Methods for forming low-k dielectric materials with reduced dielectric constant and increased density

Abstract

An exemplary semiconductor processing method may include providing a deposition precursor to a processing region of a semiconductor processing chamber. The deposition precursor may include a precursor comprising silica and carbon. A substrate may be disposed within the processing region. The method may include forming a plasma effluent of a deposition precursor. The method may include depositing a layer of a silica and carbon containing material on a substrate. The layer of silica and carbon containing material may be characterized by a dielectric constant of less than or about 4.5. The layer of silica and carbon containing material may be characterized by a density of greater than or about 2.0 g / cm3.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Patent Application No. 18 / 233,984, filed August 15, 2023, entitled “METHODS FOR FORMING LOW-K DIELECTRIC MATERIALS WITH REDUCED DIELECTRIC CONSTANT AND INCREASED DENSITY”, 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 methods for producing low-κ materials. Background Technology

[0004] Integrated circuits can be fabricated through processes that create complex patterned material layers on a substrate surface. Creating patterned materials on a substrate requires controlled methods for forming and removing the materials. Material properties can affect how a device operates and may also affect how the materials are removed relative to each other. Plasma-enhanced deposition can produce materials with certain properties that can affect device performance. The properties of the materials can be tuned or enhanced by modifying deposition conditions, such as the chemicals of the precursors provided during deposition and / or the processing conditions during deposition.

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

[0006] An exemplary semiconductor processing method may include providing a deposition precursor to a processing region of a semiconductor processing chamber. The deposition precursor may include a silicon-oxygen and carbon-containing precursor. A substrate may be disposed within the processing region. The method may include forming a plasma effluent of the deposition precursor. The method may include depositing a layer of silicon-oxygen and carbon-containing material on the substrate. The layer of silicon-oxygen and carbon-containing material may be characterized by a dielectric constant of less than or about 4.5. The layer of silicon-oxygen and carbon-containing material may be characterized by a density greater than or about 2.0 g / cm³. 3 .

[0007] In some embodiments, the silicon-oxygen-carbon precursor may be or includes dimethyldimethoxysilane, 1,1,3,3-tetramethyl-1,3-dimethoxydisiloxane, methoxy(dimethyl)silylmethane, or vinylmethyldimethoxysilane. The deposition precursor further includes a nitrogen-containing precursor. The nitrogen-containing precursor may be or includes ammonia (NH3). The flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor may be less than or about 10:1. The method may include providing helium gas along with the deposition precursor. The flow rate ratio of the silicon-oxygen-carbon precursor to helium gas may be less than or about 1:1. The plasma effluent may be formed at a plasma power of less than or about 1,500 W. The temperature in the semiconductor processing chamber may be maintained at greater than or about 250°C. The pressure in the semiconductor processing chamber may be maintained at less than or about 15 Torr. The layer of the silicon-oxygen-carbon material may be characterized by an oxygen content of greater than or about 20.0 atoms. The layer of the silicon-oxygen-carbon material may be characterized by a nitrogen content of less than or about 20.0 atoms.

[0008] Some embodiments of this technology may cover semiconductor processing methods. The method may include providing a deposition precursor to a processing region of a semiconductor processing chamber. The deposition precursor may be or include silicon-oxygen and carbon-containing precursors and nitrogen-containing precursors. A substrate may be disposed within the processing region. The method may include forming a plasma effluent of the deposition precursor. The method may include depositing a layer of silicon-oxygen and carbon-containing material on the substrate. The layer of silicon-oxygen and carbon-containing material may be characterized in that the oxygen content is greater than or about 25.0 atomic%. The layer of silicon-oxygen and carbon-containing material may be characterized in that the dielectric constant is less than or about 4.2.

[0009] In some embodiments, the silicon-oxygen-carbon precursor may be or includes dimethyldimethoxysilane. The flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor may be less than or about 10:1. The plasma effluent may be formed at a plasma power of less than or about 1,000 W. The layer of the silicon-oxygen-carbon material may be characterized by a flow rate of 0.001 A / cm 2 The breakdown voltage is greater than or about 6.5 MV / cm. The temperature within the processing area can be maintained at less than or about 500°C.

[0010] Some embodiments of this technology may cover semiconductor processing methods. The method may include providing a deposition precursor to a processing region of a semiconductor processing chamber. The deposition precursor may be or include a silicon-oxygen and carbon-containing precursor. A substrate may be disposed within the processing region. The silicon-oxygen and carbon-containing precursor may be or include dimethyldimethoxysilane. The method may include forming a plasma effluent of the deposition precursor. The method may include depositing a layer of silicon-oxygen and carbon-containing material on a substrate. The layer of silicon-oxygen and carbon-containing material may be characterized in that the oxygen content is greater than or about 25.0 atomic%. The layer of silicon-oxygen and carbon-containing material may be characterized in that the dielectric constant is less than or about 4.2. The layer of silicon-oxygen and carbon-containing material may be characterized in that the density is greater than or about 2.0.

[0011] In some embodiments, the deposition rate of the silicon-oxygen and carbon-containing material layer can be greater than or about 500 Å / min. The silicon-oxygen and carbon-containing material layer is characterized by a leakage current of less than or about 2E-08 A / cm at 2 MV / cm. 2 .

[0012] Compared to conventional processing methods, such techniques offer numerous advantages. For example, utilizing silicon-containing precursors, including oxygen, carbon, and / or hydrogen, during deposition can modify the atomic structure of the material to increase the oxygen content in the deposited material. Furthermore, the increased oxygen content in the deposited material can lower the dielectric constant and increase the density. These and other embodiments, along with their many advantages and features, will be described in more detail below in conjunction with the accompanying drawings. Brief description of the attached diagram

[0014] A further understanding of the nature and advantages of the disclosed technology can be achieved by referring to the remainder of this specification and the accompanying drawings.

[0015] Figure 1 A top plan view of an exemplary processing system according to some embodiments of the present technology is shown.

[0016] Figure 2 A schematic cross-sectional view of an exemplary plasma system according to some embodiments of the present technology is shown.

[0017] Figure 3 The operation of an exemplary semiconductor processing method according to some embodiments of the present technology is shown.

[0018] Several figures in 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 true representation, and may include exaggerated material for illustrative purposes.

[0019] In the accompanying drawings, similar parts and / or features may have the same reference numerals. Furthermore, various parts of the same type can be distinguished by following the reference numerals with letters used to differentiate similar parts. If only the first reference numeral is used in this specification, the description applies to any similar part having the same first reference numeral, regardless of the letters. Detailed Implementation

[0020] During back-end semiconductor processing, structures that facilitate metallization, such as dual damascene structures, may be generated. These structures can be produced through several processing steps utilizing a shielding and low-k film, which can be processed and removed. Removal can be performed using a chemical mechanical process, which involves physical abrasion of the material to facilitate removal. Low-k films are characterized by relatively low hardness and tensile modulus, which may limit their effectiveness during polishing, as the high shear stress during polishing can cause the low-k film to crack and lead to device failure. To increase hardness while maintaining a low kinematic value, many conventional techniques are forced to include additional processing steps such as ultraviolet (UV) curing to increase the film's hardness and / or density. These additional processes can significantly reduce yield and often require additional processing chambers on the tooling. Furthermore, these additional processes may not improve the mechanical properties to meet the required specifications.

[0021] This technique overcomes these problems by providing a low-κ film, characterized by a reduced dielectric constant and increased density. Additional oxygen can be incorporated into the deposited material by performing deposition with specific precursors, such as silicon-oxygen and carbon-containing precursors. The increased amount of oxygen in the deposited material enhances silicon-oxygen (Si-O) bonding within the film while maintaining the desired carbon fraction to preserve the reduced dielectric constant. This overcomes the natural tendency for the dielectric constant to increase with density and reduces the number of operations required during processing. In particular, this technique may eliminate the need for post-deposition processing, including UV exposure, plasma treatment, or other processing operations to improve film density. However, post-deposition processing can still be performed to further reduce the dielectric constant and / or increase the density.

[0022] 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 described are equally applicable to other deposition chambers and processes that may occur within the described chambers. Therefore, the techniques should not be considered limited to the specific deposition process or chamber described. Before describing additional details of embodiments according to the present technology, this disclosure will discuss a possible system and chamber that can be used to perform deposition processes according to embodiments of the present technology.

[0023] Figure 1 A top plan view of one embodiment of a processing system 100 comprising deposition, etching, baking, and UV processing chambers according to an embodiment is shown. In the figure, a pair of front-opening unified wafer cassettes 102 supply substrates of various sizes, which are received by a robotic arm 104 and placed into a low-pressure holding region 106, and then into one of substrate processing chambers 108a to 108f, positioned in tandem segments 109 to 109c. A second robotic arm 110 can be used to transfer substrate wafers from the holding region 106 to and from the substrate processing chambers 108a to 108f. Each substrate processing chamber 108a to 108f can be assembled to perform several substrate processing operations, including plasma-enhanced chemical vapor deposition, atomic layer deposition, physical vapor deposition, etching, UV processing, pre-cleaning, degassing, orientation, and other substrate processes, including annealing, ashing, etc.

[0024] The substrate processing chambers 108a to 108f may include one or more system components for depositing, annealing, UV treating, and / or etching dielectric or other materials on the substrate. In one configuration, two pairs of processing chambers (e.g., 108c to 108d and 108e to 108f) may be used to deposit dielectric materials on the substrate, and a third pair of processing chambers (e.g., 108a to 108b) may be used to etch the deposited dielectric. In another configuration, all three pairs of chambers (e.g., 108a to 108f) may be configured to deposit alternating stacks of dielectric materials on the substrate. Any one or more of these processes may be performed in chambers separate from the manufacturing systems shown in the different embodiments. It will be understood that system 100 considers additional configurations for chambers used for dielectric material deposition, etching, annealing, and UV treating.

[0025] 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 show a pair of processing chambers 108, which may be mounted in one or more of the aforementioned series segments 109, and may include overlay components according to embodiments of the present technology, which may be further explained below. The plasma system 200 generally includes a chamber body 202 having sidewalls 212, a bottom wall 216, and an internal sidewall 201, thereby defining a pair of processing regions 220A and 220B. Each of the processing regions 220A to 220B may be similarly configured and may include the same components.

[0026] For example, processing region 220B (whose components may also be included in processing region 220A) may include a base 228 disposed in the processing region through a channel 222 formed in the bottom wall 216 of the plasma system 200. The base 228 may provide a heater adapted to support a substrate 229 on an exposed surface (such as a body portion) of the base. The base 228 may include a heating element 232, such as a resistance heating element, which can heat and control the substrate temperature at a 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.

[0027] The body of base 228 can be coupled to rod 226 via flange 233. Rod 226 can electrically couple base 228 to a power socket or power box 203. Power box 203 may include a drive system that controls the raising and lowering of base 228 within processing area 220B. Rod 226 may also include a power interface to provide power to base 228. Power box 203 may also include power and temperature indicator interfaces, such as thermocouple interfaces. Rod 226 may include base assembly 238 adapted to be detachably coupled to power box 203. Circumferential ring 235 is shown above power box 203. In some embodiments, circumferential ring 235 may be a shoulder adapted to be a mechanical stop or drop point configured to provide a mechanical interface between base assembly 238 and upper surface of power box 203.

[0028] The rod 230 can be included through a channel 224 formed in the bottom wall 216 of the processing area 220B and can be used to position the substrate lifting rod 261 through the main body of the base 228. The substrate lifting rod 261 can selectively separate the substrate 229 from the base to facilitate the exchange of the substrate 229 using a robot for moving the substrate 229 into and out of the processing area 220B through the substrate transfer port 260.

[0029] A chamber cover 204 may be coupled to the top portion of a chamber body 202. The cover 204 may house one or more precursor distribution systems 208 coupled to the cover. The precursor distribution system 208 may include a precursor inlet channel 240 that can deliver reactants and cleaning precursors into a processing area 220B via a dual-channel spray head 218. The dual-channel spray head 218 may include an annular base plate 248 having a partition plate 244 disposed in the middle of a panel 246. A radio frequency (“RF”) source 265 may be coupled to the dual-channel spray head 218 to power the dual-channel spray head 218 to facilitate the generation of a plasma region between the panel 246 and the base 228 of the dual-channel spray head 218. The dual-channel spray head 218 and / or the panel 246 may include one or more openings allowing precursors to flow from the precursor distribution system 208 to processing areas 220A and / or 220B. In some embodiments, the opening may include at least one of a straight opening and a tapered opening. In some embodiments, the RF source may be coupled to other parts of the chamber body 202, such as the base 228, to facilitate plasma generation. A dielectric isolator 258 may be provided between the cover 204 and the dual-channel spray head 218 to prevent RF power from being conducted to the cover 204. A shadow ring 206 that engages with the base 228 may be provided around the periphery of the base 228.

[0030] Optional cooling channels 247 can be formed in the annular base plate 248 of the precursor distribution system 208 to cool the annular base plate 248 during operation. A heat transfer fluid, such as water, glycol, or gas, can be circulated through the cooling channels 247 to maintain the base plate 248 at a predetermined temperature. A liner assembly 227 can 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 can 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 exhaust ports 231 can be formed on the liner assembly 227. The exhaust port 231 can be configured to allow gas to flow from the processing area 220B to the circumferential pumping chamber 225 in a manner that facilitates processing within the system 200.

[0031] Figure 3 Operation of an exemplary semiconductor processing method 300 according to some embodiments of the present technology is shown. The method can be performed in various processing chambers, including the system 200 described above and any other chamber in which plasma deposition can be performed. Method 300 may include several optional operations, which may or may not be specifically associated with some embodiments of the method according to the present technology.

[0032] Method 300 may include a plasma-enhanced chemical vapor deposition (PECVD) process to form a deposited low-κ material. Method 300 may include optional operations prior to initiating method 300, or method 300 may include additional operations after depositing the low-κ material. In embodiments, such as Figure 3 As shown, method 300 may include providing a deposition precursor to a processing region of a semiconductor processing chamber in operation 305. When providing the deposition precursor to the semiconductor processing chamber, a substrate may be housed in the processing region of the semiconductor processing chamber. In operation 310, a plasma effluent of the deposition precursor may be formed. In operation 315, a layer of silicon-oxygen and carbon-containing material may be deposited on the substrate. In an embodiment, in optional operation 320, the layer of silicon-oxygen and carbon-containing material may be exposed to ultraviolet (UV) light.

[0033] In some embodiments, the deposition precursor may include a silicon-oxygen and carbon-containing precursor. Suitable silicon-oxygen and carbon-containing precursors may be, but are not limited to, dimethyldimethoxysilane, 1,1,3,3-tetramethyl-1,3-dimethoxydisiloxane, methoxy(dimethyl)silylmethane, or vinylmethyldimethoxysilane. By utilizing a silicon-containing precursor (which also includes oxygen), an increased amount of oxygen may be present in the plasma effluent to be incorporated into the deposited material. Therefore, an increased amount of oxygen may be present in the deposited layer of the silicon-oxygen and carbon-containing material. This increased oxygen and Si-O bonding may decrease the dielectric constant of the material while also increasing its density.

[0034] The deposition precursor may further include nitrogen-containing precursors. Usable nitrogen-containing precursors may include, but are not limited to, ammonia (NH3), hydrazine (N2H4), and any other nitrogen-containing precursors that can be used for the formation of silicon-containing materials. In embodiments, the flow rate of the nitrogen-containing precursor relative to the flow rate of the silicon-oxygen and carbon-containing precursors may be maintained at and / or adjusted to facilitate the formation of a low-κ material with a low dielectric constant (κ value) and high oxygen incorporation. The deposition precursor may also include one or more carrier gases, such as helium, argon, and nitrogen (N2). While one or more carrier gases may be transported together with other deposition precursors, the carrier gas may be considered an inert gas that does not react to form part of the deposited material. One or more carrier gases may be transported together with other deposition precursors to act as a diluent.

[0035] By utilizing silicon-containing precursors that include oxygen, such as the specific precursors listed above, an increased amount of oxygen can be incorporated into the deposited material. As previously mentioned, the increased oxygen content can decrease the dielectric constant of the deposited material. Furthermore, the increased oxygen content can provide an increased density of the deposited material. In conventional techniques, such as those that do not include silicon-oxygen and carbon-containing precursors, a trade-off may exist between dielectric constant and density.

[0036] The flow rates of the silicon-oxygen and carbon-containing precursors can be greater than or about 50 sccm, greater than or about 60 sccm, greater than or about 70 sccm, greater than or about 80 sccm, greater than or about 90 sccm, greater than or about 100 sccm, greater than or about 125 sccm, greater than or about 150 sccm, greater than or about 175 sccm, greater than or about 200 sccm, greater than or about 250 sccm, greater than or about 300 sccm, greater than or about 350 sccm, greater than or about 500 sccm, greater than or about 750 sccm, greater than or about 1,000 sccm, greater than or about 1,250 sccm, greater than or about 1,500 sccm or greater.

[0037] The flow rate of the nitrogen-containing precursor can be greater than or about 50 sccm, greater than or about 60 sccm, greater than or about 70 sccm, greater than or about 80 sccm, greater than or about 90 sccm, greater than or about 100 sccm, greater than or about 125 sccm, greater than or about 150 sccm, greater than or about 175 sccm, greater than or about 200 sccm, greater than or about 225 sccm, greater than or about 250 sccm, greater than or about 275 sccm, greater than or about 300 sccm, greater than or about 400 sccm, greater than or about 500 sccm, greater than or about 750 sccm, greater than or about 1,000 sccm, greater than or about 1,250 sccm, greater than or about 1,500 sccm or greater. The flow rate of the nitrogen-containing precursor can also be less than or about 2,500 sccm, less than or about 2,250 sccm, less than or about 2,000 sccm, less than or about 1,750 sccm, less than or about 1,250 sccm, less than or about 1,000 sccm or even smaller.

[0038] The flow rate of one or more carrier gases may be greater than or about 200 sccm, greater than or about 300 sccm, greater than or about 400 sccm, greater than or about 500 sccm, greater than or about 750 sccm, greater than or about 1,000 sccm, greater than or about 2,000 sccm, greater than or about 3,000 sccm, greater than or about 3,000 sccm, greater than or about 4,000 sccm, greater than or about 5,000 sccm, or greater.

[0039] In embodiments, the flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor can be less than or about 10:1. For example, the flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor can be less than or about 9:1, less than or about 8:1, less than or about 7:1, less than or about 6:1, or even smaller. As the flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor increases, the density may begin to decrease. Conversely, a lower flow rate ratio of the silicon-oxygen-carbon precursor to the nitrogen-containing precursor may incorporate more nitrogen into the deposited material, and the greater atomic weight of nitrogen than carbon may increase the density of the deposited material. Similarly, the flow rate ratio of the silicon-oxygen-carbon precursor to the carrier gas (such as helium) can be less than or about 1:1. For example, the flow rate ratio of the silicon-oxygen-carbon precursor to the carrier gas can be less than or about 1:2, less than or about 1:3, less than or about 1:4, less than or about 1:5, or even smaller. Furthermore, as the flow rate ratio of silicon-oxygen- and carbon-containing precursors to carrier gas increases, the density may begin to decrease. When the flow rate ratio of silicon-oxygen- and carbon-containing precursors to carrier gas decreases, the precursors may become more dilute, which may slow down the deposition rate of the material and densify the already deposited material.

[0040] Embodiments of method 300 may include forming a plasma effluent from the deposition precursor in operation 310. The plasma effluent may be generated from the deposition precursor within the processing region, such as by providing RF power to the panel to generate plasma within the processing region of the semiconductor processing chamber. In embodiments, the plasma effluent may be formed at a plasma power of less than or about 2,000 W. Increasing the plasma power, such as greater than 2,000 W, may result in increased decomposition of the silicon-oxygen and carbon-containing precursor and may remove oxygen from the deposited material. Conversely, when the plasma power is less than or about 2,000 W, decomposition may occur less frequently and Si-O bonds in the deposited material may be preserved. Therefore, plasma effluents can be formed at plasma powers of less than or about 1,750 W, less than or about 1,500 W, less than or about 1,400 W, less than or about 1,300 W, less than or about 1,200 W, less than or about 1,100 W, less than or about 1,000 W, less than or about 900 W, less than or about 800 W, less than or about 700 W, less than or about 600 W, less than or about 500 W, less than or about 400 W, less than or about 300 W, less than or about 200 W, or less.

[0041] The deposition rate of the silicon-oxygen and carbon-containing material layer can be greater than or about 500 Å / min, and can be greater than or about 525 Å / min, greater than or about 550 Å / min, greater than or about 575 Å / min, greater than or about 600 Å / min, greater than or about 625 Å / min, greater than or about 650 Å / min, greater than or about 675 Å / min, greater than or about 700 Å / min, greater than or about 725 Å / min, greater than or about 750 Å / min, greater than or about 775 Å / min, greater than or about 700 Å / min or greater.

[0042] Embodiments of method 300 may include depositing a silicon-oxygen and carbon-containing material on a substrate in operation 315. As previously described, the substrate may be present in a processing region of a semiconductor processing chamber, and the silicon-oxygen and carbon-containing material may be formed from plasma effluent generated by deposition plasma also present in the processing region. During deposition, the processing region and thus the substrate may be characterized at temperatures below or about 600°C, below or about 580°C, below or about 560°C, below or about 540°C, below or about 520°C, below or about 500°C, below or about 480°C, below or about 460°C, below or about 440°C, below or about 420°C, below or about 400°C, below or about 380°C, below or about 360°C, below or about 340°C, below or about 320°C, below or about 300°C, below or about 280°C, below or about 260°C, or lower. Furthermore, during deposition, the processing area and therefore the substrate can be characterized at temperatures above or about 250°C, above or about 275°C, above or about 300°C, above or about 325°C, above or about 350°C, above or about 375°C, above or about 400°C, above or about 425°C, above or about 450°C, above or about 475°C, above or about 500°C, or higher. When the temperature increases, such as above or about 250°C, the density of the silicon-oxygen and carbon-containing materials may increase. As the temperature increases, the absorbed molecules in the material may diffuse further and combine with already formed atomic nuclei, rather than forming new atomic nuclei. Therefore, when the temperature increases, the absorbed molecules may have more thermal energy to align in the material and may form a denser material.

[0043] During method 300, during deposition, the pressure in the semiconductor processing chamber can be greater than or about 1 Torr, greater than or about 2 Torr, greater than or about 3 Torr, greater than or about 4 Torr, greater than or about 5 Torr, greater than or about 6 Torr, greater than or about 7 Torr, greater than or about 8 Torr, greater than or about 9 Torr, greater than or about 10 Torr, greater than or about 15 Torr, greater than or about 20 Torr, or greater. Increased pressure may result in increased residence time of the deposition precursor, which allows for prolonged reaction time and increased oxygen incorporation into the deposited material. Furthermore, during deposition, the pressure in the semiconductor processing chamber can be less than or about 15 Torr, less than or about 14 Torr, less than or about 13 Torr, less than or about 12 Torr, less than or about 11 Torr, less than or about 10 Torr, less than or about 9 Torr, less than or about 8 Torr, less than or about 7 Torr, less than or about 6 Torr, less than or about 5 Torr, less than or about 4 Torr, less than or about 3 Torr, less than or about 2 Torr, less than or about 1 Torr, or less.

[0044] The oxygen content in the material can be controlled depending on the flow rate of the deposition precursor and / or processing conditions. For example, the oxygen content in the material can be greater than or about 20.0 atomic%, and can be greater than or about 21.0 atomic%, greater than or about 22.0 atomic%, greater than or about 23.0 atomic%, greater than or about 24.0 atomic%, greater than or about 25.0 atomic%, greater than or about 26.0 atomic%, greater than or about 27.0 atomic%, greater than or about 28.0 atomic%, greater than or about 29.0 atomic%, greater than or about 30.0 atomic%, greater than or about 31.0 atomic%, greater than or about 32.0 atomic%, greater than or about 33.0 atomic%, greater than or about 34.0 atomic%, greater than or about 35.0 atomic% or more. As the oxygen content increases, the density may increase due to the increased amount of Si-O bonding.

[0045] Furthermore, the nitrogen content in the material can be less than or about 20.0 atomic%, and can be less than or about 19.0 atomic%, less than or about 18.0 atomic%, less than or about 17.0 atomic%, less than or about 16.0 atomic%, less than or about 15.0 atomic%, less than or about 14.0 atomic%, less than or about 13.0 atomic%, less than or about 12.0 atomic%, less than or about 11.0 atomic%, less than or about 10.0 atomic% or less. When the nitrogen content decreases, fewer Si-N bonds may exist, which can allow for more Si-O bonding and increased density.

[0046] In an embodiment, the layer of the silicon-oxygen and carbon-containing material may be characterized by a leakage current of less than or about 2E-08 A / cm at 2 MV / cm. 2 The increased presence of Si-O bonds leads to a higher oxygen content in the material, which can reduce leakage current. In this embodiment, the leakage current at 2 MV / cm can be less than or approximately 1.9E-08 A / cm. 2 Less than or approximately 1.8E-08 A / cm 2 Less than or approximately 1.7E-08 A / cm 2 Less than or approximately 1.6E-08 A / cm 2 Less than or approximately 1.5E-08 A / cm 2 Less than or approximately 1.4E-08 A / cm 2 Less than or approximately 1.3E-08 A / cm 2 Less than or about 1.2E-08 A / cm 2 Less than or about 1.1E-08 A / cm 2 Less than or approximately 1E-08 A / cm 2 Or smaller.

[0047] The layer of the silicon-oxygen and carbon-containing material is characterized by having a strength of 0.001 A / cm.2 The breakdown voltage at that time is greater than or approximately 6.5 MV / cm. The increased oxygen content in the material due to the increased presence of Si-O bonds can reduce the leakage current. In the example, it is 0.001 A / cm. 2 The breakdown voltage at that time can be greater than or about 6.6 MV / cm, greater than or about 6.7 MV / cm, greater than or about 6.8 MV / cm, greater than or about 6.9 MV / cm, greater than or about 7.0 MV / cm, greater than or about 7.1 MV / cm, greater than or about 7.2 MV / cm, greater than or about 7.3 MV / cm or greater.

[0048] As explained above, the method of this technology includes embodiments of forming a deposition precursor and processing conditions for a low-κ material having a low dielectric constant. In an embodiment of method 300, the deposited low-κ material can be formed as a silicon-oxygen and carbon-containing material having a dielectric constant of less than or about 5.0, less than or about 4.8, less than or about 4.6, less than or about 4.4, less than or about 4.2, less than or about 4.0, less than or about 3.9, less than or about 3.8, less than or about 3.7, less than or about 3.6, less than or about 3.5, or less.

[0049] This technique includes embodiments utilizing deposition precursors and processing conditions that can also form low-κ materials with increased density. In an embodiment of method 300, the deposited low-κ material can be formed as a silicon-oxygen-carbon-containing material with a density greater than or about 2.0 g / cm³. 3 Greater than or approximately 2.05 g / cm³ 3 Greater than or approximately 2.1 g / cm³ 3 Greater than or approximately 2.15 g / cm³ 3 Greater than or approximately 2.2 g / cm³ 3 Greater than or approximately 2.25 g / cm³ 3 Greater than or approximately 2.3 g / cm³ 3 Greater than or approximately 2.35 g / cm³ 3 Greater than or approximately 2.4 g / cm³ 3 Greater than or approximately 2.45 g / cm³ 3 Greater than or approximately 2.5 g / cm³ 3 Or larger.

[0050] Embodiments of method 300 may further include exposing the deposited silicon-oxygen and carbon-containing material to ultraviolet (UV) light in optional operation 320. In embodiments, the UV treatment may be performed in a semiconductor processing chamber used for depositing low-κ materials. However, it is also contemplated that the substrate with the deposited low-κ material may be transferred to another semiconductor processing chamber where the UV treatment operation is performed. In embodiments, the UV treatment in optional operation 320 may expose the layer of the silicon-oxygen and carbon-containing material to ultraviolet light to provide a cured layer of the silicon-oxygen and carbon-containing material. The treatment may produce a cured low-κ material characterized by increased porosity and / or decreased dielectric constant (κ value) compared to the deposited material.

[0051] In some embodiments, the deposited silicon-oxygen and carbon-containing material can be deposited to a thickness greater than or about 750 Å, greater than or about 800 Å, greater than or about 850 Å, greater than or about 900 Å, greater than or about 950 Å, greater than or about 1,000 Å, greater than or about 1,100 Å, greater than or about 1,200 Å, greater than or about 1,300 Å, or greater. The deposited silicon-oxygen and carbon-containing material can be deposited in two or more deposition and UV treatment cycles to accumulate into a final UV-treated low-κ material. For example, the number of deposition and treatment cycles can be more than or about three cycles, more than or about five cycles, more than or about ten cycles, more than or about 15 cycles, more than or about 20 cycles, more than or about 30 cycles, more than or about 40 cycles, more than or about 50 cycles, or more.

[0052] In the foregoing description, numerous details have been set forth for purposes of explanation in order 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 practiced without some of these details or with additional details.

[0053] With several embodiments disclosed, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents can be used without departing from the spirit of the embodiments. Furthermore, several well-known processes and elements have not been described to avoid unnecessarily obscuring the scope of the invention. Therefore, the above description should not be considered as a limitation on the scope of the invention.

[0054] When a range of values ​​is provided, it will be understood that, unless the context explicitly specifies otherwise, each intermediate value between the upper and lower limits of the range is also specifically disclosed, up to the smallest fraction of the lower limit unit. This includes any of the stated values ​​within the range or any narrower range between the stated intermediate value and any other stated value or intermediate value within the range. The upper and lower limits of those smaller ranges may independently include or exclude the range, and each range that includes any limit value, excludes two limits, or includes two limits is also covered in the technique, but is subject to any explicitly excluded limits within the range. In cases where the range includes one or two limits, this also includes excluding those ranges that include one or both limits.

[0055] As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural references unless the context clearly specifies otherwise. Thus, for example, a reference to “a layer” includes multiple such layers, and a reference to “the precursor” includes one or more precursors and their equivalents known to those skilled in the art, and so on.

[0056] Additionally, when used in this specification and the following claims, the terms “comprise(s) / comprising,” “contain(s) / containing,” and “include(s) / including” are intended to specify the presence of the said feature, integer, component, or operation, but they do not preclude the presence or addition of one or more other features, integers, components, operations, actions, or groups.

Claims

1. A semiconductor processing method comprising: providing a deposition precursor to a processing region of a semiconductor processing chamber, wherein the deposition precursor comprises a silicon-oxygen-and-carbon- containing precursor, and wherein a substrate is disposed within the processing region; forming a plasma effluents of the deposition precursor; and depositing a layer of a silicon-oxygen-and-carbon-containing material on the substrate, wherein the layer of the silicon-oxygen-and-carbon-containing material is characterized by a dielectric constant of less than or about 4.5, and wherein the layer of the silicon-oxygen-and-carbon-containing material is characterized by a density of greater than or about 2.0 g / cm 3 .

2. The semiconductor processing method of claim 1, wherein the silicon-oxygen-and-carbon-containing precursor comprises dimethyldimethoxysilane, 1,1,3,3-tetramethyl- 1,3-dimethoxydisiloxane, methoxy(dimethyl)silylmethane, or vinylmethyldimethoxysilane.

3. The semiconductor processing method of claim 1, wherein the deposition precursor further comprises a nitrogen-containing precursor.

4. The semiconductor processing method of claim 3, wherein the nitrogen-containing precursor comprises ammonia (NH3).

5. The semiconductor processing method of claim 3, wherein a flow rate ratio of the silicon-oxygen-and-carbon-containing precursor to the nitrogen-containing precursor is less than or about 10:

1.

6. The semiconductor processing method of claim 1, further comprising: providing helium gas with the deposition precursor, wherein a flow rate ratio of the silicon-oxygen-and-carbon-containing precursor to helium gas is less than or about 1:

1.

7. The semiconductor processing method of claim 1, wherein the plasma effluents are formed at a plasma power of less than or about 1,500 W.

8. The semiconductor processing method of claim 5, wherein a temperature in the semiconductor processing chamber is maintained at greater than or about 250 °C.

9. The semiconductor processing method of claim 1, wherein a pressure in the semiconductor processing chamber is maintained at less than or about 15 Torr.

10. The semiconductor processing method of claim 1, wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by an oxygen content of greater than or about 20.0 atomic %.

11. The semiconductor processing method of claim 1, wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by a nitrogen content of less than or about 20.0 atomic %.

12. A semiconductor processing method comprising: providing a deposition precursor to a processing region of a semiconductor processing chamber, wherein the deposition precursor comprises a silicon-oxygen-and-carbon-containing precursor and a nitrogen-containing precursor, and wherein a substrate is disposed within the processing region; forming a plasma effluents of the deposition precursor; and depositing a layer of silicon-oxygen-and-carbon-containing material on the substrate, wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by an oxygen content of greater than or about 25.0 atomic %, and wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by a dielectric constant of less than or about 4.

2.

13. The semiconductor processing method of claim 12, wherein the silicon-oxygen-and-carbon-containing precursor comprises dimethyldimethoxysilane.

14. The semiconductor processing method of claim 12, wherein a flow rate ratio of the silicon-oxygen-and-carbon-containing precursor to the nitrogen-containing precursor is less than or about 10:

1.

15. The semiconductor processing method of claim 14, wherein the plasma effluents are formed at a plasma power of less than or about 1,000 W.

16. The semiconductor processing method of claim 12, wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by a breakdown voltage of greater than or about 6.5 MV / cm at 0.001 A / cm 2 2> 17. The semiconductor processing method of claim 12, wherein a temperature within the processing region is maintained at less than or about 500 °C.

18. A semiconductor processing method comprising: providing a deposition precursor to a processing region of a semiconductor processing chamber, wherein the deposition precursor comprises a silicon-oxygen-and-carbon- containing precursor, wherein a substrate is disposed within the processing region, and wherein the silicon-oxygen-and-carbon-containing precursor comprises dimethyldimethoxysilane; forming a plasma effluent of the deposition precursor; and depositing a layer of a silicon-oxygen-and-carbon-containing material on the substrate, wherein the layer of the silicon-oxygen-and-carbon-containing material is characterized by an oxygen content of greater than or about 25.0 atomic %, wherein the layer of the silicon-oxygen-and-carbon-containing material is characterized by a dielectric constant of less than or about 4.2, and wherein the layer of the silicon-oxygen-and-carbon-containing material is characterized by a density of greater than or about 2.

0.

19. The semiconductor processing method of claim 18, wherein a deposition rate of the layer of the silicon-oxygen-and-carbon-containing material is greater than or about 500 A / min.

20. The semiconductor processing method of claim 18, wherein the layer of silicon-oxygen-and-carbon-containing material is characterized by a leakage current of less than or about 2E-08 A / cm at 2 MV / cm 2 .

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