EUV dose reducing layers, related structures, and methods and systems for making same

Abstract

Methods and related systems and structures for reducing EUV dose requirements during lithographic steps. Presently disclosed methods may include forming a dose reducing layer including a doped semiconductor. The doped semiconductor may include at least one of an elemental semiconductor and a compound semiconductor.

Description

Technical Field

[0001] The present disclosure generally relates to structures, methods and systems for forming semiconductor devices. More specifically, the present disclosure relates to the field of extreme ultraviolet lithography. Background Art

[0002] Semiconductor device patterning is often designed around the characteristics of expensive lithography equipment. Reducing the time required for each wafer in the lithography step can greatly improve the yield and cost of device manufacturing, and this time can be expressed in terms of lithography dose.

[0003] Dose is equal to energy per unit space, or in other words, to the photon flux (number of photons per unit space per unit time) multiplied by the photon energy and exposure time. In the emerging field of EUV lithography, the energy of each photon is greatly increased by reducing the wavelength to improve resolution. To reduce the dose, it is necessary to reduce the photon flux or the exposure time, both of which reduce the total number of photons hitting the lithography resist to a very low amount. In addition, high-energy EUV photons are more difficult to absorb by most materials, which exaggerates the problem of low photon counts. With such a small number of photons absorbed by the resist, it is difficult to obtain high-quality lithographic structures due to the photon shot noise effect, especially when small structure sizes are pursued. Therefore, the key to actually reducing the dose is to increase the useful effect of each photon.

[0004] The usefulness of each photon can be increased in two ways: increasing the absorption of each photon, and increasing the number of electrons produced per photon. Absorption is often improved by simply inserting EUV absorbing materials into the lithographic structure. This absorption produces photoelectrons, which can cause reactions in the resist, but the conversion of one electron per photon still produces high shot noise. This problem is solved if high-energy photoelectrons are converted into multiple secondary electrons through multiple possible pathways.

[0005] There are two main known solutions for incorporating EUV absorbing and SE generating materials into the lithography stack.

[0006] One solution is to add the material directly to the resist, such as by adding a sensitizer to a chemically amplified resist (CAR), or by using a highly absorbing metal oxide resist (MOR). However, these new resists also have disadvantages. Resists have become complex structures that are difficult to control SE generation, and too high absorption in the resist prevents more photons from traveling to the bottom of the resist where they are needed. It is also undesirable that the electron path in the resist is too long, because this will compromise resolution and cause roughness. If the absorption is balanced, so that the photon is absorbed at the bottom of the resist, SE is still often lost to the substrate.

[0007] A second solution that complements the above solutions is to deposit EUV absorbing and SE generating materials into the bottom layers. These layers can be directly designed to generate many electrons and help provide SE to the bottom of the resist. However, many materials are heavy metals that have a self-limiting effect because electrons from deeper layers cannot easily move to the resist. In addition, many randomly moving electrons are still lost to the substrate. Even if materials with longer electron paths are placed below these materials, the electrons are still blocked by the upper layers and lost to the substrate. Although many highly absorbing materials are known and can be deposited, more precisely designed architectures are needed to control how electrons are generated and whether they end up where they are needed, while incorporating them into low-cost and very thin sacrificial patterned stacks. Summary of the invention

[0008] A structure that can be used as or in a photolithographically patterned stack during semiconductor wafer processing is disclosed. Also disclosed are methods and systems for producing such a structure.

[0009] Advantageously, embodiments according to the present disclosure may allow for the generation of as many secondary electrons as possible.

[0010] Thus, a structure is described herein that includes a substrate, a dose reduction layer overlying the substrate, and an extreme ultraviolet (EUV) resist overlying the dose reduction layer; wherein the dose reduction layer includes a doped semiconductor including a main component and a dopant.

[0011] In some embodiments, the doped semiconductor has a bandgap of at least 2.0 eV.

[0012] In some embodiments, the EUV resist is selected from a metal organic framework resist, a metal oxide resist, and a chemically amplified resist.

[0013] This article also describes a method, including: providing a substrate to a reaction chamber; forming a dose reduction layer on the substrate; optionally forming a glue layer on the substrate; and forming an EUV resist on the substrate; wherein: the EUV resist is used to absorb EUV radiation and generate secondary electrons; and the dose reduction layer includes a main component and a dopant.

[0014] In some embodiments, the method further comprises the step of exposing the EUV resist to EUV radiation through the mask.

[0015] In some embodiments, the major component comprises an elemental semiconductor.

[0016] In some embodiments, the elemental semiconductor includes tellurium.

[0017] In some embodiments, the main component includes a compound semiconductor.

[0018] In some embodiments, the compound semiconductor includes indium(III) oxide.

[0019] In some embodiments, the dopant includes a vacancy.

[0020] In some embodiments, the vacancies include oxygen vacancies.

[0021] In some embodiments, the dopant includes iodine.

[0022] Also described herein is a method of forming a layer, the method comprising providing a substrate to a reaction chamber via a substrate handler; performing a cyclic deposition process, the cyclic deposition process comprising a plurality of cycles, some of the plurality of cycles comprising a main component precursor pulse and a dopant reactant pulse, the main component precursor pulse comprising contacting the substrate with the main component precursor; the reactant pulse comprising contacting the substrate with the dopant reactant; wherein the main component precursor comprises tellurium; and wherein the dopant reactant comprises iodine.

[0023] In some embodiments, the main component precursor includes diisopropyl telluride.

[0024] In some embodiments, the dopant reactant includes an iodinated alkyl.

[0025] In some embodiments, the iodoalkane comprises 1,2-diiodoethane.

[0026] In some embodiments, the cyclic deposition process is a thermal cyclic deposition process.

[0027] In some embodiments, at least one of the precursor and the reactant includes a reactive species that is generated in a plasma.

[0028] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the example embodiments disclosed below. This summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 An embodiment of a structure 100 as described herein is shown.

[0030] Figure 2 An embodiment of a system 200 as described herein is shown.

[0031] Figure 3 An embodiment of a method as described herein is shown.

[0032] Figures 4 to 7 An embodiment of a system as described herein is shown.

[0033] Figure 8An embodiment of a method as described herein is shown.

[0034] Fig. 9 An embodiment of a system as described herein is shown.

[0035] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure. DETAILED DESCRIPTION

[0036] Although certain embodiments and examples are disclosed below, those skilled in the art will appreciate that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specifically disclosed embodiments described below.

[0037] As used herein, the term "substrate" may refer to any one or more underlying materials, including any one or more underlying materials that may be modified or on which a device, circuit, or film may be formed. A "substrate" may be continuous or non-continuous; rigid or flexible; solid or porous; and combinations thereof. A substrate may be in any form, such as a powder, a plate, or a workpiece. A plate-like substrate may include wafers of various shapes and sizes. A substrate may be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0038] For example, a substrate in powder form can be used in drug manufacturing. The porous substrate can include a polymer. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tool equipment, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, etc.

[0039] The continuous substrate may extend beyond the boundaries of the processing chamber in which the deposition process occurs. In some processes, the continuous substrate may be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate may be provided from a continuous substrate feed system to allow the continuous substrate to be manufactured and output in any suitable form.

[0040] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, meshes, flexible materials, bundles of continuous filaments or fibers (eg, ceramic fibers or polymer fibers). A continuous substrate may also include a carrier or sheet on which a discontinuous substrate is mounted.

[0041] In the present disclosure, "gas" may include materials that are gaseous at normal temperature and pressure (NTP), evaporated solids and / or evaporated liquids, and may be composed of a single gas or a gas mixture depending on the circumstances. Gases other than process gases, i.e., gases that are not introduced through gas distribution components, other gas distribution devices, etc., may be used, for example, to seal reaction spaces, and may include sealed gases. Precursors and reactants may be gases. Exemplary sealed gases include rare gases, nitrogen, and the like. In some cases, the term "precursor" may refer to a compound that participates in a chemical reaction that produces another compound, particularly a compound that constitutes a membrane matrix or a main skeleton of a membrane; the term "reactant" may be used interchangeably with the term precursor.

[0042] As used herein, the term "film" and / or "layer" may refer to any continuous or discontinuous structure and material, such as a material deposited by the method disclosed herein. For example, the film and / or layer may include a two-dimensional material, a three-dimensional material, nanoparticles, a partial or entire molecular layer or a partial or entire atomic layer or a cluster of atoms and / or molecules. The film or layer may include or may be at least partially composed of a plurality of dispersed atoms on the surface of the substrate, and / or may be embedded or may become embedded in the substrate and / or may be embedded or may become embedded in a device manufactured on the substrate. The film or layer may include a material or layer having pinholes and / or islands. The film or layer may be at least partially continuous. The film or layer may be patterned, such as subdivided, and may be included in a plurality of semiconductor devices. The film or layer may selectively grow on some portions of the substrate, but not on other portions.

[0043] As used herein, the term "deposition process" may refer to the introduction of precursors (and / or reactants) into a reaction chamber to deposit a layer on a substrate. A "cyclic deposition process" is an example of a "deposition process."

[0044] The term "cyclic deposition process" or "cyclic deposition process" may refer to the sequential introduction of precursors (and / or reactants) into a reaction chamber to deposit layers on a substrate, and includes processing techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition (cyclic CVD), and hybrid cyclic deposition processes including an ALD component and a cyclic CVD component.

[0045] The term "atomic layer deposition" may refer to a vapor deposition process in which a deposition cycle (usually multiple continuous deposition cycles) is performed in a processing chamber. As used herein, the term atomic layer deposition may include processes specified by related terms, such as chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, organic metal MBE, and chemical beam epitaxy when performed with alternating pulses of precursor / reactive gas and purge gas (e.g., inert carrier gas). Pulses may include exposing a substrate to a precursor or reactant. This may be achieved, for example, by introducing a precursor or reactant into a reaction chamber where a substrate is present. Additionally or alternatively, exposing a substrate to a precursor may include moving the substrate to a position in a substrate processing system where a reactant or precursor is present.

[0046] Typically, for an ALD process, during each cycle, a precursor is introduced into a reaction chamber and is chemically adsorbed onto a deposition surface (e.g., a substrate surface that may include previously deposited material from a previous ALD cycle or other material) and forms a monolayer or sub-monolayer of material that does not readily react with additional precursors (i.e., a self-limiting reaction). Thereafter, a reactant (e.g., another precursor or a reactive gas) may subsequently be introduced into the process chamber for converting the chemically adsorbed precursor to the desired material on the deposition surface. The reactant is capable of further reacting with the precursor. During one or more cycles, such as during each step of each cycle, a purge step may be utilized to remove any excess precursor from the process chamber and / or to remove any excess reactant and / or reaction byproducts from the reaction chamber.

[0047] As used herein, the term "purge" may refer to the process of providing an inert or substantially inert gas to a reaction chamber between two gas pulses that react with each other. For example, a purge may be provided between a precursor pulse and a reactant pulse, such as using a rare gas, so as to avoid or at least minimize gas phase interactions between the precursor and the reactant. It should be understood that the purge may be performed in time or space, or both. For example, in the case of a time purge, the purge step may be used, for example, in a time sequence of providing a first precursor to the reaction chamber, providing a purge gas to the reaction chamber, and providing a second precursor to the reaction chamber, wherein the substrate on which the layer is deposited does not move. For example, in the case of a space purge, the purge step may take the form of moving the substrate from a first position where the first precursor is continuously supplied to a second position where the second precursor is continuously supplied through a purge gas curtain.

[0048] As used herein, "precursor" includes a gas or a material that can be transformed into a gaseous state and can be represented by a chemical formula that includes elements that can be introduced into the deposition process described herein.

[0049] The term "oxygen reactant" may refer to a gas or a material that can become gaseous and can be represented by a chemical formula that includes oxygen. In some cases, the chemical formula includes oxygen and hydrogen.

[0050] The illustrations presented herein are not meant to be actual views of any particular material, structure, or device but are merely idealized representations used to describe embodiments of the present disclosure.

[0051] The specific embodiments shown and described are illustrations of the present invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, the traditional manufacturing, connection, preparation and other functional aspects of the system may not be described in detail. In addition, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in actual systems, and / or may not exist in some embodiments.

[0052] It should be understood that the configuration and / or method described herein are exemplary in nature, and these specific embodiments or examples should not be considered restrictive, because many variations are possible. The specific routine or method described herein can represent one or more of any number of processing strategies. Therefore, the various actions shown can be performed in the order shown, in other orders, or omitted in some cases.

[0053] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts and / or properties disclosed herein, and any and all equivalents thereof.

[0054] In some respects, reference Figure 1 , a structure 100 is described herein. The structure 100 may include a substrate 110, a dose reduction layer overlying the substrate 120, and an extreme ultraviolet (EUV) resist 130 overlying the dose reduction layer 120. The dose reduction layer 120 may include a doped semiconductor. The doped semiconductor may include a main component and a dopant.

[0055] The EUV resist may be constructed and arranged to absorb EUV radiation and generate secondary electrons. The EUV resist layer may include any suitable resist, such as a molecular, metal oxide, or chemically amplified resist. It should be understood that the resist may be formed using any suitable deposition technique, including chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), and plasma enhanced atomic layer deposition (PEALD).

[0056] The dopant in the doped semiconductor can increase the conductivity of the doped semiconductor relative to the undoped variant. A certain degree of conductivity can advantageously allow replenishment of electrons lost during secondary electron emission, which can improve secondary electron generation in the dose reduction layer, which in turn can help reduce the EUV dose required for full resist exposure.

[0057] In some embodiments, the introduction of a dopant into the dose reduction layer can reduce the electron affinity of the dose reduction layer relative to an undoped version. This can increase the electron escape probability, thereby resulting in the generation of more secondary electrons.

[0058] In some embodiments, the dopant may have a relatively high capture cross-section for EUV radiation, which may reduce the dose requirements of the lithography stack.

[0059] In some embodiments, the doped semiconductor has a band gap of at least 2.0 eV. In some embodiments, the doped semiconductor has a band gap of at least 2.5 eV, at least 3.0 eV, at least 4.0 eV, where eV stands for "electron volts."

[0060] In some embodiments, the doped semiconductor has a band gap of at most 6.0 eV, at most 5.0 eV, or at most 4.0 eV.

[0061] In some embodiments, the doped semiconductor has a band gap of at least 2.0 eV to at most 4.0 eV.

[0062] Materials with relatively wide band gaps, such as semiconductors with relatively wide band gaps, can suppress, prevent or limit the energy loss of low-energy secondary electrons through electron-electron collisions, resulting in a large escape depth of secondary electrons and a large secondary electron yield. However, excessively high band gaps make it difficult to make the doped material conductive by adding doping elements, so there is a practical limit to the maximum band gap that is practical.

[0063] In some embodiments, the doped semiconductor includes a compound semiconductor. In other words, the main component of the doped semiconductor may include a compound semiconductor.

[0064] Suitable compound semiconductors include semiconductor oxides.

[0065] In some embodiments, the doped semiconductor includes indium oxide, such as indium (III) oxide, i.e., In2O3. In other words, the main component of the doped semiconductor may include In2O3. In some embodiments, when the main component of the doped semiconductor includes In2O3, the dopant may include iodine.

[0066] In some embodiments, the doped semiconductor includes tin oxide, such as tin (IV) oxide, ie, SnO 2. In other words, the main component of the doped semiconductor may include SnO 2. In some embodiments, when the main component of the doped semiconductor includes tin oxide, the dopant may include iodine.

[0067] In some embodiments, the doped semiconductor includes antimony oxide. In other words, the main component of the doped semiconductor may include antimony oxide. In some embodiments, when the main component of the doped semiconductor includes antimony, the dopant may include iodine. In some embodiments, the doped semiconductor may include antimony oxide, such as antimony oxide doped with iodine. Antimony may be in a +III or +V oxidation state. In some embodiments, the antimony oxide may include an oxide, such as a non-stoichiometric oxide, such as Sb2O x An oxide of the form of wherein x is a real number from at least 3 to at most 5. In some embodiments, x is 3. In some embodiments, x is 4. In some embodiments, x is 5.

[0068] In some embodiments, the doped semiconductor includes tellurium oxide. In other words, the main component of the doped semiconductor may include tellurium oxide. In some embodiments, when the main component of the doped semiconductor includes tellurium oxide, the dopant may include iodine.

[0069] In some embodiments, for example when the doped semiconductor includes a semiconductor oxide such as indium oxide, tin oxide, antimony oxide, or tellurium oxide, the dopant may include oxygen vacancies.

[0070] Suitable compound semiconductors include semiconductor halides, such as semiconductor iodides or bromides. In some embodiments, the main component of the doped semiconductor includes tin iodide. In such embodiments, the dopant may include a chalcogenide, such as tellurium.

[0071] In some embodiments, the doped semiconductor includes an elemental semiconductor. Suitable elemental semiconductors include tellurium, ie, Te. In other words, the main component of the doped semiconductor may include tellurium.

[0072] In some embodiments, such as when the major constituent of the doped semiconductor includes tellurium, the dopant may include a halogen, such as iodine.

[0073] Advantageously, the dopant may have a relatively high capture cross section for EUV radiation. For example, the dopant may have a cross section greater than 2×10 6 cm 2 / mol of EUV cross section (σα). For example, the dopant may include one or more of lead (Pb), cesium (Cs), bismuth (Bi), indium (In), aluminum (Al), magnesium (Mg), titanium (Ti), yttrium (Y), lanthanum (La), strontium (Sr), terbium (Tb), antimony (Sb), tellurium (Te), germanium (Ge), hafnium (Hf) and ytterbium (Yb).

[0074] In some embodiments, the dopant includes a halogen. Suitable halogens include bromine and iodine. For example, halogens such as iodine and bromine can be used to dope stoichiometric or non-stoichiometric semiconductors, such as semiconductor oxides. For example, a semiconductor doped with bromine or iodine can be selected from silicon oxycarbide, silicon oxide, tellurium oxide, tin oxide, indium oxide, and germanium oxide.

[0075] In some embodiments, the dopant comprises an alkali metal. Suitable alkali metals include cesium.

[0076] In some embodiments, the dopant comprises a chalcogenide. Suitable chalcogenides include selenium.

[0077] The dose reduction layer according to the present disclosure may be formed by any suitable method, such as by atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0078] Methods of forming a layer are further described herein. Suitably, the layer can be used as a dose reduction layer as described herein. In some embodiments, the methods described herein can include providing a substrate to a reaction chamber. This can be accomplished, for example, by a substrate handler, such as a segmented robotic arm, a linear actuator, a rotary actuator, a conveyor belt, an air cushion, and the like.

[0079] The method according to an embodiment of the present disclosure may further include performing a cyclic deposition process. The cyclic deposition process may include a plurality of cycles. Some of the plurality of cycles may include a main component precursor pulse and a dopant reactant pulse. The main component precursor pulse may include contacting the substrate with the main component precursor. The dopant reactant pulse may include contacting the substrate with the dopant reactant.

[0080] In some embodiments, the layer, such as a dose reduction layer, may include a doped elemental semiconductor. Suitable elemental semiconductors include diamond, diamond-like carbon, tin, indium, selenium, germanium, antimony, and tellurium.

[0081] In some embodiments, the main component precursor includes a carbon precursor and the dopant reactant includes a boron reactant. Thus, a layer with excellent secondary electron yield, such as a dose-reduced layer including boron-doped diamond or boron-doped diamond-like carbon, can be produced. Nitrogen is a deep donor in diamond, and N-doped diamond samples are insulators at room temperature. It has been shown that the secondary electron yield (SEY) of N-doped diamond is very low. In contrast, boron is a shallow acceptor in diamond, so boron-doped diamond samples are advantageously conductive and have a high SEY.

[0082] In some embodiments, the cyclic deposition process includes a main component precursor pulse, a main component reactant pulse using an oxygen reactant, and a dopant reactant pulse. The main component reactant pulse using an oxygen reactant may be referred to as an oxygen reactant pulse. The main component precursor pulse may include contacting the substrate with the precursor. The reactant pulse may include contacting the substrate with the dopant reactant. The oxygen reactant pulse may include contacting the substrate with the oxygen reactant.

[0083] In some embodiments, the oxygen reactant includes an oxygen-containing gas, such as N2O, NO, NO2, NO3, N2O4, N2O5, H2O, H2O2, O2, or O3.

[0084] In some embodiments, the oxygen reactant includes an active species. Suitable active species include ions and free radicals. The active species can be generated using a plasma. In some embodiments, the plasma contacts the substrate. A suitable plasma can be generated using a plasma gas containing O2, so-called O2 plasma, which can suitably generate oxygen atoms and oxygen free radicals, which can be used alone or in combination as oxygen reactants.

[0085] When a relatively strong oxygen reactant such as O3 or O2 plasma is used, an oxide semiconductor with a small or negligible amount of oxygen vacancies will be produced, resulting in a resistive film. For example, doped In2O3 can be manufactured using a main component precursor containing indium (i.e., an indium precursor), a dopant reactant, and a main component reactant containing oxygen (i.e., an oxygen reactant). When O3 is used as an oxygen reactant, the process produces a more perfect In2O3 stoichiometry compared to the In2O3 stoichiometry produced using water as an oxygen reactant, with fewer oxygen vacancies, resulting in an increase in resistivity and therefore less secondary electron emission. The introduction of a dopant in such a high resistivity film can advantageously increase the electrical conductivity, thereby increasing electron emission. In some embodiments, indium oxide may be doped with one or more dopants selected from cesium, iodine, and tellurium.

[0086] In some embodiments, the main component precursor includes a tellurium precursor containing tellurium. In some embodiments, the tellurium precursor is selected from Te(OEt)4, Te(SiMe3)2, Te(SiEt3)2, TeCl4 and TeRR', wherein R and R' are independently any C1-C6 alkyl or alkenyl. It should be understood that Et represents ethyl and Me represents methyl. In some embodiments, the tellurium precursor is selected from Te(vinyl)4, Te(allyl)4, Te(iPr)2, Te chloride, Te ethanolate, Te[NH(Si(CH3)3)]2.

[0087] In some embodiments, the main component precursor includes a tin precursor containing tin. In some embodiments, the tin precursor is selected from tin alkenyls such as Sn(vinyl)4 and Sn(allyl)4, tin alkyls such as SnMe4 and tin alkylamines such as tetrakis(dimethylamino)tin(IV). In some embodiments, the tin precursor is selected from tin halides such as SnCl4, alkyl tins such as SnHBu3, dimethylamino-2-methyl-2-propoxy-tin(II) (Sn(dmamp)2), bis(diisopropylacetamidine)tin(II) (Sn(iPr2AMD)2), bis(N,N'-diisopropylformamidino)tin(II) (Sn(iPr2FMD)2), alkyl tins such as Sn(NEtMe)4, alkyl tins such as Sn(OtBu)4, tin halides such as SnI4, alkyl tins such as SnEt4 and β-diketonate tins such as acetylacetonate tin(II) (Sn(acac)2). It should be understood that Me represents methyl, Bu represents butyl, and tBu represents tert-butyl.

[0088] In some embodiments, the main component precursor includes an antimony precursor containing antimony. In some embodiments, the antimony precursor may include one or more of the following: antimony halides such as SbCl3 and SbCl5, alkyl silyl antimony such as Sb(SiMe3)3 and Sb(SiEt3)3, alkyl amine antimony such as Sb(NMe2)3, alkyl antimony such as SbEt3 and SbR3, wherein R is a C1-C6 alkyl, alkoxy antimony such as SbOEt3. It should be understood that Me represents methyl, Et represents ethyl, and OEt represents ethanolate.

[0089] In some embodiments, the dopant reactant comprises a halogen. Exemplary halogens include fluorine, chlorine, bromine, and iodine.

[0090] In some embodiments, the dopant reactant includes iodine. Suitable iodine-containing reactants include iodinated alkanes, such as 1,2-diiodoethane, CH3I and CH2I2. In some embodiments, the dopant reactant may include a metal iodide, such as a late transition metal iodide, such as SnI4. In some embodiments, the dopant reactant includes elemental iodine I2. In some embodiments, the dopant reactant includes iodine-substituted saturated or unsaturated cyclic hydrocarbons, such as iodine-substituted saturated cyclic hydrocarbons, such as cyclopentyl iodide or cyclohexyl iodide. In some embodiments, the dopant reactant is selected from C1-C10 iodine alkyl, C2-C10 iodine alkenyl and C6-C10 iodine aryl, which may contain at least 1 to 4 iodine atoms. In some embodiments, the dopant reactant is selected from diiodomethane, 1,2-diiodoethane, 1-iodobutane, 1-iodohexane, iodobenzene, iodotoluene, allyl iodide and vinyl iodide.

[0091] In some embodiments, the dopant reactant includes bromine. Suitable bromine-containing reactants include bromoalkanes, such as 1,2-dibromoethane, CH3Br, and CH2Br2. In some embodiments, the dopant reactant may include a metal bromide, such as a late transition metal bromide, such as SnBr4. In some embodiments, the dopant reactant includes elemental bromine, Br2.

[0092] In some embodiments, the dopant reactant comprises a hydrocarbyl iodide, such as an iodinated C1-C10 straight or branched alkyl, or an iodinated C6-C10 substituted aryl, wherein the alkyl or aryl group may include one to four iodine atoms, which may be on the same, adjacent or non-adjacent atoms. In some embodiments, the dopant reactant comprises a compound selected from phenyl iodide, 1-iodohexane and 1-iodobutane.

[0093] In some embodiments, the dopant reactant comprises a hydrocarbyl bromide, such as a brominated C1-C10 straight or branched alkyl, or a brominated C6-C10 substituted aryl, wherein the alkyl or aryl group may include one to four bromine atoms, which may be on the same, adjacent or non-adjacent atoms. In some embodiments, the dopant reactant comprises a compound selected from phenyl bromide, 1-bromohexane and 1-bromobutane.

[0094] In some embodiments, the dopant reactant is selected from HBr, HI, N-bromosuccinimide, N-iodosuccinimide, TiBr4, and TiI4.

[0095] In some embodiments, the dopant reactant includes cesium, that is, includes a cesium reactant. Suitable cesium reactants include alkylsilylamides, such as cesium bis(trimethylsilyl)amide, Cs[Y(β-diketonyl)4] type precursors, such as Cs[Y(ptac)4], and cesium halides, such as CsI. It should be understood that the β-diketonyl ligand can have the general formula CF3COCHCOR, where R is tert-butyl in the case of ptac, R is CF3 in the case of hfac, R is methyl in the case of tfac, and R is phenyl in the case of btfac. Suitable cesium alkoxides include branched or linear alkoxides, such as C3-C7 alkoxides, such as Cs(OtBu), where OtBu represents tert-butyl alkoxide.

[0096] In some embodiments, the dopant reactant includes a selenium reactant comprising selenium. Suitable selenium reactants include SeO2, selenium halides such as SeCl4, H2Se, selenylsilyls such as Se(SiMe3)2 and Se(SiEt3)2, and selenyls such as Se2Et2 and SeEt2, wherein Me is methyl and Et is ethyl.

[0097] In some embodiments, the main component reactant includes oxygen. In other words, the main component reactant may include an oxygen reactant. Suitable oxygen reactants may be selected from O3, O2, H2O, H2O2, N2O, NO, NO2 and NO3.

[0098] In some embodiments, the cyclic deposition process is a thermal cyclic deposition process. A thermal process may include activating a chemical reaction by thermal energy. A thermal process may be contrasted with a plasma process, in which a plasma may be used to generate active species, such as ions or free radicals, which may activate a chemical reaction at a relatively low temperature.

[0099] According to exemplary embodiments of the present disclosure, a thermal cycle deposition process may be performed in an embodiment of the system 200. The system 200 may be used to perform the methods described herein and / or form portions of structures or devices described herein.

[0100] In the illustrated example, the system 200 includes one or more reaction chambers 202 , a first precursor gas source 204 , a reactant gas source 206 , a purge gas source 208 , an exhaust 210 , and a controller 212 .

[0101] The reaction chamber 202 may include any suitable reaction chamber, such as an ALD or CVD reaction chamber.

[0102] The first precursor gas source 204 may include a container and one or more precursors as described herein, either alone or mixed with one or more carrier gases (e.g., inert gases). The second precursor gas source 206 may include a container and one or more reactants as described herein, either alone or mixed with one or more carrier gases.

[0103] The purge gas source 208 may include one or more noble gases as described herein. Although four gas sources 204-208 are shown, the system 200 may include any suitable number of gas sources. The gas sources 204-208 may be coupled to the reaction chamber 202 via lines 214-218, which may each include a flow controller, a valve, a heater, etc.

[0104] The exhaust device 210 may include one or more vacuum pumps.

[0105] Controller 212 includes electronic circuits and software to selectively operate valves, manifolds, heaters, pumps and other components included in system 200. Such circuits and components are used to introduce precursors and purge gases from respective sources 204-208. Controller 212 can control the timing of gas pulse sequences, the temperature of substrates and / or reaction chambers, the pressure in the reaction chambers, and various other operations to provide proper operation of system 200. Controller 212 can include control software to control the flow of precursors, reactants and purge gases into and out of reaction chamber 202 by electrically or pneumatically controlling valves. Controller 212 can include modules that perform specific tasks, such as software or hardware components, such as FPGA or ASIC. Modules can advantageously be configured to reside on an addressable storage medium of a control system and configured to perform one or more processes.

[0106] Other configurations of the system 200 are possible, including different numbers and types of precursor and reactant sources and purge gas sources. In addition, it should be understood that there are many arrangements of valves, conduits, precursor sources, and purge gas sources that can be used to achieve the goal of selectively supplying gases into the reaction chamber 202. In addition, as a schematic representation of the system, many components have been omitted for simplicity of illustration, and these components may include, for example, various valves, manifolds, purifiers, heaters, containers, vents, and / or bypasses.

[0107] During operation of reactor system 200, a substrate, such as a semiconductor wafer (not shown), is transferred from, for example, a substrate handling system to reaction chamber 202. Once the substrate is transferred to reaction chamber 202, one or more gases, such as precursors, reactants, carrier gases, and / or purge gases, are introduced into reaction chamber 202 from gas sources 204-208.

[0108] As described herein, embodiments of the reactor system 200 may be used to perform a cyclic deposition process, such as an atomic layer deposition process.

[0109] Figure 3 A schematic diagram of an embodiment of a cyclic deposition process, such as an atomic layer deposition process, is shown. The process includes a step 311 of positioning a substrate on a substrate support. The process includes a plurality of deposition cycles 319. Some deposition cycles from the plurality of deposition cycles may include a main component precursor pulse 312, an optional post-main component precursor purge 313, an optional main component reactant pulse 314, an optional post-main component reactant purge 315, a dopant reactant pulse 316, and a post-dopant reactant purge 317. After a predetermined number of deposition cycles 319 have been performed, the process may end 318.

[0110] The main component precursor pulse 312 may include exposing the substrate to a main component precursor, as described herein. The main component precursor post-purge 313 may include exposing the substrate to a purge gas, as described herein. The main component reactant pulse 314 may include exposing the substrate to a main component reactant, as described herein. The post-main component reactant purge 315 may include exposing the substrate to a purge gas, as described herein. The dopant reactant pulse 316 may include exposing the substrate to a dopant reactant, as described herein. The post-dopant reactant purge 317 may include exposing the substrate to a purge gas, as described herein.

[0111] In some embodiments, at least one of the precursor and the reactant comprises a reactive species. In some embodiments, the reactive species is generated in a plasma.

[0112] In some embodiments, the dose reduction layer comprises tin oxide doped with iodine. Such a dose reduction layer can advantageously be manufactured using a plasma enhanced cyclic deposition process, for example by plasma enhanced atomic layer deposition. Exemplary embodiments of a plasma enhanced cyclic deposition process may include multiple deposition cycles. The deposition cycle may include a precursor pulse, a first plasma pulse, a reactant pulse, and a second plasma pulse in a given order. The precursor pulse may include exposing the substrate to a tin precursor. The first plasma pulse may include exposing the substrate to an oxygen plasma, i.e., to a plasma generated using a plasma gas, the plasma gas including oxygen and an optional rare gas, such as He or Ar. The reactant pulse may include exposing the substrate to a halogen-containing reactant, such as an iodine-containing reactant. The second plasma pulse may include exposing the substrate to a rare gas plasma, such as an argon plasma.

[0113] In some embodiments, a dose reduction layer comprising a halogen-doped tin oxide (e.g., iodine-doped tin oxide) can be fabricated by first forming a tin oxide layer and then exposing the tin oxide layer to a halogen-containing reactant (e.g., an iodine-containing reactant). For example, the tin oxide layer can be formed using thermal or plasma enhanced atomic layer deposition.

[0114] For example, you can use Figure 3 In some embodiments, manufacturing such a dose reduction layer may include: Figure 3 Plasma may be generated during one or more steps of an embodiment of the present invention. For example, the main component precursor pulse 312 may include generating active species using plasma. For example, the post-main component precursor purge 313 may include generating active species using plasma. For example, the main component reactant pulse 314 may include generating active species using plasma and exposing the substrate to these active species. For example, the post-main component reactant purge 315 may include generating active species using plasma and exposing the substrate to these active species. For example, the dopant reactant pulse 316 may include generating active species using plasma and exposing the substrate to these active species. For example, the post-dopant reactant purge 317 may include generating active species using plasma and exposing the substrate to these active species. The active species may include at least one of ions and free radicals.

[0115] In some embodiments, the Figure 8 An embodiment of the process described in is used to manufacture a dose reduction layer. Figure 8 The process includes a step of positioning a substrate on a substrate support 811. The process then includes performing a plurality of super cycles 817. Some super cycles from the plurality of super cycles 817 include a dopant reactant pulse 814 and one or more (e.g., a plurality of) sub-cycles 816. Each sub-cycle includes a main component precursor pulse 812 and a main component reactant pulse 813. After a predetermined number of super cycles have been performed, a layer having a suitable thickness has been deposited, and the process ends 815. Optionally, one or more of the above pulses may be separated by a purge step.

[0116] The main component precursor pulse 812 may include exposing the substrate to a main component precursor, as described herein. The main component reactant pulse 813 may include exposing the substrate to a main component reactant, as described herein. The dopant reactant pulse 814 may include exposing the substrate to a dopant reactant, as described herein. In some embodiments, the dopant reactant includes a dopant precursor, and the dopant reactant pulse may occur thermally, i.e., without exposing the substrate to reactive species generated in the plasma. In some embodiments, the dopant reactant pulse may include exposing the substrate to one or more reactive species, such as ions and radicals generated in the plasma.

[0117] In an exemplary embodiment, and in accordance with Figure 8In an embodiment of the process of the process, the main component precursor may include indium, the main component reactant may include oxygen, and the dopant reactant may include an active substance, such as at least one of a free radical or an ion. Suitable free radicals include hydrogen free radicals. Suitable ions include oxygen ions. Suitably, at least one of the hydrogen free radicals and the oxygen free radicals may be generated in a hydrogen plasma. Suitable hydrogen plasma may include a hydrogen source such as H2 and a rare gas such as He, Ne, Ar, Xe or Kr. Advantageously, an indium oxide layer containing oxygen vacancies may thus be obtained. The oxygen vacancies may serve as dopants.

[0118] In some embodiments, methods described herein may include exposing a substrate to a plasma, such as a hydrogen plasma. "Hydrogen plasma" may refer to a plasma in which the plasma gas includes hydrogen, for example, together with one or more noble gases, such as He, Ne, Ar, Kr, or Xe.

[0119] In some embodiments, when the main component of the doped semiconductor includes a compound semiconductor such as a semiconductor oxide such as In2O3, a hydrogen plasma post-deposition treatment may be applied.

[0120] Advantageously, the hydrogen plasma post-treatment can extract one or more constituent elements from the doped semiconductor, such as oxygen from the semiconductor oxide, which can lead to the generation of oxygen vacancies. The oxygen vacancies can act as electron donor sites, i.e., n-type dopants, thereby enhancing the conductivity in the semiconductor oxide, which in turn can enhance the secondary electron yield from the dose reduction layer.

[0121] The layers formed in the methods according to the present disclosure may be formed in any suitable apparatus, including in Figure 4 Similarly, the structures provided herein or portions thereof can be manufactured in any suitable apparatus, including Figure 4 The reactor shown. Figure 4 Schematic diagram of a plasma enhanced atomic layer deposition (PEALD) apparatus, which is ideally combined with a controller programmed to perform the following sequence, can be used in some embodiments of the present disclosure. In this figure, a plasma is ignited between the electrodes by providing a pair of parallel and mutually facing conductive plate electrodes 402, 404 in the interior 411 (reaction zone) of a reaction chamber 403, applying RF power (e.g., 13.56 MHz and / or 27 MHz) to one side from a power supply 425, and electrically grounding the other side 412.

[0122] A temperature regulator may be provided in the lower platform 402, i.e., in the lower electrode. The substrate 401 is placed thereon, and its temperature is kept constant at a given temperature. The upper electrode 404 may also be used as a shower plate, and reactant gas and / or dilution gas (if any) and precursor gas may be introduced into the reaction chamber 403 through gas lines 421 and 422 and through the shower plate 404, respectively. In addition, in the reaction chamber 403, a circular conduit 413 having an exhaust line 417 is provided, through which the gas in the interior 411 of the reaction chamber 403 is discharged. In addition, the transfer chamber 405 is provided below the reaction chamber 403, and a gas sealing line 424 is provided to introduce a sealing gas into the interior 411 of the reaction chamber 403 through the interior 416 of the transfer chamber 405, wherein a partition plate 414 for separating a reaction zone and a transfer zone is provided. Note that a gate valve is omitted in the figure, by which a wafer may be transferred into or out of the transfer chamber 405. The transfer chamber is also provided with an exhaust line 406. In some embodiments, the formation of the dose reduction layer and the formation of the EUV resist are completed in the same reaction chamber. In some embodiments, they can be formed in separate reaction chambers included in a cluster system, in which the substrate can be transferred from one reaction chamber to another without breaking the vacuum, or while keeping the substrate in an inert gas environment, such as a rare gas environment.

[0123] Figure 5A schematic diagram of an embodiment of a subsystem 500 as described herein is shown. For example, it can be used to form at least one of a dose reduction layer and an EUV resist. The subsystem 500 includes a reaction chamber 510 in which a plasma 520 is generated. In particular, the plasma 520 is generated between a showerhead injector 530 and a substrate support 540. This is a direct plasma configuration using a capacitively coupled plasma. In the configuration shown, the subsystem 500 includes two alternating current (AC) power supplies: a high frequency power supply 521 and a low frequency power supply 522. In the configuration shown, the high frequency power supply 521 provides radio frequency (RF) power to the showerhead injector, and the low frequency power supply 522 provides an AC signal to the substrate support 540. The RF power may be provided, for example, at a frequency of 13.56 MHz or more, for example, at a frequency of at least 100 kHz to at most 50 MHz, or at a frequency of at least 50 MHz to at most 100 MHz, or at a frequency of at least 100 MHz to at most 200 MHz, or at a frequency of at least 200 MHz to at most 500 MHz, or at a frequency of at least 500 MHz to at most 1000 MHz, or at a frequency of at least 1000 MHz to at most 2000 MHz. The low frequency AC signal may be provided, for example, at a frequency of 2 MHz or less, for example, at a frequency of at least 100 kHz to at most 200 kHz, or at a frequency of at least 200 kHz to at most 500 kHz, or at a frequency of at least 500 kHz to at most 1000 kHz, or at a frequency of at least 1000 kHz to at most 2000 kHz. A process gas containing a precursor, a reactant, or both is provided to the conical gas distributor 550 via a gas line 560. The process gas then passes through holes 531 in the showerhead injector 530 to the reaction chamber 510 .

[0124] Although the high frequency power supply 521 is shown as being electrically connected to the showerhead injector, and the low frequency power supply 522 is shown as being electrically connected to the substrate support 540, other configurations are possible. For example, in some embodiments (not shown), both the high frequency power supply and the low frequency power supply may be electrically connected to the showerhead injector; or both the high frequency power supply and the low frequency power supply may be electrically connected to the substrate support; or the high frequency power supply may be electrically connected to the substrate support and the low frequency power supply may be electrically connected to the showerhead injector.

[0125] Figure 6 A schematic diagram of another embodiment of a subsystem 600 as described herein is shown. For example, it can be used to form at least one of a dose reduction layer and an EUV resist. Figure 6The configuration can be described as an indirect plasma system. The subsystem 600 includes a reaction chamber 610, which is separated from a plasma generation space 625 where plasma 620 is generated. In particular, the reaction chamber 610 is separated from the plasma generation space 625 by a showerhead injector, and the plasma 620 is generated between the showerhead injector 630 and the plasma generation space ceiling 626.

[0126] In the configuration shown, the subsystem 600 includes three alternating current (AC) power supplies: a high frequency power supply 621 and two low frequency power supplies 622, 623: a first low frequency power supply 622 and a second low frequency power supply 623. In the configuration shown, the high frequency power supply 621 provides radio frequency (RF) power to the plasma generation space ceiling, the first low frequency power supply 622 provides an AC signal to the showerhead injector 630, and the second low frequency power supply 623 provides an AC signal to the substrate support 640. The substrate 641 is disposed on the substrate support 640. For example, the RF power may be provided at a frequency of 13.56 MHz or higher. For example, the low frequency AC signals of the first and second low frequency power supplies 622, 623 may be provided at a frequency of 2 MHz or lower.

[0127] Process gas containing precursors, reactants or both is provided to the plasma generation space 625 through gas line 660 passing through the plasma generation space ceiling 626. Reactive species (e.g., ions and radicals) generated from the process gas by the plasma 625 pass through holes 631 in the showerhead injector 630 to the reaction chamber 610.

[0128] Figure 7 Schematic diagram of another embodiment of the subsystem 700 described herein is shown. It can be used, for example, to form at least one of a secondary electron reflective layer, a secondary electron generating layer, a glue layer, and an EUV resist. Figure 7 The configuration can be described as a remote plasma system. Subsystem 700 includes a reaction chamber 710, which is operably connected to a remote plasma source 725, in which plasma 720 is generated. Any type of plasma source can be used as remote plasma source 725, such as inductively coupled plasma, capacitively coupled plasma, or microwave plasma.

[0129] In particular, reactive species are provided from plasma source 725 to reaction chamber 710 via reactive species conduit 760, to conical distributor 750, through holes 731 in shower plate injector 730, to reaction chamber 710. Thus, reactive species may be provided to the reaction chamber in a uniform manner.

[0130] In the configuration shown, the subsystem 700 includes three alternating current (AC) power supplies: a high frequency power supply 721 and two low frequency power supplies 722, 723: a first low frequency power supply 722 and a second low frequency power supply 723. In the configuration shown, the high frequency power supply 721 provides radio frequency (RF) power to the plasma generation space ceiling, the first low frequency power supply 722 provides an AC signal to the showerhead injector 730, and the second low frequency power supply 723 provides an AC signal to the substrate support 740. The substrate 741 is disposed on the substrate support 740. For example, the RF power may be provided at a frequency of 13.56 MHz or higher. For example, the low frequency AC signals of the first and second low frequency power supplies 722, 723 may be provided at a frequency of 2 MHz or lower.

[0131] In some embodiments (not shown), an additional high frequency power source may be electrically connected to the substrate support. Thus, a direct plasma may be generated in the reaction chamber.

[0132] A process gas including a precursor, a reactant, or both is provided to the plasma source 725 through a gas line 760. Reactive species (eg, ions and radicals) generated from the process gas by the plasma 725 are directed to the reaction chamber 710.

[0133] refer to Fig. 9 , an embodiment of a system 900 is further described herein, which can be used to form a structure including a dose reduction layer and an EUV resist. The structure can be formed on a substrate that is maintained in a vacuum or inert gas environment during and between the formation of the dose reduction layer and the EUV resist. The system 900 includes a dose reduction layer reaction chamber 910, which is constructed and arranged to form a dose reduction layer on a substrate. The system 900 also includes an EUV resist reaction chamber 920, which is constructed and arranged to form an EUV resist on the dose reduction layer. The system also includes a wafer handling robot 930, which is constructed and arranged to move a substrate from the dose reduction layer reaction chamber 910 to the EUV resist reaction chamber 920. Advantageously, this can be done without breaking vacuum, or while the substrate is maintained in an inert, i.e., non-reactive, gas environment, such as a rare gas environment.

[0134] In an exemplary embodiment, reference Figure 1, which shows an embodiment of structure 100, wherein the dose reduction layer 120 includes tellurium doped with iodine. The dose reduction layer includes carbon, which can advantageously adjust the surface free energy of the dose reduction layer to a desired value. The dose reduction layer is formed by a plasma enhanced cyclic deposition process. The cyclic deposition process includes a plurality of cycles. Some cycles from the plurality of cycles include a tellurium precursor pulse, an argon plasma step, an iodine reactant pulse, and a post-iodine reactant purge in a given order. The tellurium precursor pulse includes exposing the substrate to a tellurium precursor. The argon plasma step includes exposing the substrate to an argon plasma. The iodine reactant pulse includes exposing the substrate to an iodine reactant. The post-iodine reactant purge includes exposing the substrate to a purge gas, such as a rare gas, such as argon. Note that the substrate is not exposed to plasma between the subsequent iodine reactant pulse and the tellurium precursor pulse. In other words, the post-iodine reactant purge is performed thermally. Diisopropyl telluride is used as a tellurium precursor. 1,2-Diiodoethane is used as an iodine precursor. Other iodinated alkanes, for example diiodinated alkanes, such as diiodomethane, may alternatively be used as the iodine precursor. The result is characterized by an iodine to tellurium ratio of 17 to 39 atomic % and advantageously has low roughness. Advantageously, a dose reduction of 13% is obtained.

Claims

1. A structure comprising: - substrate, - a dose reduction layer overlying the substrate, and - Extreme ultraviolet (EUV) resist covering the dose reduction layer; The dose reduction layer includes a doped semiconductor, and the doped semiconductor includes a main component and a dopant.

2. The structure according to claim 1, wherein: The doped semiconductor has a band gap of at least 2.0 eV.

3. The structure according to claim 1 or 2, wherein: The EUV resist is selected from metal organic framework resist, metal oxide resist and chemical amplification resist.

4. A method comprising: - providing a substrate to a reaction chamber; - forming a dose reduction layer on the substrate; -optionally, forming a glue layer on the substrate; as well as - forming an EUV resist on a substrate; in: - an EUV resist arranged to absorb EUV radiation and generate secondary electrons; and - The dose reduction layer comprises a main component and a dopant.

5. The method of claim 4, further comprising the step of exposing the EUV resist to EUV radiation through a mask.

6. The structure or method according to any one of claims 1 to 5, wherein: The main components include elemental semiconductors.

7. The structure or method according to claim 6, wherein: The elemental semiconductor includes tellurium.

8. The structure or method according to any one of claims 1 to 5, wherein: The main component includes a compound semiconductor.

9. The structure or method according to claim 8, wherein: The compound semiconductor includes indium (III) oxide.

10. The structure or method according to claim 8 or 9, wherein: The dopant includes a vacancy.

11. The structure or method according to claim 10, wherein: The vacancies include oxygen vacancies.

12. The structure or method according to any one of claims 1 to 9, wherein: The dopant includes iodine.

13. A method of forming a layer, the method comprising: - providing a substrate to the reaction chamber via a substrate handler; - performing a cyclic deposition process, the cyclic deposition process comprising a plurality of cycles, some of the plurality of cycles comprising pulses of a principal constituent precursor and pulses of a dopant reactant, - a main component precursor pulse comprises contacting the substrate with the main component precursor; - the reactant pulse comprises contacting the substrate with a dopant reactant; wherein the main component precursor comprises tellurium; and wherein the dopant reactant comprises iodine.

14. The method according to claim 13, wherein: The main component precursor includes alkyl tellurium.

15. The method according to claim 14, wherein: The telluryl group includes diisopropyl telluride.

16. The method according to claim 14 or 15, wherein: The dopant reactant includes an alkyl iodide.

17. The method according to claim 16, wherein: The iodinated alkane includes 1,2-diiodoethane.

18. The method according to any one of claims 13 to 17, wherein: The cyclic deposition process is a thermal cyclic deposition process.

19. The method according to any one of claims 13 to 18, wherein: At least one of the precursor and the reactant includes a reactive species, the reactive species being generated in a plasma.

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