosed, those skilled in the art will recognize that various modifications, alternative structures, and equivalents may be used without departing from the spirit of the embodiments. Additionally, to avoid unnecessarily obscuring the technology, many well-known processes and elements have not been described. Therefore, the above description should not be construed as limiting the scope of the technology.

[0059]

[0063] Where a range of values is provided, each intervening value between the upper and lower limits of that range is specifically disclosed to the minimum unit of the lower limit's unit, unless the context clearly indicates otherwise. All narrower ranges between any of the recited values or intervening values not recited in the recited range, and any other recited value or intervening value within such recited range, are included. The upper and lower limits of such narrower ranges may be individually included or excluded from the range, and each range where one or both of the limiting values are included or neither of them is included in the narrower range is also encompassed by this technology and is subject to any limiting values specifically excluded from the recited range. Where the recited range includes one or both of the limiting values, ranges excluding one or both of these included limiting values are also included.

[0060]

[0064] As used in this specification and the claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a precursor" includes a plurality of such precursors, a reference to "the layer" includes a reference to one or more layers known to those skilled in the art and their equivalents, and so on.

[0061]

[0065] Furthermore, the terms "comprise(s)", "comprising", "contain(s)", "containing", "include(s)", and "including" as used in this specification and the claims are intended to specify the presence of the stated feature, integer, component, or step, and are not intended to exclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.

Claims

1. Depositing and processing a first portion of a silicon nitride material on a semiconductor substrate, wherein the first portion of the silicon nitride material is formed using a first deposition plasma and processed using a first processing plasma, depositing and processing a first portion of the silicon nitride material, Depositing a second portion of the silicon nitride material on the processed first portion of the silicon nitride material, wherein the second portion of the silicon nitride material is deposited using a second deposition plasma formed of one or more deposition precursors including a silicon-containing precursor, depositing a second portion of the silicon nitride material, Processing the second portion of the silicon nitride material using a second processing plasma formed of a second processing mixed gas including helium and nitrogen, Depositing a third portion of the silicon nitride material on the processed second portion of the silicon nitride material, wherein the third portion of the silicon nitride material is deposited using a third deposition plasma, depositing a third portion of the silicon nitride material, and Processing the third portion of the silicon nitride material using a third processing plasma formed of a third processing mixed gas including helium and nitrogen comprising, A processing method, wherein a flow rate ratio of helium to nitrogen in the second processing mixed gas is greater than a flow rate ratio of helium to nitrogen in the third processing mixed gas.

2. The processing method according to claim 1, wherein the first processing plasma is formed of a first processing mixed gas including helium and nitrogen, and a flow rate ratio of helium to nitrogen in the first processing mixed gas is greater than a flow rate ratio of helium to nitrogen in the second processing mixed gas.

3. The processing method according to claim 1, wherein the second processing plasma is formed using a plasma output source set to a second output level, the third processing plasma is formed using the plasma output source set to a third output level, and the second output level is greater than the third output level.

4. The processing method according to claim 3, wherein the first processing plasma is formed using the plasma output source set to a first output level that is smaller than the second output level and the third output level.

5. The processing method according to claim 4, wherein the first output level is 200 watts or less.

6. The processing method according to claim 1, wherein the second deposition plasma is formed using a plasma output source operated in a pulsed mode.

7. The processing method according to claim 1, wherein the second processing plasma is formed using a plasma output source operated in a continuous wave mode.

8. The processing method according to claim 1, wherein one or more of the deposition precursors forming the second deposition plasma further comprise a nitrogen-containing precursor.

9. The processing method according to claim 8, wherein the nitrogen-containing precursor comprises ammonia or dinitrogen.

10. The processing of the second portion of the silicon nitride material using the second processing plasma includes consolidating the second portion of the silicon nitride material, enhancing the airtightness of the second portion of the silicon nitride material, and reducing the hydrogen content of the second portion of the silicon nitride material. The processing method according to claim 1.

11. The processing method according to claim 1, wherein the silicon-containing precursor comprises at least one of silane and aminosilane.

12. The processing method according to claim 1, wherein the second portion of the silicon nitride material has a thickness smaller than that of the third portion of the silicon nitride material.

13. A processing method including performing two or more cycles of depositing and processing a silicon nitride material on a semiconductor substrate, each of the two or more cycles of depositing and processing the silicon nitride material comprising: depositing a silicon nitride material using a plasma emission of a deposition plasma, wherein the deposition plasma is formed of one or more deposition precursors including a silicon-containing precursor, depositing the silicon nitride material, and processing the silicon nitride material using a processing plasma, wherein the processing plasma is formed of a processing mixed gas including helium and nitrogen, processing the silicon nitride material including, A processing method, wherein the flow rate ratio of helium to nitrogen in the processing mixed gas in a previous cycle of depositing and processing a silicon nitride material is greater than the flow rate ratio of helium to nitrogen in the processing mixed gas in a subsequent cycle of depositing and processing a silicon nitride material.

14. The processing method according to claim 13, wherein the processing plasma is formed using a plasma output source, and the plasma output source is set to an output level of a preceding cycle for depositing and processing a silicon nitride material that is greater than an output level of a subsequent cycle for depositing and processing a silicon nitride material.

15. The processing method according to claim 14, wherein the semiconductor substrate includes an initial layer of a silicon nitride material deposited in a substrate feature.

16. The initial layer of the silicon nitride material is deposited using a first deposition plasma formed with a silicon-containing deposition precursor and processed using a first processing plasma formed with a first processing mixed gas containing helium and nitrogen. The first processing mixed gas has a helium-to-nitrogen flow rate ratio that is greater than a helium-to-nitrogen flow rate ratio of the processing mixed gas in a preceding cycle and a subsequent cycle for depositing and processing a silicon nitride material. The first processing plasma is formed using a plasma output source set to a first output level of 200 W or less. The method according to claim 15.

17. The processing method according to claim 13, wherein the one or more deposition precursors include the silicon-containing precursor and ammonia.

18. Depositing a first portion of a silicon nitride material on a semiconductor substrate using a first deposition plasma. Processing the first portion of the silicon nitride material using a first processing plasma formed with a first processing mixed gas containing helium and nitrogen, wherein the first processing plasma does not substantially reduce the amount of hydrogen in the first processing plasma. Depositing a second portion of a silicon nitride material on the processed first portion of the silicon nitride material, wherein the second portion of the silicon nitride material is deposited using a second deposition plasma. Processing the second portion of the silicon nitride material using a second processing plasma formed with a second processing mixed gas containing helium and nitrogen, wherein the second processing plasma reduces the amount of hydrogen in the second portion of the deposited silicon nitride material. A method including the above steps.

19. The processing method according to claim 18, wherein the first processing plasma is formed using a plasma output source set to a first output level of 200 watts or less, and the second processing plasma is formed using the plasma output source set to a second output level of 500 watts or more.

20. The processing method according to claim 19, wherein the first processing mixed gas has a first flow rate ratio of helium to nitrogen that is larger than a second flow rate ratio of helium to nitrogen of the second processing mixed gas.

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