KR102591277B1 - Method for collapse-free drying of high aspect ratio structures - Google Patents

Abstract

A method for drying a substrate comprising a plurality of high aspect ratio (HAR) structures includes using at least one of (a) a wet etching solution, (b) a wet cleaning solution, and (c) a wet rinsing solution, respectively. After at least one of (i) wet etching, (ii) wet cleaning, and (iii) wet rinsing, and without drying the substrate, a solution comprising a polymer component, a nanoparticle component, and a solvent is applied to the plurality of HAR structures. wherein, when the solvent is vaporized, a sacrificial bracing material precipitates from the solution and at least partially fills the plurality of HAR structures, wherein the sacrificial bracing material (i) forms a polymer from the polymer component of the solution; depositing a solution comprising a material and (ii) a solvent comprising nanoparticle material from a nanoparticle component of the solution, between the plurality of HAR structures; and exposing the substrate to a plasma generated using plasma gas chemistry to vaporize the sacrificial bracing material.

Description

Method for drying high aspect ratio structures without collapse {METHOD FOR COLLAPSE-FREE DRYING OF HIGH ASPECT RATIO STRUCTURES}

This disclosure relates to systems and methods for processing substrates, and more particularly to systems and methods for drying HIGH ASPECT RATIO (HAR) structures without collapse.

The background description provided herein is generally intended to provide context for the disclosure. Achievements of the present inventors to the extent described in this background section and aspects of the technology that may not be recognized as prior art at the time of filing are not explicitly or implicitly recognized as prior art for this disclosure.

Fabrication of substrates, such as semiconductor wafers, typically requires multiple processing steps that may include material deposition, planarization, feature patterning, feature etching, and/or feature cleaning. These processing steps are typically repeated one or more times during processing of the substrate.

As semiconductor devices continue to shrink to smaller feature sizes, high aspect ratio (HAR) structures become increasingly necessary to achieve targeted device performance objectives. The use of HAR structures creates challenges for some of the substrate processing steps.

For example, wet processes such as etching and encapsulation pose challenges for HAR structures due to the capillary forces created during drying of the substrate. The strength of the capillary force is determined by surface tension, contact angle of the etching fluid, cleaning fluid or rinsing fluids to be dried, feature spacing and/or aspect ratio of the structures. If the capillary force generated during drying is too high, the HAR structures will deform or collapse into each other, and friction forces may occur, which seriously deteriorates device yield.

One way to prevent collapse and friction is to use rinsing liquids that have a lower surface tension than deionized water to prevent the structures from collapsing. Although generally successful for relatively low aspect ratio structures, this method may have the same collapse and friction problems for higher aspect ratio structures because the methods use deionized water. Rinsing fluids still have a finite amount of surface tension, creating forces during drying that are still too strong for fragile HAR structures.

An alternative method for drying HAR structures involves decomposing and flushing the rinsing fluid using a supercritical fluid. Supercritical fluids have no surface tension when processed correctly. However, several technical and manufacturing challenges arise when using supercritical fluids. These challenges arise from high equipment and safety costs, long process times, variable solvent quality during the process, extreme sensitivity due to the diffusion and tunable properties of the fluid, and interaction of the supercritical fluid with components of the processing chamber. Includes wafer defects and contamination problems that occur.

Another strategy to prevent collapse of HAR structures is to add a permanent mechanical bracing structure to support the structures. There are several trade-offs with this method, such as higher cost and process complexity, which may negatively impact throughput and yield. Additionally, permanent mechanical bracing structures may be limited to certain types of HAR structures.

Freeze drying has also been proposed as a method for drying HAR structures. Freeze drying eliminates disintegration by first freezing the solvent and then sublimating it directly under vacuum. Freeze drying prevents the liquid/gas interface, minimizing capillary forces. Although it appears promising, freeze drying has relatively high costs, low throughput, and high defects compared to competing methods.

Surface modification of the sidewalls of HAR structures may be performed. In this method, those molecules may be chemically bonded to the sidewalls of the HAR structures. Those molecules improve collapse performance by preventing friction between materials when they come into contact, or by changing the contact angle of wet chemistry to minimize Laplace pressure. Surface modification does not completely eliminate drying forces, and structures may deform during the drying process, which may cause damage. Additionally, when surface materials are changed, newly tailored molecules are needed to bind to the sidewalls of HAR structures.

In one aspect, a method for drying a substrate comprising a plurality of high aspect ratio (HAR) structures is described. The method includes (i) wet etching, and (ii) wet cleaning, and (iii) a substrate using at least one of (a) a wet etching solution, and (b) a wet cleaning solution, and (c) a wet rinsing solution, respectively. After at least one of wet rinsing, and without drying the substrate, depositing a solution comprising a polymer component, a nanoparticle component, and a solvent between the plurality of HAR structures, and when the solvent is vaporized, a sacrificial bracing material ( A sacrificial bracing material is precipitated from the solution and at least partially fills the plurality of HAR structures, comprising exposing the substrate to a plasma generated using plasma gas chemistry to volatilize the sacrificial bracing material, comprises (i) a polymeric material from the polymeric component of the solution and (ii) a nanoparticle material from the nanoparticle component of the solution.

In one aspect, a system for drying a substrate comprising a plurality of high aspect ratio (HAR) structures is described. The system includes a processing chamber; A substrate support disposed within the processing chamber; a gas delivery system for delivering the gas mixture to the processing chamber; a fluid delivery system configured to deliver a solution to a substrate; a plasma generator configured to generate plasma within the processing chamber; and a controller in communication with the fluid delivery system, gas delivery system, and plasma generator. The controller controls (i) wet etching, and (ii) wet cleaning, and (iii) of the substrate using at least one of (a) a wet etching solution, or (b) a wet cleaning solution, or (c) a wet rinsing solution, respectively. After at least one of wet rinsing and without drying the substrate, depositing a solution comprising polymer components, nanoparticle components, and solvent between the plurality of HAR structures and plasma gas chemistry to volatilize the sacrificial bracing material. It is configured for the operation of exposing the substrate to plasma generated using. When the solvent evaporates, a sacrificial bracing material precipitates from the solution and at least partially fills the plurality of HAR structures, the sacrificial bracing material comprising (i) a polymeric material from the polymeric component of the solution and (ii) a nanoparticle component of the solution. It contains nanoparticle materials.

Additional areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of the disclosure.

The present disclosure will be more fully understood from the detailed description and accompanying drawings.
1 is a flow chart illustrating an example of a method for drying a plurality of HAR features of a substrate using plasma.
2A-2D are side views illustrating an example of a substrate during drying using plasma.
3A is a functional block diagram illustrating a spin coating processing chamber and a plasma processing chamber.
3B is a functional block diagram illustrating a combined spin coating and plasma processing chamber.
4 is a functional block diagram of an exemplary spin coating processing chamber.
Figure 5 is a functional block diagram of an example plasma processing chamber.
6 is a functional block diagram of an exemplary combined spin coating and plasma processing chamber.
7A is an exemplary side view of a sacrificial bracing material without a substrate and nanoparticle material.
7B is an exemplary side view of a sacrificial bracing material comprising a substrate and nanoparticle material.
Figure 8 is an example graph of glass transition temperature versus nanoparticle weight fraction for different polymers.
Figure 9A is a side view of the nanoparticle sacrificial bracing material without a portion of the substrate and without the polymer added material before annealing.
Figure 9B is a side view after annealing of the nanoparticle sacrificial bracing material without a portion of the substrate and without the polymer added material.
Figure 10A is a side view of a nanoparticle sacrificial bracing material including a portion of the substrate and polymer additive material before annealing.
Figure 10B is a side view of a nanoparticle sacrificial bracing material comprising a portion of the substrate and polymer additive material after annealing.
Figure 11A is an exemplary side view after annealing of a sacrificial bracing material comprising a substrate and nanoparticle material but no polymer.
FIG. 11B is an exemplary side view of a substrate and a sacrificial bracing material comprising nanoparticle material and polymer after annealing.
In the drawings, reference numbers may be reused to identify similar and/or identical elements.

Cross-reference to related applications

This disclosure is a continuation-in-part of U.S. Patent Application No. 14/507,080, filed October 6, 2014. The entire disclosure of the above-referenced applications is incorporated herein by reference.

Some sacrificial bracing methods have been used to prevent collapse of high aspect ratio (HAR) structures. By way of example only, U.S. Patent Application No. 13, filed June 21, 2013, entitled “Method of Collapse-Free Drying of High Aspect Ratio Structures,” which is incorporated herein by reference in its entirety. /924,314 discloses a sacrificial bracing method. As described in the above application, a sacrificial bracing material, such as a glassy polymer or fullerene solution, is deposited into the HAR structures immediately after the wet etching or cleaning process, but before drying the wafers.

As the solvent evaporates, the sacrificial bracing material precipitates out of solution and fills the structures. Mechanical bracing is formed within the HAR structures to counteract the capillary forces generated during solvent vaporization. Afterwards, the sacrificial bracing material is removed using a dry plasma process. The plasma process may use reactants such as N ₂ , O ₂ , H ₂ , and/or O ₃ gases. As used herein, HAR refers to HAR structures with an AR greater than 8:1, 10:1, 15:1, 20:1, or 50:1. The distance between adjacent structures in HAR applications is less than 40 nm, less than 30 nm, or less than 20 nm.

Some sacrificial bracing materials, such as some polymeric sacrificial bracing materials, may undergo a glass transition and form melts during sacrificial bracing material removal. The melt may behave like a liquid and induce HAR structure collapse during removal of sacrificial bracing material.

According to the present disclosure, sacrificial bracing materials include nanoparticle materials (e.g., fullerols) and polymers. The nanoparticle material raises the glass transition temperature of the sacrificial bracing material above that of the polymer. A higher glass transition temperature may enable higher ash temperatures resulting in a faster plasma removal rate of sacrificial bracing material, reducing processing time and increasing throughput. The relative amounts of nanoparticle material and polymer used may be selected to reduce surface tension and/or increase fluidity to increase filling of spaces between HAR structures.

Referring now to FIG. 1, a method 100 for drying a substrate comprising a plurality of HAR structures is shown. A substrate comprising a plurality of HAR structures is wet etched or cleaned at 122 using a targeted etchant solution, such as an acid, and/or a cleaning solution. After wet etching or cleaning, the substrate is not dried and the wet etching or cleaning solution remains on the substrate.

In some examples, HAR structures are lines/spaces, STI, FinFETs, or cylindrical capacitors. Materials may include metallic, semiconductor or dielectric materials. In some examples, etching and cleaning processes will be performed within a spin coating processing chamber.

At 123, a rinse solution may be used to repel a wet etching or cleaning solution. After rinsing, the substrate is not dried and the rinsing solution remains on the substrate.

At 124, an optional transfer solvent may be used to push the rinsing solution. The transfer solvent is determined by the chemical make-up and compatibility of the rinsing solutions and the solvent used to dissolve the bracing material.

At 126, the rinsing solutions or optional transfer solvent are repelled by the solvent containing the sacrificial bracing material. In some examples, the sacrificial bracing material includes one or more polymers and nanoparticle additives. Surfactants may also be included. As will be appreciated, the substrate remains wet during steps 122, 123, 124, and 126. In some examples, the sacrificial bracing material includes a carbon-containing material that can be volatilized through plasma chemistry.

At 130, excess solvent may optionally be spun off. Sacrificial mechanical bracing fills the plurality of HAR structures on the substrate. More specifically, when the solvent evaporates, the sacrificial bracing material precipitates out of solution and fills the structures. Mechanical bracing is formed within the HAR structures to counteract the capillary forces generated during solvent drying. The substrate may optionally be annealed or baked at 132 to, for example, remove crosslinks, residual solvent, and/or relieve stresses. The substrate is transferred to the plasma processing chamber or is not transferred and processing continues if a combined spin coating plasma processing chamber is used.

In some examples, the substrate support or platen heats the substrate to a temperature between 25° C. and 400° C. during exposure to the plasma. At 134, the substrate is exposed to plasma gas chemicals. For example, the substrate may be exposed to hydrogen-rich plasma gas chemistry. Other gases may be mixed with the hydrogen-rich gas to improve residue or etch rate without modifying the surface of the HAR structures. In some examples, additional gases may include mild oxidizing agents or inert gases. Examples of weak oxidizing agents include carbon dioxide, carbon monoxide, nitrous oxide, nitrogen monoxide, nitrogen dioxide, sulfur oxide, sulfur dioxide, water, and oxygen-containing hydrocarbons. In some examples, the mixture includes less than 10% CO ₂ . Inert gases including nitrogen, argon, xenon, krypton, helium, and neon may also be added. In some examples, H ₂ -rich molecules such as methane (CH ₄ ) or ammonia (NH ₃ ) may be used. These H-rich or H ₂ -rich molecules may be used alone or in combination with inert gases and/or weak oxidizing agents. Although examples of hydrogen-rich plasma gas chemistries are provided, other suitable plasma gas chemistries such as oxygen-rich plasma chemistries and/or ozone may also be used.

At 138, the plasma is struck within the processing chamber and the substrate is exposed to the plasma to remove sacrificial bracing material. In some examples, the plasma is a remote plasma or downstream plasma. In some examples, process conditions include a plasma generated using 500 W to 10 kW of RF power, a vacuum pressure of 0.1 Torr to 3 Torr, and a total gas flow of 500 to 10000 sccm, although other process conditions may be used. there is. At 140, selectable substrate RF bias may be used.

At 142, the substrate is removed from the plasma processing chamber after removal of the sacrificial bracing material.

Referring now to Figures 2A-2D, an example of substrate 200 during drying using sacrificial bracing is illustrated. In FIG. 2A , substrate 200 includes a plurality of HAR structures 204 extending upwardly from lower substrate layer 212 . For example, the plurality of HAR structures 204 may include one or more pillars 216 or other structures, such as lines/spaces, capacitors, etc., extending upwardly from the lower substrate layer 212. However, other HAR structures can also be considered.

Fluid 224 remains on substrate 200 after wet etching or wet cleaning. By way of example only, fluid 224 may fill spaces 220 between pillars 216 . 2B, an optional transfer solvent 238 may be used to force fluid 224. 2C, solvent 240 containing sacrificial bracing material may be used to repel fluid 224 or optional transfer solvent 238 (if used). As partially shown at 241 in FIG. 2D , plasma may be used to remove sacrificial bracing material without damaging the plurality of HAR structures 204 .

Referring now to FIGS. 3A and 3B, examples of processing chambers for drying a substrate having a plurality of HAR structures are shown. 3A, wet etching, cleaning, and/or rinsing may be performed in spin coating processing chamber 300. Additionally, a solvent with sacrificial bracing material (or a transfer solvent and a solvent with sacrificial bracing material) may be applied to the substrate within spin coating processing chamber 300. The substrate may then be transferred to a plasma processing chamber 304 for plasma processing to remove sacrificial bracing material without damaging the plurality of HAR structures.

In Figure 3B, a combined spin coating and plasma processing chamber 310 is shown. Wet etching, cleaning, and/or rinsing may be performed using spin coating components of a combined spin coating and plasma processing chamber 310. Solvent with sacrificial bracing material (or transfer solvent and solvent with sacrificial bracing material) may be applied using spin coating components. The plasma components of the combined spin coating and plasma processing chamber 310 may then be used for plasma processing to remove the sacrificial bracing material of the substrate without damaging the HAR structures.

Referring now to FIG. 4 , an example of a system 409 including a spin coating processing chamber 404 is shown. A substrate support 408, such as a pedestal or platen, may be provided. Substrate 410 is placed on substrate support 408. Motor 412 may be used to selectively rotate substrate support 408 as needed to spin coat liquids on substrate 410. Substrate support 408 may include an embedded coil (not shown) connected to heater 422.

The fluid transfer system 424 transfers fluids from one or more liquid sources 426-1, 426-2, ..., and 426-N (collectively liquid sources 426) to the substrate 410. It is used to do so. Fluid delivery system 424 may include one or more valves 428-1, 428-2, ..., and 428-N (collectively valves 428). A divert valve 430 may be used to flush liquid from the fluid delivery system 424. Fluid delivery system 424 may be configured to deliver fluids for wet etching, wet cleaning, flushing fluid, solvent including structural bracing material, and/or other fluids. Valve 452 and pump 454 may be used to discharge reactants from spin coating processing chamber 404 if necessary. One or more sensors 458 may be provided to monitor conditions such as temperature and pressure within the process chamber 404.

Controller 460 may be used to control one or more devices within system 409. More specifically, controller 460 may be used to control motor 412, heater 422, fluid delivery system 424, and/or valve 452 and pump 454. Controller 460 may operate in part based on feedback from one or more sensors 458.

Referring now to FIG. 5, an example of a substrate processing system 510, in accordance with the present disclosure, is shown. Substrate processing system 510 includes a processing chamber 512 and a gas distribution device 513. In some examples, remote plasma may be supplied to or generated within the gas distribution device 513, as described further below. A substrate support 516, such as a pedestal or platen, may be disposed within the processing chamber 512. During use, a substrate 518, such as a semiconductor wafer, or other type of substrate, may be placed on the substrate support 516.

Substrate processing system 510 includes a gas delivery system 520. By way of example only, gas delivery system 520 may include one or more gas sources 522-1, 522-2, ..., and 522-N (collectively gas sources 522), where N is is an integer greater than 0), valves 524-1, 524-2, ..., and 524-N (collectively valves 524), and mass flow controllers (MFC) 526-1, 526-2, ..., and 526-N) (collectively, MFC 526). The outputs of gas delivery system 520 may be mixed within manifold 530 and delivered to a remote plasma source and/or gas distribution device 513. Gas delivery system 520 supplies plasma gas chemicals.

Controller 540 may be coupled to one or more sensors 541 that monitor operating parameters within process chamber 512, such as temperature, pressure, etc. A heater 542 may be provided to heat the substrate support 516 and the substrate 518 as needed. A valve 550 and pump 552 may be provided to vent gas from the processing chamber 512.

By way of example only, a plasma generator 556 may be provided. In some examples, plasma generator 556 is a downstream plasma source. Plasma generator 556 may include a plasma tube, induction coil, or another device to generate a remote plasma. By way of example only, plasma generator 556 may use radio frequency (RF) or microwave power to generate a remote plasma using the gas chemistries identified above. In some examples, an induction coil is wound around the upper stem portion of the showerhead and excited by an RF signal generated by the RF source and matching network. The reactive gas flowing through the stem portion is excited into a plasma state by an RF signal passing through the induction coil.

Controller 540 may be used to control plasma produced by gas delivery system 520, heater 542, valve 550, pump 552, and remote plasma generator 556.

Referring now to Figure 6, a combined spin coating and plasma processing chamber 610 is shown. The combined spin coating and plasma processing chamber 610 includes a controller 620 configured to control wet etching or wet cleaning, wet rinsing, application of a selectable transfer solvent, application of a solvent comprising a sacrificial bracing material, and generation of plasma. Includes.

More specifically, controller 620 delivers a wet etching solution or a cleaning solution or a wet rinsing solution to the substrate. Controller 620 then delivers a solvent comprising the sacrificial bracing material (or an optional transfer solvent and then a solvent comprising the sacrificial bracing material). During or after fluid delivery, the controller may use the motor 412 to rotate the substrate support 408 to spin-coat the fluid on the substrate. Rotation of the substrate support 408 may also spin off excess solvent/sacrificial bracing material.

After application, the solvent vaporizes, leaving behind a sacrificial bracing material that supports the HAR structures. Subsequently, controller 620 controls gas delivery system 520 and plasma generator 556 to generate plasma to remove sacrificial bracing material and dry HAR structures without damaging the HAR structures. Although an example of removal of sacrificial bracing material involving plasma is shown and described, sacrificial bracing material may instead be removed using ozone.

In some examples, the sacrificial bracing material includes polymer components and nanoparticle components. The sacrificial bracing material is delivered via solvent as described above. By way of example only, suitable solvents include organic solvents and deionized water, although other solvents may be used. A sacrificial bracing material containing nanoparticles may be thermally stable and enable higher ashing temperatures, thereby enabling higher throughput.

Examples of nanoparticle components include, but are not limited to, organic polymers, organic particles, latexes, and inorganic nanoparticles, including nanoparticles or carbon-based nanoparticles (e.g., fullerenes or fullerols). (eg, SiO ₂ ). In some examples, the maximum size of the nanoparticle material used is less than 12 nm, less than 10 nm, or less than 8 nm. In some examples, the maximum size of the nanoparticle material is less than half the (e.g., minimum) distance between adjacent HAR structures. In some examples, nanoparticle materials can be volatilized using plasma chemistry.

Examples of polymers include low molecular weight polymers or oligomers. Low molecular weight polymers have a molecular weight of less than 15,000 g/mol, less than 10,000 g/mol, less than 8,000 g/mol, less than 5,000 g/mol, less than 3,000 g/mol, less than 2,000 g/mol, or less than 1,000 g/mol. It may also refer to polymers. In some examples, polymers with a molecular weight of approximately 600 g/mol may be used. In some examples, the maximum size of the polymer is less than one-half the (e.g., minimum) distance between adjacent HAR structures. In some examples, the polymer may be volatilized using plasma chemistry.

In some examples, the sacrificial bracing material may be polymer-rich compared to the nanoparticle material. In some examples, the polymer-rich is a weight ratio of polymer to nanoparticle material of at least 1:1, at least 2:1, at least 3:1, at least 5:1, at least 10:1, at least 25:1, or at least 50:1. It may also be referred to as . In some examples, the weight ratio of solid to solvent may be less than 0.40, less than 0.25, less than 0.2, less than 0.15, less than 0.1, or less than 0.05. Solids may include polymeric solids and nanoparticle solids. As mentioned above, examples of solvents may include organic solvents and water.

The sacrificial bracing material may also include one or more surfactants to lower the surface tension and/or improve the coating uniformity of the HAR structures and the filling of spaces between the HAR structures. The surfactant used may be selected based on miscibility, removal ability using plasma, and surface tension effects.

The high temperature and exothermic reactions that occur during plasma removal of the sacrificial bracing material may induce a glass transition of the sacrificial bracing material. This glass transition can also lead to the formation of a melt. The melt may behave like a liquid and induce HAR structure collapse during removal of sacrificial bracing material. Collapse can be prevented by designing complex, cross-linked bracing materials and/or limiting the temperature during bracing material removal. However, this may reduce processing throughput because removal of the bracing material may take a long time to complete.

Adding nanoparticle material increases the glass transition temperature of the sacrificial bracing material. Sacrificial bracing materials with higher glass transition temperatures and increased thermal stability are desirable to improve processing throughput. The glass transition temperature of the sacrificial bracing material comprising both polymer and nanoparticle material is higher than the glass transition temperature of the sacrificial bracing material not comprising nanoparticle material. Nanoparticle materials increase the glass transition temperature of sacrificial bracing materials due to polymer interactions with particle surfaces, which slows down polymer chain dynamics. Raising the glass transition temperature allows higher temperatures to be used for plasma ablation of the sacrificial bracing material, increasing the plasma ablation rate and reducing processing time.

Nanoparticulate materials can also adhere on the walls of HAR structures and prevent friction. Some materials that precipitate from a solvent (eg, silicates) may form chemical bonds, such as silica bridges. Nanoparticulate materials may prevent this chemical bond/bridge formation due to the nanoparticle materials having larger sizes. Therefore, nanoparticles may reduce or prevent friction.

By way of example only, a solution providing a sacrificial bracing material has a higher glass transition temperature than the polymer and contains 10 wt% polyacrylamide (polymer), 1 wt% fullerols (nanoparticle material), 0.2 wt% ammonium. Dodecyl sulfate (surfactant), and deionized water (solvent). In another example, a solution providing a sacrificial bracing material has a higher glass transition temperature than the polymer and contains 10 wt% polyacrylamide (polymer), 0.2 wt% fullerols (nanoparticle material), 0.2 wt% ammonium. Dodecyl sulfate (surfactant), and deionized water (solvent). As mentioned above, the weight ratios of the components of the composite can be selected/adjusted to optimize the filling, coating uniformity, film thickness, and desired temperature characteristics of the resulting sacrificial bracing materials. In some polymer-rich examples, the solution may contain up to 20 wt% polymer, up to 10 wt% nanoparticles, up to 5 wt% surfactant, and the remainder solvent.

Referring now to FIG. 7A, the exemplary portion of the substrate includes sacrificial bracing material 704 that does not include nanoparticle material. Sacrificial bracing material 704 may undergo a glass transition and form a melt during plasma ablation. The melt may lead to HAR structure collapse when the sacrificial bracing material 704 is removed. Additionally, bridging or chemical bonding may occur between adjacent HAR structures.

Referring now to FIG. 7B, an example portion of the substrate that includes sacrificial bracing material 708 includes nanoparticle material. By way of example only, C60-fullerols (nanoparticle materials) and polyacrylamide (PAM) polymers may be used. Nanoparticulate materials increase the glass transition temperature of the resulting sacrificial bracing material. Accordingly, higher temperatures may be used during plasma removal of sacrificial bracing material 708. Additionally, nanoparticle materials may prevent friction by minimizing or preventing chemical bonding/bridging between adjacent HAR structures.

Referring now to Figure 8, raising the glass transition temperature of sacrificial braces may also allow polymers with lower glass transition temperatures (Tg) to be used. Therefore, additional options may be available for preparing less expensive composites and still producing drying without collapse. Just as an example, the glass transition temperatures for different types of polymers are expressed as a function of fullerene nanoparticle weight fraction. Figure 8 illustrates the use of different polymers based on the amount and type of nanoparticle material.

Some types of nanoparticle materials may only partially fill the spaces between HAR structures or leave voids (unfilled areas) between adjacent HAR structures. Partial filling of the spaces between HAR structures may stress the HAR structures. In some cases, annealing may help the sacrificial bracing material fill voids and reduce stresses on HAR structures. In other cases, the sacrificial bracing material may not undergo a glass transition or phase transition at temperatures below the maximum allowable device processing temperature. As such, annealing may not help the sacrificial bracing material fill voids prior to removal.

In some examples, the sacrificial bracing material may be nanoparticle-rich compared to polymers. In some examples, nanoparticle-rich refers to a weight ratio of nanoparticle material to polymer of at least 1:1, at least 1.05:1, at least 1.1:1, at least 1.2:1, at least 1.5:1, at least 2:1. In some examples, the weight ratio of solid to solvent may be less than 0.40, less than 0.25, less than 0.2, less than 0.15, less than 0.1, or less than 0.05. Solids may include polymeric solids and nanoparticle material solids. As mentioned above, examples of solvents may include organic solvents and water.

The sacrificial bracing material may also include one or more surfactants to lower the surface tension and/or improve the coating uniformity of the HAR structures and the filling of the spaces between the HAR structures. As mentioned above, the surfactants used may be selected based on miscibility, removal ability using plasma, and surface tension effects.

The polymer may be liquid or solid and improves the fluidity of the sacrificial bracing material. The polymer may include organic-based polymers, organic-based oligomers, one or more organic molecules, and/or ionic liquids. In some examples, the polymer may be volatilized using plasma chemistry. In some examples, the polymer can be miscible in a solvent with the nanoparticle material.

An example of a solution that provides a sacrificial bracing material with increased fluidity for better packing is 7 wt% fullerol (nanoparticles), 5 wt% polyacrylamide (polymer) with a molecular weight less than 15000 g/mol ), 0.2 wt% of ammonium dodecyl sulfate (surfactant), and the remainder is deionized water (solvent). Another exemplary solution that provides a sacrificial bracing material with increased flowability for better packing is 7 wt% fullerol (nanoparticle material), 3 wt% polyethylene glycol with a molecular weight less than 1000 g/mol ( polymer), 0.2 wt% of ammonium dodecyl sulfate (surfactant), and deionized water (solvent). In some nanoparticle-rich examples, the solution may include up to 10 wt% polymer, up to 20 wt% nanoparticles, up to 5 wt% surfactant, and the remainder solvent. Although specific examples are provided, weight ratios or materials can be adjusted to optimize fill, coating uniformity, film thickness, and desired thermal properties of the composite sacrificial bracing material.

Referring now to Figures 9A and 9B, examples of sacrificial bracing materials are shown. 9A, a portion of the substrate is shown including two pillars 216, the space 220 between the two pillars 216, and sacrificial bracing material 904 before annealing. 9B, a portion of the substrate including two pillars 216, the space 220 between pillars 216, and sacrificial bracing material 904 is shown after annealing.

In the examples of FIGS. 9A and 9B , the sacrificial bracing material 904 does not include polymer and only partially fills the space 220 , leaving a void 908 near the substrate 212 . By way of example only, sacrificial bracing material 904 can be prepared from an exemplary solution comprising 7 wt% fullerol (nanoparticle material), 0.2 wt% ammonium dodecyl sulfate (surfactant), and deionized water (solvent). It may happen. Despite performing the annealing at temperatures up to the maximum allowable device processing temperature, the sacrificial bracing material 904 does not undergo a glass transition during annealing. Therefore, voids 908 remain after annealing.

Referring now to FIGS. 10A and 10B, another example of a sacrificial bracing material is shown. 10A, a portion of the substrate is shown including pillars 216, space 220 between pillars 216, and sacrificial bracing material 1004 before annealing. 10B, a portion of the substrate including pillars 216, space 220 between pillars 216, and sacrificial bracing material 1004 is shown after annealing. In the examples of FIGS. 10A and 10B, sacrificial bracing material 1004 includes a polymer. Sacrificial bracing material 1004 may also include a surfactant. By way of example only, sacrificial bracing material 1004 includes 7 wt% fullerol (nanoparticle material), 0.2 wt% ammonium dodecyl sulfate (surfactant), 3 wt% polyethylene glycol (polymer), and It may also arise from exemplary solutions containing ionic water (solvent).

In FIG. 10A , the sacrificial bracing material 1004 may only partially fill the space 220 , leaving a void 1008 near the substrate 212 . 10B, sacrificial bracing material 1004 is shown after flowing into space 220 and filling void 1008. Sacrificial bracing material 1004 may flow into space 220 and fill voids 1008 with or without annealing. Sacrificial bracing material 1004 flowing into and filling voids 1008 helps prevent collapse of the HAR structure following complete or partial removal of sacrificial bracing material 1004.

Referring now to FIG. 11A , a substrate is shown comprising a plurality of pillars 216 and spaces 220 between the pillars 216 . In Figure 11A, a sacrificial bracing material containing no polymer was used. By way of example only, the sacrificial bracing material of FIG. 11A is prepared from an exemplary solution comprising 7 wt% fullerol (nanoparticle material), 0.2 wt% ammonium dodecyl sulfate (surfactant), and deionized water (solvent). It may happen. As shown, even after annealing, the pillars 216 may be drawn toward each other due to voids between adjacent pillars.

Referring now to FIG. 11B , the substrate includes a plurality of pillars 216 and spaces 220 between the pillars 216 . In Figure 11b, a sacrificial bracing material comprising polymer was used and annealing was performed. By way of example only, the sacrificial bracing material of FIG. 11B includes 7 wt% fullerol (nanoparticle material), 0.2 wt% ammonium dodecyl sulfate (surfactant), 3 wt% polyethylene glycol (polymer) molecular weight 600 g. /mol, and deionized water (solvent). As shown, the pillars 216 are drawn toward each other less than in the example of FIG. 11A.

In one aspect, a method for drying a substrate comprising a plurality of high aspect ratio (HAR) structures is described. The method includes (i) wet etching, and (ii) wet cleaning, and (iii) a substrate using at least one of (a) a wet etching solution, and (b) a wet cleaning solution, and (c) a wet rinsing solution, respectively. After at least one of wet rinsing, and without drying the substrate, depositing a solution comprising a polymer component, a nanoparticle component, and a solvent between the plurality of HAR structures, wherein when the solvent evaporates, the sacrificial bracing material is formed. A polymer component that precipitates from solution and at least partially fills the plurality of HAR structures, wherein the sacrificial bracing material comprises (i) a polymer material from the polymer component in solution and (ii) a nanoparticle material from the nanoparticle component in solution. depositing a solution comprising , nanoparticle components, and a solvent between the plurality of HAR structures; and exposing the substrate to a plasma generated using plasma gas chemistry to volatilize the sacrificial bracing material.

In other features, the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1:1. In other features, the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. In other features, the solution includes 5% by weight polyacrylamide having a molecular weight of less than 15,000 g/mol, 7% fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. In other features, the solution includes 7 weight percent fullerol, 3 weight percent polyethylene glycol with a molecular weight less than 1000 g/mol, 0.2 weight percent ammonium dodecyl sulfate, and the balance deionized water. In other features, the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1.2:1. In other features, the solution includes a surfactant. In other features, the maximum size of the nanoparticle material is less than one-half the distance between two adjacent HAR structures of the plurality of HAR structures. In other features, the maximum size of the nanoparticle material is less than 20 nm. In other features, the maximum size of the polymer material is less than one-half the distance between two adjacent HAR structures of the plurality of HAR structures. In other features, the maximum size of the polymer material is less than 20 nm. In other features, the molecular weight of the polymeric material is less than 15,000 g/mol. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 5:1. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 10:1. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 1:1. In other features, the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. In other features, the solution includes 10% polyacrylamide, 0.2% fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. In other features, the solution includes 1 weight percent fullerol, 10 weight percent polyacrylamide, 0.2 weight percent ammonium dodecyl sulfate, and the balance deionized water. In other features, the first glass transition temperature of the polymeric material is lower than the second glass transition temperature of the sacrificial bracing material. In other features, the plasma is a downstream plasma.

In one aspect, a system for drying a substrate comprising a plurality of high aspect ratio (HAR) structures is described. The system includes a processing chamber; A substrate support disposed within the processing chamber; a gas delivery system for delivering the gas mixture to the processing chamber; a fluid delivery system configured to deliver a solution to a substrate; a plasma generator configured to generate plasma within the processing chamber; and a controller in communication with the fluid delivery system, gas delivery system, and plasma generator. The controller controls (i) wet etching, and (ii) wet cleaning, and (iii) of the substrate using at least one of (a) a wet etching solution, or (b) a wet cleaning solution, or (c) a wet rinsing solution, respectively. After at least one of wet rinsing and without drying the substrate, depositing a solution comprising polymer components, nanoparticle components, and solvent between the plurality of HAR structures and plasma gas chemistry to volatilize the sacrificial bracing material. It is configured for the operation of exposing the substrate to plasma generated using. When the solvent evaporates, a sacrificial bracing material precipitates from the solution and at least partially fills the plurality of HAR structures, the sacrificial bracing material comprising (i) a polymeric material from the polymeric component of the solution and (ii) a nanoparticle component of the solution. It contains nanoparticle materials.

In other features, the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1:1. In other features, the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. In other features, the solution includes 5% by weight polyacrylamide having a molecular weight of less than 15,000 g/mol, 7% fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. In other features, the solution includes 7 weight percent fullerol, 3 weight percent polyethylene glycol with a molecular weight less than 1000 g/mol, 0.2 weight percent ammonium dodecyl sulfate, and the balance deionized water. In other features, the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1.2:1. In other features, the solution includes a surfactant. In other features, the maximum size of the nanoparticle material is less than one-half the distance between two adjacent HAR structures of the plurality of HAR structures. In other features, the maximum size of the nanoparticle material is less than 20 nm. In other features, the maximum size of the polymer material is less than one-half the distance between two adjacent HAR structures of the plurality of HAR structures. In other features, the maximum size of the polymer material is less than 20 nm. In other features, the molecular weight of the polymeric material is less than 15,000 g/mol. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 5:1. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 10:1. In other features, the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 1:1. The solution contains a weight fraction of solids to solvent of not more than 0.4. In other features, the solution includes 10% polyacrylamide, 0.2% fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. In other features, the solution includes 1 weight percent fullerol, 10 weight percent polyacrylamide, 0.2 weight percent ammonium dodecyl sulfate, and the balance deionized water. In other features, the first glass transition temperature of the polymeric material is lower than the second glass transition temperature of the sacrificial bracing material. In other features, the plasma generator is configured to generate a downstream plasma within the processing chamber.

The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, their application or uses in any way. The broad teachings of the disclosure may be embodied in various forms. Accordingly, although the disclosure includes specific examples, the true scope of the disclosure should not be so limited, as other modifications will become apparent from a study of the drawings, the specification, and the following claims. As used herein, at least one of the phrases A, B, and C should be interpreted to mean logically (A or B or C), using the non-exclusive logical OR, and "at least one A , at least one B, and at least one C". It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without changing the principles of the disclosure.

In some implementations, a controller is part of a system that may be part of the examples described above. These systems may include semiconductor processing equipment, including a processing tool or tools, a chamber or chambers, a platform or platforms for processing, and/or specific processing components (wafer pedestals, gas flow systems, etc.) . These systems may be integrated with electronics to control the operation of semiconductor wafers or substrates before, during, and after processing. An electronic device may be referred to as a “controller” that may control a system or various components or sub-parts of systems. The controller controls delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, and power settings, depending on the processing requirements and/or type of system. , radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, tools and other transfer tools and/or It may also be programmed to control any of the processes disclosed herein, including wafer transfers into and out of loadlocks connected or interfaced with a particular system.

Generally speaking, a controller has various integrated circuits, logic, memory, and/or software to receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, etc. It may also be defined as an electronic device. Integrated circuits are chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one that executes program instructions (e.g., software). It may also include one or more microprocessors or microcontrollers. Program instructions may be instructions delivered to the controller or to the system in the form of various individual settings (or program files) that specify operating parameters for executing a particular process on or for a semiconductor wafer. In some embodiments, operating parameters may be used to achieve one or more processing steps during fabrication of dies of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or wafers. It may be part of a recipe prescribed by an engineer.

The controller may, in some implementations, be coupled to or part of a computer that may be integrated into the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be all or part of a fab host computer system or within the “cloud,” which may enable remote access to wafer processing. The computer monitors the current progress of manufacturing operations, examines the history of past manufacturing operations, examines trends or performance metrics from multiple manufacturing operations, changes parameters of current processing, and performs processing steps that follow the current processing. You can also enable remote access to the system to configure, or start new processes. In some examples, a remote computer (eg, a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and/or settings that are later transferred to the system from the remote computer. In some examples, the controller receives instructions in the form of data that specify parameters for each of the process steps to be performed during one or more operations. It should be understood that these parameters may be specific to the type of tool the controller is configured to control or interface with and the type of process to be performed. Accordingly, as discussed above, the controller may be distributed, for example, by comprising one or more individual controllers that are networked together and cooperate for a common purpose, for example, the processes and controls described herein. An example of a distributed controller for these purposes is one or more integrated circuits on the chamber that communicate with one or more remotely located integrated circuits (e.g., at the platform level or as part of a remote computer) that combine to control the process on the chamber. It could be circuits.

Without limitation, example systems include a plasma etch chamber or module, a plasma strip chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, physical vapor deposition (PVD) chamber or module, chemical vapor deposition (CVD) chamber or module, atomic layer deposition (ALD) chamber or module, atomic layer etch (ALE) chamber or module, ion implantation chamber or module, track It may also include a chamber or module, and any other semiconductor processing systems that may be used in or associated with the fabrication and/or fabrication of semiconductor wafers.

As described above, depending on the process step or steps to be performed by the tool, the controller may be used in material transfer to move containers of wafers to and from tool locations and/or load ports within the semiconductor fabrication plant. It may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a main computer, another controller or tools. .

Claims (40)

In a method for drying a substrate containing a plurality of high aspect ratio (HAR) structures,
The above method is,
(i) wet etching, and (ii) wet cleaning, and (iii) wet rinsing of the substrate using at least one of (a) a wet etching solution, and (b) a wet cleaning solution, and (c) a wet rinsing solution, respectively. After at least one of rinsing, and without drying the substrate:
depositing a solution comprising a polymer component, a nanoparticle component, and a solvent between the plurality of HAR structures; and
When the solvent evaporates, sacrificial bracing material precipitates from the solution and at least partially fills the plurality of HAR structures, volatilizing the sacrificial bracing material,
The sacrificial bracing material comprises (i) polymeric material from the polymeric component of the solution and (ii) nanoparticle material from the nanoparticle component of the solution. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1:1. According to claim 2,
A method for drying a substrate containing HAR structures, wherein the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. According to claim 2,
The solution contains 5% by weight polyacrylamide with a molecular weight of less than 15,000 g/mol, 7% fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. A method for drying a substrate containing According to claim 2,
The solution comprises 7% by weight fullerol, 3% by weight polyethylene glycol with a molecular weight of less than 1000 g/mol, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. Method for drying. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1.2:1. According to claim 1,
A method for drying a substrate containing HAR structures, wherein the solution further includes a surfactant. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the maximum size of the nanoparticle material is less than half the distance between two adjacent HAR structures of the plurality of HAR structures. According to claim 8,
A method for drying a substrate containing HAR structures, wherein the maximum size of the nanoparticle material is less than 20 nm. According to claim 8,
A method for drying a substrate comprising HAR structures, wherein the maximum size of the polymer material is less than half the distance between two adjacent HAR structures of the plurality of HAR structures. According to claim 10,
A method for drying a substrate containing HAR structures, wherein the maximum size of the polymer material is less than 20 nm. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the polymeric material has a molecular weight of less than 15,000 g/mol. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 5:1. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 10:1. According to claim 1,
A method for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 1:1. According to claim 15,
A method for drying a substrate containing HAR structures, wherein the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. According to claim 15,
A method for drying a substrate containing HAR structures, wherein the solution includes 10% by weight polyacrylamide, 0.2% by weight fullerol, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. According to claim 15,
The solution comprises 1% by weight fullerol, 10% by weight polyacrylamide, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. According to claim 15,
A method for drying a substrate comprising HAR structures, wherein the first glass transition temperature of the polymer material is lower than the second glass transition temperature of the sacrificial bracing material. According to claim 1,
Wherein volatilizing the sacrificial bracing material includes exposing the substrate to a plasma generated using a plasma gas chemistry, wherein the plasma is a downstream plasma. A system for drying a substrate comprising a plurality of high aspect ratio (HAR) structures, comprising:
The system is,
processing chamber;
a substrate support disposed within the processing chamber;
a gas delivery system for delivering a gas mixture to the processing chamber;
a fluid delivery system configured to deliver a solution to the substrate;
communicate with the fluid delivery system and the gas delivery system;
(i) wet etching, and (ii) wet cleaning, and (iii) wet rinsing of the substrate using at least one of (a) a wet etching solution, or (b) a wet cleaning solution, or (c) a wet rinsing solution, respectively. After either rinsing, and without drying the substrate:
depositing a solution comprising a polymer component, a nanoparticle component, and a solvent between the plurality of HAR structures;
a controller configured to volatilize the sacrificial bracing material when the solvent evaporates, causing the sacrificial bracing material to precipitate from the solution and at least partially fill the plurality of HAR structures;
The system for drying a substrate comprising HAR structures, wherein the sacrificial bracing material comprises (i) polymeric material from the polymeric component of the solution and (ii) nanoparticle material from the nanoparticle component of the solution. According to claim 21,
A system for drying a substrate comprising HAR structures, wherein the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1:1. According to claim 22,
A system for drying a substrate containing HAR structures, wherein the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. According to claim 22,
The solution comprises HAR structures, comprising 5% by weight polyacrylamide with a molecular weight of less than 15,000 g/mol, 7% by weight fullerol, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. A system for drying substrates. According to claim 22,
The solution comprises 7% by weight fullerol, 3% by weight polyethylene glycol with a molecular weight of less than 1000 g/mol, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. A system for drying. According to claim 21,
A system for drying a substrate containing HAR structures, wherein the weight ratio of the nanoparticle component of the solution to the polymer component of the solution is at least 1.2:1. According to claim 21,
A system for drying a substrate containing HAR structures, wherein the solution further comprises a surfactant. According to claim 21,
A system for drying a substrate comprising HAR structures, wherein the maximum size of the nanoparticle material is less than half the distance between two adjacent HAR structures of the plurality of HAR structures. According to clause 28,
A system for drying a substrate containing HAR structures, wherein the maximum size of the nanoparticle material is less than 20 nm. According to clause 28,
A system for drying a substrate comprising HAR structures, wherein the maximum size of the polymer material is less than half the distance between two adjacent HAR structures of the plurality of HAR structures. According to claim 30,
A system for drying a substrate containing HAR structures, wherein the maximum size of the polymer material is less than 20 nm. According to claim 21,
A system for drying a substrate containing HAR structures, wherein the molecular weight of the polymeric material is less than 15,000 g/mol. According to claim 21,
A system for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 5:1. According to claim 21,
A system for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 10:1. According to claim 21,
A system for drying a substrate comprising HAR structures, wherein the weight ratio of the polymer component of the solution to the nanoparticle component of the solution is at least 1:1. According to claim 35,
A system for drying a substrate containing HAR structures, wherein the solution comprises a weight fraction of solids to solvent of less than or equal to 0.4. According to claim 35,
A system for drying a substrate containing HAR structures, wherein the solution comprises 10% by weight polyacrylamide, 0.2% by weight fullerol, 0.2% ammonium dodecyl sulfate, and the balance deionized water. According to claim 35,
A system for drying a substrate containing HAR structures, wherein the solution includes 1% by weight fullerol, 10% by weight polyacrylamide, 0.2% by weight ammonium dodecyl sulfate, and the balance deionized water. According to claim 35,
A system for drying a substrate comprising HAR structures, wherein the first glass transition temperature of the polymer material is lower than the second glass transition temperature of the sacrificial bracing material. According to claim 21,
further comprising a plasma generator configured to generate a downstream plasma within the processing chamber;
wherein the controller is configured to volatilize the sacrificial bracing material by exposing the substrate to a plasma generated by the plasma generator.