Selective Deposition of Carbon onto a Photoresist Layer for Lithography Applications

Abstract

To provide a method of selective deposition of carbon on a photoresist layer.SOLUTION: Embodiments disclosed within include a method for etching a hardmask layer on a bottom anti-reflective coating (BARC) layer, the method including: forming a photoresist layer comprising an organometallic material on a hardmask layer comprising a metal-containing material; exposing the photoresist layer to ultraviolet radiation through a mask having a selected pattern; removing un-irradiated areas of the photoresist layer to pattern the photoresist layer; selectively depositing passivation over a top surface of a patterned photoresist layer, and trimming undesired portions of the passivation material to form a passivation layer; etching the hardmask layer exposed by the patterned photoresist layer having the passivation layer formed thereon; and etching the BARC layer exposed by the patterned hardmask layer.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001]

[0001] Embodiments of the present specification generally relate to a method, and more specifically, to a method for selectively depositing carbon onto a photoresist layer.

Background Art

[0002] Description of Related Art

[0002] Reliably fabricating features smaller than sub-micron and even smaller features is one of the critical requirements for very large scale integration (VLSI) and ultra very large scale integration (ULSI) of semiconductor devices. However, with the continuous miniaturization of circuit technology, the size and pitch of circuit features such as interconnects are demanding even more in terms of processing power. The multi-level interconnects at the core of this technology require precise imaging and placement of high aspect ratio features (such as vias and other interconnects). Reliably forming these interconnects is important for further increasing the density of devices and interconnects. In addition, it is required to form features and interconnects with sizes less than sub-micron while reducing waste of intermediate materials (such as resist and hard mask materials).

[0003]

[0003] As the feature size is miniaturized, the requirement for an increase in the aspect ratio (defined as the ratio of the depth of the feature to the width of the feature) is steadily increasing and has reached 1:5 or more. There are important issues in realizing a film laminate and an etching process capable of reliably forming features having such a high aspect ratio. However, due to inaccurate control of the lithographic exposure and development process or low resolution, the dimensions of the photoresist layer used to transfer the features into the film laminate become inaccurate, and as a result, unacceptable line width roughness (LWR) can occur. The LWR caused by the lithographic exposure and development process and the undesirable bending of the profile of the photoresist layer result in inaccurate feature transfer to the film laminate, which can ultimately lead to device failures and yield losses.

[0004]

[0004] Furthermore, in the etching of the film stack, re-deposition or accumulation of by-products or other materials generated during this etching process accumulates on the top and / or sidewalls of the feature being etched, and as a result, the openings of the features formed within the material layer may be undesirably blocked. By selecting different materials for the film stack, the amount or profile of the by-products redeposited on the film stack can vary. Further, since the openings of the etched features are narrowed and / or sealed by the accumulation of the redeposited material, the reactive etchant is prevented from reaching the lower surface of the feature, and as a result, the achievable aspect ratio is limited. In addition, since the accumulation of the redeposited material or by-products adheres randomly and / or irregularly to the upper surface and / or sidewalls of the feature being etched, the resulting irregular profile and growth of the redeposited material changes the flow path of the reactive etchant, and as a result, may result in a curved or twisted profile of the feature formed within the material layer. Incorrect profiles or structural dimensions lead to degradation of the device structure and may ultimately result in device failures and reduced product yields. Insufficient selectivity of the etching with respect to the materials contained in the film stack results in an undesirable result of inaccurate profile control and may ultimately lead to device failures.

[0005]

[0005] Therefore, in the art, there is a need for a suitable film stack and an etching method for etching features with desirable profiles and small dimensions in such a film stack.

Summary of the Invention

[0006]

[0006] A method is provided for forming a film stack and etching the film stack to form high aspect ratio features therein. By the method described herein, profile and dimension control of features having a high aspect ratio and having a desirable material selected for the film stack is facilitated through a suitable sidewall and bottom management scheme.

[0007]

[0007] In one embodiment, a method for etching a hard mask layer is provided. The method includes forming a photoresist layer containing an organometallic material on a hard mask layer containing a metal-containing material, exposing the photoresist layer to ultraviolet irradiation through a mask having a selected pattern, removing the non-irradiated regions of the photoresist layer to form a patterned photoresist layer, forming a passivation layer selectively containing a carbon-containing material on the upper surface of the patterned photoresist layer, and etching the hard mask layer exposed by the patterned photoresist layer having the passivation layer formed thereon.

[0008]

[0008] In another embodiment, a method for etching a film stack is provided. The method includes forming a hard mask layer, forming a photoresist layer containing an organometallic material on the hard mask layer, exposing the photoresist layer to ultraviolet irradiation through a mask having a selected pattern, removing the non-irradiated regions of the photoresist layer to form a patterned photoresist layer, forming a passivation layer selectively containing a carbon-containing material on the upper surface of the patterned photoresist layer, etching the hard mask layer exposed by the patterned photoresist layer having the passivation layer formed thereon to form a patterned hard mask layer, and etching the film stack exposed by the patterned hard mask layer.

[0009]

[0009] In yet another embodiment, a method for forming a passivation layer is provided. The method includes selectively depositing a passivation material on the upper surface of a patterned photoresist layer and trimming unwanted portions of the passivation material. The passivation layer contains a carbon-containing material.

[0010] As described above, the features of the embodiments of this specification are realized and can be more specifically understood. A more detailed description of the present disclosure, which was briefly summarized above, can be obtained by referring to the examples. Such examples are shown in the accompanying drawings.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figures 3A - 3F

Figures 3G - 3I

Figures 4A - 4B

Modes for Carrying Out the Invention

[0012]

[0015] To facilitate the understanding of the embodiments, the same reference numbers are used, if possible, to indicate the same elements common to multiple figures. The elements and features of one embodiment are assumed to be beneficially incorporated into other embodiments without further description. However, it should be noted that since the present invention may admit other equally valid embodiments, the accompanying drawings merely show exemplary embodiments and should not be regarded as limiting the scope of the examples.

[0013]

[0016] A method is provided for forming a film stack and etching the film stack to form high aspect ratio features therein. By the method described herein, through an appropriate sidewall and bottom management scheme, profile and dimension control of features having a high aspect ratio and having a desired material selected for the film stack is facilitated. In particular, the method described herein provides a metal-containing photoresist layer having a carbon-containing passivation layer selectively disposed thereon, the layer having a high etching selectivity from the underlying metal-containing hard mask layer, leading to a higher precision control of the profile of the openings etched in the hard mask layer. Additionally, the method disclosed herein includes a method of forming a passivation layer that includes selectively depositing a passivation material on top of the upper surface of the patterned photoresist layer and trimming unwanted portions of the passivation material.

[0014]

[0017] As used herein, the term "about" refers to a variation of + / - 10% from a nominal value. It is to be understood that such variations can be included in any value provided herein.

[0015]

[0018] FIG. 1 shows a cross-sectional view of a processing chamber 100 according to one embodiment. In one example, the processing chamber 100 is suitable for performing a patterning process to etch a film stack having a hard mask layer fabricated from a metal-containing material. Suitable processing chambers that can be adapted for use with the teachings disclosed herein include, for example, ENABLER™, or SYM3™ processing chambers available from Applied Materials, Inc., Santa Clara, Calif. Although a processing chamber 100 is shown that includes a plurality of features enabling excellent etching performance, it is contemplated that other processing chambers can also be adapted to benefit from one or more of the advanced features disclosed herein.

[0016]

[0019] As shown in the figure, the processing chamber 100 includes a chamber body 102 and a lid 104 that surround an internal space 106. The chamber body 102 is manufactured from aluminum, stainless steel, or other suitable materials. The chamber body 102 includes side walls 108 and a bottom 110. A substrate support pedestal access port (not shown) is generally defined in the side wall 108 and is selectively sealed by a slit valve (not shown) to facilitate the entry and exit of the substrate 103 from the processing chamber 100. An exhaust port 126 is defined within the chamber body 102. The exhaust port 126 connects the internal space 106 to a pump system 128. The pump system 128 includes one or more pumps and throttle valves that are utilized to evacuate the internal space 106 of the processing chamber 100 and regulate the pressure within the internal space 106. The pump system 128 maintains the pressure inside the internal space 106 at an operating pressure of from about 10 mTorr to about 500 Torr.

[0017]

[0020] The lid 104 is hermetically supported on the side walls 108 of the chamber body 102. The lid 104 is configured to be opened to increase the volume from the internal space 106 of the processing chamber 100. The lid 104 includes a window 142 that facilitates optical process monitoring. The window 142 includes quartz or other suitable materials that transmit signals utilized by an optical monitoring system 140 attached outside the processing chamber 100.

[0018]

[0021] The optical monitoring system 140 is positioned to view at least one of the interior space 106 of the chamber body 102 and / or the substrate 103 positioned on the substrate support pedestal assembly 148 through the window 142. The optical monitoring system 140 is connected to the lid 104 and facilitates an integrated deposition process using optical measurement methods, providing information that enables process adjustment to compensate for incoming substrate pattern feature mismatches (e.g., thickness), and, if necessary, provides monitoring of the process state (e.g., plasma monitoring, temperature monitoring). One optical monitoring system that can be adapted to benefit from the present invention is the EyeD® full-spectrum interferometry module available from Applied Materials, Inc. of Santa Clara, California.

[0019]

[0022] To provide process gas and / or cleaning gas to the interior space 106, a gas panel 158 is connected to the processing chamber 100. Injection ports 132’, 132’’ are provided in the lid 104 to enable the supply of gas from the gas panel 158 to the interior space 106 of the processing chamber 100.

[0020]

[0023] The showerhead assembly 130 is connected to the inner surface 114 of the lid 104. The showerhead assembly 130 includes a plurality of apertures that enable gas to flow from the injection ports 132’, 132’’ through the showerhead assembly 130 into the interior space 106. The plurality of apertures enable gas to flow in a predefined distribution across the surface of the substrate 103 being processed in the processing chamber 100.

[0021]

[0024] A remote plasma source 177 is connected to a gas panel 158 to facilitate dissociating a mixed gas prior to entering an internal space 106 for processing. A radio frequency (RF) power supply 143 is connected to a showerhead assembly 130 via a matching network 141. The RF power supply 143 is configured to produce up to about 3000 W of power at an adjustable frequency in the range from about 50 kHz to about 200 MHz.

[0022]

[0025] The showerhead assembly 130 further includes a light transmissive region (or also referred to as a light transmissive passageway) 138. The light transmissive region 138 transmits a light measurement signal. The light transmissive region 138 is suitable for an optical monitoring system 140 to visually observe the internal space 106 and / or a substrate 103 positioned on a substrate support pedestal assembly 148. The light transmissive region 138 can be an aperture or a plurality of apertures formed or disposed in the showerhead assembly 130. The light transmissive region 138 substantially transmits the wavelength of the energy generated by and reflected back by the optical monitoring system 140. The light transmissive region 138 includes a window 142 to prevent gas leakage through the light transmissive region 138. The window 142 can be a sapphire plate, a quartz plate, or other suitable material. In one embodiment, the window 142 is alternatively disposed within the lid 104 directly below the optical monitoring system 140.

[0023]

[0026] The showerhead assembly 130 is configured to have a plurality of zones that enable individual control of the gases flowing into the internal space 106 of the processing chamber 100. The showerhead assembly 130 has an inner zone 134 and an outer zone 136 that are individually connected to the gas panel 158 through respective injection ports 132’, 132’’.

[0024]

[0027] The substrate support pedestal assembly 148 is disposed below the showerhead assembly 130 within the internal space 106 of the processing chamber 100. The substrate support pedestal assembly 148 supports the substrate 103 during processing. The substrate support pedestal assembly 148 may include a plurality of lift pins (not shown) disposed to pass through the substrate support pedestal assembly 148 and configured to raise the substrate 103 from the substrate support pedestal assembly 148 to facilitate the exchange of the substrate 103 by a robot (not shown) in a conventional manner. The inner liner 118 surrounds the outer periphery of the substrate support pedestal assembly 148.

[0025]

[0028] As shown, the substrate support pedestal assembly 148 includes a mounting plate 162, a base 164, and an electrostatic chuck 166. The mounting plate 162 is connected to the bottom 110 of the chamber body 102. The mounting plate 162 includes passages for delivering utilities (e.g., among other things, fluids, power lines, and sensor leads) to the base 164 and the electrostatic chuck 166. The electrostatic chuck 166 includes at least one clamping electrode 180 for holding the substrate 103 below the showerhead assembly 130. The electrostatic chuck 166 is driven by a chuck power supply 182 to generate an electrostatic force that holds the substrate 103 against the chuck surface. In one embodiment, the substrate 103 is held by the substrate support pedestal assembly 148 by a combination of an electrostatic force generated by the electrostatic chuck 166 and a clamp, vacuum, or gravity. In another embodiment, the substrate 103 is held by the substrate support pedestal assembly 148 by a clamp, vacuum, or gravity, and the electrostatic chuck is not included.

[0026]

[0029] At least one of the base 164 or the electrostatic chuck 166 includes at least one embedded heater 176, at least one embedded isolator 174, and a plurality of conduits 168, 170 to control the lateral temperature profile of the substrate support pedestal assembly 148. The conduits 168, 170 are fluidly connected to a fluid source 172, and the fluid source 172 circulates temperature-regulating fluid through the conduits. The heater 176 is regulated by a power source 178. The conduits 168, 170 and the heater 176 are utilized to control the temperature of the base 164, whereby the temperature profile of the electrostatic chuck 166 and ultimately the substrate 103 disposed thereon is heated and / or cooled. The temperatures of the electrostatic chuck 166 and the base 164 are monitored using a plurality of temperature sensors 190, 192. In one embodiment, the electrostatic chuck 166 further includes a plurality of gas passages (such as grooves, not shown), which are formed on the substrate support pedestal support surface of the electrostatic chuck 166 and are fluidly connected to a source of heat-conducting gas (or back gas) such as helium gas (He). During operation, the back gas is provided into the gas passages at a controlled pressure to enhance the heat conduction between the electrostatic chuck 166 and the substrate 103.

[0027]

[0030] The substrate support pedestal assembly 148 is configured as a cathode and includes a clamp electrode 180 connected to a plurality of RF bias power sources 184, 186. The RF bias power sources 184, 186 are connected between the electrode 180 disposed within the substrate support pedestal assembly 148 and another electrode (e.g., the showerhead assembly 130 or the lid 104 of the chamber body 102). The RF bias power excites the gas disposed within the processing region of the chamber body 102 to maintain a plasma discharge formed from the gas.

[0028]

[0031] Dual RF bias power supplies 184, 186 are connected through matching circuit 188 to electrode 180 disposed within substrate support pedestal assembly 148. The signals generated by RF bias power supplies 184, 186 are sent through matching circuit 188 to substrate support pedestal assembly 148 in a single feed to ionize the hybrid gas provided within process chamber 100. Thus, RF bias power supply 184 provides the ion energy necessary to perform deposition or other plasma enhanced processes. RF bias power supplies 184, 186 are configured to generate RF signals having a frequency from about 50 kHz to about 200 MHz and a power from about 0 W to about 8000 W, such as from about 1 W to about 5000 W. An additional bias power supply 189 is connected to electrode 180 to control the characteristics of the plasma.

[0029]

[0032] During operation, substrate 103 is disposed on substrate support pedestal assembly 148 within process chamber 100. Process gas and / or hybrid gas is introduced from gas panel 158 through showerhead assembly 130 into chamber body 102. The deposition by-products are removed while the pressure inside chamber body 102 is maintained by pump system 128.

[0030]

[0033] To control the operation of the processing chamber 100, a controller 150 is connected to the processing chamber 100. The controller 150 includes a central processing unit (CPU) 152, a memory 154, and support circuitry 156 that are utilized to control the process sequence and regulate the gas flow from the gas panel 158. The CPU 152 is a general-purpose computer processor in any form that can be used in an industrial environment. Software routines can be stored in the memory 154, such as random access memory, read-only memory, floppy or hard disk drives, or other forms of digital storage. The support circuitry 156 is connected to the CPU 152 in a conventional manner and can include a cache, a clock circuit, an input / output system, a power supply device, and the like. Bidirectional communication between the controller 150 and the various components of the processing chamber 100 is handled via a number of signal cables.

[0031]

[0001] FIG. 2 is a flowchart of a method 200 for a patterning process according to one embodiment described herein. FIGS. 3A - 3I are cross-sectional views of a structure 300 according to the same embodiment. The method 200 is utilized to form features such as trenches, vias, openings, etc. having desired critical dimensions and profiles. The dimensions of such features are from about 14 nm to about 22 nm, for example, about 18 nm. The structure 300 can be utilized in a gate structure, a contact structure, or an interconnect structure in a front-end process or a back-end process. Alternatively, the method 200 can be beneficially utilized to etch other types of structures used in the technical field of semiconductor manufacturing. The method 200 can be stored in or accessible to the controller 150 as a computer-readable medium containing instructions, and when such instructions are executed by the CPU 152 of the controller, the method 200 is caused to be executed in the processing chamber 100.

[0032]

[0034] Those skilled in the art should understand that the entire process of forming semiconductor devices and related structures is not illustrated and not described in this specification. Although various operations are illustrated and described in this specification, it is suggested that there are no restrictions regarding the order of such operations and whether an operation is present or not. The operations shown or described in sequence are only presented in that way for the sake of explanation and, unless explicitly stated otherwise, each operation may be executed actually simultaneously or at least partially overlapping, rather than entirely sequentially.

[0033]

[0035] Method 200 begins, in operation 210, by transporting or providing the film stack 302 shown in FIG. 3A into a processing chamber (such as processing chamber 100 shown in FIG. 1). In one embodiment, the film stack 302 has several layers stacked vertically on a substrate (not shown). The film stack 302 includes one or more layers of materials used in semiconductor manufacturing processes. For example, the film stack 302 includes a metal-containing dielectric layer and one or more silicon-containing dielectric layers. In some embodiments, the metal-containing dielectric layer is formed of a high-k material having a dielectric constant greater than 4. Suitable examples of high-k materials include, among others, aluminum oxide (Al 2 O 3 ), tantalum oxide (Ta 2 O5), tantalum nitride (TaN), oxynitride tantalum (TaNxOy, 0 ≦ x, y ≦ 1), titanium oxide (TiO 2 ), titanium nitride (TiN), zirconium dioxide (ZrO 2 ), hafnium dioxide (HfO 2 ), hafnium silicon oxide (HfSiO 4 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), strontium titanate (SrTiO 3 ), barium strontium titanate (BST, BaSrTiO 3 ), bismuth-doped strontium titanate (Bi:SrTiO 3) Lead zirconate titanate (PZT, Pb[ZrxTi1-x]O 3 , where 0≦x≦1). The silicon-containing dielectric layer can be formed from silicon oxide (SiO 2 ), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), silicon oxycarbide (SiOxCy, 0≦x, y≦1), etc.

[0034]

[0036] The substrate can be any of a semiconductor substrate, a silicon wafer, a glass substrate, etc. The substrate can be formed from materials such as crystalline silicon (e.g., Si<100> or Si<111>), silicon oxide, strained silicon, silicon germanium, germanium, doped or undoped polysilicon, doped or undoped silicon wafers and patterned or unpatterned wafer silicon on insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, or sapphire. The substrate has various dimensions (e.g., about 200 mm, about 300 mm, about 450 mm, or other diameters) and is a rectangular or square panel.

[0035]

[0037] In operation 220, as shown in FIG. 3A, a bottom anti-reflective coating (BARC) layer 304 is formed on the film stack 302. In some embodiments, the BARC layer 304 is made of a carbon-containing material such as boron-doped amorphous carbon. The BARC layer 304 can be a Saphira (trademark) Advanced Patterning Film (APF) carbon hard mask produced by Applied Materials, Inc. of Santa Clara, California. In some embodiments, the BARC layer 304 is a high-density carbon-containing layer and has excellent film quality such as improved hardness and density. Due to such hardness and density, the BARC layer 304 can act as a much stronger barrier against metal intrusion than a conventional spin-on carbon (SOC) hard mask and can prevent and reduce extremely small defects.

[0036]

[0038] The BARC layer 304 can be formed by a physical vapor deposition (PVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, or other suitable deposition processes. In one embodiment, the BARC layer 304 is a diamond-like carbon layer formed by a chemical vapor deposition (CVD) (plasma enhanced and / or thermal) process using a hydrocarbon-containing mixed gas including precursors such as C 2 H 2 , C 3 H 6 , CH 4 , C 4 H 8 , 1,3-dimethyladamantane, bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene), adamantane (C10H1 6 ), norbornene (C7H10), or combinations thereof. The deposition process is carried out at a temperature in the range of about -50 °C to about 600 °C. The deposition process is carried out at a pressure in the range of about 0.1 mTorr to about 10 Torr within the internal space 106 of the processing chamber 100. The hydrocarbon-containing mixed gas may further include a carrier gas such as He, Ar, Xe, N 2 , H 2 , or combinations thereof, and an etchant gas such as Cl 2 , CF 4 , NF 3 , or combinations thereof to improve the film quality. Plasma (e.g., capacitively coupled plasma) can be formed from either the top and bottom electrodes or the side electrodes of the processing chamber 100. The electrodes can be formed from a single power supply electrode, a dual power supply electrode, or more electrodes having multiple frequencies (e.g., but not limited to, 350 KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz, and 100 MHz) and can be used alternatively or simultaneously in a CVD system.

[0037]

[0039] In operation 230, as shown in FIG. 3B, a hard mask layer 306 is formed on the BARC layer 304. The hard mask layer 306 is any conventional hard mask used in the field of photolithography technology. The hard mask layer 306 can be a metal oxide layer. In one embodiment, the material selected for the hard mask layer 306 affects the reflection and / or absorption efficiency of extreme ultraviolet (EUV) radiation having a wavelength of about 5 nm to about 20 nm, for example, about 13.5 nm, during the lithography exposure process. Therefore, by appropriately selecting the material of the hard mask layer 306, the performance of the EUV lithography exposure process can be enhanced (for example, lithography resolution is increased, defects are reduced, the profile of the photoresist layer is controlled, the energy dose is reduced, and / or the line edge roughness is reduced). For example, materials with higher metal concentrations provide higher absorption coefficients for EUV radiation. Thus, the hard mask layer 306 is formed from a metal-containing material such as a metal dielectric layer containing one or more metal elements having an atomic number greater than 28, such as 29-32, 37-51, and 55-83. Suitable metal elements include tin (Sn), tantalum (Ta), indium (In), gallium (Ga), zinc (Zn), zirconium (Zr), aluminum (Al), or combinations thereof.

[0038]

[0040] Furthermore, low concentrations of silicon dopants and / or oxygen elements in the metal-containing material can further increase free carriers, enhance the absorption coefficient of EUV radiation, and reduce the likelihood of defect generation. Suitable examples of metal-containing materials for the hard mask layer 306 include tin oxide (SnO), tin silicon oxide (SnSiO), tantalum oxide (TaO), indium tin oxide (InSnO), indium gallium zinc oxide (IGZO), one or more alloys thereof, one or more dopants thereof, or any combination thereof having a ratio of metal element to silicon element or oxygen element (metal:Si / O) of about 80:1 / 19 to about 90:1 / 9. The metal-containing material of the hard mask layer 306 has an absorption coefficient of about 1×10 5 (cm 2It may have an EUV absorption cross-section exceeding 10-20 cm2 / atom. The hard mask layer 306 has a thickness of from about 10 Å to about 500 Å, for example, from about 20 Å to about 200 Å, for example, from about 50 Å to about 100 Å.

[0039]

[0041] In some embodiments, the hard mask layer 306 includes a plurality of layers. In these embodiments, the hard mask layer 306 has a plurality of layers formed from different metal-containing materials. The selection of the metal-containing materials for the plurality of layers is based on the different absorption coefficients of the metal-containing materials. For example, a plurality of layers having high-to-low, low-to-high, or alternating high and low absorption coefficients are sequentially formed to enhance the reflection of EUV radiation during the lithography exposure process. In one or more examples, the metal element selected for one of the plurality of layers has an atomic number greater than 28, for example greater than 35, and another may have an atomic number less than 28.

[0040]

[0042] In some embodiments, the hard mask layer 306 includes a bilayer structure, which has a first portion (e.g., the upper portion or the upper layer) containing a metal element having an atomic number greater than 28 (e.g., 29 - 32, 37 - 51, and 55 - 83) and a second portion (e.g., the lower portion or the lower layer) containing an element having an atomic number less than 28 (e.g., 3 - 8, 11 - 16, and 19 - 27).

[0041]

[0043] In some embodiments, the hard mask is formed as a gradient, and in this gradient layer, the ratio of metal elements, silicon elements, and / or oxygen elements in the hard mask layer 306 is different to provide different absorption coefficients along the bulk film body of the hard mask layer 306. For example, the metal element concentration of the hard mask layer 306 gradually increases or decreases as the thickness of the hard mask layer 306 increases. Alternatively, each layer of the bilayer structure or multiple layers of the hard mask layer 306 is a gradient layer. For example, in the bilayer structure of the hard mask layer 306, the upper portion of the hard mask layer 306 has a relatively high metal element concentration (or even with a pure metal layer such as a metal Sn layer) and has a low resistance, while the lower portion of the hard mask layer 306 has a high concentration of silicon and / or oxygen.

[0042]

[0044] The hard mask layer 306 is formed by any conventional process used in the art to form a hard mask. For example, the hard mask layer 306 is formed using a CVD process, a PVD process, an atomic layer deposition (ALD) process, a spin-on coating process, a spray coating process, or other suitable deposition processes. In some embodiments, during the plasma CVD or PVD process for forming the hard mask layer 306, a carrier gas and / or an inert gas having a relatively high atomic weight such as Xe or Kr is flowed. The temperature of the process region during the formation of the hard mask layer 306 is from about -50°C to about 250°C. A relatively low temperature of the process region (e.g., less than about 250°C) is considered to assist in forming the hard mask layer 306 at a relatively slow deposition rate while forming the hard mask layer 306 and can provide a film surface having a relatively smooth surface.

[0043]

[0045] In operation 240, as shown in FIG. 3C, a photoresist layer 308 is formed on the hard mask layer 306. In the embodiments described herein, the photoresist layer 308 is formed of an organometallic material containing an organic ligand. For example, the organometallic material has a metal oxo ligand (O 2 -) and hydroxo ligand (OH - ) and is formed from a polymeric metal oxo / hydroxo network that is bonded to an organic ligand or a polynuclear metal oxo / hydroxo species having an organic ligand.

[0044]

[0046] The photoresist layer 308 is formed by any conventional method used in the art to produce a photoresist. For example, the photoresist layer 308 is formed by a CVD process, a PVD process, an ALD process, a spin-on coating process, a spray coating process, or other suitable deposition process using a precursor solution containing a metal oxohydroxo cation having an organic ligand in an organic solvent. The metal (M) oxohydroxo cation herein refers to one or more M ions that form an oxo ligand (O - ) with the release of hydrogen ions (H 2 - ) and / or hydroxo ligand (OH - ) upon binding to an oxygen atom (O). The M oxohydroxo cation further binds to an organic ligand to form one or more metal-carbon (M-C) ligand bonds and / or metal carboxylate (M-O 2C) Forms a ligand bond. M suitable for the formation of metal oxo / hydroxo cations includes Group 13, Group 14, and Group 15 metals such as tin (Sn), antimony (Sb), and indium (In). Additional metals, such as Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, Lu, or combinations thereof can be combined in the precursor solution to generate more complex polynuclear metal oxo / hydroxo cations (i.e., containing two or more metal atoms). The additional metals can be alternatives or additions to tin (Sn), antimony (Sb), and / or indium (In). When a blend of metal ions is used, the molar ratio of non-tin / antimony / indium ions per tin / antimony / indium metal ion is up to about 1 in one embodiment and from about 0.1 to about 0.75 in other embodiments. In some embodiments, tin (Sn) or indium (In) is used in the precursor solution to form a photoresist layer having strong absorption of EUV at a wavelength of about 13.5 nm, which, in combination with an organic ligand, forms good absorption of ultraviolet (UV) radiation at a wavelength of about 193 nm. In some embodiments, Hf is used to provide good absorption of electron beam materials and EUV radiation. In some embodiments, one or more metal compositions containing Ti, V, Mo, W, or combinations thereof are added to shift the absorption edge to a longer wavelength to provide sensitivity to UV radiation at a wavelength of about 248 nm.

[0045]

[0047] The organic ligands can include alkyl (e.g., methyl, ethyl, propyl, butyl, t-butyl, aryl (phenyl, benzyl)), alkenyl (e.g., vinyl, allyl), and carboxylates (e.g., acetate, propanoate, butanoate benzoate). The ratio of the concentration of the organic ligand to the concentration of the metal oxohydroxo cation in the precursor solution is from about 0.25 to about 4 in one embodiment, from about 0.5 to about 3.5 in another embodiment, from about 0.75 to about 3 in another embodiment, and from about 1 to about 2.75 in other embodiments. Those skilled in the art will understand that additional ranges of organic ligand concentrations within the above explicit ranges are contemplated and are within the scope of the present disclosure.

[0046]

[0048] The organic solvent may include an alcohol, an ester, or a combination thereof. In some embodiments, the organic solvent includes aromatic compounds (e.g., xylene, toluene), esters (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, anisole), ketones (e.g., methyl ethyl ketone), and the like.

[0047]

[0049] In some embodiments, the deposited photoresist layer 308 has a thickness of from about 1 nm to about 1 μm, such as from about 8 nm to about 13 nm.

[0048]

[0050] In operation 250, as shown in FIG. 3D, the photoresist layer 308 is exposed to radiation according to a selected pattern that includes features such as trenches, vias, openings, etc. having the desired critical dimensions and profiles to be formed within the film stack 302. The selected pattern is transferred to a corresponding pattern or latent image in the photoresist layer 308 in the irradiated and non-irradiated regions. When exposed to radiation, the photoresist layer 308 absorbs the radiation, which results in providing energy to break the bonds (i.e., M-C ligand bonds and / or M-O 2 C ligand bonds) between the metal and the organic ligand in the irradiated region of the photoresist layer 308. The breaking of this bond can lead to a compositional change in the irradiated region of the photoresist layer 308 via the formation of M-OH ligand bonds or via condensation to form M-O-M ligand bonds.

[0049]

[0051] Due to the absorption of a sufficient amount of radiation, there is a contrast in material properties between the irradiated region of the photoresist layer 308 that does not have or substantially does not have an organic ligand, and the non-irradiated region of the photoresist layer 308 where the organic ligand is not damaged. For example, the non-irradiated region of the photoresist layer 308 having an organic ligand is relatively hydrophobic, and the irradiated region of the photoresist layer 308 without an organic ligand is less hydrophobic (i.e., more hydrophilic) than the non-irradiated region of the photoresist layer 308. Using this contrast, the photoresist layer 308 provides positive patterning (the irradiated region becomes soluble in the developer) and negative patterning (the irradiated region becomes insoluble in the developer) with an appropriate developer.

[0050]

[0052] The radiation includes electromagnetic radiation, an electron beam, or other suitable radiation. The radiation is directed at the photoresist layer 308 through the mask 310. In another embodiment, the radiation beam is controllably scanned across the photoresist layer 308. The electromagnetic radiation has any desired wavelength or wavelength range, such as visible radiation, UV radiation (including EUV radiation from about 10 nm to about 121 nm, from about 100 nm to about 400 nm, and far ultraviolet (FUV) radiation from about 122 nm to about 200 nm), or x-ray radiation (including soft x-rays from about 0.1 nm to about 10 nm), depending on the desired spatial resolution for patterning the underlying film stack 302. Higher resolution patterns are achieved with radiation of shorter wavelengths, such as UV radiation, x-ray radiation, or an electron beam. For example, EUV radiation generated from a Xe or Sn plasma source excited using a high-energy laser or a discharge pulse is used for lithography at about 13.5 nm. In some embodiments, the contrast is enhanced by a post-irradiation heat treatment.

[0051]

[0053] In operation 260, the photoresist layer 308 is developed to pattern the photoresist layer 308 according to the selected pattern, as shown in FIG. 3E. The patterned photoresist layer 308A defines an opening 312 that exposes the surface 314 of the underlying hard mask layer 306 for etching.

[0052]

[0054] The developer for developing the irradiated photoresist layer 308 and removing the non-irradiated regions of the photoresist layer 308 (i.e., negative patterning) to form the patterned photoresist layer 308A may include an organic solvent such as the solvent used in the precursor solution. In some embodiments, suitable developers include aromatic compounds (e.g., benzene, xylene, toluene), esters (e.g., propylene glycol monomethyl ester acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, isopropanol, anisole), ketones (e.g., methyl ethyl ketone, acetone, cyclohexanone), ethers (e.g., tetrahydrofuran, dioxane), and the like. The development is carried out in one example for about 5 seconds to about 30 minutes, for example about 8 seconds to about 15 minutes, or about 10 seconds to about 10 minutes.

[0053]

[0055] In some embodiments, the developer includes additional compositions that facilitate the development process, such as improving contrast, sensitivity, and LWR, and suppressing the formation and precipitation of metal oxide particles. Suitable additives include, for example, ammonium, d-block metal cations (such as hafnium, zirconium, lanthanum, etc.), f-block metal cations (such as cerium, lutetium, etc.), p-block metal cations (such as aluminum, tin, etc.), alkali metals (such as lithium, sodium, potassium, etc.), and dissolved salts with cations selected from the group consisting of combinations thereof, and fluorides, chlorides, bromides, iodides, nitrates, sulfates, phosphates, silicates, borates, peroxides, butoxides, formates, ethylenediaminetetraacetic acid (EDTA), tungstates, molybdates, etc., and dissolved salts with anions selected from the group consisting of combinations thereof. Other potentially useful additives include, for example, molecular chelating agents such as polyamines, alcoholamines, amino acids, or combinations thereof. If any additives are present, the developer contains, in one embodiment, up to about 10 wt% of the additives and, in another embodiment, up to about 5 wt% of the additives. Those skilled in the art will understand that additional ranges of additive concentrations within the above explicit ranges are contemplated and are within the scope of the present disclosure.

[0054]

[0056] The developer is applied to the irradiated photoresist layer 308 using any conventional method used in the art. For example, the developer is applied using a spin-on coating process, a spray coating process, or other suitable coating process. In some embodiments, spin rinsing and / or drying is performed to complete the development process. Suitable rinse solutions include ultrapure water, methyl alcohol, ethyl alcohol, propyl alcohol, and combinations thereof.

[0055]

[0057] In some embodiments, the patterned photoresist layer 308A is treated to further condense the material and further dehydrate the material. In some embodiments, the patterned photoresist layer 308A is heated to a temperature of from about 100°C to about 600°C, such as from about 175°C to about 500°C, or such as from about 200°C to about 400°C. The heating is carried out for at least about 1 minute, such as from about 2 minutes to about 1 hour, or such as from about 2.5 minutes to about 25 minutes. The heating can be carried out in an ambient environment of air, vacuum, or inert gas. The inert gas ambient environment can include argon gas (Ar) and / or nitrogen gas (N 2 ). Those skilled in the art will understand that additional ranges of temperature and time for the heat treatment within the above explicit ranges are envisioned and are within the scope of the present disclosure.

[0056]

[0058] In some embodiments, adjacent linear segments of adjacent structures can have an average pitch of less than about 60 nm (e.g., less than about 50 nm, or less than about 40 nm).

[0057]

[0059] In operation 270, as shown in FIG. 3F, a passivation layer 316 is selectively formed on the patterned photoresist layer 308A before etching the hard mask layer 306. The passivation layer 316 is formed from a carbon-containing material. The passivation layer 316 can be formed on the patterned photoresist layer 308A by supplying a deposition mixture gas into a PVD chamber or in-situ in an etching chamber. In the embodiments described herein, the passivation layer 316 is mainly formed on the upper surface 318 of the patterned photoresist layer 308A rather than on the sidewalls 320 of the patterned photoresist layer 308A or the exposed surface 314 of the hard mask layer 306. Thus, the profile (e.g., dimensions and shape dimensions) of the opening 312 defined by the patterned photoresist layer 308A is maintained unchanged, thereby facilitating the transfer of the opening 312 to the hard mask layer 306 without a change in the profile.

[0058]

[0060] Although not bound by theory, carbon atoms are thought to bond to the upper surface 318 (i.e., the irradiated region) of the photoresist layer 308 having M-OH ligand bonds and M-O-M ligand bonds due to the cleavage of the bonds between the metal and the organic ligand (i.e., M-C ligand bonds and / or M-O 2 C ligand bonds). The sidewalls 320 of the patterned photoresist layer 308A maintain the composition of the non-irradiated photoresist layer 308 having organic ligands and thus do not contain M-OH ligand bonds and M-O-M ligand bonds to which carbon atoms can bond. The exposed surface 314 of the hard mask layer 306 also does not contain M-OH ligand bonds and M-O-M ligand bonds, and thus carbon atoms do not bond to the exposed surface 314 of the hard mask layer 306.

[0059]

[0061] In some embodiments, the deposition mixed gas includes a carbon-containing gas such as carbon monoxide (CO) or methane (CH 4 )). The deposition mixed gas can be deposited while applying a source power of about 400 W to about 600 W, such as about 500 W. Operation 270 can be performed for a period of about 1 second to about 20 seconds, such as about 7 seconds. The chamber pressure can be maintained at about 1 mTorr to about 20 mTorr, such as about 10 mTorr.

[0060]

[0062] As described above, the hard mask layer 306 is formed of a material containing a metal element such as tin (Sn), and the photoresist layer 308 is also formed of a material containing a metal element such as tin (Sn), leading to poor etching selectivity between the hard mask layer 306 and the photoresist layer 308. Thus, when the hard mask layer 306 having the photoresist layer 308 disposed thereon is etched, the control of the profile of the opening etched in the hard mask layer 306 becomes inaccurate, which can ultimately lead to device failures. The patterned photoresist layer 308B has a passivation layer 316 disposed thereon, has a higher etching selectivity than the hard mask layer 306, and leads to a higher-precision control of the profile of the opening etched in the hard mask layer 306.

[0061]

[0063] In one embodiment, operation 270 includes two sub-operations 270A and 270B. In sub-operation 270A, the passivation material 317 is selectively deposited on the upper surface 318 as shown in FIG. 4A. As shown, the passivation material 317 includes an undesired portion 316A and a desired portion 316B. The desired portion 316B is desirably left on the upper surface 318 after completion of operation 270. The undesired portion 316A is desirably removed after completion of operation 270. For example, the desired portion 316B is formed into a desired shape of a passivation layer 316 such as a rectangle, while the undesired portion 316A bulges out such that the passivation material 317 has a circular or other non-rectangular shape. However, the present disclosure is not so self-limiting, and any undesired portion 316A that makes the passivation material 317 an undesired shape may be covered by the disclosure herein. Sub-operation 270A may be performed as described above for the description of operation 270.

[0062]

[0064] In sub-operation 270B, as shown in FIG. 4B, the undesired portion 316A is removed. The undesired portion 316A is removed such that the desired portion 316B remains. The undesired portion 316A is removed using an etching procedure. In one example, the undesired portion is removed using reactive ion etching (RIE). In another example, the undesired portion 316A is removed using radical etching that preferentially attacks the large surface portion of the undesired portion 316A. For example, the relatively large surface area of the undesired portion 316A increases the etching rate of the undesired portion compared to the desired portion 316B having a relatively small surface area.

[0063]

[0065] In some embodiments, the radical etching includes an etching gas. The etching gas includes CF 4 、CHF 3 、C 4 F 8 、CxFyHz (where x, y, and z are arbitrary integers), H2 , N 2 , O 2 , and any combination thereof, such as CH 4 and N 2 , or H 2 and O 2 , or CH 4 and H 2 is included. The etching gas containing a fluorine-containing gas was advantageously found to etch more rapidly in the lateral direction (i.e., the direction parallel to the upper surface 318) than the hydrogen-containing gas. In some embodiments, the radical etching includes a flow rate ratio of CF 4 to N 2 of about 1:1 to about 1:10, for example, a ratio of about 1:6. The radical etching includes applying a source power of about 500 W to about 1500 W, such as about 1000 W, to the etching gas. Operation 270 can be performed for a period of about 1 second to about 20 seconds, such as about 7 seconds. The chamber pressure can be maintained at about 1 mTorr to about 30 mTorr, such as about 20 mTorr.

[0064]

[0066] The sub-operations 270A, 270B can be repeated any number of times until the passivation layer 316 reaches the desired shape and dimensions (e.g., the height of the passivation layer 316). For example, the sub-operations 270A, 270B can be repeated 5 times. The LWR can be reduced to less than about 2.5 nm, such as less than about 1.5 nm. The number of sub-operation 270A, 270B cycles can be adjusted to the desired height and LWR of the passivation layer 316.

[0065]

[0067] In operation 280, the hard mask layer 306 is etched to transfer the openings 312 of the patterned photoresist layer 308A to the hard mask layer 306, as shown in FIG. 3G. The patterned hard mask layer 306A defines openings 322 that expose the surface 324 of the underlying BARC layer 304 for etching. In one or more embodiments, the etching process in operation 280 is performed by supplying an etching gas mixture into the processing chamber 100 while maintaining the temperature of the substrate support pedestal assembly 148 from room temperature (e.g., about 23° C.) to about 150° C.

[0066]

[0068] In some embodiments, the etching gas mixture includes at least one halogen-containing gas. The halogen-containing gas may include a fluorine-containing gas, a chlorine-containing gas, or a bromide-containing gas. Suitable examples of the halogen-containing gas include SF 6 , SiCl 4 , Si 2 Cl 6 , NF 3 , HBr, Br 2 , CHF 3 , CH 2 F 2 , CF 4 , C 2 F, C 4 F 6 , C 3 F 8 , HCl, C 4 F 8 , Cl 2 , HF, CCl 4 , CHCl 3 , CH 2 Cl 2 , and CH 3 Cl are included. In some embodiments, a silicon-containing gas may also be supplied into the etching gas mixture. Suitable examples of the silicon-containing gas include SiCl 4 , Si 2 Cl 6 , SiH 4 , Si 2 H 6 and the like. Examples of the chlorine-containing gas include HCl, Cl 2 , CCl 4 , CHCl3 , CH 2 Cl 2 , CH 3 Cl, SiCl 4 , Si 2 Cl 6 etc. are included. Examples of bromide-containing gases include HBr, Br 2 etc. Reactive gases (e.g., O 2 , N 2 , N 2 O, NO 2 , O 3 , H 2 O, etc., oxygen-containing gases or nitrogen-containing gases) can also be supplied into the etching mixed gas as needed. In one embodiment, the etching mixed gas includes HBr, CH 4 , and Ar. The flow rate of HBr / CH 4 / Ar is from about 1:1:1 to about 2:1:10, such as about 5:4:20.

[0067]

[0069] In one or more embodiments, the halogen-containing gas used to etch the hard mask layer 306 includes a chlorine-containing gas or a bromide-containing gas. While supplying the etching mixed gas into the processing chamber, an inert gas can be supplied into the etching mixed gas as needed to assist in profile control. Examples of the inert gas supplied into the mixed gas include Ar, He, Ne, Kr, Xe, etc. In a specific embodiment, the etching mixed gas used to etch the hard mask layer 306, such as a metal-containing material (e.g., Sn / SnO / SnSiO layer), includes HBr, Cl 2 , Ar, He, or a combination thereof.

[0068]

[0070] During etching, the chamber pressure of the etching mixed gas is also adjusted. The process pressure in the plasma processing chamber is adjusted from about 2 mTorr to about 100 mTorr (for example, from about 3 mTorr to about 20 Torr, for example, about 6 mTorr). In the presence of the etching mixed gas, RF bias power can be applied as needed to maintain a plasma formed from a continuous mode or a pulse mode. For example, to maintain the plasma inside the etching chamber, an RF power source having a frequency of about 13.56 MHz is applied to an inductively coupled antenna source at an energy level from about 200 W to about 1000 W (for example, about 500 W). In addition, the RF bias power is applied at less than about 500 W, for example, from about 0 W to about 450 W, for example, about 150 W. The RF bias power is applied at a frequency from about 2 MHz to about 13.56 MHz.

[0069]

[0071] In one embodiment, the RF bias power and the RF power source are pulse-supplied into the processing chamber 100 during etching in operation 280. The pulsed RF bias power and the RF power source can be synchronized or asynchronous with each other. For example, before the RF bias power is pulse-supplied, the RF power source is pulse-supplied to the processing chamber. For example, the RF bias power is in a pulse mode that is synchronized with the RF power source or has a time delay with respect to the RF power source. In one or more embodiments, the RF power source and the RF bias power are pulse-supplied at about 5% to about 75% of each duty cycle. Each duty cycle between each time unit is from about 0.1 millisecond (ms) to about 10 ms.

[0070]

[0072] In one embodiment of the etching mixed gas supplied in operation 280, O 2 gas is supplied into the chamber at a rate from about 0 sccm to about 50 sccm. The halogen-containing gas (for example, HBr) can be supplied at a flow rate from about 25 sccm to about 250 sccm (for example, about 100 sccm).

[0071]

[0073] In operation 290, the BARC layer 304 is etched to transfer the opening 322 of the patterned hard mask 306A to the BARC layer 304, as shown in FIG. 3H. The patterned BARC layer 304A defines an opening 326 that exposes the surface 328 of the underlying film stack 302. In operation 290, the etch gas mixture utilized to etch the BARC layer 304 can be the same as the etch gas mixture utilized to etch the hard mask layer 306 in operation 280. Alternatively, in operation 290, the etch gas mixture utilized to etch the BARC layer 304 is different from the etch gas mixture utilized to etch the hard mask layer 306 in operation 280. In one or more embodiments, in operation 290, the etch gas mixture utilized to etch the BARC layer 304 includes a chlorine-containing gas (such as HCl gas or Cl 2 gas). In one embodiment, the etch gas mixture includes O 2 , CH 4 , and N 2 . The flow rate of O 2 / CH 4 / N 2 is from about 1:1:1 to about 1:1:10, such as about 1:1:7.

[0072]

[0074] After the opening 326 is formed in the BARC layer 304, a scum removal or strip process can be performed to remove any remaining passivation layer 316, as shown in FIG. 3I. It is noted that a further etching process or patterning process can be performed to continue the transfer of the opening 326 into the film stack 302 and form a selected pattern within the film stack 302 that includes features having a desired coastal dimension and profile, such as trenches, vias, openings, etc.

[0073]

[0075] In the embodiments described herein, a method is provided for forming a metal-containing photoresist layer having a carbon-containing passivation layer selectively disposed thereon, the layer having a high etching selectivity from a underlying metal-containing hardmask layer, leading to a higher precision control of the profile of the openings etched in the hardmask layer. Thus, lithographic exposure accuracy, such as high resolution, low energy dose, good photoresist profile control, and low line edge roughness, can be enhanced.

[0074]

[0076] Certain embodiments and features are described using a set of upper numerical limits and a set of lower numerical limits. It should be understood that ranges are contemplated to include any combination of two values (e.g., any combination of any lower value and any upper value, any combination of any two lower values, and / or any combination of any two upper values), unless otherwise indicated. One or more of the following claims recite specific lower limits, upper limits, and ranges.

Claims

1. 1. A method for etching a hard mask layer, comprising: forming a patterned photoresist layer; forming a passivation layer comprising a selectively deposited carbon-containing material on an upper surface of the patterned photoresist layer in a repetitive process in a first chamber, the passivation layer comprising: selectively depositing a passivation material over the top surface in the first chamber; and trimming unwanted portions of the passivation material in the first chamber. forming a passivation layer comprising: Etching the hard mask layer exposed by the patterned photoresist layer over which the passivation layer is formed; A method comprising:

2. 10. The method of claim 1, wherein sidewalls of the patterned photoresist layer are free of passivation material when selectively depositing the passivation material over the top surface.

3. The method of claim 1 , wherein by increasing the number of repetitions, the mask height is also increased.

4. Forming the passivation layer includes: The number of times the selective deposition process and the trimming process are performed determines the mask height. The method of claim 1 further comprising:

5. The method of claim 1 , wherein the patterned photoresist layer comprises one or more metallic elements and organic ligands.

6. The method of claim 5 , wherein the one or more metallic elements comprises tin (Sn).

7. The method of claim 1 , wherein trimming the unwanted portions comprises exposing the passivation material to a radical etch.

8. 10. The method of claim 1, wherein forming the passivation layer comprises supplying a deposition gas comprising CO gas onto the patterned photoresist layer.

9. 1. A method for etching a film stack, comprising: forming a hard mask layer; forming a photoresist layer including a metal material on the hard mask layer; patterning the photoresist layer; In an iterative process, selectively forming a passivation layer comprising a carbon-containing material on an upper surface of the patterned photoresist layer, wherein forming the passivation layer includes: selectively depositing a passivation material over the top surface in a first chamber; and trimming unwanted portions of the passivation material in the first chamber. forming a passivation layer comprising: Etching the hard mask layer exposed by the patterned photoresist layer over which the passivation layer is formed to form a patterned hard mask layer; Etching the film stack exposed by the patterned hard mask layer; A method comprising:

10. 10. The method of claim 9, wherein sidewalls of the patterned photoresist layer are free of the passivation material when selectively depositing the passivation material over the top surface.

11. The method of claim 9 , wherein by increasing the number of repetitions, the mask height is also increased.

12. The method of claim 9 , wherein the metallic material comprises one or more metallic elements and an organic ligand.

13. The method of claim 12 , wherein the one or more metallic elements include tin (Sn).

14. 13. The method of claim 12, wherein the organic ligand is selected from the group consisting of alkyl, alkenyl, and carboxylate.

15. 10. The method of claim 9, wherein forming the passivation layer comprises supplying a deposition gas comprising CO gas onto the patterned photoresist layer.

16. 10. The method of claim 9, wherein the hardmask layer comprises tin (Sn).

17. 17. The method of claim 16, wherein the metal-containing material of the hard mask layer is selected from the group consisting of tin oxide (SnO), tin silicon oxide (SnSiO), tantalum oxide (TaO), indium tin oxide (InSnO), indium gallium zinc oxide (IGZO), and combinations thereof.

18. 1. A method for forming a passivation layer in an iterative process, comprising: Selectively depositing a passivation material on a top surface of the patterned photoresist layer in a first chamber; trimming unwanted portions of the passivation material in the first chamber, the passivation layer including a carbon-containing material; A method comprising:

19. 20. The method of claim 18, wherein selectively depositing the passivation material and trimming the unwanted portions of the passivation material are each repeated two or more times in the same chamber.

20. Trimming the undesired portion comprises ２ 20. The method of claim 19, comprising exposing the passivation material to a radical etch having an etching gas comprising:

21. 20. The method of claim 18, wherein selectively depositing the passivation material comprises supplying a deposition gas comprising CO gas onto the patterned photoresist layer.

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