Dry development process of photoresist

Abstract

To provide a patterning method for a metal oxo photoresist using a non-wet process, with superior sensitivity, resolution, line edge roughness (LER), etching resistance, and thin film formability, in the field of semiconductor processing.SOLUTION: The present invention relates to a method for developing a metal oxo photoresist using a non-wet process. A metal oxo photoresist substrate comprising an exposed region and an unexposed region with a carbon concentration higher than that of the exposed region is provided. A gas is introduced into a chamber to react the gas with the unexposed region, thereby generating volatile by-products.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Nonprovisional Application No. 17 / 349,534, filed June 16, 2021, which claims the benefit of U.S. Provisional Application No. 63 / 047,160, filed July 1, 2020, the entire contents of which are incorporated herein by reference.

[0002] TECHNICAL FIELD Embodiments of the present disclosure relate to the field of semiconductor processing, and in particular to a method for patterning metal-oxo photoresists using a non-wet process. [Background technology]

[0003] 2. Description of Related Art Lithography has been used in the semiconductor industry for decades to create 2D and 3D patterns in microelectronic devices. The lithography process involves spin-on deposition of a film (photoresist), irradiating the film with an energy source with a selected pattern (exposure), and removing (etching) the exposed (positive tone) or unexposed (negative tone) areas of the film by dissolving them in a solvent. A bake is performed to drive off any residual solvent.

[0004] Photoresist should be a radiation-sensitive material, and upon irradiation, a chemical transformation occurs in the exposed parts of the film, which allows for a change in solubility between exposed and unexposed areas. This change in solubility is used to remove (develop) either the exposed or unexposed areas of the photoresist. As used herein, "develop" refers to the process of forming a pattern in the photoresist. Once the photoresist is developed, the pattern can be transferred to the underlying thin film or substrate by etching. After the pattern is transferred, the remaining photoresist is removed. This process can be repeated many times to obtain 2D and 3D structures used in microelectronic devices.

[0005] Several properties are important in the lithography process. Such properties include sensitivity, resolution, low line edge roughness (LER), etch resistance, and ability to form thin layers. The higher the sensitivity, the less energy is required to change the solubility of the deposited film. This allows for improved efficiency in the lithography process. Resolution and LER determine how narrow features can be achieved by the lithography process. Pattern transfer to form deep structures requires materials with high etch resistance. Materials with high etch resistance also allow for thinner films. The thinner the film, the more efficient the lithography process. Summary of the Invention

[0006] Embodiments disclosed herein include a method of developing a metal-oxo photoresist in a non-wet process. In one embodiment, the method includes providing a substrate having a metal-oxo photoresist in a chamber. In one embodiment, the metal-oxo photoresist includes exposed and unexposed regions, the unexposed regions having a higher carbon concentration than the exposed regions. In one embodiment, the method further includes flowing a gas into the chamber, the gas reacting with the unexposed regions to generate volatile by-products.

[0007] An embodiment may also include a method of developing a metal-oxo photoresist, the method including providing a substrate having a metal-oxo photoresist on a surface thereof and exposing the metal-oxo photoresist to form exposed and unexposed regions. In one embodiment, the unexposed regions have a higher carbon concentration than the exposed regions. In one embodiment, the method may further include placing the substrate in a plasma chamber, flowing a gas into the plasma chamber, and striking a plasma in the plasma chamber. In one embodiment, the plasma reacts with the unexposed regions to produce volatile by-products. In one embodiment, the method may further include purging the plasma chamber.

[0008] The embodiment may also include a method of developing a metal-oxo photoresist, the method including providing a substrate having a metal-oxo photoresist comprising SnOC in a plasma chamber. In one embodiment, the metal-oxo photoresist comprises exposed and unexposed regions, the unexposed regions having a higher carbon concentration than the exposed regions. In one embodiment, the method further includes flowing a gas comprising Cl2 and Ar into the plasma chamber and generating a plasma in the plasma chamber. In one embodiment, the plasma reacts with the unexposed regions to generate volatile by-products. The method may further include purging the plasma chamber. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a flow diagram illustrating a process for developing a metal-oxo photoresist using a plasma process according to one embodiment of the present disclosure. [Figure 2A] 2A-2D are cross-sectional views of a substrate and photoresist illustrating steps in the flow diagram of FIG. 1 according to one embodiment of the present disclosure. [Figure 2B] 2A-2D are cross-sectional views of a substrate and photoresist illustrating steps in the flow diagram of FIG. 1 according to one embodiment of the present disclosure. [Figure 2C] 2A-2D are cross-sectional views of a substrate and photoresist illustrating steps in the flow diagram of FIG. 1 according to one embodiment of the present disclosure. [Figure 2D] 2A-2D are cross-sectional views of a substrate and photoresist illustrating steps in the flow diagram of FIG. 1 according to one embodiment of the present disclosure. [Diagram 3] 2 is a cross-sectional view of a processing tool that may be used to implement portions of the process of FIG. 1 according to one embodiment of the present disclosure. [Figure 4] FIG. 1 illustrates a block diagram of an exemplary computer system according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] This document describes a method for patterning metal-oxo photoresist using a non-wet process. In the following description, numerous specific details for developing photoresist (such as reactive plasma processes and material regimes) are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to one of ordinary skill in the art that the embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known aspects, such as the fabrication of integrated circuits, have not been described in detail in order to not unnecessarily obscure the embodiments of the present disclosure. Furthermore, it should be understood that the various embodiments depicted in the figures are illustrative representations and are not necessarily drawn to scale.

[0011] To further aid in understanding, photoresist systems used in extreme ultraviolet (EUV) lithography suffer from inefficiencies. That is, existing photoresist material systems for EUV lithography require high doses to provide the solubility switch necessary to enable development of the photoresist material. Organic-inorganic hybrid materials (e.g., metal-oxo material systems) have been proposed as material systems for EUV lithography due to their high sensitivity to EUV radiation. Such material systems typically include metals (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. In some cases, metal-oxo material systems may also include nitrogen and hydrogen. Metal-oxo-based organic-inorganic hybrid materials have also been found to provide low LER and high resolution, which are necessary properties for forming narrow features.

[0012] In metal-oxo photoresist systems, exposure to EUV radiation removes carbon and crosslinks the metal oxide network. The difference in carbon percentage and bond strength between exposed and unexposed areas is used as a solubility switch during development. Specifically, the unexposed areas with high carbon content and weak bond strength are preferentially etched by the developer.

[0013] Metal-oxo photoresist systems are currently developed using wet chemistry; that is, after exposure, the unexposed areas of the photoresist are developed by an organic solvent / base solution used in a spin-dry process. A post-bake annealing process may also be included. However, when dealing with high aspect ratio features, wet methods can be difficult due to the risk of pattern collapse (especially for line and pillar structures). In addition, since the wet process uses mechanical forces to remove the solvent and dissolved by-products, it may not remove all the material that should be removed, and film material / by-products / solvent / etc. may be trapped in small features. Furthermore, when the features are smaller and more complex, it becomes difficult for the solvent (whose molecules are usually large) to penetrate all the areas of the unexposed resist. This leads to partial development of the photoresist, resulting in defects. The spin-dry process can even cause wiggling and fall-off of the lines. This limits the thickness and aspect ratio of the photoresist.

[0014] Accordingly, embodiments of the present disclosure provide a plasma etch process for developing metal-oxo photoresist that: 1) eliminates the production of wet by-products; 2) reduces waste streams by processing dry chemicals through an abatement system; 3) reduces defects and impurities; 4) improves LER, LWR, and any low frequency roughness caused by surface tension, capillary forces, and spin-dry processes; 5) provides a batch process for developing the photoresist and transferring the pattern to the underlying layer; and 6) increases etch selectivity of unexposed areas relative to exposed areas of the metal-oxo photoresist. The advantage is provided.

[0015] The embodiments disclosed herein provide a plasma etch process that is performed after a metal-oxo photoresist is partially exposed to a suitable electromagnetic radiation source (e.g., an EUV source). In one embodiment, a substrate including the exposed metal-oxo photoresist is placed in a plasma chamber. A gas including a reactive gas and an inert gas is flowed into the plasma chamber and a plasma is generated. The reactive gas is a gas having a component that reacts with the metal of the metal-oxo photoresist to form a volatile species. For example, the reactive gas can be Cl2, H2, Br2, HBr, HCl, BCl3, CH x Cl y , CH4, BBr3, and CH x Br y In one particular embodiment, the reactive gas comprises HBr and the inert gas comprises Ar. In some embodiments, gases are flowed into the chamber but no plasma is generated (i.e., a thermal process). In other embodiments, a plasma may be generated. In one embodiment, the etch selectivity of unexposed metal-oxo photoresist over exposed metal-oxo photoresist may be 10:1 or greater. In one particular embodiment, the etch selectivity is approximately 12:1. In one embodiment, the pattern in the developed metal-oxo photoresist may be transferred to an underlying layer without removing the substrate from the plasma chamber.

[0016] 1, a flow diagram illustrating a process 120 for developing a metal-oxo photoresist on a substrate surface is provided, according to one embodiment of the present disclosure. Figures 2A-2D are cross-sectional views of a substrate 261 and a metal-oxo photoresist 262 after various steps in the process 120.

[0017] In one embodiment, the process 120 may begin at step 121 with providing a substrate having a metal-oxo photoresist. FIG. 2A is a cross-sectional view of the substrate 261 with a metal-oxo photoresist 262 disposed over the surface of the substrate 261. In one embodiment, the substrate 261 may include any substrate material or materials characteristic of a semiconductor manufacturing environment. For example, the substrate 261 may include a semiconductor material. The substrate 261 may include a semiconductor device or a portion of a semiconductor device. Examples of such semiconductor devices include, but are not limited to, memory devices or complementary metal oxide semiconductor (CMOS) transistors fabricated in a silicon substrate and encapsulated in a dielectric layer. The substrate 261 may further include a plurality of metal interconnects formed in the surrounding dielectric layer above the devices or transistors and may be used to electrically couple the devices or transistors to form an integrated circuit. In one embodiment, the substrate 261 may be a wafer.

[0018] In one embodiment, the metal-oxo photoresist 262 (also referred to simply as "photoresist 262") can be any metal-oxo material system. Such material systems typically include a metal (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. In one particular embodiment, the photoresist 262 includes SnOC. Embodiments may also include metal-oxo material systems that further include nitrogen and hydrogen in addition to SnOC.

[0019] The photoresist 262 may be disposed on the surface of the substrate 261 using any suitable deposition process. In one embodiment, the photoresist is disposed on the surface of the substrate 261 using wet chemistry using a spin-on process. In an alternative embodiment, the photoresist is disposed on the surface of the substrate 261 using a gas phase process (i.e., a dry process). In a gas phase process, a metal precursor and an oxidant may be vaporized into a vacuum chamber. The metal precursor and the oxidant then react to deposit a metal-oxo photoresist 262 on the surface of the substrate 261. Such dry processes may be characterized as a chemical vapor deposition (CVD) process, an atomic layer deposition (ALD) process, a plasma-enhanced CVD (PE-CVD) process, or a plasma-enhanced ALD (PE-ALD) process.

[0020] In one embodiment, process 120 may continue with step 122, which includes partially exposing the metal-oxo photoresist to create exposed and unexposed areas. Figure 2B is a cross-sectional view illustrating the exposure process. As shown, electromagnetic radiation 264 passes through a mask 263 to expose exposed areas 262. E The non-exposed area is exposed. 262U is shielded from the electromagnetic radiation by a mask 263. In one embodiment, the electromagnetic radiation is EUV radiation. If EUV radiation is used, the EUV radiation 264 may be reflected off the mask rather than passing through it. Although EUV radiation is specifically disclosed herein, it should be appreciated that any suitable wavelength of electromagnetic radiation capable of triggering a solubility switch in the metal-oxo photoresist 262 may be used. For example, in some embodiments, DUV radiation may be used.

[0021] In one embodiment, the solubility switch is brought about by loss of carbon and cross-linking of the metal-oxo network in the exposed regions. In particular, exposure to electromagnetic radiation causes the exposed regions 262 E Carbon is removed from the unexposed area 262. U The higher carbon content and increased number of weak bonds in the non-exposed regions makes them more susceptible to patterning in a subsequent non-wet development process.

[0022] In one embodiment, the process 120 may continue to step 123, which includes placing the substrate in a plasma chamber. In one embodiment, the plasma chamber may be any chamber suitable for generating plasma at sub-atmospheric pressure conditions. The plasma chamber may also include heating / cooling capabilities to provide thermal control of the plasma process. For example, the chuck on which the substrate 261 rests may be an actively heated and / or cooled chuck. Additionally, in some embodiments, the walls of the plasma chamber may be actively heated and / or cooled. A more detailed description of a suitable plasma chamber is provided below in connection with FIG. 7.

[0023] In one embodiment, the process 120 may continue with steps 124 and 125, which include flowing a gas into a plasma chamber and generating a plasma in the plasma chamber. In one embodiment, the gas includes a reactive gas and an inert gas. The reactive gas may be Cl2, Br2, HBr, HCl, H2, BCl3, CH x Cl y , CH4, BBr3, and CH x Br y In one embodiment, the inert gas may include Ar, N2, or He. In one particular embodiment, the reactive gas includes HBr and the inert gas includes Ar. In one embodiment, the plasma formed by the reactive gases irradiates the unexposed regions 262 of the metal-oxo photoresist. U For example, a metal M (e.g., Sn) reacts with Cl to form a volatile by-product MCL4. UAn example of the developed photoresist after converting the volatile by-products to volatile by-products is shown in FIG. 2C. It should be recognized that generating a plasma is optional; that is, in some embodiments, a non-wet process may include flowing reactive gases into the chamber without generating a plasma. Such a process may be considered a thermal process as opposed to a plasma process. In such a case, the reactive gas does not need to be ionized, and the reactive gas will ionize the unexposed regions 262 of the metal-oxo photoresist. U can react directly with

[0024] In one embodiment, the ratio of the inert gas flow rate to the reactive gas flow rate is between 0:1 and 50:1. For example, the inert gas flow rate may be 300 sccm and the reactive gas flow rate may be 50 sccm. Diluting the chemicals slows down the etch rate and improves etch uniformity. The inert gas helps distribute the reactive gas evenly throughout the plasma chamber, improving uniformity. Additionally, increasing the reactive gas flow rate generally increases the etching rate of the exposed area 262. E compared to the non-exposed area 262 U It has been found that this increases the etching of . In one embodiment, the pressure can be between about 1 mtorr and about 100 mtorr. In one particular embodiment, the pressure can be between about 5 mtorr and about 20 mtorr. In yet another embodiment, the pressure can be between about 1 mtorr and about 10 torr.

[0025] In one embodiment, in steps 124 and 125, the substrate 261 may have a controlled temperature. For example, the temperature may vary between about 0° C. and about 500° C. In one particular embodiment, the temperature may vary between about 50° C. and about 150° C. A lower temperature (e.g., less than 500° C.) is beneficial because such a lower temperature typically does not result in thermal decomposition of the metal-oxo photoresist. In yet another embodiment, the temperature may be less than about 200° C. For example, the temperature may be between about 40° C. and about 100° C.

[0026] In one embodiment, the RF power of the plasma etch process may be controlled. Generally, lower RF power may improve etch selectivity. In one embodiment, the source power may be between approximately 200 W and approximately 1200 W. In a specific embodiment, the source power may be approximately 400 W. In one embodiment, the bias power may be between approximately 0 W and approximately 200 W. In a specific embodiment, the bias power may be approximately 50 W. Increasing the bias power to approximately 100 W may result in increased etching selectivity in the unexposed regions 262. U The etch selectivity of the exposed area 262 E It is known that the effect of

[0027] In one embodiment, step 125 may be implemented using a pulsed bias. The duty cycle of the pulsing may be between 0% and 100%. In one particular embodiment, the duty cycle is approximately 50%. Such a duty cycle allows time for by-products to be removed and reduces ion bombardment. Thus, the non-exposed regions 262 U The etch selectivity of the exposed area 262 E Improves against.

[0028] In one embodiment, step 125 may be implemented for any desired duration. A longer period results in more unexposed areas 262. U In one embodiment, step 125 may have a duration between approximately 5 seconds and approximately 120 seconds. In one particular embodiment, step 125 may have a duration of approximately 15 seconds.

[0029] By varying various parameters of the plasma development process as described above, the unexposed areas 262 of the metal-oxo photoresist are U The etch selectivity of the exposed area 262 of the metal-oxo photoresist is EFor example, the etch selectivity can be approximately 10:1 or greater. In one particular embodiment, the etch selectivity can be approximately 12:1. The increased etch selectivity provides several advantages. One such advantage is that the thickness of the photoresist can be reduced, which allows for a reduction in the dose of electromagnetic radiation used to fully develop the photoresist.

[0030] In one embodiment, process 120 may continue with step 126, which includes purging the plasma chamber. Purging the plasma chamber removes by-products from the reaction in step 125 from the plasma chamber. In one embodiment, a single purge may be implemented after the etching in step 125 is completed. In an alternative embodiment, steps 124 / 125 and 126 may define a cycle that includes a pulse of etching followed by a purge. In such an embodiment, the unexposed regions 262 of the photoresist are purged. U The cycle may be repeated multiple times to remove

[0031] The embodiments disclosed herein provide the additional advantage of being implemented in one plasma chamber. This is particularly beneficial when subsequent patterning of the substrate 261 is performed using plasma etching. In particular, the substrate 261 does not need to be removed from the plasma chamber after the photoresist development process. That is, a one-time approach (i.e., one-time chamber) for pattern development and pattern transfer to an underlying layer is provided.

[0032] In one embodiment, the process 120 may continue with optional step 127, which includes etching the substrate 261. FIG. 2D shows exposed areas 262 of the metal-oxo photoresist. E2 is a cross-sectional view of substrate 261 after the pattern of has been transferred to substrate 261. As shown, the pattern transfer may form trenches 265 in substrate 261. In one embodiment, etching of substrate 261 may be implemented using a plasma etching process. The plasma etching process may be performed in the same chamber used to develop the metal-oxo photoresist.

[0033] 3 is a schematic diagram of a plasma chamber configured to perform plasma-based development of metal-oxo photoresist, according to one embodiment of the present disclosure. The plasma chamber 300 includes a grounded chamber 305. A substrate 310 is loaded through an opening 315 and clamped to a temperature-controlled chuck 320.

[0034] Process gases are supplied to the interior of the chamber 305 from gas sources 344 through respective mass flow controllers 349. In certain embodiments, a gas distribution plate 335 is provided for distribution of the process gases 344 (such as Cl2, Br2, H2, HCl, HBr, and / or inert gases). The chamber 305 is evacuated via an exhaust pump 355.

[0035] When RF power is applied during processing of the substrate 310, a plasma is formed in the chamber processing region above the substrate 310. A bias power RF generator 325 is coupled to the temperature controlled chuck 320. The bias power RF generator 325 provides bias power and excites the plasma if necessary. The bias power RF generator 325 may have a low frequency, for example, between about 2 MHz and 60 MHz, and in one specific embodiment, is in the 13.56 MHz band. In some embodiments, the plasma chamber 300 includes a third bias power RF generator 326 with a frequency in the 2 MHz band, which is connected to the same RF match 327 as the bias power RF generator 325. A source power RF generator 330 is coupled to the plasma generating element (e.g., gas distribution plate 335) through a match (not shown) to provide source power and excite the plasma. The source RF generator 330 may have a frequency, for example, between 100 and 180 MHz, and in one specific embodiment, is in the 162 MHz band. As substrate diameters have changed over time from 150 mm to 200 mm to 300 mm, etc., it is common in the art to normalize the source power and bias power of plasma etch systems to the substrate area.

[0036] The plasma chamber 300 is controlled by a controller 370. The controller 370 may include a CPU 372, a memory 373, and an I / O interface 374. The CPU 372 may perform process steps in the plasma chamber 300 according to instructions stored in the memory 373. For example, one or more processes (such as portions of process 120 described above) may be performed in the plasma chamber by the controller 370.

[0037] 4 illustrates an exemplary embodiment of a diagrammatic representation of a machine in a computer system 400 on which a set of instructions for causing the machine to perform any one or more of the methodologies described herein may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a local area network (LAN), an intranet, an extranet, or the Internet. The machine may operate in the role of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a web appliance, a server, a network router, switch, or bridge, or any machine capable of executing a set of instructions (sequential or non-sequential) that specify operations to be performed by the machine. Further, although only a single machine is illustrated, the term "machine" should also be construed to include any collection of machines (e.g., a computer) that individually or in concert executes a set of instructions (or multiple sets of instructions) to perform any one or more of the methodologies described herein.

[0038] The exemplary computer system 400 includes a processor 402, a main memory 404 (e.g., read only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 406 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and a secondary memory 418 (e.g., a data storage device), which communicate with each other via a bus 430.

[0039] Processor 402 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. More specifically, processor 402 may be a Complex Instruction Set Computing (CISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Word (VLIW) microprocessor, or a processor implementing any other instruction set or combination of instruction sets. Processor 402 may also be one or more special purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. Processor 402 is configured to execute processing logic 426 for performing the operations described herein.

[0040] The computer system 400 may further include a network interface device 408. The computer system 400 may also include a video display unit 410 (such as a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 412 (e.g., a keyboard), a cursor control device 414 (e.g., a mouse), and a signal generating device 416 (e.g., a speaker).

[0041] The secondary memory 418 may include a machine-accessible storage medium (or, more specifically, a computer-readable storage medium) 432 having stored thereon one or more sets of instructions (such as software 422) embodying any one or more of the methodologies or functions described herein. The software 422 may reside, in whole or at least partially, within the main memory 404 and / or the processor 402 while it is being executed by the computer system 400, with the main memory 404 and the processor 402 also constituting machine-readable storage media. The software 422 may further be transmitted or received over the network 420 via the network interface device 408.

[0042] While in an exemplary embodiment, the machine-accessible storage medium 432 is illustrated as a single medium, the term "machine-readable storage medium" should be interpreted to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of instructions. The term "machine-readable storage medium" should also be interpreted to include any medium capable of storing or encoding a set of instructions that are executed by a machine and that cause the machine to perform any one or more of the methodologies of the present disclosure. Thus, the term "machine-readable storage medium" should be interpreted to include, but is not limited to, solid-state memories, and optical and magnetic media.

[0043] According to one embodiment of the present disclosure, a machine-accessible storage medium has instructions stored thereon that cause a data processing system to perform a method of developing metal-oxo photoresist on a substrate using a plasma process. The method includes exposing the metal-oxo photoresist to provide exposed and unexposed regions, and placing the substrate with the exposed photoresist in a vacuum chamber. In one embodiment, gas is flowed into the plasma chamber and a plasma is generated. The gas may include reactive and inert gases. In one embodiment, the plasma reacts with the unexposed regions of the photoresist to convert the unexposed regions of the photoresist into volatile by-products. The volatile by-products may be purged from the plasma chamber. For example, the reactive gas may include one or more of Cl2, Br2, HBr, HCl, and H2.

[0044] Thus, a method for developing metal-oxo photoresists using a plasma process has been disclosed.

Claims

1. 1. A method for developing a metal oxo photoresist, comprising the steps of: providing a substrate having the metal-oxo photoresist in a chamber, the metal-oxo photoresist including exposed and unexposed regions, the unexposed regions having a higher carbon concentration than the exposed regions; and flowing a gas into the chamber, the gas reacting with the unexposed areas to produce volatile by-products. method.

2. The method of claim 1 , further comprising generating a plasma in the chamber.

3. The gas is Cl ２ , B ２ , H ２ , HBr, HCl, BCl ３ , C.H. ｘ C ｙ , C.H. ４ , BBr ３ , and C.H. ｘ B ｙ The method of claim 1 , further comprising reacting the reactant gas with one or more of:

4. The method of claim 3 , wherein the gas further comprises an inert gas.

5. 5. The method of claim 4, wherein the ratio of the flow rate of the inert gas to the flow rate of the reactive gas is between 0:1 and 50:

1.

6. The method of claim 1 , wherein reacting the gas with the non-exposed areas is implemented in a non-plasma thermal process.

7. The method of claim 1 , wherein the substrate has a substrate temperature of 200° C. or less.

8. 2. The method of claim 1, wherein the source power is 1200W or less and the bias power is 200W or less.

9. 9. The method of claim 8, wherein the bias power is pulsed and the duty cycle of the pulsing is between 0% and 100%.

10. The method of claim 1 , wherein the metal oxo photoresist comprises SnOC.

11. The method of claim 1 , wherein the exposed areas comprise a crosslinked metal oxide network and the unexposed areas comprise metal oxide clusters.

12. 1. A method for developing a metal oxo photoresist, comprising the steps of: providing a substrate having said metal oxo photoresist thereon; exposing the metal-oxo photoresist to light to form exposed and unexposed areas, the unexposed areas having a higher carbon concentration than the exposed areas; placing the substrate in a plasma chamber; flowing a gas into the plasma chamber; generating a plasma in the plasma chamber, the plasma reacting with the unexposed areas to generate volatile by-products; and purging the plasma chamber.

13. The gas includes a reactive gas and an inert gas, and the reactive gas is Cl ２ , B ２ , H ２ , HBr, HCl, BCl ３ , C.H. ｘ C ｙ , C.H. ４ , BBr ３ , and C.H. ｘ B ｙ The method of claim 12 , comprising one or more of:

14. 14. The method of claim 13, wherein the ratio of the inert gas flow rate to the reactive gas flow rate is between 0:1 and 50:

1.

15. The method of claim 12 , further comprising etching the substrate prior to removing the substrate from the plasma chamber.

16. The method of claim 12 , wherein the metal oxo photoresist comprises SnOC.

17. 13. The method of claim 12, wherein exposing the metal-oxo photoresist comprises exposing the metal-oxo photoresist to extreme ultraviolet (EUV) radiation.

18. 1. A method for developing a metal oxo photoresist, comprising the steps of: providing a substrate having the metal-oxo photoresist in a plasma chamber, the metal-oxo photoresist comprising SnOC and including exposed and unexposed regions, the unexposed regions having a higher carbon concentration than the exposed regions; In the plasma chamber, Cl ２ and flowing in a gas containing Ar; generating a plasma in the plasma chamber, the plasma reacting with the unexposed areas to generate volatile by-products; and purging the plasma chamber.

19. 20. The method of claim 18, wherein the etch selectivity between the unexposed areas and the exposed areas is 10:1 or greater.

20. The flow rate of Ar and the flow rate of Cl ２ 20. The method of claim 18, wherein the ratio of the flow rate of the suction to the flow rate of the exhaust is between 0:1 and 50:1.

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