Vapor deposition of carbon-doped metal oxides for use as photoresists

Abstract

The embodiments disclosed herein include a method for forming a metal-oxygenated photoresist on a substrate. In one embodiment, the method includes repeated deposition cycles, wherein each repetition of the deposition cycle includes: a) flowing a metal precursor into a chamber including the substrate; and b) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal precursor to form a metal-oxygenated photoresist.

Description

Technical Field

[0001] The entire contents of the priority interest in this application filed on December 17, 2020, U.S. Provisional Application No. 63 / 126,977, are incorporated herein by reference.

[0002] Embodiments of the present invention relate to the field of semiconductor processing, and more specifically to the deposition of a photoresist layer onto a substrate using vapor phase processing. Prior Technology

[0003] Lithography has been used in the semiconductor industry for decades to create 2D and 3D patterns in microelectronic devices. The lithography process involves spin-coating a film (photoresist), irradiating the film with a selected pattern using an energy source (exposure), and removing (etching) the exposed (positive-tone) or unexposed (negative-tone) areas of the film by dissolving it in a solvent. Baking can be performed to remove any remaining solvent.

[0004] The photoresist should be a radiation-sensitive material, and upon irradiation, a chemical transformation occurs in the exposed portion of the film, allowing for a change in solubility between the exposed and unexposed areas. Using this solubility change, either the exposed or unexposed area of ​​the photoresist is removed (etched). The photoresist is now developed, and the pattern can be transferred to the underlying thin film or substrate by etching. After pattern transfer, removing residual photoresist and repeating this process multiple times yields 2D and 3D structures that will be used in microelectronic devices.

[0005] Several important properties exist in photolithography. These include sensitivity, resolution, low line-edge roughness (LER), etch resistance, and the ability to form thinner layers. Higher sensitivity requires less energy to alter the solubility of the as-deposited film, resulting in higher efficiency in photolithography. Resolution and LER determine the narrowness of features achievable through photolithography. Higher etch resistance is required for pattern transfer to form deep structures. Higher etch resistance also allows for thinner films. Thinner films increase the efficiency of photolithography. Summary of the Invention

[0006] The embodiments disclosed herein include a method for forming a metal-oxygenated photoresist on a substrate. In one embodiment, the method includes repeated deposition cycles, wherein each repetition of the deposition cycle includes: a) flowing a metal precursor into a chamber containing the substrate; and b) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal precursor to form a metal-oxygenated photoresist.

[0007] Additional embodiments include a method for forming a metal-oxygenated photoresist on a substrate. In one embodiment, the method includes repeated deposition cycles, wherein each repetition of the deposition cycle includes: a) flowing a metal precursor into a chamber containing the substrate; and b) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal precursor to form the metal-oxygenated photoresist. In one embodiment, the method further includes treating the metal-oxygenated photoresist with plasma treatment after a first number of repetitions of the deposition cycle.

[0008] In yet another embodiment, a method for forming a metal-oxygenated photoresist on a substrate is disclosed. In one embodiment, the method comprises repeated deposition cycles, wherein each repetition of the deposition cycle comprises: a) flowing a metal precursor into a chamber containing the substrate, wherein the metal precursor comprises the general formula MR XL Y, where X = 0–4 and Y = 4–X, and wherein M is a metal, R is a straight-chain alkyl, branched alkyl, or cycloalkyl group, and L is an alkylamine, Cl, Br, CN, CNO, SCN, N3, or SeCN; b) purging the chamber; c) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal precursor to form a metal-oxygenated photoresist, wherein the oxidant comprises one or more of water, O2, ethylene glycol, alcohols, peroxides, and acids; and d) purging the chamber. Simple Explanation of the Diagram

[0009] Figure 1 is a flowchart illustrating a process for depositing metal oxide photoresist on a substrate using vacuum deposition according to an embodiment.

[0010] Figure 2 is a flowchart illustrating an additional process for depositing metal oxide photoresist on a substrate using a vacuum deposition process with plasma treatment according to one embodiment.

[0011] Figure 3 is a plan view of a processing tool according to an embodiment that allows for the use of a space atomic layer deposition process for depositing metal oxide photoresist on a substrate.

[0012] Figure 4A is a cross-sectional view of a substrate with metal-oxygen photoresist according to an embodiment.

[0013] Figure 4B is a cross-sectional drawing of a substrate having a first layer and a second layer of metal oxide photoresist according to an embodiment.

[0014] Figure 5 is a cross-sectional view of a processing tool that can be used to perform the processing shown in Figure 1 or Figure 2 according to an embodiment of the present invention.

[0015] Figure 6 illustrates a block diagram of an exemplary computer system according to an embodiment of the present invention. Implementation

[0016] This section describes a method for depositing photoresist on a substrate using vapor phase processing. In the following description, numerous specific details are set forth to provide a complete understanding of embodiments of the invention. Without these specific details, it will be apparent to those skilled in the art that embodiments of the invention can be practiced. In other instances, well-known forms, such as integrated circuit fabrication, are not described in detail to avoid unnecessarily obscuring embodiments of the invention. Furthermore, it will be understood that the various embodiments shown in the figures are illustrative and not necessarily drawn to scale.

[0017] For background, photoresist systems used in extreme ultraviolet (EUV) lithography suffer from low efficiency. Specifically, current photoresist material systems for EUV lithography require high doses to provide the necessary solubility conversion to allow for photoresist development. Due to increased sensitivity to EUV radiation, organic-inorganic hybrid materials (e.g., metal oxy-based material systems) have been proposed as material systems for EUV lithography. Such material systems typically contain metals (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. Metal oxy-based organic-inorganic hybrid materials have also been shown to provide lower LER and higher resolution, properties required for forming narrow features.

[0018] Metal-oxygenated photoresist systems are currently mounted on a substrate using a wet process. The system is dissolved in a solvent and spread over a substrate (e.g., a wafer) using a wet chemical deposition process (such as spin coating). Wet chemical deposition of photoresist faces several challenges. One negative aspect is the generation of significant amounts of wet byproducts. These byproducts are undesirable, and the semiconductor industry actively works to minimize them. Furthermore, wet chemical deposition can cause non-uniformity issues. For example, spin coating can provide photoresist layers with non-uniform thickness or non-uniform distribution of metal-oxygen molecules. Additionally, metal-oxygenated photoresist materials have been shown to suffer from thickness reduction after exposure, which is problematic in lithography processes. Moreover, in spin coating, the percentage of metal in the photoresist is fixed and cannot be easily adjusted.

[0019] Therefore, embodiments of the present invention provide a vacuum deposition process for providing a metal-oxygen photoresist layer. Vacuum deposition processes (e.g., atomic layer deposition (ALD) processes) overcome the shortcomings of the aforementioned wet deposition processes. In particular, vacuum deposition processes offer the following advantages: 1) elimination of wet byproducts; 2) provision of a highly uniform photoresist layer; 3) resistance to thickness reduction after exposure; and 4) provision of a mechanism to adjust the metal percentage in the photoresist.

[0020] The embodiments disclosed herein provide various vacuum deposition processes comprising the reaction of a metal precursor with an oxidant. In a first embodiment, the vacuum deposition process may be an ALD process. In some embodiments, the vacuum deposition process may be a thermal treatment. In other embodiments, the vacuum deposition process may be a plasma-enhanced (PE) deposition process (e.g., PE-ALD). The vacuum deposition process may further include plasma treatment (e.g., before deposition, after a predetermined number of deposition cycles, and / or after the final deposition cycle).

[0021] In addition to providing increased uniformity (e.g., thickness uniformity, compositional uniformity across the surface, etc.), ALD processing offers significant flexibility in the composition of the metal-oxygen photoresist (in the thickness direction). For example, the composition can be modified by changing the precursor during different cycles of the deposition process. This modifiable metal-oxygen structure allows for well-tuning of the photoresist for different applications. In one such application, the major portions of the metal-oxygen photoresist are optimized for dose, and different compositions at the interface immediately adjacent to the underlying substrate are tuned for adhesion, sensitivity to EUV photons, sensitivity to developing chemicals, or the like. This improves subsequent lithography profile control, such as scumming, defects, and resist collapse / stripping. Furthermore, the stages of metal-oxygen photoresist variation can be optimized for pattern type. For example, pillars require improved adhesion, while line / spaced patterns require lower adhesion and can be optimized for improved dose sensitivity.

[0022] In one embodiment, the vacuum deposition process relies on a chemical reaction between a metal precursor and an oxidant. The metal precursor and oxidant are evaporated into a vacuum chamber. The metal precursor and oxidant react to form a photoresist layer containing metal oxygen groups on the surface of a substrate. In some embodiments, the metal precursor and oxidant are provided to the vacuum chamber in alternating pulses. In ALD or PE-ALD processes, the vacuum chamber can be purged between the pulses of the metal precursor and oxidant.

[0023] Referring now to Figure 1, a process 100 for depositing metal oxide photoresist on a substrate according to one embodiment is shown. In one embodiment, the metal oxide photoresist is deposited on a substrate, such as, but not limited to, a silicon wafer. It will be appreciated that the substrate may comprise materials other than silicon.

[0024] In one embodiment, process 100 begins with operation 101, which includes providing a metal precursor into a vacuum chamber containing a substrate. In one embodiment, the metal precursor may have the general formula MR XL Y, where X = 0–4 and Y = 4–X. M is a metal, such as one or more of Sn, Hf, Zr, Co, Cr, Mn, Fe, Cu, Ni, Mo, W, Ta, Os, Re, Pd, Pt, Ti, V, In, Sb, Al, As, Ge, Se, Cd, Ag, Pb, Au, Er, Yb, Pr, La, Na, and Mg. In one embodiment, R is an alkyl group (e.g., C1–C10). The alkyl group may be a straight-chain alkyl group, a branched alkyl group, or a cycloalkyl group (e.g., tBu, nBu, sec-butyl, or iPr). R may also be alkenyl, alkynyl, aryl, or benzyl. Structures (1) and (2) are illustrated examples of a pair of suitable MR structures. In one embodiment, L is an alkylamine group (C1-C10), such as dimethylamino or methylethylamino. L may also contain Cl, Br, CN, CNO, SCN, N3, or SeCN. Structures (3), (4), and (5) are illustrated examples of suitable ML structures. An example of a complete metal precursor (e.g., a tin precursor) is shown in structure (6). The R component can be modified to change the exposure sensitivity of the metal oxide film. The reactivity between the metal precursor and the oxidant can be modulated by changing R and / or L on the metal precursor. (1) (2) (3) (4) (5) (6)

[0025] In one embodiment, a single metal precursor species may flow into the chamber. In other embodiments, two or more different metal precursor species may flow into the chamber. For example, in some embodiments, metal precursors with different metals M may be used. In one embodiment, the metal precursor may flow into the chamber by itself. In other embodiments, an inert carrier gas may also flow into the chamber along with the metal precursor. The carrier gas may be an inert gas, such as Ar, N₂, or He. In one embodiment, the metal precursor is adsorbed onto the surface of the substrate.

[0026] In one embodiment, process 100 may continue with operation 102, which includes purging the vacuum chamber. Purging is optional in some embodiments. That is, in some embodiments, process 100 may continue directly from operation 101 to operation 103. Purging the chamber may include introducing an inert gas such as Ar, N₂, or He into the chamber.

[0027] In one embodiment, process 100 may continue to operation 103, which includes providing an oxidant into a vacuum chamber. The oxidant reacts with a metal precursor to form a metal-oxygenated film over a substrate. Typically, the metal-oxygenated film contains MO and MC bonds in the MOC network. Upon exposure (e.g., UV or EUV light), the MC bonds break and the carbon percentage in the film decreases. This results in selective etching during the development process. In one embodiment, the oxidant may comprise one or more of water, O2, ethylene glycol, alcohols (e.g., methanol, ethanol, etc.), peroxides (e.g., H2O2), and acids (e.g., formic acid, acetic acid, etc.).

[0028] In one embodiment, process 100 continues with operation 104, which includes purging the vacuum chamber. The purging operation is optional in some embodiments. That is, in some embodiments, process 100 may continue directly from operation 103 to operation 101. Purging the chamber may include infusing an inert gas such as Ar, N₂, or He into the chamber.

[0029] As indicated by the arrows from operation 104 to operation 101, process 100 can be repeated any number of cycles to provide a metal oxide film of desired thickness. In one embodiment, the same process gas is used for each repetition of the deposition cycle. In other embodiments, the process gas can be changed between cycles. For example, a first deposition cycle may utilize a first metal precursor vapor, and a second deposition cycle may utilize a second metal precursor vapor. In some embodiments, subsequent deposition cycles may continuously alternate between the first metal precursor vapor and the second metal precursor vapor. In one embodiment, multiple oxidant vapors can be alternated between cycles in a similar manner. In yet another embodiment, a first metal precursor and a first oxidant can be used to provide a metal oxide layer with high adhesion strength, and a second metal precursor and a second oxidant can be used in subsequent deposition cycles to provide a highly sensitive metal oxide film.

[0030] In one embodiment, each of processing operations 101-104 can be performed for any duration. For example, processing operations 101-104 can be performed for a period between approximately 1 millisecond and 1 minute. The duration of each operation 101-104 does not need to be the same in some embodiments. The duration of each operation 101-104 may also be different between deposition cycles.

[0031] In one embodiment, process 100 is performed as a heat treatment. That is, process 100 can be performed in the absence of plasma. This type of treatment may be referred to as ALD treatment in some embodiments. In one embodiment, the temperature of the substrate can be maintained between approximately -40°C and approximately 500°C.

[0032] In yet another embodiment, plasma may be excited during one or more of the processing operations 101-104. In such examples, the presence of plasma can enhance the chemical reactions used to form the metal-oxygen photoresist. This embodiment may be referred to as PE-ALD processing. In one embodiment, any plasma source can be used to form plasma. For example, plasma sources may include, but are not limited to, capacitively coupled plasma (CCP) sources, inductively coupled plasma (ICP) sources, remote plasma sources, or microwave plasma sources.

[0033] In the illustrated embodiment, process 100 is shown to begin with operation 101. However, it will be appreciated that process 100 may begin with any of operations 101 to 104. For example, starting with operation 103 may help process the surface of the substrate to improve the adhesion between the metal precursor and the substrate.

[0034] In one embodiment, the vacuum chamber utilized in process 100 can be any suitable chamber capable of providing subatmospheric pressure. In one embodiment, the vacuum chamber may include temperature control features for controlling the chamber wall temperature and / or for controlling the substrate temperature. In one embodiment, the vacuum chamber may also include features for providing plasma within the chamber. A detailed description of a suitable vacuum chamber is provided later with reference to Figure 3 or Figure 5.

[0035] It will be understood that specific processing parameters can be selected during the execution of process 100 to enhance one or more properties of the metal oxide film. Typically, processing conditions may include a spray head temperature between approximately -20°C and approximately 175°C. The stage temperature may also be between approximately -20°C and approximately 175°C. In one embodiment, the pressure in the chamber may be less than approximately 10 Torr. In other embodiments, the pressure may be between approximately 0.01 Torr and approximately 10 Torr. The spacing between the substrate and the spray head may be between approximately 100 mils and approximately 4,000 mils. Regarding gas flow, the precursor gas may have a flow rate between approximately 0.1 slm and approximately 5 slm. The precursor flow rate may include a carrier gas (e.g., Ar or N₂). The oxidant (e.g., H₂O) flow rate may be between approximately 50 mgm and approximately 500 mgm. The carrier gas (e.g., Ar or N₂) may be used to carry the oxidant into the chamber. The carrier gas can have a flow rate between approximately 0.01 slm and approximately 5 slm.

[0036] Referring now to Figure 2, a flowchart of process 210 according to an additional embodiment is shown. In one embodiment, process 210 may be initiated by operation 211, which includes treating the substrate with plasma treatment in a vacuum chamber. Operation 211 may be used to prepare the surface of the substrate to provide improved adhesion to the metal oxide film. In some embodiments, initiating plasma treatment operation 211 is optional. That is, process 210 may be initiated by operation 212 in some embodiments.

[0037] In one embodiment, operation 212 may include providing a metal precursor into a vacuum chamber containing a substrate. In one embodiment, the metal precursor may be substantially similar to the metal precursor described in process 100, and will not be repeated here.

[0038] In one embodiment, process 210 may continue with operation 213, which includes purging the vacuum chamber. In one embodiment, the purging operation is optional. That is, in some embodiments, process 210 may proceed directly to operation 214 after operation 212. Purging the chamber may include infusing an inert gas such as Ar, N2, or He into the chamber.

[0039] In one embodiment, process 210 may continue with operation 214, which includes providing an oxidant into a vacuum chamber. In one embodiment, the oxidant reacts with a metal precursor to form a metal oxide film over a substrate. In one embodiment, the oxidant in operation 214 may be substantially similar to the oxidant in operation 103 and will not be repeated here.

[0040] In one embodiment, process 210 may continue with operation 215, which includes purging the vacuum chamber. In one embodiment, the purging operation is optional. That is, in some embodiments, process 210 may proceed directly to operation 216 after operation 214. Purging the chamber may include infusing an inert gas such as Ar, N2, or He into the chamber.

[0041] In one embodiment, process 210 may continue with operation 216, which includes determining whether a predetermined number of deposition cycles has been completed. Each deposition cycle may refer to a repetition of operations 212-215. If the predetermined number of deposition cycles has not been completed, then process 210 loops back to operation 212 to begin a new deposition cycle. If the predetermined number of deposition cycles has been completed, then process 210 continues to operation 217.

[0042] In one embodiment, operation 217 includes treating the metal-oxygen film with plasma treatment. In one embodiment, plasma treatment may include plasma generated from one or more inert gases such as Ar, N₂, He, etc. In one embodiment, the inert gas or gases may also be mixed with one or more oxygen-containing gases, such as O₂, CO₂, CO, NO, NO₂, H₂O, etc. In one embodiment, the vacuum chamber may be purged after operation 217. Purge may include pulses of inert gases such as Ar, N₂, He, etc.

[0043] After operation 217, process 210 can continue with operation 218. Operation 218 may include determining whether the desired metal oxide film thickness has been reached. If the desired thickness has not been reached, the process can continue by looping back to operation 212. If the desired thickness has been reached, the process can continue to operation 219, at which point process 210 ends. In this example, the final plasma treatment of operation 217 can be considered a "post-processing". In some embodiments, process 210 may end before performing post-processing.

[0044] In some embodiments, plasma processing operation 217 is performed periodically after a predetermined number of deposition cycles. For example, plasma processing operation 217 may be performed every 10 deposition cycles. In other embodiments, the predetermined number of deposition cycles between plasma processing operations 217 may vary. For example, a first plasma processing operation 217 may be performed after 10 deposition cycles, and a second plasma processing operation 217 may be performed after another 20 deposition cycles.

[0045] Similar to process 100, process 210 can be performed as a heat treatment or a plasma-enhanced treatment. For example, plasma can be stimulated during one or more of operations 212-215. Furthermore, although the deposition cycle (i.e., operations 212-215) begins with a flowing metal precursor, it will be appreciated that the deposition cycle may optionally begin with a flowing oxidant.

[0046] In one embodiment, the vacuum chamber utilized in process 210 can be any suitable chamber capable of providing subatmospheric pressure. In one embodiment, the vacuum chamber may include temperature control features for controlling the chamber wall temperature and / or for controlling the substrate temperature. In one embodiment, the vacuum chamber may also include features for providing plasma within the chamber. A detailed description of a suitable vacuum chamber is provided later with reference to Figure 3 or Figure 5.

[0047] It will be understood that specific processing parameters can be selected during the execution of process 210 to enhance one or more properties of the metal oxide film. Typically, processing conditions may include a spray head temperature between approximately -20°C and approximately 175°C. The stage temperature may also be between approximately -20°C and approximately 175°C. In one embodiment, the pressure in the chamber may be less than approximately 10 Torr. In other embodiments, the pressure may be between approximately 0.01 Torr and approximately 10 Torr. The spacing between the substrate and the spray head may be between approximately 100 mils and approximately 4,000 mils. Regarding gas flow, the precursor gas may have a flow rate between approximately 0.1 slm and approximately 5 slm. The precursor flow rate may include a carrier gas (e.g., Ar or N₂). The oxidant (e.g., H₂O) flow rate may be between approximately 50 mgm and approximately 500 mgm. The carrier gas (e.g., Ar or N₂) may be used to carry the oxidant into the chamber. The carrier gas can have a flow rate between approximately 0.01 slm and approximately 5 slm.

[0048] In yet another embodiment, a deposition process utilizing multiple metal precursors is employed. The first metal precursor may have the general formula MR xL 4-X. The first metal precursor may be substantially similar to the metal precursors described above. The second metal precursor may have the general formula ML 4, where L is an alkylamine. That is, the second metal precursor may not include the R group containing carbon. Therefore, adjustments between the first and second metal precursors can be used to adjust the carbon content in the film.

[0049] In one embodiment, the deposition process may utilize a loop comprising a first cycle and a second cycle. The first cycle comprises flowing an oxidant after flowing a first metal precursor. The first cycle may be repeated any number of times. This loop may then continue with a second cycle, which comprises flowing an oxidant after flowing a second metal precursor. The second cycle may also be repeated any number of times. In one embodiment, this loop may be repeated any number of times to provide a film with a desired thickness. It will be appreciated that the deposition loop may begin with a repetition of the first cycle or with a repetition of the second cycle.

[0050] This deposition process offers flexibility in the composition of the film. For example, loops starting with a second cycle (or including a large number of repetitions of the second cycle) can be used to form a film with a lower carbon concentration at the interface with the underlying substrate. This can provide improved adhesion. Furthermore, by gradually changing the number of repetitions of the first and second cycles in each loop, a compositional gradient can be achieved in the film.

[0051] Referring now to Figure 3, a plan view of a chamber 330 according to one embodiment is shown. In one embodiment, the chamber 330 can be controlled to perform one or more metal oxide deposition processes according to instructions stored in memory. For example, one or more processes such as processes 100 and 210 described above can be performed in the vacuum chamber 330. In one embodiment, the chamber 330 may contain a plurality of regions 331 A to D. Although four regions 331 are shown, it will be appreciated that the chamber 330 may contain two or more regions 331. In one embodiment, a substrate 335 is provided in the regions 331. The substrate 335 rotates through the different regions 331 as indicated by the arrows.

[0052] In one embodiment, each region 331 of chamber 330 is responsible for performing one of the processing operations in a deposition cycle of metal-oxygen photoresist. For example, in region 331A, a metal precursor may flow into the chamber; in region 331B, a decontamination may be provided; in region 331C, an oxidant may flow into the chamber; and in region 331D, a decontamination may be provided. In some embodiments, the boundaries between regions 331 may include features for decontamination. In this embodiment, regions 331A and 331C provide the metal precursor, and regions 331B and 331D provide the oxidant. Thus, two deposition cycles can occur on substrate 335 with each complete rotation of chamber 330.

[0053] Referring now to Figure 4A, a cross-sectional view of a wafer 440 according to one embodiment is shown. The wafer 440 includes a substrate 441 and a metal-oxygenated photoresist 442 disposed above the substrate 441. The substrate 441 may comprise silicon or other materials used in semiconductor manufacturing. In one embodiment, the metal-oxygenated photoresist 442 is deposited above the substrate 441 using a process such as described above. In one embodiment, the metal-oxygenated photoresist 442 has a uniform composition and uniform thickness. This embodiment can be provided when each of the deposition cycles is substantially consistent.

[0054] However, it will be appreciated that non-uniform material is possible across the thickness of the metal-oxygen photoresist 442. An example of this embodiment is shown in Figure 4B. As shown, an interface layer 443 is provided between the metal-oxygen photoresist 442 and the substrate 441. The interface layer 443 may be a metal-oxygen material, adapted to have improved adhesion strength compared to the metal-oxygen photoresist 442. In one embodiment, the interface layer 443 may have a thickness of approximately several nanometers to several hundred nanometers. The interface layer 443 may be formed by a deposition cycle (or multiple cycles) different from the deposition cycle used to form the remainder of the metal-oxygen photoresist 442. For example, different metal precursors and / or different oxidants may be used to form the interface layer 443 and the metal-oxygen photoresist 442.

[0055] Using vapor phase processing, such as that described in the examples above, to provide metal-oxygenated photoresist films offers significant advantages over wet chemical methods. One such advantage is the elimination of wet byproducts. Vapor phase processing eliminates liquid waste and simplifies byproduct removal. Furthermore, vapor phase processing provides a more uniform photoresist layer. This uniformity can refer to the thickness uniformity throughout the wafer and / or the uniformity of the metal composition distribution in the metal-oxygenated film. In particular, ALD and PE-ALD processes have demonstrated superior thickness and composition uniformity.

[0056] Furthermore, vapor phase processing offers excellent control over the percentage and composition of metals in the photoresist. The percentage of metals can be adjusted by increasing / decreasing the flow rate of the metal precursor into the vacuum chamber and / or by adjusting the pulse length of the metal precursor / oxidant. Vapor phase processing also allows for the inclusion of multiple different metals in the metal oxide film. For example, a single pulse flowing two different metal precursors can be used, or alternating pulses of two different metal precursors can be used.

[0057] Furthermore, it has been shown that metal-oxygen photoresists formed using vapor phase processing are more resistant to thickness reduction after exposure. This resistance to thickness reduction, not limited to any specific mechanism, is believed to be at least partly attributable to the reduction in carbon loss during exposure.

[0058] Figure 5 is a schematic diagram of a vacuum chamber configured to perform vapor deposition of metal-oxygen photoresist according to an embodiment of the present invention. The vacuum chamber 500 includes a grounded chamber 505. A substrate 510 is loaded through an opening 515 and held in a temperature-controlled chuck 520.

[0059] Processing gases are supplied from gas source 544 and delivered to the interior of chamber 505 via individual mass flow controllers 549. In some embodiments, a gas distribution plate 535 provides distribution of processing gases, such as metal precursors, oxidants, and inert gases. Chamber 505 is emptied via exhaust pump 555.

[0060] When RF power is applied during processing of substrate 510, plasma forms over substrate 510 in the chamber processing area. A bias power RF generator 525 is coupled to a temperature-controlled chuck 520. The bias power RF generator 525 provides bias power to enable the plasma when desired. The bias power RF generator 525 may have a low frequency, for example, between about 2 MHz and 60 MHz, and in a particular embodiment, in the 13.56 MHz band. In some embodiments, the vacuum chamber 500 includes a third bias power RF generator 526 with a frequency in the about 2 MHz band, which is connected to the same RF match 527 as the bias power RF generator 525. A source power RF generator 530 is coupled to a plasma generating element (e.g., a gas distribution plate 535) via a match (not shown) to provide source power to enable the plasma. The source RF generator 530 may have a frequency, for example, between 100 and 180 MHz, and in a particular embodiment, in the 162 MHz band. As substrate diameters have progressed over time, from 150mm, 200mm, 300mm, and so on, it is common in the field to normalize the source of plasma etching systems and bias power for substrate area.

[0061] The vacuum chamber 500 is controlled by a controller 570. The controller 570 may include a CPU 572, a memory 573, and an I / O interface 574. The CPU 572 can perform processing operations within the vacuum chamber 500 according to instructions stored in the memory 573. For example, one or more of the processes 100 and 210 described above can be implemented in the vacuum chamber by the controller 570.

[0062] Figure 6 illustrates a graphical representation of a machine in an exemplary form of computer system 600, in which a set of instructions can be executed to cause the machine to perform any or more of the methods described herein. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), intranet, extranet, or internet. The machine may operate as a client machine in a server-side or master-slave architecture networking environment, or as a peer machine in a peer-to-peer (or distributed) networking environment. The machine may be a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, network device, server, network router, switch, or bridge, or any machine capable of executing a set of instructions (sequentially or otherwise) specifying the actions to be performed by the machine. Furthermore, although only a single machine is depicted, the term "machine" should be used to include any set of machines (e.g., computers) that individually or jointly execute a set (or more) of instructions to perform any or more of the methods described herein.

[0063] The example computer system 600 includes a processor 602, main memory 604 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), static memory 606 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and secondary memory 618 (e.g., data storage device), wherein they are interconnected via bus 630.

[0064] Processor 602 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, or the like. More specifically, processor 602 may be a Complex Instruction Set Computing (CISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Set Computing (VLIW) microprocessor, a processor that implements other instruction sets, or a processor that implements a combination of instruction sets. Processor 602 may also be one or more special-purpose processing devices, such as an Application Special Purpose Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), a Network Processor, or the like. Processor 602 is configured to implement processing logic 626 for performing the operations described herein.

[0065] The computer system 600 may further include a network interface device 608. The computer system 600 may also include a video display unit 610 (e.g., a liquid crystal display (LCD), a light-emitting diode display (LED), or a cathode ray tube (CRT)), a digit input device 612 (e.g., a keyboard), a cursor control device 614 (e.g., a mouse), and a signal generating device 616 (e.g., a speaker).

[0066] Secondary memory 618 may include machine-accessible storage medium (or more specifically, machine-readable storage medium) 632, storing one or more sets of instructions (e.g., software 622) that perform any or more of the methods or functions described herein. During execution of software 622 by computer system 600, software 622 may also reside wholly or at least partially in main memory 604 and / or processor 602, which also constitute machine-readable storage medium. Software 622 may further be transmitted or received on network 620 via network interface device 608.

[0067] Although machine-accessible storage medium 632 is shown as a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be understood to include single media or multiple media (e.g., centralized or distributed databases and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" should also include any medium capable of storing or encoding a set of instructions for use by a machine to perform and cause the machine to execute any or more of the methods of the present invention. The term "machine-readable storage medium" should therefore include, but is not limited to, solid-state memory and optical or magnetic media.

[0068] According to one embodiment of the present invention, a machine can access a storage medium having instructions stored thereon, which instruct a data processing system to perform a method of depositing metal-oxygen photoresist on a substrate. This method includes evaporating a metal precursor into a vacuum chamber and evaporating an oxidant into the vacuum chamber. The metal precursor and oxidant may be sequentially provided into the vacuum chamber. The reaction between the metal precursor and the oxidant results in the formation of metal-oxygen photoresist on the substrate. In some embodiments, the metal-oxygen photoresist may be treated with plasma.

[0069] Therefore, a method for forming metal-oxygen photoresists using vapor phase processing has been revealed.

[0070] 100: Processing 101, 102, 103, 104: Operations 210: Processing 211,212,213,214,215,216,217,218,219: Operations 330: Chamber 331 A, 331 B, 331 C, 331 D: District 335:Substrate 440: Wafer 441: Substrate 442: Metal Oxide Photoresist 443: Interface Layer 500: Vacuum chamber 505: Chamber 510:Substrate 515: Opening 520: Temperature-controlled clamp 525: Bias Power RF Generator 526: Third Bias Power RF Generator 527:RF Matching 530: Source Power RF Generator 535: Gas Distribution Plate 544: Gas Source 549: Mass Flow Controller 555: Exhaust pump 570: Controller 572: CPU 573: Memory 574:I / O interface 600: Computer System 602: Processor 604: Main Memory 606: Static Memory 608: Network Interface Device 610: Video display unit 612: Digital Input Device 614: Vernier control device 616: Signal generating device 618: Secondary Memory 620: Internet 622: Software 626: Processing Logic 630: Busbar 632: Machine-accessible storage media

[0071] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A method for forming a metal-oxygenated photoresist on a substrate, comprising the steps of: repeating a deposition cycle, wherein each repetition of the deposition cycle comprises: a) flowing a metal-containing precursor into a chamber containing the substrate; and b) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal-containing precursor to form the metal-oxygenated photoresist, wherein the metal-containing precursor comprises a general formula MRXLY, wherein X = 1, 2, or 3 and Y = 4–X, and wherein M is a metal, R is a straight-chain alkyl, a branched alkyl, or a cycloalkyl, and L is Br, CN, CNO, SCN, or SeCN.

2. The method as described in claim 1, wherein the chamber is cleaned between operation a) and operation b) in at least one repetition of the deposition cycle.

3. The method as described in claim 1, wherein in at least one repetition of the deposition cycle, the chamber is cleaned after operation b) and before operation a) of a subsequent deposition cycle.

4. The method as claimed in claim 1, wherein the oxidant comprises two or more components, and / or wherein the metal precursor comprises two or more components.

5. The method as claimed in claim 1, wherein a first deposition cycle includes a first metal-containing precursor, and wherein a second deposition cycle includes a second metal-containing precursor, the second metal-containing precursor being different from the first metal-containing precursor.

6. The method as claimed in claim 1, wherein a first deposition cycle includes a first oxidant, and wherein a second deposition cycle includes a second oxidant, the second oxidant being different from the first oxidant.

7. The method as described in request item 1, wherein operation b) is performed before operation a).

8. The method as described in claim 1 further comprises the steps of: generating a plasma during operation a) in one or more repetitions of the deposition cycle and / or generating a plasma during operation b) in one or more repetitions of the deposition cycle.

9. The method as claimed in claim 1, wherein operation a) is performed in a first region of the chamber and operation b) is performed in a second region of the chamber, and wherein the substrate rotates between the first region of the chamber and the second region of the chamber.

10. The method as described in Request 1, wherein M is Sn.

11. The method as claimed in claim 1, wherein the oxidant comprises one or more of water, O2, alcohols, peroxides, and acids.

12. The method as described in claim 1, wherein the substrate is rotated between different sections of the chamber to perform operations a) and b).

13. A method for forming a metal-oxygenated photoresist on a substrate, comprising the steps of: repeating a deposition cycle, wherein each repetition of the deposition cycle comprises: a) flowing a metal-containing precursor into a chamber containing the substrate; and b) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal-containing precursor to form the metal-oxygenated photoresist, wherein the metal-containing precursor comprises a general formula MRXLY, wherein X = 1, 2, or 3 and Y = 4–X, and wherein M is a metal, R is a straight-chain alkyl, a branched alkyl, or a cycloalkyl, and L is Br, CN, CNO, SCN, or SeCN; and treating the metal-oxygenated photoresist with a plasma treatment after a first number of repetitions of the deposition cycle.

14. The method as described in claim 13 further comprises the step of: treating the substrate with an initiation plasma treatment prior to a first repetition of the deposition cycle.

15. The method as described in claim 13 further comprises the step of: restarting the repetition of the deposition cycle after the plasma treatment.

16. The method as described in claim 15 further comprises the step of: treating the metal-oxygen photoresist with a second plasma treatment after a second number of repetitions of the deposition cycle.

17. The method as described in claim 16, wherein the first number of repetitions of the deposition cycle is different from the second number of repetitions of the deposition cycle.

18. A method for forming a metal-oxygenated photoresist on a substrate, comprising the steps of: repeating a deposition cycle, wherein each repetition of the deposition cycle comprises: a) flowing a metal-containing precursor into a chamber containing the substrate, wherein the metal-containing precursor comprises a general formula MRXLY, wherein X = 1, 2, or 3 and Y = 4–X, and wherein M is a metal, R is a straight-chain alkyl, a branched alkyl, or a cycloalkyl, and L is Br, CN, CNO, SCN, or SeCN; b) purging the chamber; c) flowing an oxidant into the chamber, wherein the oxidant reacts with the metal-containing precursor to form the metal-oxygenated photoresist, wherein the oxidant comprises one or more of water, O2, alcohols, peroxides, and acids; and d) purging the chamber.

19. The method as described in claim 18 further comprises the step of: generating a plasma during one or more repetitions of operation a) and / or operation c) of the deposition cycle.

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