Method and apparatus using an adjustable reactive gas source

Abstract

Photon-activated species, such as reactive radicals, are generated in a semiconductor processing apparatus using a tunable light source. A ground-state reaction gas is flowed into the optical cavity of the semiconductor processing apparatus. The reaction gas is exposed to radiation from a tunable light source to dissociate the reaction gas, form reactive radicals, and / or impart energy to the reactive radicals from the ground state to the excited state. The light source may be tuned to (1) a specific intensity and / or (2) a specific wavelength or wavelength range to control the energy or energy distribution of the photon-activated species. The photon-activated species generated by the tunable light source may be applied to etch materials on a semiconductor substrate, process the surface of a semiconductor substrate, clean the surface of a semiconductor substrate, deposit one or more materials on a semiconductor substrate, or clean the internal surface of a processing chamber.

Description

[Technical Field]

[0001] Embedding by reference A PCT application is filed concurrently with this application as part of this application. Each application claiming any interest or priority identified in a PCT application filed concurrently with this application is incorporated herein by reference in its entirety for any purpose.

[0002] This disclosure relates to semiconductor processing equipment and tools used in semiconductor manufacturing operations. [Background technology]

[0003] As the semiconductor device industry continues to advance, semiconductor processing equipment and tools that use reactive gases to process semiconductor substrates are becoming increasingly important. Reactive gases can be applied to a wide variety of semiconductor processing applications. Reactive gases can be used to deposit materials onto substrate surfaces. Reactive gases can be used to etch materials such as silicon oxide, silicon, silicon nitride, metals or metal oxides, silicon germanium, and many other materials. Many semiconductor manufacturing operations involve the selective etching of one or more materials within a semiconductor substrate. Reactive gases can be used to clean the internal surfaces of semiconductor processing chambers. Reactive gases can be used to process or clean substrate surfaces. Reactive gases can be used to deposit materials onto substrate surfaces. In some cases, the reactivity of a reactive gas can be increased by forming a plasma of the reactive gas.

[0004] Plasma has long been used to process substrates. Plasma processes are commonly used in the manufacture of semiconductor devices. High-energy ions and radicals from plasma can be used to react materials on the substrate surface. Alternatively, high-energy ions and radicals from plasma can be used to clean the internal surfaces of semiconductor processing chambers. However, such high-energy ions and radicals generated by a plasma source produce high concentrations of energy species with a broad energy distribution. This can lead to substrate damage, material selectivity issues, and unsuitability for applications requiring isotropic etching.

[0005] The background art provided herein is intended to provide an overall picture of the current state of the art. To the extent described in this background art section, the inventors' research, as well as any aspects of the description that may not be recognized as prior art at the time of filing, are not explicitly or implicitly recognized as prior art to the present art. [Overview of the project] [Means for solving the problem]

[0006] A semiconductor processing apparatus is provided herein. The semiconductor processing apparatus includes a processing chamber, a substrate support configured to support a semiconductor substrate within the processing chamber, a gas distributor fluidly communicating with the processing chamber, a gas source fluidly communicating with the gas distributor, the gas source configured to supply one or more reaction gases to the gas distributor, and a light source configured to emit radiation to generate at least one photon-activated species of the reaction gases.

[0007] In some embodiments, the light source is tuned to emit radiation having (1) a selected intensity and (2) a selected wavelength or wavelength range in order to obtain a desired energy distribution of photon-activated species. In some embodiments, the light source is tuned according to a selected wavelength or wavelength range in order to achieve a target etching rate and selectivity of one or more materials to be etched on a semiconductor substrate. In some embodiments, the light source is tuned according to a selected intensity in order to achieve a target etching rate and selectivity of one or more materials to be etched on a semiconductor substrate. In some embodiments, one or more reaction gases comprise a mixture of reaction gases, and the light source is tuned according to a selected wavelength or wavelength range in order to selectively generate one photon-activated species of the reaction gases in the mixture relative to the rest of the reaction gases in the mixture. In some embodiments, the semiconductor processing apparatus further comprises an optical cavity optically coupled to the light source to receive radiation from the light source, and at least one of the reaction gases is converted into a photon-activated species within the optical cavity. In some embodiments, the optical cavity includes a gas cell through which one or more reaction gases flow, and an optical cell surrounding or located above the gas cell, with a light source positioned on one or more surfaces of the optical cell to emit radiation through the gas cell. In some embodiments, the optical cell has a different geometric shape from the gas cell. In some embodiments, the optical cell has a cylindrical, rectangular, or octagonal geometric shape. In some embodiments, the optical cell includes one or more mirrors or reflective materials for reflecting radiation emitted from the light source. In some embodiments, the gas cell includes one or more mirrors or reflective materials for reflecting radiation emitted from the light source. In some embodiments, the material of the gas cell is transparent or substantially transparent to radiation emitted from the light source. In some embodiments, the optical cell includes a window located above the gas cell, with a light source positioned on the window and including multiple light-emitting diodes (LEDs) that emit radiation into the gas cell.In some embodiments, the optical cell includes a ring surrounding a gas cell, and the light source includes a plurality of LEDs positioned on the ring and emitting radiation into the gas cell. In some embodiments, the optical cavity includes one or more mirrors or reflective surfaces. In some embodiments, the optical cavity does not include mirrors or reflective surfaces. In some embodiments, the light source includes a laser. In some embodiments, the light source includes a flash lamp. In some embodiments, the light source includes a plurality of LEDs. In some embodiments, the plurality of LEDs include a first LED configured to emit radiation of a first wavelength and a second LED configured to emit radiation of a second wavelength different from the first wavelength. In some embodiments, the light source is further configured to expose a semiconductor substrate to the emitted radiation in order to promote or hinder a surface reaction on the semiconductor substrate. In some embodiments, the light source includes a plurality of LEDs positioned above a gas distributor, and the gas distributor is transparent or substantially transparent to the emitted radiation. In some embodiments, the optical cavity is positioned between the gas distributor and the gas source so that photon activation occurs in front of the gas distributor. In some embodiments, the optical cavity is located within a gas distributor so that photon activation occurs within the gas distributor. In some embodiments, the optical cavity is located within a processing chamber so that photon activation occurs within the processing chamber. In some embodiments, one or more reaction gases include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or combinations thereof. In some embodiments, at least one photon-activating species of the reaction gas includes a ground-state or excited-state molecular radical, a ground-state or excited-state atomic radical, and / or an energy-granted reaction gas in an excited vibrational state.

[0008] A semiconductor processing apparatus is also provided herein. The semiconductor processing apparatus includes a processing chamber, a substrate support configured to support a semiconductor substrate in the semiconductor processing chamber, a gas distributor fluidly communicating with the semiconductor processing chamber, a gas source fluidly communicating with the gas distributor, the gas source configured to supply one or more ground-state reaction gases to the gas distributor, a light source configured to emit radiation and to be tuned to (1) a selected intensity and (2) a selected wavelength or wavelength range, and an optical cavity disposed between the gas source and the gas distributor, the optical cavity configured to receive radiation from the light source and to convert one or more reaction gases within the optical cavity into photon-activated species.

[0009] A semiconductor processing apparatus is also provided herein. The semiconductor processing apparatus comprises a semiconductor processing chamber, a substrate support configured to support a semiconductor substrate in the semiconductor processing chamber, a gas distributor fluidly communicating with the semiconductor processing chamber, and a gas source fluidly communicating with the gas distributor, the gas source comprising a gas source configured to supply one or more ground-state reaction gases to the gas distributor, and a light source configured to emit radiation and to be tuned to (1) a selected intensity and (2) a selected wavelength or wavelength range, wherein the gas distributor functions as an optical cavity configured to receive radiation from the light source and convert one or more reaction gases into photon-activated species within the gas distributor.

[0010] A semiconductor processing apparatus is also provided herein. The semiconductor processing apparatus comprises a processing chamber, a substrate support configured to support a semiconductor substrate in the processing chamber, a gas distributor fluidly communicating with the processing chamber, and a gas source fluidly communicating with the gas distributor, the gas source comprising a gas source configured to supply one or more ground-state reaction gases to the gas distributor, and a light source configured to emit radiation and to be tuned to (1) a selected intensity and (2) a selected wavelength or wavelength range, wherein the processing chamber functions as an optical cavity configured to receive radiation from the light source and convert one or more reaction gases in the processing chamber into photon-activated species.

[0011] A method for generating photon-activated species for use in a processing chamber is also provided herein. The method includes the steps of flowing one or more reaction gases toward a gas distributor for distributing one or more reaction gases into a processing chamber; emitting radiation from a light source at (1) a selected intensity and (2) a selected wavelength or wavelength range; and generating at least one photon-activated species of the reaction gas in an optical cavity by exposing one or more reaction gases to the radiation emitted from the light source.

[0012] In some embodiments, the method further includes the step of etching one or more materials on a semiconductor substrate in a processing chamber by exposing the semiconductor substrate to photon-activated species. In some embodiments, one or more materials are etched with etching rate and selectivity based at least partially on (1) a selected intensity and (2) a selected wavelength or wavelength range. In some embodiments, the step of etching one or more materials includes etching silicon oxide rather than silicon and / or silicon nitride, and the photon-activated species includes radicals of oxygen-containing gases and / or hydrogen-containing gases. In some embodiments, the step of etching one or more materials includes the step of etching silicon rather than silicon oxide and / or silicon nitride, and the photon-activated species includes radicals of halogen gases and / or methane gases. In some embodiments, the step of etching one or more materials includes the step of etching silicon rather than silicon germanium, silicon oxide, silicon nitride, or a combination thereof, and the photon-activated species includes radicals of nitrogen-containing gases mixed with fluorine-containing gases and / or hydrogen-containing gases. In some embodiments, the step of etching one or more materials includes etching silicon nitride rather than silicon oxide, silicon, silicon germanium, or a combination thereof, and the photon-activating species includes radicals of fluorine-containing gases and / or nitrogen-containing gases. In some embodiments, the step of etching one or more materials includes etching a metal or metal oxide, and the photon-activating species includes radicals of fluorine-containing gases. In some embodiments, the method further includes the step of treating the surface of a semiconductor substrate by exposing the semiconductor substrate to a photon-activating species to desorb etching byproducts from the surface of the semiconductor substrate. In some embodiments, the step of etching one or more materials includes etching silicon germanium rather than silicon, and the photon-activating species include radicals of fluorine-containing species and / or chlorine-containing species.In some embodiments, the concentration of photon-activated species for etching one or more materials is adjustable by controlling (1) a selected intensity of emitted radiation and (2) a selected wavelength of emitted radiation. In some embodiments, the method further includes the step of treating the surface of a semiconductor substrate in a processing chamber by exposing the semiconductor substrate to photon-activated species. In some embodiments, the method further includes the step of cleaning the internal surface of the processing chamber by exposing the internal surface to photon-activated species. In some embodiments, the optical cavity is located upstream of a gas distributor and integrated with the gas distributor, or integrated with the processing chamber. In some embodiments, the optical cavity includes one or more mirrors or reflective materials configured to reflect radiation emitted from a light source within the optical cavity. In some embodiments, the light source includes multiple LEDs, which emit at the same wavelength or a combination of different wavelengths. In some embodiments, the photon-activated species are generated independently of any plasma. In some embodiments, the photon-activated species include ground-state or excited-state molecular radicals, ground-state or excited-state atomic radicals, and / or energy-conjugated reaction gases in an excited vibrational state. In some embodiments, one or more reaction gases include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or combinations thereof. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of an exemplary plasma processing apparatus that generates a plasma containing high-energy ions and radicals, according to several embodiments. [Figure 2] This is a schematic diagram of an exemplary plasma processing apparatus that generates a plasma containing high-energy ions and radicals, according to several other embodiments. [Figure 3A]Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species and an optical cavity between a gas distributor and a gas source, in accordance with some embodiments. [Figure 3B] Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species and an optical cavity between a gas distributor and a gas source, in accordance with some other embodiments. [Figure 3C] Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species within a gas distributor, in accordance with some embodiments. [Figure 3D] Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species within a gas distributor, in accordance with some other embodiments. [Figure 3E] Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species within a processing chamber, in accordance with some embodiments. [Figure 3F] Schematic diagram of an exemplary semiconductor processing apparatus including a light source for generating photon-activated species within a processing chamber, in accordance with some other embodiments. [Figure 4] Graph illustrating the optical absorption of a halogen gas as a function of wavelength associated with radiation emitted from a light source, in accordance with some embodiments. [Figure 5] Schematic diagram of an exemplary optical cavity including an optical cell having a light source and a gas cell through which one or more reaction gases pass, in accordance with some embodiments. [Figure 6A] Schematic diagram of an exemplary optical cavity including a rectangular optical cell and a cylindrical gas cell, in accordance with some embodiments. [Figure 6B] Schematic diagram of an exemplary optical cavity including a cylindrical optical cell and a cylindrical gas cell, in accordance with some embodiments. [Figure 6C] Schematic diagram of an exemplary optical cavity including an octagonal optical cell and a cylindrical gas cell, in accordance with some embodiments. [Figure 6D]This is a schematic diagram of an exemplary optical cavity, including a circular window located above the gas cell, according to several embodiments. [Figure 6E] This is a schematic diagram of an exemplary optical cavity, including an annular window surrounding a gas cell, according to several embodiments. [Figure 7A] This is a schematic diagram of an exemplary semiconductor processing apparatus, according to several embodiments, which includes a light source positioned above a gas distributor, and the light source may be configured to generate photon-activated species within an optical cavity. [Figure 7B] This is a schematic diagram of an exemplary semiconductor processing apparatus, according to several embodiments, which includes a light source positioned above a gas distributor, and the light source may be configured to irradiate a semiconductor substrate in a processing chamber. [Figure 8] This is a schematic plan view of an exemplary light source, including multiple light-emitting diodes (LEDs) for emitting radiation at different wavelengths, according to several embodiments. [Figure 9A] This is a flowchart illustrating an exemplary method for generating photon-activated species for use in a processing chamber, according to several embodiments. [Figure 9B] This is a flowchart illustrating exemplary methods for generating and using photon-activated species in a processing chamber, according to several embodiments. [Figure 10] This is a schematic diagram of an exemplary process tool for carrying out the disclosed embodiments. [Modes for carrying out the invention]

[0014] The following descriptions include numerous specific details to provide a complete understanding of the presented implementations. The disclosed implementations may be implemented without some or all of these specific details. In other examples, well-known process behaviors are not described in detail to avoid unnecessarily obscuring the disclosed implementations. While the disclosed implementations are described in conjunction with specific implementations, it should be understood that this is not intended to limit the disclosed implementations.

[0015] The embodiments disclosed herein may describe the processing of materials on a substrate, such as a wafer, a substrate, or other workpiece. The workpiece may be of various shapes, sizes, and materials. In this application, the terms “semiconductor wafer,” “wafer,” “substrate,” “wafer substrate,” and “partially manufactured integrated circuit” are used interchangeably. Those skilled in the art will understand that the term “partially manufactured integrated circuit” may refer to a silicon wafer in the middle of any of the many stages of integrated circuit manufacturing on it. Wafers or substrates used in the semiconductor device industry typically have diameters of 200 mm, 300 mm, or 450 mm. Unless otherwise specified, the processing details enumerated herein (e.g., flow rate, power level, etc.) relate to processing a 300 mm diameter substrate, or processing a chamber configured to process a 300 mm diameter substrate and which can be appropriately scaled to substrates or chambers of other sizes. In addition to semiconductor wafers, other workpieces that may be used in the embodiments disclosed herein include various articles such as printed circuit boards. The processes and apparatus can be used to manufacture semiconductor devices, displays, LEDs, photovoltaic panels, and the like.

[0016] Introduction Plasma has long been used to process substrates and semiconductor devices. Plasma generation may use capacitively coupled plasma technology, inductively coupled plasma technology, electron cyclotron technology, or microwave technology. Plasma is generated by supplying a reaction gas to a plasma generation chamber and applying a strong radio frequency (RF) electromagnetic field. Electrons are accelerated by the oscillating electric field, and the electrons collide with reaction gas molecules, ionizing them and stripping them of their electrons, thereby generating a plasma of ions and more electrons. Plasma generally contains ions, electrons, and neutral or radical species in excited and ground states. Thus, plasma can contain charged and uncharged species that have both high kinetic energy and high chemical potential. In some cases, high-energy ions and radicals from the plasma may be delivered to the substrate surface to etch one or more materials deposited on the substrate. In some cases, high-energy ions and radicals from the plasma may be delivered to the substrate surface to process the substrate surface or remove contaminants. In some cases, high-energy ions and radicals from the plasma may be delivered to the internal surface of a semiconductor processing chamber to clean its internal surface.

[0017] Figure 1 shows a schematic diagram of an exemplary plasma processing apparatus that generates a plasma containing high-energy ions and radicals, according to several embodiments. The plasma processing apparatus 100 has a single processing chamber 110 having a substrate holder 118 (e.g., a pedestal or electrostatic chuck) in an internal volume that can be maintained under vacuum or other desired chamber pressure by a vacuum pump 130. A gas delivery system 102 and a showerhead 104 are fluidly coupled to the processing chamber 110 to deliver film precursors, carrier gas and / or purge gas and / or process gas, secondary reactants, etc. Apparatus for generating plasma within the processing chamber 110 is also shown in Figure 1.

[0018] The plasma processing apparatus 100 is in fluid communication with a gas delivery system 102 to deliver process gas. The gas delivery system 102 may include a mixing vessel 106 for mixing and / or adjusting the process gas for delivery to the showerhead 104. One or more mixing vessel inlet valves 108A and 108B may control the introduction of process gas into the mixing vessel 106.

[0019] A showerhead 104 distributes process gas and / or reactants (e.g., etching gas) toward a substrate 114, the flow of which is controlled by one or more valves upstream of the showerhead (e.g., valves 108A, 108B, and 116). The substrate 114 is located beneath the showerhead 104 and is shown resting on a substrate holder 118. A chamber space 120 is located beneath the showerhead 104. In some embodiments, the substrate holder 118 may be raised or lowered to expose the substrate 114 to the chamber space 120 and / or to change the volume of the chamber space 120. The showerhead 104 and the substrate holder 118 are electrically connected to an RF power supply 122 and a matching network 124 for powering the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the process station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse timing (e.g., via a system controller having appropriate machine-readable instructions and / or control logic). For example, the RF power supply 122 and matching network 124 may operate at any appropriate power to form a plasma in the chamber space 120. The plasma may be a capacitively coupled plasma containing high-energy ions and radicals. The plasma formed in the chamber space 120 may be used to etch one or more materials from the substrate 114, process the substrate 114, deposit a film on the substrate 114, or clean the internal surface of the processing chamber 110. The plasma processing apparatus 100 also includes a DC power supply 126 configured to supply a DC current to the substrate holder 118 in order to generate an electrostatic clamping force and provide it to the substrate holder 118 and the substrate 114. The substrate holder 118 may also have one or more temperature control elements 128 configured to heat and / or cool the substrate 114.

[0020] Figure 2 shows a schematic diagram of an exemplary plasma processing apparatus that generates a plasma containing high-energy ions and radicals according to several other embodiments. The plasma processing apparatus 200 comprises a remote plasma source 250 and a processing chamber 225 separate from the remote plasma source 250. The remote plasma source 250 is configured to generate a remote plasma 260. The remote plasma 260 may be an inductively coupled plasma containing high-energy ions and radicals. The high-energy ions and radicals of the remote plasma 260 may be introduced through a showerhead 254. The substrate 220 may be supported on a substrate support 210.

[0021] The process gas 202 may be supplied to the remote plasma source 250 via a gas distributor 252. One or more valves may control the introduction of the process gas 202 to the remote plasma source 250. The remote plasma source 250 may be a vessel of any suitable shape, such as dome-shaped, conical, or cylindrical. A coil 256 may surround at least a portion of the vessel of the remote plasma source 250. The coil 256 may be electrically connected to an RF power supply for generating the remote plasma 260 within the remote plasma source 250. The remote plasma 260 may be ignited by exciting the coil 256 to form an active species 204 which may contain high-energy ions and radicals. The active species 204 pass through the showerhead 254 toward the substrate 220. The active species 204 of the remote plasma 260 may be used to etch one or more materials from the substrate 220, process the substrate 220, deposit a film on the substrate 220, or clean the internal surface of the processing chamber 225.

[0022] In some embodiments, an in situ plasma 230 may be generated between the showerhead 254 and the substrate support 210, and the in situ plasma may be a capacitively coupled plasma. A gas or gas mixture 206 may be introduced into the processing chamber 225. An electric field may be generated between the showerhead 254 and the substrate support 210, and the ionization of the gas or gas mixture 206 may ignite the in situ plasma 230 to form activated species including high-energy ions and radicals. In some embodiments, the in situ plasma 230 may be used to etch one or more materials from the substrate 220, process the substrate 220, deposit a film on the substrate 220, or clean the internal surface of the processing chamber 225.

[0023] The plasma processing apparatus 200 may further include a controller 240. The controller 240 may be programmed to control various processes performed by the plasma processing apparatus 200, including gas delivery, temperature setting, pressure setting, vacuum setting, power setting, RF generator setting, RF matching circuit setting, frequency setting, flow rate setting, fluid delivery setting, position and movement setting, and transfer of the substrate into and out of the tool and / or load lock.

[0024] Photon activation in semiconductor processing equipment Implementations of this disclosure use photons or photon-activated species in semiconductor processing equipment instead of plasma or plasma-activated species. Several implementations of this disclosure relate to a reactive gas source for generating photon-activated species. Rather than generating high-energy-conjugated ions and radicals by plasma ignition, this disclosure generates photon-activated species so that their energy can be tuned, selected, or controlled. By exposing the reactive gas to radiation emitted from a light source, such as a laser, lamp, or array of LEDs, the reactive gas may be energy-conjugated to form excited-oscillating reactive radicals and / or excited molecules. The light source can be tuned according to a specific wavelength and / or intensity to control the energy or energy distribution of the photon-activated species of the reactive gas. In a mixture of gases, a specific wavelength may be selected to photon-activate a target gas species while leaving all other gas species in an inactive ground state. In some embodiments, the photon-activated species may include excited-state reactive radicals, ground-state reactive radicals, and / or energy-conjugated reactive gases in an excited-oscillating state. Photon-activated species may be used to etch one or more materials on a semiconductor substrate, to treat the surface of a semiconductor substrate, or to clean the internal surface of a processing chamber. In some implementations, photon-activated species may be used to carry out other processing steps such as oxidation, nitriding, atomic layer etching, surface cleaning, and deposition.

[0025] In some implementations of this disclosure, a semiconductor processing apparatus is configured to generate photon-activated species. The semiconductor processing apparatus may include a processing chamber and a gas distributor (e.g., a showerhead) for delivering a reaction gas into the processing chamber. A light source may be optically coupled to the processing chamber, the gas distributor, or an optical cavity upstream of the gas distributor. The ground-state reaction gas may be exposed to a light source in the processing chamber, the gas distributor, or the optical cavity to generate photon-activated species of the reaction gas. For example, the light source may include a plurality of LEDs configured to emit radiation from above the showerhead to generate photon-activated species in an optical cavity above the showerhead. In some cases, the plurality of LEDs may be configured to emit radiation through the showerhead to directly expose a semiconductor substrate to radiation. In some embodiments, direct exposure of the semiconductor substrate to radiation may promote or hinder surface reactions. In some embodiments, the photon-activated species generated in the processing chamber, the gas distributor, or the optical cavity may be used to etch one or more materials on the semiconductor substrate, to treat the surface of the semiconductor substrate, or to clean the internal surface of the processing chamber. In some cases, photon-activated species generated in a processing chamber, gas distributor, or optical cavity may be used to deposit material onto a semiconductor substrate, clean the surface of the semiconductor substrate, carry out oxidation, carry out nitriding, or carry out atomic layering, etc.

[0026] Figures 3A to 3F show schematic diagrams of various configurations for implementing a light source within a semiconductor processing apparatus for generating photon-activated species. The light source may be adjustable. In Figures 3A to 3F, the semiconductor processing apparatus 300 includes a processing chamber 310 and a substrate support 320 configured to support a substrate 322 within the processing chamber 310. In some embodiments, the substrate support 320 is a pedestal or an electrostatic chuck. The semiconductor processing apparatus 300 further includes a gas distributor 330 that is in fluid communication with the processing chamber 310. The gas distributor 330 is configured to distribute process gases and reactants into the processing chamber 310. In some embodiments, the gas distributor 330 may be configured to distribute process gases and reactants toward the substrate 322. In some embodiments, the gas distributor 330 is a showerhead.

[0027] The semiconductor processing apparatus 300 may further include a gas source 340. The gas source 340 is upstream of the gas distributor 330 and provides one or more reaction gases. The one or more reaction gases may include a molecular gas in the ground state. The ground state represents an energy state which is an unexcited energy state. An atom or molecule can exist in either its ground state or an excited state. An atom or molecule can be excited in several different ways, such as plasma excitation or photon excitation. After excitation to an excited state, the atom or molecule eventually relaxes to a low energy state or the ground state. Here, the one or more reaction gases supplied by the gas source 340 have not been excited by plasma or photon excitation.

[0028] In some embodiments, one or more reaction gases include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or combinations thereof. Examples of halogen gases include fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2). Examples of hydrogen halides include hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI). Exemplary oxidizing gases include oxygen (O2), nitric oxide (NO), nitrogen dioxide (NO2), nitrous oxide (N2O), nitrite (HONO), water (H2O), hydrogen peroxide (H2O2), and ozone (O3). In some embodiments, one or more reaction gases include fluorine-based species such as nitrogen trifluoride (NF3), carbon tetrafluoride (CF4), sulfur hexafluoride (SF6), trifluoromethane (CHF3), difluoromethane (CH2F2), fluoromethane (CH3F), silicon tetrafluoride (SiF4), hexafluorobutadiene (C4F6), hexafluoroethane (C2F6), tetrafluoroethylene (C2F4), germanium tetrafluoride (GeF4), or xenon difluoride (XeF2). In some embodiments, one or more reaction gases include carbon-containing species such as carbonyl sulfide (COS), carbon monoxide (CO), carbon dioxide (CO2), or methane (CH4). In some embodiments, one or more reaction gases include hydrogen-containing species such as ammonia (NH3), hydrogen (H2), or silane (SiH4). In some embodiments, one or more reaction gases include amine species.

[0029] Typically, in a plasma, the reactive gas forms high-energy ions and excited radicals. A radical is an atom or molecule containing one or more unpaired electrons. Plasmas are generally characterized by the presence of a significant proportion of charged particles in any combination of ions or electrons. Uncharged particles (e.g., radicals) are also present. Furthermore, both charged and uncharged species in the plasma may have high thermal kinetic energy. Plasmas may be characterized by particles with high thermal kinetic energy and high concentrations of energy species (ions and radicals). High concentrations of energy species in the plasma may be characterized by a broad energy distribution. Without being limited by any theory, varying amounts of charged and uncharged species in the plasma, the thermal kinetic energy of particles in the plasma, and the varying excitation levels of particles can contribute to a broad energy distribution. More specifically, the energies of reactive species in a plasma may differ by only a few electron volts or tens of electron volts (eV). In some cases, the energy distribution of reactive species in a plasma may be on the order of tens of eV.

[0030] Instead of activating and exciting the reactive gas by plasma, activation and excitation of the reactive gas can occur by photons. Electromagnetic radiation, such as ultraviolet (UV), visible light, or infrared (IR), may be emitted by the light source. The energy of a photon is inversely proportional to the wavelength of the emitted radiation. The light source may emit radiation having one or more wavelengths within a narrow light source spectral linewidth. This narrow light source spectral linewidth can provide a narrow energy distribution for photons, thereby resulting in a narrow energy distribution for reactive radicals. Excitation of the reactive gas by photon energy can avoid ionization and thus avoid the transfer of kinetic energy to the reactive gas. Instead, excitation of the reactive gas by photon energy can generate excited radicals with a narrow energy distribution. Additionally or alternatively, excitation of the reactive gas by photon energy can generate reactive gases in excited oscillatory states.

[0031] Ground-state molecules can be excited to an excited energy state by exposure to photon energy. Additionally or alternatively, these ground-state molecules can be decomposed by exposure to photon energy, forming ground-state or excited-state radicals. Reactive radicals generated from a light source may be in molecular or atomic form.

[0032] The semiconductor processing apparatus 300 may further include a light source 350 configured to emit electromagnetic radiation such as UV radiation, IR radiation, or visible light. In some embodiments, the UV radiation may have wavelengths between about 100 nm and about 400 nm, the visible light may have wavelengths between about 400 nm and about 1000 nm, and the IR radiation may have wavelengths greater than about 1000 nm. The light source 350 may be configured to emit radiation adjusted to (1) a selected wavelength or wavelength range and / or (2) a selected intensity. One or more reaction gases supplied by the gas source 340 may be exposed to radiation emitted from the light source 350. Exposure of one or more reaction gases to radiation emitted from the light source 350 generates photon-activated species of one or more reaction gases. Specifically, the photon-activated species may include reactive radicals in the ground state or excited state of one or more reaction gases, or energy-granted reaction gases in an excited vibrational state. In some embodiments, the light source 350 may be configured to emit radiation to directly irradiate the substrate 322.

[0033] In some embodiments, the light source 350 may include, but is not limited to, any suitable laser or lamp, a mercury lamp, a deuterium lamp, a pulsed xenon lamp, an excimer lamp, and an excimer laser. Such a lamp / laser may be tuned to provide an emission spectrum for exciting and / or decomposing one or more reaction gases. For example, the light source 350 may be a UV lamp or laser. A UV light source may produce UV radiation having wavelengths between about 100 nm and about 400 nm, and the UV radiation may have sufficient energy to decompose molecular species of one or more reaction gases and / or form radicals in an excited state. However, it will be understood that the light source 350 may operate in other wavelength ranges, including visible light wavelengths and IR wavelengths. In some embodiments, the light source 350 using a laser or lamp is tuned within a wavelength range such as between about 193 nm and about 10 μm. The spectral linewidth is defined as the wavelength range from which the light source emits light. The spectral linewidth of a laser or lamp can be about 1 nm.

[0034] In some embodiments, the light source 350 may include any suitable LED or array of LEDs. An LED is a semiconductor light source that emits light having a wavelength based on the energy bandgap of the semiconductor. The LED may emit IR light, visible light, or UV light. Examples of semiconductor materials for LEDs include, but are not limited to, gallium arsenide (GaAs), gallium phosphide (GaP), gallium nitride (GaN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), aluminum gallium phosphide (AlGaP), aluminum gallium phosphide (AlGaInP), aluminum gallium phosphide (AlGaInN), aluminum gallium arsenide (AlGaAs), silicon carbide (SiC), silicon (Si), zinc selenide (ZnSe), aluminum nitride (AlN), and boron nitride (BN). In some embodiments, the light source 350 using an LED or array of LEDs is tuned to a wavelength range such as between about 193 nm and about 10 μm. The spectral linewidth of an LED or an array of LEDs can be approximately 10 nm.

[0035] In some embodiments, the light source 350 may be configured to emit discrete wavelengths. Lasers and LEDs may also emit radiation at discrete wavelengths. In some other embodiments, the light source 350 may be configured to emit wavelengths over a broadband range. "Broadband" can refer to a light source having a wide spectral bandwidth (e.g., greater than about 50 nm). Lasers and some types of LEDs are nearly monochromatic light sources, but broadband light sources such as arc discharge lamps may be nearly polychromatic light sources. Some other types of LEDs are also broadband light sources, e.g., white light LEDs. Arrays of LEDs consisting of LEDs emitting at different wavelengths may also be used.

[0036] In some embodiments, the light source 350 may operate in continuous mode or pulsed mode. In some embodiments, the light source 350 may be positioned relative to the surface of the substrate 322 so that the surface of the substrate 322 is exposed to its emitted radiation. In some embodiments, the light source 350 may be positioned relative to the surface of the substrate 322 to avoid exposure to its emitted radiation. For example, the light source 350 may emit radiation in an optical cavity separate from the processing chamber 310, or it may emit radiation within the processing chamber 310 at an angle that does not collide with the surface of the substrate 322.

[0037] Figure 4 is a graph showing the optical absorption of halogen gases as a function of wavelength related to the radiation emitted from a light source, according to several embodiments. The light source (e.g., light source 350) may be configured to emit discrete wavelengths or wavelength ranges that optimize optical absorption by the halogen gas. The selected wavelengths ensure photonic activation and excitation by the halogen gas to form photonic activated species. Such photonic activated species include halogen-based radicals in an excited state. As an example, the wavelengths selected to optimize absorption by fluorine gas may be between approximately 200 nm and approximately 380 nm, or between approximately 220 nm and approximately 365 nm. By using radiation tuned to one or more selected wavelengths, it is possible to optimize the absorption of a particular gas, such as fluorine gas, more than other gases in a gas mixture.

[0038] In some embodiments, the light source (e.g., light source 350) may be configured to a selected intensity. In other words, the intensity of radiation emitted from the light source may be adjustable. In some embodiments, the light source is approximately 0.001 W / cm² 2 From approximately 100W / cm² 2 Between or approximately 0.01 W / cm² 2 From approximately 10W / cm² 2 It may be configured to emit radiation having an intensity between .

[0039] Photon-activated species, including reactive radicals in the ground or excited state, are generated by irradiation from a light source (e.g., light source 350). These photon-activated species may be highly reactive radicals with a narrow energy distribution. Since the spectral linewidth of the radiation from the light source can be narrow, e.g., within 1 nm or 10 nm, the energy distribution of the photon-activated species is also narrow. In some embodiments, the energy distribution of the photon-activated species generated by irradiation from the light source is approximately 10 meV or less. In some embodiments, the energy distribution of the photon-activated species generated by irradiation from the light source is approximately 100 meV or less. This allows for more precise control and targeting of the energy of the highly reactive radicals. Unlike plasma excitation, which generates activated species with a broad energy distribution, photon excitation generates activated species with a narrower energy distribution, suitable for more targeted applications.

[0040] Returning to Figures 3A to 3F, the photon-activated species may be applied to a variety of semiconductor processing applications. For example, the photon-activated species may be applied to etch one or more materials on the substrate 322, to process the surface of the substrate 322, or to clean the internal surface of the processing chamber 310 (e.g., the chamber wall). In addition, the photon-activated species may be applied to carry out oxidation, nitriding, atomic layer etching, substrate surface cleaning, and deposition.

[0041] In some embodiments, photon-activated species are used to etch one or more materials on a substrate 322 in a processing chamber 310. One or more reaction gases for etching may include halogens such as F2, Cl2, Br2, and I2, oxidizing agents such as O2, NO, NO2, N2O, HONO, O3, H2O2, and H2O, hydrogen halides such as HF, HCl, HBr, and HI, and other etching chemicals such as NF3, CH4, CHF3, SF6, NH3, SiF4, and H2. Any or a combination thereof of the aforementioned reaction gases may form highly reactive radicals in the ground state or excited state. As an example, one or more reaction gases for etching may include F2. When exposed to appropriate radiation from a light source 350, molecular fluorine gas (F2) dissociates, forming fluorine reactive radicals (F2). * ) can be formed. Fluorine radicals may be in the ground state or excited state to etch one or more materials on the substrate 322, such as silicon, silicon oxide, silicon nitride, or silicon germanium.

[0042] Material etch rate and selectivity may be controlled in a variety of different ways. Typically, material etch rate and selectivity may be controlled by altering the chemistry of the etchant, or by altering the ratio of the combination of etchant chemistries (e.g., the ratio of NF3 to H2). In some embodiments of the present disclosure, material etch rate and selectivity may be controlled by adjusting the light source energy (e.g., wavelength) from the light source 350. By adjusting the light source energy, this can change the ratio of radicals in different excited states. For example, higher energy can excite more radicals to a higher energy state, and lower energy can excite fewer radicals to a higher energy state, or even bring more radicals to a lower energy state (e.g., ground state). A higher concentration of radicals in a higher energy state can increase the etch rate of one or more materials. In one example, the selected wavelength of light source 350 causes more fluorine radicals (F * ) and thereby can change the etch rate and selectivity of materials such as silicon, silicon oxide, silicon nitride, or silicon germanium on the substrate 322. In some embodiments of the present disclosure, material etch rate and selectivity may be controlled by adjusting the light source intensity from the light source 350. By adjusting the light source intensity, the ratio of radical atoms in the excited state to radical atoms or molecules in the ground state can be varied. For example, a higher intensity can dissociate a higher concentration of the reactive gas to form excited state radical atoms, while a lower intensity can dissociate a lower concentration of the reactive gas, or even generate more radical atoms in a lower energy state (e.g., ground state) than in a higher energy state. In one example, the selected intensity of light source 350 or other characteristics of light source 350 modulates the ratio of F2 species to F * species, or F * (excited state) and F *The ratio to the ground state may be modulated, thereby changing the etching rate and selectivity of materials such as silicon, silicon oxide, silicon nitride, or silicon germanium. In another example, the selected wavelength of the light source 350 may excite at least one of the reaction gases from the mixture of reaction gases to dissociate and / or a higher energy state. In this way, a particular reaction gas may form a photon-activated species depending on the selected wavelength, while the other reaction gases are not activated by radiation from the light source 350. The etching rate and selectivity can be adjusted by controlling the light source wavelength and / or light source intensity. This allows for greater control when performing selective etching across one or more materials on the substrate 322.

[0043] In some embodiments, photon-activated species are used to treat the surface of the substrate 322. One or more reaction gases may form highly reactive radicals used to treat the surface of the substrate 322 without damaging the underlying film on the substrate 322, or with minimal damage to the underlying film on the substrate. In contrast to plasma-generated species containing high-energy ions and radicals, photon-generated species containing ground-state or excited-state reactive radicals have less energy (e.g., less kinetic energy) to minimize damage to the substrate 322. In some embodiments, excited-oscillating reactive radicals or reaction gases generated by exposure can function to remove surface contaminants. Excited-oscillating reactive radicals or reaction gases can function to remove various contaminants, including carbon (C), hydrocarbons (CH), fluorocarbons (CF), hydrofluorocarbons (CHF), etc. In some embodiments, excited-oscillating reactive radicals or reaction gases generated by exposure can function to remove damaged material or layers. Reactive radicals or reactive gases in excited vibrational states can function to remove, for example, damaged silicon (Si), silicon oxide (SiO2), silicon oxycarbon nitride (SiOCN), or silicon nitride (Si3N4).

[0044] In some embodiments, photon-activated species are used to clean the internal surface of the processing chamber 310. One or more reaction gases may form highly reactive radicals or reaction gases in an excited vibrational state, which are used to remove material deposited on the internal surface of the processing chamber 310. The internal surface may include, but is not limited to, the internal chamber walls, ceiling, floor, showerhead, substrate support, lift pins, gas lines, nozzles, etc. If the processing chamber 310 is not cleaned, the wafer is vulnerable to particle contamination and drift of the processing results, and the processing chamber 310 is subject to degradation and erosion. In some cases, cleaning of the internal surface of the processing chamber 310 may proceed within the processing chamber 310 without a substrate, such as in waferless automated cleaning (WAC). In contrast to plasma-generated species with high kinetic energy, photon-activated species have low kinetic energy and are more easily distributed throughout the processing chamber 310. Therefore, reactive radicals or reaction gases in an excited vibrational state generated by exposure can function to remove material deposited on the chamber surface, such as chamber deposited material containing silicon, carbon, hydrocarbons, fluorocarbons, hydrofluorocarbons, metals, etc.

[0045] Although not shown in Figures 3A to 3F, the semiconductor processing apparatus 300 may further include a controller consisting of instructions for performing various operations. The controller may control various activities of the semiconductor processing apparatus 300. The controller runs system control software that includes an instruction set for controlling gas flow timing, gas mixture, gas concentration, chamber pressure, chamber temperature, substrate temperature, pedestal position, light source wavelength(s), light source intensity, light source operating mode, exposure timing, selection of light source from multiple light sources, and other parameters. In some other implementations, other computer programs stored in a memory device associated with the controller may be used.

[0046] The semiconductor processing apparatus 300 shown in Figures 3A to 3F may be a standalone apparatus for generating photon-activated species using a light source. Alternatively, the semiconductor processing apparatus 300 may be implemented using both a plasma source for generating plasma-activated species and a light source for generating photon-activated species. By integrating the light source and plasma source into the semiconductor processing apparatus 300, the plasma source and light source may coexist within the semiconductor processing apparatus 300 and be used for various processing operations. The plasma source may be used for processing involving high-energy ions and radicals, and the light source may be used for processing involving reactive radicals at lower energies. For example, the plasma source may be used for anisotropic etching of a material on a substrate, and the light source may be used for subsequent processing of the damaged layer after anisotropic etching. By integrating the plasma source and light source into a single tool, such processes may be carried out without vacuum breaks between operations. In some embodiments, any of the configurations shown in Figures 3A to 3F may be incorporated into the plasma-based apparatus of Figures 1 and 2.

[0047] Figure 3A shows a schematic diagram of an exemplary semiconductor processing apparatus, according to several embodiments, which includes a light source for generating photon-activated species and an optical cavity between a gas distributor and a gas source. In Figure 3A, the optical cavity 360 is located between the gas source 340 and the gas distributor 330. The optical cavity 360 is fluid-coupled to the gas source 340 to receive one or more reaction gases. The one or more reaction gases are in the ground state. The optical cavity 360 is fluid-coupled to the gas distributor 330 to deliver the photon-activated species to the gas distributor 330. The light source 350 is optically coupled to the optical cavity 360. The light source 350 is optically coupled to allow light to pass into the optical cavity 360. For example, the light source 350 may be introduced into the optical cavity 360 by passing light through a window 362.

[0048] The interior of the optical cavity 360 may include one or more mirrors or be coated with a reflective material 364. As used herein, the term “optical cavity” may refer to a space in which photons exist. In other words, an “optical cavity” is a space configured to receive radiation from a light source. The interior of the optical cavity may or may not include a reflective surface. The mirrors or reflective material 364 may exhibit high reflectivity in appropriate spectra (e.g., UV spectrum, visible light spectrum, IR spectrum). Radiation emitted from the light source 350 may be repeatedly reflected inside the optical cavity 360 to increase the likelihood that one or more reaction gases are exposed to the radiation. Having a reflective coating or mirrors reduces residence time and increases optical path length. This increases the overall absorption of radiation, resulting in the generation of higher concentrations of photon-activated species. As a result, this ensures that a significant amount of one or more reaction gases supplied to the optical cavity 360 is converted into photon-activated species. It will be understood that photon-activated species include reactive radicals in the excited state, but photon-activated species may also include reactive radicals in the ground state and / or energy-conjugated reactive gases in the excited vibrational state.

[0049] In Figure 3A, the photon-activated species are generated in an optical cavity 360 separate from the processing chamber 310. In this configuration, the semiconductor processing apparatus 300 can be more easily maintained and serviced by the separate optical cavity 360. The photon-activated species may include excited-state reactive radicals that flow from the optical cavity 360 through the gas distributor 330 into the processing chamber 310. The photon-activated species may have a relatively long lifetime. Once formed, the photon-activated species may have a lifetime of about 1 second or more, about 5 seconds or more, or about 10 seconds or more. The lifetime of the excited-state reactive radical may correspond to the length of time before the excited-state reactive radical transitions to the ground state or recombines. The photon-activated species may include dissociated atoms / molecules that can eventually recombine. Fluorine-activated species, for example, may have a lifetime of more than 10 seconds. The photon-activated species may remain in the active state for a sufficient amount of time before recombining or transitioning to the ground state. In this way, a significant portion of the photon-activated species may remain active before recombination or transition to the ground state to etch one or more materials on the substrate 322, treat the surface of the substrate 322, or clean the internal surface of the processing chamber 310.

[0050] Figure 3B shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source for generating photon-activated species and an optical cavity between a gas distributor and a gas source, according to several other embodiments. In Figure 3B, the optical cavity 360 is located between the gas source 340 and the gas distributor 330. The optical cavity 360 is fluid-coupled to the gas source 340 to receive one or more reaction gases, which are in a ground state. The optical cavity 360 is fluid-coupled to the gas distributor 330 to deliver the photon-activated species to the gas distributor 330. The light source 350 is optically coupled to the optical cavity 360. The light source 350 is optically coupled to allow light to pass into the optical cavity 360. For example, the light source 350 may be introduced into the optical cavity 360 by passing light through a window 362.

[0051] The light source 350 may include an LED or an array of LEDs. An LED or an array of LEDs may emit radiation at discrete wavelengths or multiple discrete wavelengths, while an LED may emit radiation over a broadband range of discrete or continuous wavelengths. In Figure 3B, the array of LEDs may be arranged along the perimeter of the optical cavity 360 to increase the likelihood that one or more reaction gases will be exposed to radiation. In some cases, the LEDs may be arranged on the top and / or side surfaces of the optical cavity 360. The density and arrangement of the LEDs may be optimized to ensure that a significant amount of one or more reaction gases supplied to the optical cavity 360 is converted into photon-activated species. In some embodiments, the optical cavity 360 may include one or more mirrors or be coated with a reflective material (not shown). In some embodiments, the light source 350 is not limited to an LED or an array of LEDs and may include one or more broadband light sources, such as one or more lasers or arc discharge lamps.

[0052] In Figure 3B, the photon-activated species are generated in an optical cavity 360 separate from the processing chamber 310. In such a configuration, the semiconductor processing apparatus 300 is more easily maintainable and serviceable by the separate optical cavity 360. The photon-activated species may include excited-state reactive radicals that flow from the optical cavity 360 into the processing chamber 310 through the gas distributor 330. A significant portion of the photon-activated species may be active to etch one or more materials on the substrate 322, process the surface of the substrate 322, or clean the internal surface of the processing chamber 310 before recombining or transitioning to the ground state.

[0053] Figure 3C shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source for generating photon-activated species within a gas distributor, according to several embodiments. In Figure 3C, the gas distributor 330 simultaneously functions as an optical cavity for generating photon-activated species and delivering them to the processing chamber 310. Because the gas distributor 330 functions as an optical cavity, a separate optical cavity is not required in the semiconductor processing apparatus 300. A gas source 340 is fluid-coupled to the gas distributor 330, which receives one or more reaction gases, one or more of which are in a ground state. A light source 350 is optically coupled to the gas distributor 330. The light source 350 is optically coupled to allow light to pass into the gas distributor 330. For example, the light source 350 may be introduced into the gas distributor 330 by passing light through a window 332.

[0054] The interior of the gas distributor 330 may include one or more mirrors or be coated with a reflective material 334. The mirrors or reflective material 334 may exhibit high reflectivity in appropriate spectra (e.g., UV spectrum, visible light spectrum, IR spectrum). Radiation emitted from the light source 350 may be repeatedly reflected inside the gas distributor 330 to increase the likelihood that one or more reaction gases will be exposed to the radiation. The reflective coating or mirrors reduce residence time and increase optical path length, thereby ensuring that a considerable amount of one or more reaction gases supplied to the gas distributor 330 are converted into photon-activated species.

[0055] In Figure 3C, the photon-activated species are generated in a gas distributor 330 fluid-coupled to the processing chamber 310. In this configuration, the photon-activated species can be uniformly distributed from the gas distributor 330 to the processing chamber 310. The photon-activated species may include excited-state reactive radicals flowing from the gas distributor 330 into the processing chamber 310. A significant portion of the photon-activated species may be active before recombination or transition to the ground state to etch one or more materials on the substrate 322, treat the surface of the substrate 322, or clean the internal surface of the processing chamber 310.

[0056] Figure 3D shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source for generating photon-activated species within a gas distributor, according to several other embodiments. In Figure 3D, the gas distributor 330 simultaneously functions as an optical cavity for generating photon-activated species and delivering them to the processing chamber 310. Because the gas distributor 330 functions as an optical cavity, a separate optical cavity is not required in the semiconductor processing apparatus 300. A gas source 340 is fluid-coupled to the gas distributor 330, which receives one or more reaction gases, one or more of which are in a ground state. A light source 350 is optically coupled to the gas distributor 330. The light source 350 is optically coupled to allow light to pass into the gas distributor 330. For example, the light source 350 may be introduced into the gas distributor 330 by passing light through a window 332.

[0057] The light source 350 may include an LED or an array of LEDs. An LED or array of LEDs may emit radiation at discrete wavelengths or multiple discrete wavelengths, while an LED may emit radiation over a broadband range of discrete or continuous wavelengths. The array of LEDs may be arranged around the gas distributor 330 to increase the likelihood that one or more reaction gases are exposed to radiation. In some cases, the LEDs may be arranged on the side surfaces of the gas distributor 330. The density and arrangement of the LEDs may be optimized to ensure that a significant amount of one or more reaction gases supplied to the gas distributor 330 are converted into photon-activated species. In some embodiments, the gas distributor 330 may include one or more mirrors or be coated with a reflective material (not shown). In some embodiments, the light source 350 is not limited to an LED or an array of LEDs and may include one or more broadband light sources, such as one or more lasers or arc discharge lamps.

[0058] In Figure 3D, the photon-activated species are generated in a gas distributor 330 fluid-coupled to the processing chamber 310. In this configuration, the photon-activated species can be uniformly distributed from the gas distributor 330 to the processing chamber 310. The photon-activated species may include excited-state reactive radicals flowing from the gas distributor 330 into the processing chamber 310. A significant portion of the photon-activated species may be active before recombination or transition to the ground state to etch one or more materials on the substrate 322, treat the surface of the substrate 322, or clean the internal surface of the processing chamber 310.

[0059] Figure 3E shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source for generating photon-activated species within a processing chamber, according to several embodiments. In Figure 3E, the processing chamber 310 simultaneously functions as an optical cavity for generating photon-activated species and for processing the substrate 322 or cleaning the internal surface of the processing chamber 310. Because the processing chamber 310 functions as an optical cavity, a separate optical cavity is not required in the semiconductor processing apparatus 300. A gas source 340 is fluid-coupled to a gas distributor 330, which receives one or more reaction gases, one or more of which are in a ground state. A light source 350 is optically coupled to the processing chamber 310. The light source 350 is optically coupled to allow light to pass into the processing chamber 310. For example, the light source 350 may transmit light through a window 312 into the processing chamber 310.

[0060] The interior of the processing chamber 310 may include one or more mirrors or be coated with a reflective material 314. The mirrors or reflective material 314 may exhibit high reflectivity in appropriate spectra (e.g., UV spectrum, visible light spectrum, IR spectrum). Radiation emitted from the light source 350 may be repeatedly reflected inside the processing chamber 310 to increase the likelihood that one or more reaction gases will be exposed to the radiation. The reflective coating or mirrors reduce residence time and increase optical path length, thereby ensuring that a considerable amount of one or more reaction gases supplied to the processing chamber 310 are converted into photon-activated species.

[0061] In Figure 3E, the photon-activated species are generated directly within the processing chamber 310. In such a configuration, the photon-activated species are generated as close as possible to the internal surface of the substrate 322 and / or the processing chamber 310 for maximum efficiency. By generating the photon-activated species directly within the processing chamber 310, the possibility of recombination of reactive radicals or transition of reactive radicals from the excited state to the ground state is minimized. Thus, a significant portion of the photon-activated species may be active to etch one or more materials on the substrate 322, treat the surface of the substrate 322, or clean the internal surface of the processing chamber 310 before recombination or transition to the ground state.

[0062] Figure 3F shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source for generating photon-activated species within a processing chamber, according to several other embodiments. In Figure 3F, the processing chamber 310 simultaneously functions as an optical cavity for generating photon-activated species and for processing the substrate 322 or cleaning the internal surface of the processing chamber 310. Because the processing chamber 310 functions as an optical cavity, a separate optical cavity is not required in the semiconductor processing apparatus 300. A gas source 340 is fluid-coupled to a gas distributor 330, which receives one or more reaction gases. One or more reaction gases are in a ground state. A light source 350 is optically coupled to the processing chamber 310. The light source 350 is optically coupled to allow light to pass into the processing chamber 310. For example, the light source 350 may transmit light through a window 312 into the processing chamber 310.

[0063] The light source 350 may include an LED or an array of LEDs. An LED or array of LEDs may emit radiation at discrete wavelengths or multiple discrete wavelengths, while an LED may emit radiation over a broadband range of discrete or continuous wavelengths. The array of LEDs may be arranged around the perimeter of the processing chamber 310 to increase the likelihood that one or more reaction gases will be exposed to radiation. In some cases, the LEDs may be arranged on the side surfaces or chamber walls of the processing chamber 310. The density and arrangement of the LEDs may be optimized to ensure that a significant amount of one or more reaction gases supplied to the processing chamber 310 is converted into photon-activated species. In some embodiments, the processing chamber 310 may include one or more mirrors or be coated with a reflective material (not shown). In some embodiments, the light source 350 is not limited to an LED or an array of LEDs and may include one or more broadband light sources, such as one or more lasers or arc discharge lamps.

[0064] In Figure 3F, the photon-activated species are generated directly within the processing chamber 310. In such a configuration, the photon-activated species are generated as close as possible to the internal surface of the substrate 322 and / or the processing chamber 310 for maximum efficiency. By generating the photon-activated species directly within the processing chamber 310, the possibility of recombination of reactive radicals or transition of excited reactive radicals to the ground state is minimized. Thus, a significant portion of the photon-activated species can be active to etch one or more materials on the substrate 322, process the surface of the substrate 322, or clean the internal surface of the processing chamber 310 before recombination or transition to the ground state.

[0065] Figure 5 shows a schematic diagram of an exemplary optical cavity, according to several embodiments, which includes an optical cell having a light source and a gas cell through which one or more reaction gases pass. The optical cavity 500 may be implemented in a semiconductor processing apparatus, such as one of the semiconductor processing apparatuses described in Figures 3A to 3F and Figures 7A to 7B. The optical cavity 500 represents a space or volume adapted for the generation of photon-activated species, through which radiation from a light source is received.

[0066] The optical cavity 500 includes an optical cell 510 and a gas cell 520. The optical cell 510 may represent a structural component containing one or more light sources 512. In some cases, the optical cell 510 may further include windows and / or transparent materials to allow radiation emitted from one or more light sources 512 to pass through. In some cases, the optical cell 510 may further include mirrors and / or reflective materials to reflect radiation emitted from one or more light sources 512. The reflective walls or surfaces can confine photons within the optical cavity 500 to increase light absorption. This allows the reaction gas to encounter photons as many times as possible within the optical cavity 500.

[0067] The gas cell 520 can represent a structural component through which the reaction gas passes. In some embodiments, the gas cell 520 can be fluidly coupled to the processing chamber. The optical cell 510 can be positioned relative to the gas cell 520 so that radiation from one or more light sources 512 can be absorbed by the reaction gas in the gas cell 520. The gas cell 520 may have a gas inlet 522 configured to receive the reaction gas and a gas outlet 524 configured to discharge the reaction gas. The reaction gas that exits the gas cell 520 at the outlet 524 can be photon-activated. In some embodiments, the gas cell 520 may be made of a material that is transparent or substantially transparent to radiation from one or more light sources 512. For example, the walls of the gas cell 520 may include silicon dioxide (e.g., quartz) or aluminum oxide (e.g., sapphire).

[0068] In some embodiments, the optical cell 510 has the same geometric shape as the gas cell 520. In some embodiments, the optical cell 510 has a different geometric shape from the gas cell 520. The optical cell 510 may have a different geometric shape from the gas cell 520 to facilitate manufacturing. The optical cell 510 may have a cylindrical, rectangular, octagonal, or other polygonal geometric shape. The gas cell 520 may have a cylindrical, rectangular, octagonal, or other polygonal geometric shape. As shown in Figure 5, the optical cell 510 has a rectangular geometric shape, and the gas cell 520 has a cylindrical geometric shape.

[0069] One or more light sources 512 may be disposed, placed, mounted, attached, or positioned on one or more surfaces of the optical cell 510. One or more light sources 512 may direct radiation into the gas cell 520 so that the reaction gas interacts with the photons of radiation in the gas cell 520. In Figure 5, one or more light sources 512 may include an array of LEDs. In some embodiments, the array of LEDs may include a first LED that emits radiation at a first wavelength, a second LED that emits radiation at a second wavelength, and so on. Thus, the array of LEDs may be configured to emit radiation at different wavelengths. In one example, the array of LEDs may include multiple banks of LED arrays, each bank of which may include several LEDs arranged in the array. In the example shown in Figure 5, one or more light sources 512 may include a 5 × 3 array of LED banks, each LED bank of which includes 10 LEDs, and thus one or more light sources 512 may include 150 LEDs on the surface of the optical cell 510.

[0070] Mirrors or other reflective materials may be disposed, placed, mounted, fitted, or positioned within the optical cavity 500. The mirrors or other reflective materials may be inside and / or outside the gas cell 520. In some embodiments, the mirrors or other reflective materials are located outside the gas cell 520. For example, the mirrors or other reflective materials may be located on one or more surfaces of the optical cell 510. In such designs, the mirrors or other reflective materials can avoid exposure to reactive gases (e.g., corrosive gases) that could reduce the reflectivity of the mirrors or other reflective materials. However, this may result in higher optical loss compared to mirrors or other reflective materials located inside the gas cell 520. Higher optical loss may be due to the radiation emitted from one or more light sources 512 and the reflected radiation from the mirrors or other reflective materials encountering more interfaces as they pass through the gas cell 520. To facilitate reflected radiation passing through the gas cell 520, the gas cell 520 may be made of a transparent material, which contributes to higher optical loss as the radiation encounters more interfaces.

[0071] Figures 6A to 6E show various designs of an optical cavity that includes a gas cell separate from the optical cell. The designs in Figures 6A to 6E are merely illustrative, and it should be understood that various modifications or changes can be made to alternative designs. Therefore, these examples are illustrative and not limiting.

[0072] Figure 6A shows a schematic diagram of an exemplary optical cavity including a rectangular optical cell and a cylindrical gas cell according to several embodiments. The rectangular optical cell 602 surrounds the cylindrical gas cell 604. The rectangular optical cell 602 may include a plurality of LEDs 606 located on one or more surfaces of the rectangular optical cell 602 and arranged around the cylindrical gas cell 604. The plurality of LEDs 606 may be configured to illuminate the cylindrical gas cell 604. In some embodiments, the plurality of LEDs 606 may be arranged as a string or array of LEDs on multiple surfaces of the rectangular optical cell 602. The reactive gas flowing through the cylindrical gas cell 604 may be activated by radiation emitted from the plurality of LEDs 606. In some embodiments, reflective mirrors (not shown) may be located outside and around the cylindrical gas cell 604. For example, the reflective mirrors may be located on one or more surfaces of the rectangular optical cell 602. In some embodiments, the rectangular optical cell 602 may be a cube with a reflective surface. The cylindrical gas cell 604 may be formed from a transparent or substantially transparent material such as quartz. Reflective mirrors can cause multiple reflections, thus increasing the effective path length and thus increasing the LED light power used to activate the reaction gas in the cylindrical gas cell 604.

[0073] Figure 6B shows a schematic diagram of an exemplary optical cavity including a cylindrical optical cell and a cylindrical gas cell according to several embodiments. The cylindrical optical cell 612 surrounds the cylindrical gas cell 614. The cylindrical optical cell 612 may include a plurality of LEDs 616 located at one end of the cylinder of the cylindrical optical cell 612. Additionally or alternatively, the plurality of LEDs 616 may be located along the curved surface of the cylinder of the cylindrical optical cell 612. The reactive gas flowing through the cylindrical gas cell 614 can be activated by radiation emitted from the plurality of LEDs 616. In some embodiments, reflective mirrors (not shown) can be placed outside and around the cylindrical gas cell 614. For example, the reflective mirrors may be located on the curved surface of the cylindrical optical cell 612 or at one end of the cylinder of the cylindrical optical cell 612. The cylindrical gas cell 614 may be formed of a transparent or substantially transparent material such as quartz. The reflective mirror can cause multiple reflections, thus increasing the effective path length and thus increasing the LED light power used to activate the reaction gas in the cylindrical gas cell 614.

[0074] Figure 6C shows a schematic diagram of an exemplary optical cavity including an octagonal optical cell and a cylindrical gas cell according to several embodiments. The octagonal optical cell 622 surrounds the cylindrical gas cell 624. The octagonal optical cell 622 may include a plurality of LEDs 626 located on one or more sides of the octagonal optical cell 622 and arranged around the cylindrical gas cell 624. The plurality of LEDs 626 may be configured to illuminate the cylindrical gas cell 624. In some cases, the plurality of LEDs 626 can be arranged as a string or array of LEDs on one or more surfaces of the octagonal optical cell 622. The reactive gas flowing through the cylindrical gas cell 624 can be activated by radiation emitted from the plurality of LEDs 626. In some embodiments, reflective mirrors (not shown) can be placed outside and around the cylindrical gas cell 624. For example, the reflective mirrors may be located on one or more sides of the octagonal optical cell 622, or they may be formed on all sides of the octagonal optical cell 622. The cylindrical gas cell 624 may be formed of a transparent or substantially transparent material such as quartz. The reflective mirrors can cause multiple reflections, thus increasing the effective path length and thus increasing the LED light power used to activate the reaction gas in the cylindrical gas cell 624.

[0075] Figure 6D shows a schematic diagram of an exemplary optical cavity including a circular window located above a gas cell, according to several embodiments. The circular window 632 is located above the gas cell 634. The circular window 632 includes a plurality of LEDs 636 located on the main surface of the circular window 632. The plurality of LEDs 636 may include several substrates or banks of LEDs arranged across the main surface of the circular window 632. For example, the LED substrates may be arranged concentrically, and each LED substrate may contain a plurality of LEDs. In one example, the plurality of LEDs 636 may include 18 substrates of 12 LEDs each. The plurality of LEDs 636 illuminate the gas cell 634 located below the circular window 632. The reactive gas flowing through the gas cell 634 can be activated by the radiation emitted from the plurality of LEDs 636. In some embodiments, a reflective mirror (not shown) may be located inside or outside the gas cell 634. However, in some other embodiments, a reflective mirror is not used. Multiple LEDs 636 may emit radiation into the gas cell 634 without the help of a reflective mirror or surface to activate the reaction gas in the gas cell 634. Thus, radiation from multiple LEDs 636 may pass through the gas cell 634 only once. In some cases, the gas cell 634 may form a space between a circular window 632 and a showerhead 638. The circular window 632 may be positioned above the showerhead 638, and photon-activated species of the reaction gas may pass through the showerhead 638 into the processing chamber.

[0076] Figure 6E shows a schematic diagram of an exemplary optical cavity including an annular window surrounding a gas cell, according to several embodiments. Rather than a circular window located above the gas cell 644, the annular window 642 is positioned around the gas cell 644, along its periphery. The annular window 642 may be molded as a ring. The annular window 642 may include a plurality of LEDs 646 arranged around the annular window 642. The annular window 642 may be formed from a transparent or substantially transparent material such as quartz or sapphire. The plurality of LEDs 646 arranged around the annular window 642 may illuminate the gas cell 644. The reactive gas flowing through the gas cell 644 may be activated by radiation emitted from the plurality of LEDs 646. The radial arrangement of the LEDs 646 around the ring (i.e., the annular window 642) allows for an increase in path length for improved light absorption by the reactive gas. In some embodiments, a reflective mirror (not shown) may be located inside or outside the gas cell 644. In some embodiments, reflective mirrors are not used. The embodiment in Figure 6E may be similar to the embodiment in Figure 6D, except that the window with the multiple LEDs 646 is located around the gas cell 644 rather than above it. The gas cell 644 may be formed of a transparent or substantially transparent material such as quartz or sapphire to facilitate the transmission of radiation from the multiple LEDs 646 through the gas cell 644.

[0077] Any of the optical cavities described above in Figures 6A to 6E may be incorporated into a semiconductor processing apparatus, such as the semiconductor processing apparatus described in Figures 1, 2, 3A to 3F, and 7A to 7B, and the optical cavity may include a specific design of an optical cell optically coupled to a gas cell. The semiconductor processing apparatus may include a processing chamber, a gas distributor fluidly coupled to the processing chamber, and a substrate support within the processing chamber configured to support a semiconductor substrate. The reaction gas may flow through the gas cell of the optical cavity, and at least one of the reaction gases is converted into a photon-activated species by irradiation. One or more light sources (e.g., LEDs) on the optical cell may irradiate the gas cell to generate the photon-activated species. As discussed above, the optical cavity may be located upstream of the gas distributor, incorporated into the gas distributor, or incorporated into the processing chamber. Figures 7A to 7B show an exemplary semiconductor processing apparatus including a processing chamber, a gas distributor, and an optical cavity located above or upstream of the gas distributor. Figure 7A shows a semiconductor processing apparatus used to generate photon-activated species within an optical cavity. Figure 7B shows a semiconductor processing apparatus used for direct irradiation of a semiconductor substrate within a processing chamber.

[0078] Figure 7A shows a schematic diagram of an exemplary semiconductor processing apparatus, according to several embodiments, including a light source positioned above a gas distributor, which may be configured to generate photon-activated species within an optical cavity. The semiconductor processing apparatus 700 includes a processing chamber 710 and a substrate support 720 configured to support a semiconductor substrate 722 within the processing chamber 710. The substrate support 720 may be a pedestal or an electrostatic chuck. The semiconductor processing apparatus 700 further includes a gas distributor 730, such as a showerhead, which is in fluid communication with the processing chamber 710. The gas distributor 730 may be configured to distribute process gases and reactants into the processing chamber 710. In some embodiments, the gas distributor 730 may be a plate having a plurality of through-holes through which process gases and reactants flow. In some embodiments, the gas distributor 730 may include a transparent or substantially transparent material, such as quartz or sapphire, to allow electromagnetic radiation to pass through the gas distributor 730 into the processing chamber 710.

[0079] The semiconductor processing apparatus 700 may further include a gas source 740. The gas source 740 may be located upstream of the gas distributor 730 and may supply one or more reaction gases to the optical cavity 760. One or more reaction gases may include ground-state atomic or molecular gases. In some embodiments, one or more reaction gases include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or a combination thereof. The gas source 740 may be in fluid communication with the optical cavity 760. One or more reaction gases flow from the gas source 740 through the optical cavity 760 to the gas distributor 730.

[0080] The semiconductor processing apparatus 700 may further include a light source 750. The light source 750 may be optically coupled to an optical cavity 760. The light source 750 may be configured to emit radiation into the optical cavity 760 to impart energy to one or more reaction gases in the ground state to generate at least one photon-activated species of the reaction gases, and / or to excite the reaction gases. The light source 750 may be tunable. Specifically, the light source 750 may be tuned to a selected wavelength or a plurality of wavelengths to dissociate at least one of the reaction gases, impart energy to an excited oscillatory state, activate it to form a reactant radical, and / or excite the reactant radical from the ground state to an excited state. In some embodiments, the selected wavelength or a plurality of wavelengths may be tuned to the UV spectrum (100 to 400 nm). In some embodiments, the selected wavelength or a plurality of wavelengths may be tuned to the visible light spectrum (400 to 1000 nm). In some embodiments, the selected wavelength or a plurality of wavelengths may be tuned to the IR spectrum (above 1000 nm). In the IR spectrum, for example, the reaction gas may be energized into an excited vibrational state without undergoing dissociation. Additionally or alternatively, the light source 750 may be adjusted to a selected intensity. The selected intensity may be adjusted to control the energy distribution of one or more photon-activated species of the reaction gas. For example, the intensity can control the ratio of excited reactant radicals to ground reactant radicals.

[0081] In some embodiments, the light source 750 may include a laser. In some embodiments, the light source 750 may include a flash lamp. In some embodiments, the light source 750 may include multiple LEDs. Similar to the design in Figure 6D, the light source 750 may include multiple LEDs positioned above the optical cavity 760. In some embodiments, the light source 750 is positioned on a window 770, such as a circular window. The window 770 may include a transparent or substantially transparent material, such as quartz or sapphire. The multiple LEDs emit radiation through the window 770 into the optical cavity 760 toward the gas distributor 730. One or more reaction gases interact with the radiation in the optical cavity 760 to convert at least one of the reaction gases into a photon-activated species in the optical cavity 760.

[0082] In some embodiments, the optical cavity 760 may include one or more reflective mirrors or reflective surfaces. Radiation emitted from the light source 750 may be reflected inside the optical cavity 760 to increase the likelihood that one or more reaction gases will be exposed to the radiation. This can increase the optical path length and effective LED power for photon activation of one or more reaction gases. In some other embodiments, the optical cavity 760 does not include reflective mirrors or reflective surfaces. This may simplify manufacturing. This also avoids exposure of the mirrors or reflective surfaces to corrosive gases. Radiation emitted from the light source 750 may pass through the optical cavity 760 only once.

[0083] Photon-activated species generated in the optical cavity 760 may flow into the processing chamber 710 through the gas distributor 730. While photon-activated species include excited-state reactive radicals, it will be understood that photon-activated species may also include ground-state reactive radicals and / or energized-oscillating reaction gases. Without the aid of plasma, one or more reaction gases are activated by photons and used to clean the internal surface of the processing chamber 710 or to process the semiconductor substrate 722 within the processing chamber 710. Within the processing chamber 710, the photon-activated species function to etch one or more materials on the semiconductor substrate 722, process the surface of the semiconductor substrate 722, clean the surface of the semiconductor substrate 722, deposit one or more materials on the semiconductor substrate 722, carry out oxidation on the semiconductor substrate 722, carry out nitriding on the semiconductor substrate 722, atomic layer etching of the semiconductor substrate 722, or clean the internal surface of the processing chamber 710. The light source 750 may be tuned to a specific wavelength and / or intensity to control the energy distribution of one or more photon-activated species of reaction gases in order to influence the reactivity / selectivity of the reaction occurring on the semiconductor substrate 722 or the internal surface of the processing chamber 710.

[0084] Figure 7B shows a schematic diagram of an exemplary semiconductor processing apparatus, including a light source positioned above a gas distributor, according to several embodiments, the light source may be configured to irradiate a semiconductor substrate in the processing chamber. In some embodiments, the light source 750 is configured to directly expose the semiconductor substrate 722 to radiation of a selected wavelength and / or intensity. Direct irradiation or exposure to radiation may promote or inhibit surface reactions on the semiconductor substrate 722. In some embodiments, the radiation emitted from the light source 750 may pass through a gas distributor 730 to expose the semiconductor substrate 722 to radiation in the processing chamber 710. Instead of activating a reaction gas, the light source 750 may be configured to emit radiation at a selected wavelength and / or intensity for processing the semiconductor substrate 722. In some embodiments, the gas distributor 730 includes a transparent or substantially transparent material, such as quartz, sapphire, or other inert material, to facilitate the light transmission of radiation into the processing chamber 710.

[0085] In some embodiments, the light source 750 is tuned to a selected wavelength and / or intensity to promote or inhibit surface reactions on the semiconductor substrate 722. For example, the light source 750 may be tuned to a selected wavelength and / or intensity to avoid the generation of reactive radicals by dissociation. In fact, the selected wavelength and / or intensity can induce vibrational excitations in chemical species on the surface of the semiconductor substrate 722. Such vibrational excitations can occur with IR exposure, rather than with electronic excitations that can occur with UV exposure. Vibrational excitations can provide additional energy to the surface of the semiconductor substrate 722 to promote or inhibit surface reactions.

[0086] In some embodiments, the light source 750 is tuned to a selected wavelength and / or intensity to facilitate the desorption of by-products formed on the surface of the semiconductor substrate 722. For example, etching of one or more materials on the semiconductor substrate 722 may be performed using photon-activated species generated in an optical cavity 760 and flowing into a processing chamber 710. During and after the etching process, undesirable etching by-products may form on the surface of the semiconductor substrate 722. High temperatures are often required for the thermal desorption of etching by-products. However, the light source 750 may also be used to directly irradiate the semiconductor substrate 722 and may be tuned to a selected wavelength and / or intensity to facilitate the desorption of etching by-products. This can reduce the temperature required to perform the thermal desorption of etching by-products.

[0087] Figure 8 shows a schematic plan view of an exemplary light source, including multiple LEDs for emitting radiation at different wavelengths, according to several embodiments. Vibrational or electronic excitation of the chemical properties of different gases occurs at different wavelengths. Depending on the chemical properties of the reaction gases, the wavelength of the light source 800 can be adjusted to activate the reaction gases. In some embodiments, the light source 800 can emit radiation at a first wavelength to activate a first reaction gas, and then emit radiation at a second wavelength to activate a second reaction gas. The light source 800 can be adjusted to emit radiation at two or more different wavelengths.

[0088] As shown in Figure 8, the light source 800 may include a substrate having a plurality of LEDs 810, 820, 830, and 840. The light source 800 may include a plurality of first LEDs 810 configured to emit radiation of a first wavelength, a plurality of second LEDs 820 configured to emit radiation of a second wavelength, a plurality of third LEDs 830 configured to emit radiation of a third wavelength, and a plurality of fourth LEDs 840 configured to emit radiation of a fourth wavelength. The light source 800 may be configured to emit different discrete wavelengths. A specific wavelength may be selected based on the chemical properties of the reaction gas used in the semiconductor processing. If a gas mixture is included, the light source 800 may be configured to tune to the selected wavelength such that only a portion of the reaction gas in the gas mixture is converted into a photon-activated species. If a continuous introduction of reaction gases is included, the light source 800 may be configured to tune to a first wavelength to photon-activate a first reaction gas, and then the light source 800 may be configured to tune to a second wavelength to photon-activate a second reaction gas. In some cases, multiple wavelengths can be turned on depending on the needs of the process. For example, the wavelength of light source 800 can be UV, visible, or IR spectrum.

[0089] In some embodiments, different LEDs 810, 820, 830, and 840, configured to emit radiation at different wavelengths, are integrated on a substrate as a single light source. In some embodiments, the light source 800 may include a power connector 850 for supplying power to the LEDs 810, 820, 830, and 840. In some embodiments, the light source 800 may further include a thermistor 860 for maintaining the LEDs 810, 820, 830, and 840 within a desired temperature range and limiting the effects of overheating. In some embodiments, the light source 800 may further include a transient voltage suppression diode 870 used to protect against electrostatic discharge (ESD).

[0090] Use of photon-activated species in semiconductor processing Plasma-activated species, including high-energy ions and radicals, can readily damage substrate layers and materials. Plasma can be characterized by a broad energy distribution, which is less suitable for targeted applications. In contrast, photon-activated species include reactive radicals in ground or excited energy states. Photon-activated species may also, additionally or alternatively, include molecular gases in excited vibrational energy states. Generally, photon-activated species do not contain high-energy species that readily damage substrate layers and materials. Photon-activated species can be characterized by a narrower energy distribution for more targeted applications. Photon-activated species may be used to etch one or more materials in a semiconductor substrate or to treat the surface of a semiconductor substrate.

[0091] Photon-activated species may be used to control the amount of reactive species in advanced oxide applications. In some embodiments, ozone is used as silicon oxide (SiO₂). xOxide materials may be used as oxidizing agents in the formation of oxide materials such as silicon oxide. The oxide material may include thermal oxides and / or fluid oxides. It may be desirable to etch such oxide materials to flatten the etching front, minimize or eliminate isolated / high-density feature loading, eliminate seam blowout little or no, and have a selectivity of fluid oxides to thermal oxides of about 1:1. Oxidizing agents such as ozone decompose readily, and it is often difficult to control the amount of decomposition that occurs. By introducing a tunable light source, it is possible to control the amount of O2 radicals relative to O radicals. Oxygen-based radicals can be generated as photon-activated species. The ratio of O2 radicals to O radicals can be adjusted, or the ratio of O2 radicals to molecular O2 can be adjusted. Selected wavelengths and / or intensities of radiation emitted from a tunable light source can control ozonolysis. This can be useful in controlling the oxidation of oxide materials such as silicon oxide. In some embodiments, photon-activated hydrogen species may be used when etching oxide materials such as silicon oxide rather than other materials such as silicon and silicon nitride. Hydrogen-based radicals such as H2 radicals or H radicals can be generated as photon-activated species. The ratio of H2 radicals to H radicals or H radicals to molecular H2 may be adjusted. Selected wavelengths and / or intensities of radiation emitted from an adjustable light source can control hydrogen-based radical generation. This can be useful for controlling the etching of silicon oxide more than silicon and silicon nitride. In some cases, ozone and hydrogen (O3 / H2) can be introduced as a gas mixture for the oxidation of silicon and etching of silicon oxide, and the decomposition of O3 and H radical generation can be controlled by photon activation. In some cases, nitrite (HNO2) can be used to etching silicon oxide more than silicon and silicon nitride. Etching of silicon oxide can produce various etching byproducts. Examples of etching byproducts include salt byproducts such as ammonium hexafluorosilicate ((NH4)SiF6).Desorption of etching byproducts may be assisted by wafer irradiation using a tunable light source. The tunable light source can directly expose the semiconductor substrate to radiation that promotes byproduct desorption and lowers the temperature required to achieve desorption.

[0092] In some embodiments, halogen species are used as etching agents for silicon. Silicon-on-insulator (SOI), polysilicon (poly-Si), and amorphous silicon (a-Si) are examples of silicon materials that can be etched using etching agents containing halogen species. Etching of silicon is more likely to occur than with other materials such as silicon oxide (e.g., thermal oxide) and silicon nitride. Etching of silicon can be useful for a variety of applications, including dummy poly removal (DPR). Dummy poly removal can be used in the fabrication of gate structures. It may be desirable to etch silicon at a high etching rate, with good selectivity, and in a way that avoids pitting corrosion. In some embodiments, the silicon etching agent may contain halogen gases such as fluorine (F2) or chlorine (Cl2). It is possible to control the amount of F2 radicals or F radicals, or Cl2 radicals or Cl radicals, using an adjustable light source. A tunable light source can emit radiation at a wavelength and / or intensity selected for targeted bond dissociation, such that the ratio of F2 / F radicals to molecular F2 can be adjusted, or the ratio of Cl2 / Cl radicals to molecular Cl2 can be adjusted. This provides tunability with respect to etching of silicon materials. In some embodiments, the silicon etchant may include a mixture of gases. The gas mixture may include one or more halogen species (e.g., F2, Cl2) combined with one or more nitrogen-containing species, oxygen-containing species, and / or carbon-containing species. An example of a carbon-containing species is methane, and an example of a nitrogen-containing species is nitric oxide; an exemplary gas mixture may include NO / F2 / Cl2 / CH4. In the gas mixture, the tunable light source can selectively target a particular reactive gas for dissociation to generate reactive radicals. In some cases, the tunable light source can target the dissociation of F2 to generate fluorine radicals. In some other cases, the tunable light source can target the dissociation of CH4 to generate alkyl radicals.While plasma energizes and activates all species in a gas mixture, a tunable light source can be configured to energize and activate only specific species in the gas mixture. This can provide greater control over the etching and selectivity of etching materials such as silicon.

[0093] In some embodiments, selective etching of the target material may involve a gas mixture with an additive. One such additive may include an amine, which has the chemical formula NR 1 R 2 It can refer to R, in the formula 1 and R 2 Each of these is independently selected from hydrogen, aliphatic, heteroaliphatic, haloaliphatic, haloheteroaliphatic, aromatic, or any combination thereof as defined herein, or R 1 and R 2These atoms, together with the nitrogen atom to which they are bonded, form a heterocycline group. In some embodiments, the amine is pyridine. The etching selectivity of the gas mixture can be adjusted by the amount of additive in the gas mixture. For example, very high selectivity of silicon oxide over silicon nitride can be achieved by controlling the halogen source:additive ratio (e.g., HF:pyridine), or very high selectivity of silicon oxide over silicon and silicon germanium (SiGe) can be achieved by controlling the halogen source:additive ratio (e.g., HF:pyridine). In some embodiments, very high selectivity of silicon over silicon nitride, field oxide, and silicon germanium can be achieved by controlling the relative amounts of F2 / HF / additive. Typically, additives such as pyridine react vigorously with F2 and HF in the gas phase. A tunable light source can target the activation of the additive to limit its reactivity with F2 and HF in the gas phase. In particular, a tunable light source can target the activation of additives such as pyridine at a location adjacent to the surface of the semiconductor substrate. In this way, when the additive is close enough to the substrate surface, the activation of the additive can occur. Additives can remain relatively inert up to that point. This can provide targeted activation in terms of timing and position, resulting in greater control over the etching and selectivity of the material. One application of such targeted additive (e.g., amine) activation near the substrate surface is found in back-side power supply networks (BSPDNs).

[0094] In some embodiments, selective etching of a target material may involve a gas mixture with one or more fluorine-containing gases. The fluorine-containing gas may be used to etch silicon, such as silicon-on-insulators, polysilicon, and amorphous silicon, more than other materials, such as silicon germanium, thermal oxides, and silicon nitride. It may be desirable to etch silicon with high etching rates and high selectivity for some of the aforementioned materials. Etching rates and selectivity may be controlled by controlling the amount of fluorine-containing gas in the gas mixture. In one example, the relative amounts of germanium tetrafluoride and fluorine (GeF4 / F2) can be adjusted to shift the equilibrium to etch silicon more than silicon germanium. In another example, the amount of fluorine relative to ammonia and methane (F2 / NH3 / CH4) can be adjusted to control the selectivity of silicon for other materials. Targeted bond dissociation may be performed using an adjustable light source to generate a specific type of reactive radical, such as a fluorine-containing gas, while avoiding the activation / dissociation of other gases in the gas mixture. Therefore, not only is the relative amount of fluorine-containing gas in the gas mixture controlled, but the relative amount of fluorine-containing radicals in the gas mixture is also controlled. This can also be applied in the context of back-side power supply networks and other semiconductor processing applications.

[0095] In some embodiments, one or more fluorine-containing gases may be used for selective silicon nitride etching. Silicon nitride can be etched using a fluorine-containing gas such as F2, where F2 is NO xIt may be combined with an oxidizing gas such as NO2, NO, N2O or a hydrogen-containing gas such as CH4 or H2. Historically, plasmas of F2 / NO gas mixtures have been used for selective etching of silicon nitride. As an example, silicon nitride may be etched more than other materials such as silicon oxide (e.g., thermal oxides), silicon, and silicon germanium. It may be desirable to achieve highly selective and controllable etching with low roughness. A tunable light source can generate photon-activated species of fluorine-containing gases used for selective silicon nitride etching. Fluorine radicals can combine to produce FNO or FNO2 species. Additionally or alternatively, a tunable light source can generate photon-activated species of oxidizing gases used for selective silicon nitride etching. Radiation emitted from a tunable light source can generate, for example, NO to produce nitrogen radicals and oxygen radicals. x This allows for the separation of these elements. Depending on the wavelength of the emitted radiation, specific reactive radicals can be generated in the F2 / NO gas mixture to control the selectivity and / or etching rate of silicon nitride etching.

[0096] In some embodiments, halogenated gases may be used for etching metals or metal oxides. Etching of metals or metal oxides is typically performed using atomic layer etching (ALE) processes. Atomic layer etching processes are effective in terms of selectivity but can be very slow in terms of etching rate. Plasma-based etchants can be very fast in terms of etching rate but can be very insufficient in terms of selectivity. It may be desirable to increase etching per cycle while maintaining high selectivity. A tunable light source can be used to adjust the amount of halogenated radicals generated in the etchant to selectively etch the metal or metal oxide. In one example, hafnium oxide can be etched using a mixture of hydrogen fluoride and boron trichloride (HF / BCl3) or a mixture of fluorine and boron trichloride (F2 / BCl3). In another example, molybdenum oxide can be etched using a mixture of hydrogen fluoride and ozone (HF / O3) or a mixture of fluorine and ozone (F2 / O3). Hydrogen fluoride, boron trichloride, and ozone can all be targeted by a tunable light source for generating reactive radicals to selectively etch metal oxides. Hafnium oxide can selectively etch other materials such as silicon, silicon nitride, silicon oxide, and titanium nitride. Molybdenum oxide can selectively etch other materials such as silicon, silicon nitride, and silicon oxide. The tunable light source can generate photon-activated species for etching metals or metal oxides, achieving high etching rates and high selectivity. In some cases, the tunable light source can also be used to directly irradiate semiconductor substrates to promote or inhibit surface reactions. For example, the tunable light source can directly expose a semiconductor substrate to radiation to promote the desorption of etching byproducts. Fluorinated byproducts can be generated during the etching of metals or metal oxides. These fluorinated byproducts can be desorbed from the semiconductor substrate surface at high temperatures (e.g., above about 300°C).However, with the help of direct irradiation from an adjustable light source, desorption of etching byproducts can occur at lower temperatures (e.g., below approximately 275°C).

[0097] In some embodiments, selective etching of silicon-germanium against other materials such as silicon may be achieved in the fabrication of full-gate (GAA) devices. Silicon-germanium may also be used as a sacrificial material when forming channels in GAA devices. Many techniques have been developed for the selective removal of silicon-germanium. Existing plasma-driven techniques rely on fluorine radicals generated from fluorine-containing gases such as nitrogen trifluoride (NF3), carbon tetrafluoride (CF4), sulfur hexafluoride (SF6), silicon tetrafluoride (SiF4), fluorine (F2), or combinations thereof. Thermal-driven techniques often rely on fluorine (F2), which can provide improved selectivity, but can result in non-uniform etching rates that can lead to the formation of non-ideal etching fronts within the silicon-germanium material. Different portions of silicon-germanium within a layer may have different compositions, and these compositions can vary with respect to the concentrations of Si and Ge, as well as other elements that may be present in the layer. These compositional differences can result in non-uniform etching fronts. It may be desirable to etch silicon-germanium rather than silicon at a relatively flat etching front while minimizing silicon loss. Plasma-driven processes utilize high concentrations of fluorine radicals, which can achieve a relatively flat etching front. However, plasma-driven processes utilizing high concentrations of fluorine radicals can also result in high silicon loss. On the other hand, thermal-driven processes utilizing molecular F2 can minimize silicon loss but may result in a non-uniform etching front. By using a tunable light source, it is possible to control the ratio of fluorine radicals to molecular F2 in a gas mixture containing a fluorine-containing gas. In other words, the amount of fluorine radicals relative to molecular F2 can be carefully controlled using a tunable light source configured to emit radiation at a selected wavelength and / or intensity. This makes it possible to strike a perfect balance to control SiGe:SiGe selectivity and Si:SiGe selectivity while minimizing silicon loss.In this way, the photon-activated species of the fluorine-containing gas can be adjusted to achieve a flat etching front with minimal silicon loss. The gas mixture for selective silicon-germanium etching of silicon may contain one or more fluorine-containing gases. In some examples, the gas mixture contains fluorine (F2 / NO2) combined with nitrogen dioxide. In some examples, the gas mixture contains fluorine (F2 / NO) combined with nitric oxide. In some examples, the gas mixture contains sulfur hexafluoride (SF6). In some examples, the gas mixture contains fluorine (F2 / SiF4) combined with silicon tetrafluoride. In some examples, the gas mixture contains fluorine (F2) alone. In some examples, the gas mixture contains fluorine (F2 / Cl2) combined with chlorine. In some examples, the gas mixture contains fluorine (F2 / CH3F) combined with fluoromethane. In some examples, the gas mixture contains fluorine (F2 / N2) combined with nitrogen. 2- ) include. In some examples, the gas mixture includes fluorine (F2 / O2) combined with oxygen. In some other examples, the gas mixture may include a chlorine-containing gas such as molecular chlorine (Cl2). An adjustable light source can control the amount of reactive radicals generated in the gas mixture to optimize selectivity during etching and achieve a flat etching front.

[0098] Using photon-activated species generated from a tunable light source allows for control of the concentration or ratio of reactive species (e.g., reactive radicals) in a gas mixture, provides targeted bond dissociation, controls the decomposition of reactive species, provides targeted activation of specific reactive species near the wafer surface, facilitates the desorption of etching byproducts, improves material selectivity during etching, and offers many other advantages not typically available in plasma-based or thermal-based processes. While the generation of photon-activated species from a tunable light source can be achieved using any one of the semiconductor processing apparatuses of this disclosure, it will be understood that the generation of photon-activated species from a tunable light source is not limited to the semiconductor processing apparatuses of this disclosure. Other configurations or modifications of the semiconductor processing apparatus may be used as designed by those skilled in the art.

[0099] Method for generating photon-activated species Figure 9A shows a flowchart of an exemplary method for generating photon-activated species for use in a processing chamber, according to several embodiments. The operation of process 900 may be carried out in a different order and / or with different, fewer, or additional operations. One or more operations of process 900 may be carried out using the apparatus described in any one of Figures 1, 2, 3A–3F, 5, 6A–6E, and 7A–7B. In some embodiments, the operation of process 900 may be implemented at least in part according to software stored on one or more non-temporary computer-readable media.

[0100] In block 910 of process 900, one or more reaction gases are flowed toward a gas distributor for distributing the one or more reaction gases into the processing chamber. One or more reaction gases are in the ground state. In other words, one or more reaction gases are in a non-excited energy state. One or more reaction gases may include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or a combination thereof. In some embodiments, one or more reaction gases include halogen gases such as fluorine, chlorine, bromine, or iodine. In some embodiments, one or more reaction gases include hydrogen halides such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, or hydrogen iodide. In some embodiments, one or more reaction gases include oxidizing gases such as oxygen, nitric oxide, nitrogen dioxide, nitrous oxide, nitrite, water, hydrogen peroxide, or ozone.

[0101] A processing chamber may be part of a semiconductor processing apparatus for processing one or more substrates. A gas distributor may be fluidly coupled to the semiconductor processing chamber. The gas distributor may be configured to receive one or more reaction gases from a gas source. The gas source may be located upstream of the gas distributor. The gas distributor may be a showerhead having one or more holes for delivering process gases into the processing chamber. The semiconductor processing apparatus may include a substrate support configured to support a semiconductor substrate. The substrate support may be a pedestal or an electrostatic chuck. In some embodiments, the semiconductor substrate may include one or more materials disposed on the substrate surface. Such materials may include oxide materials such as silicon oxide, silicon-on-insulators, polysilicon, and amorphous silicon, silicon nitride materials, metal or metal oxide materials, or silicon germanium materials. In some embodiments, the processing chamber may include one or more materials deposited on the internal surface of the processing chamber.

[0102] A semiconductor processing apparatus may include an optical cavity. An optical cavity may refer to a hardware component or structure of the semiconductor processing apparatus configured to receive radiation from a light source. In some embodiments, the optical cavity is located between a gas distributor and a gas source. In some embodiments, the optical cavity is integrated with the gas distributor. In some embodiments, the optical cavity is integrated with the processing chamber. In some embodiments, the optical cavity includes a window through which radiation emitted from a light source is transmitted. Thus, the light source is optically coupled to the optical cavity. In some embodiments, the optical cavity includes one or more mirrors and / or reflective materials configured to reflect radiation emitted from a light source.

[0103] In some embodiments, the optical cavity includes an optical cell and a gas cell. The optical cell may include a light source, and the gas cell may allow the flow of one or more reaction gases through it. The optical cell and the gas cell may have different geometric shapes from each other. In some examples, each of the optical cell and the gas cell has a cylindrical, rectangular, or octagonal geometric shape.

[0104] In block 920 of process 900, radiation is emitted from a light source at a selected intensity and a selected wavelength or wavelength range. The light source may be a tunable light source. The light source may be tunable according to its wavelength or wavelength range, intensity, and operating mode. The tunability of the light source affects the energy distribution of the photon-activated species. In some embodiments, the light source includes a laser, a lamp, or an LED. For example, the light source may include multiple LEDs. In some cases, the light source may include a broadband light source such as an arc discharge lamp. The light source may be configured to emit discrete wavelengths, a wavelength range, or a broadband of wavelengths.

[0105] The light source may be tunable according to its wavelength or wavelength range. In some embodiments, the light source is configured to emit radiation such as UV radiation, IR radiation, or visible light. In some embodiments, the light source is configured to emit radiation having a wavelength or wavelength range between about 100 nm and about 10 μm. The wavelength or wavelength range may be selected to obtain a desired energy distribution of radicals in their ground state or excited state. With the desired energy distribution, the light source may be tuned according to the selected wavelength to obtain a target etching rate and selectivity of one or more materials to be etched onto a semiconductor substrate. Some examples of target materials to be etched onto a semiconductor substrate are described above.

[0106] Additionally or alternatively, the light source may be adjustable according to its intensity. In some embodiments, the light source intensity is approximately 0.001 W / cm². 2 From approximately 100W / cm² 2 Between, or approximately 0.01 W / cm² 2 From approximately 10W / cm² 2 The range may be between these two ranges. The light source intensity may be selected to obtain a desired energy distribution of the radicals in their ground or excited states. With the desired energy distribution, the light source may be adjusted according to the selected light source intensity to obtain a target etching rate and selectivity for one or more materials to be etched onto the semiconductor substrate.

[0107] Additionally or alternatively, the light source may be adjustable according to its operating mode. In some cases, the light source may be configured to operate in continuous mode or pulsed mode. In some cases, the light source may be positioned to expose or not expose the surface of the semiconductor substrate by radiation.

[0108] In block 930 of process 900, one or more reaction gases are exposed to radiation emitted from a light source, thereby generating photon-activated species of one or more reaction gases within an optical cavity. The light source is optically coupled to the optical cavity. The light source may direct the emitted radiation into the optical cavity through an opening or window. The optical cavity may be integrated with a gas distributor, integrated with a processing chamber, or installed as a separate hardware component between the gas distributor and the gas source. One or more reaction gases flow into the optical cavity in the ground state and exit the optical cavity as photon-activated species.

[0109] Photon-activated species are generated independently of the plasma. One or more reaction gases may flow into the optical cavity in the ground state. After exposure to radiation from a light source, molecular species of one or more reaction gases may be decomposed and / or excited, thereby forming photon-activated species. In some embodiments, one or more reaction gases may be energized into an excited vibrational state. Photon-activated species may include reactive radicals in the ground state or excited state. Photon-activated species may exclude ions or ionized species. In some embodiments, reactive radicals in one or more energy states may be generated from halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or combinations thereof. As an example, if the reaction gas contains F2, the reactive radicals will be F2 after exposure to radiation from a light source. * or F * This may include: Since the energy and / or intensity of the light source can be adjusted, the energy and energy distribution of the reactive radicals in the ground state or excited state can be adjusted. Furthermore, reactive radicals for molecular fluorine (e.g., F2) * and F *The ratio of ) may be adjusted. This allows for more precise control for substrate processing or chamber processing applications. Examples of substrate processing or chamber processing applications are discussed above and are also shown in Figure 9B.

[0110] Figure 9B shows a flowchart of an exemplary method for generating and using photon-activated species in a processing chamber according to several embodiments. The operation of process 950 may be carried out in a different order and / or with different, fewer, or additional operations. One or more operations of process 950 may be carried out using the apparatus described in any one of Figures 1, 2, 3A–3F, 5, 6A–6E, and 7A–7B. In some embodiments, the operation of process 950 may be implemented at least in part according to software stored on one or more non-temporary computer-readable media.

[0111] Blocks 910, 920, and 930 of process 950 in Figure 9B are identical to blocks 910, 920, and 930 of process 900 in Figure 9A. For brevity, the descriptions related to blocks 910, 920, and 930 will not be repeated here. Once photon-activated species are generated in the optical cavity in block 930, these species can be utilized to carry out various processing steps such as etching, surface treatment, or chamber cleaning.

[0112] In block 940 of process 950, one or more materials on a semiconductor substrate are etched, the surface of the semiconductor substrate is treated, the surface of the semiconductor substrate is cleaned, one or more materials are deposited on the semiconductor substrate, oxidation is performed on the semiconductor substrate, nitriding is performed on the semiconductor substrate, atomic layer etching is performed on the semiconductor substrate, or the internal surface of the semiconductor processing chamber is cleaned. It will be understood that photon-activated species can be used in a variety of situations related to semiconductor processing.

[0113] In some embodiments, process 950 further includes the step of etching one or more materials on a semiconductor substrate. One or more reaction gases for etching may include halogens such as F2, Cl2, Br2, and I2; oxidizing agents such as O2, NO, NO2, N2O, H2O2, and H2O; hydrogen halides such as HF, HCl, HBr, and HI; and other etching chemicals such as HONO, GeF4, NF3, CH4, CHF3, SiF4, SF6, BCl3, and H2. Any combination of the aforementioned species may be used in the gas mixture for etching. The material etching rate and selectivity may be controlled by adjusting the light source energy according to a selected wavelength or wavelength range. This allows for variations in the ratio of radicals in different excited states. The material etching rate and selectivity may also be controlled by adjusting the light source intensity according to a selected intensity. This allows for variations in the ratio of excited-state radical atoms to ground-state radical atoms or molecules.

[0114] In some embodiments of process 950, the step of etching one or more materials includes etching silicon oxide rather than silicon and / or silicon nitride, and the photon-activated species include radicals of oxygen-containing gases and / or hydrogen-containing gases. In some embodiments of process 950, the step of etching one or more materials includes etching silicon rather than silicon oxide and / or silicon nitride, and the photon-activated species include radicals of halogen gases and / or methane gases. In some embodiments of process 950, the step of etching one or more materials includes etching silicon rather than silicon germanium, silicon oxide, silicon nitride, or a combination thereof, and the photon-activated species include radicals of nitrogen-containing gases mixed with fluorine-containing gases and / or hydrogen-containing gases. In some embodiments of process 950, the step of etching one or more materials includes etching silicon nitride rather than silicon oxide, silicon, silicon germanium, or a combination thereof, and the photon-activated species include radicals of fluorine-containing gases and / or nitrogen-containing gases. In some embodiments of process 950, the step of etching one or more materials includes the step of etching a metal or metal oxide, and the photon-activating species includes radicals of a fluorine-containing gas. In some embodiments of process 950, the step of etching one or more materials includes the step of etching silicon germanium rather than silicon, and the photon-activating species include radicals of a fluorine-containing species and / or a chlorine-containing species.

[0115] In some embodiments, process 950 further includes a step of treating the surface of the semiconductor substrate. Treatment of the semiconductor substrate surface may include the removal of contaminants or damaged layers. In some cases, high-energy ions from the plasma can readily damage the substrate layers and materials. This may include, for example, damaged Si, SiO2, SiOCN, or Si3N4. In some cases, carbon or polymer-based contaminants may form on the surface of the semiconductor substrate. This may include, for example, C, CH, CF, CHF, etc. Photon-activated species can treat the surface of the semiconductor substrate without damaging the semiconductor substrate or the underlying film. In some embodiments, process 950 may include treatment of the semiconductor substrate surface by direct exposure to radiation from a light source. Such direct exposure can facilitate the desorption of by-products on the surface of the semiconductor substrate.

[0116] In some embodiments, process 950 further includes a step of cleaning the internal surfaces of the semiconductor processing chamber. Unwanted materials may accumulate on the chamber walls, ceiling, floor, showerhead, substrate support, lift pins, gas lines, nozzles, etc. Such unwanted materials may include, for example, Si, C, CH, CF, CHF, metals, etc. Without the use of plasma, unwanted materials may be removed by exposure to photon-activated species. In some cases, unwanted materials may be removed by exposure to radiation from a light source.

[0117] Figure 10 shows a schematic diagram of an exemplary process tool for carrying out the disclosed embodiment. The process tool may include an arrangement of transfer modules and processing modules, which may be referred to as a “cluster tool architecture” system. Various modules may interface with a vacuum transfer module (VTM) 1038. An airlock 1030, also known as a load lock or transfer module, is shown in the VTM 1038 having four processing modules 1020a, 1020b, 1020c, and 1020d. Processing modules 1020a, 1020b, 1020c, and 1020d may be optimized to carry out various manufacturing processes. For example, processing modules 1020a, 1020b, 1020c, and 1020d may be implemented to carry out substrate etching, deposition, substrate processing, ion implantation, substrate cleaning, sputtering, and / or other semiconductor processes. One or more of the substrate processing modules (1020a, 1020b, 1020c, and 1020d) may be implemented to perform substrate etching, substrate processing, or chamber cleaning as disclosed herein using photon-activated species. The airlock 1030 and process module 1020 may be referred to as “stations”. Each station has a facet 1036 that interfaces the station to VTM 1038. Inside each facet, sensors 1-18 are used to detect the passage of the substrate 1026 as it moves between the respective stations.

[0118] Robot 1022 transports the substrate 1026 between stations. In one embodiment, robot 1022 has one arm, and in another embodiment, robot 1022 has two arms, each arm having an end effector 1024 for picking up substrates such as substrate 1026 for transport. Front-end robot 1032 in air transport module (ATM) 1040 is used to transport substrate 1026 from a cassette or front opening integrated pod (FOUP) 1034 in load port module (LPM) 1042 to airlock 1030. Module center 1028 in process module 1020 is one location for placing substrate 1026. Aligner 1044 in ATM 1040 is used to align the substrate.

[0119] In an exemplary processing method, the substrate is placed in one of the FOUPs 1034 within the LPM 1042. The front-end robot 1032 moves the substrate from the FOUP 1034 to the aligner 1044, which allows the substrate 1026 to be properly centered before etching or processing. After alignment, the substrate 1026 is moved into the airlock 1030 by the front-end robot 1032. Because the airlock module has the ability to match the environments between the ATM and VTM, the substrate 1026 can move between the two pressure environments without being damaged. From the airlock module 1030, the substrate 1026 is moved by the robot 1022 through the VTM 1038 into one of the processing modules 1020a, 1020b, 1020c, and 1020d. To achieve this substrate movement, the robot 1022 uses the end effectors 1024 of each of its arms. Once substrate 1026 is processed, it is moved by robot 1022 from process module 1020a, 1020b, 1020c, or 1020d to airlock module 1030. From there, substrate 1026 may be moved by front-end robot 1032 to one of FOUP 1034 or aligner 1044.

[0120] The computer controlling wafer movement can be local to the cluster architecture, or it can be located outside the cluster architecture within the manufacturing floor, or remotely, and connected to the cluster architecture via a network. The controller described above with respect to Figures 1 and 2 may be implemented using the tool shown in Figure 10.

[0121] conclusion The examples and embodiments described herein are for illustrative purposes only, and it should be understood that various modifications or changes will be suggested to those skilled in the art in light thereof. Various design alternatives may be implemented, although various details have been omitted for clarity. Accordingly, these examples should be considered illustrative and not limiting, and this disclosure is not limited to the details shown herein and may be modified within the scope of this disclosure. [Explanation of symbols]

[0122] 100 Plasma processing apparatus, 102 Gas delivery system, 104 Shower head, 106 Mixing vessel, 108A Mixing vessel inlet valve, 108B Mixing vessel inlet valve, 110 Processing chamber, 114 Substrate, 118 Substrate holder, 120 Chamber space, 122 RF power supply, 124 Matching network, 126 DC power supply, 128 Temperature control element, 130 Vacuum pump, 200 Plasma processing apparatus, 202 Process gas, 204 Activated species, 206 Gas mixture, 210 Substrate support, 220 Substrate, 225 Processing chamber, 230 In situ plasma, 240 Controller, 250 Remote plasma source, 252 Gas distributor, 254 Shower head, 256 Coil, 260 Remote plasma, 300 Semiconductor processing apparatus, 310 Processing chamber, 312 Window, 314 Reflective material, 320 Substrate support, 322 Substrate, 330 Gas distributor, 332 Window, 334 Reflective material, 340 Gas source, 350 Light source, 360 Optical cavity, 362 Window, 364 Reflective material, 500 Optical cavity, 510 Optical cell, 512 Light source, 520 Gas cell, 522 Gas inlet, 524 Gas outlet, 602 Rectangular optical cell, 604 Cylindrical gas cell, 606 LED, 612 Cylindrical optical cell, 614 Cylindrical gas cell, 616 LED, 622 Octagonal optical cell, 624 Cylindrical gas cell, 626 LED, 632 Circular window, 634 Gas cell, 636 LED, 638 Shower head, 642 Annular window, 644 Gas cell, 646 LED, 700 Semiconductor processing apparatus, 710 Processing chamber, 720 Substrate support, 722 Semiconductor substrate, 730 Gas distributor, 740 Gas source, 750 Light source, 760 Optical cavity, 770 Window, 800 Light source, 810 LED, 820 LED, 830 LED, 840 LED, 850 Power connector, 860 Thermistor, 870 Transient voltage suppression diode, 900 Process, 910 Block, 920 Block, 930 Block, 940 Block, 950 Process, 1020 Process module, 1020a Processing module, 1020b Processing module, 1020c Processing module, 1022 Robot, 1024 End effector, 1026 Substrate, 1028 Module center, 1030 Airlock module, 1032Front-end robot, 1034 Front opening integrated pod, 1036 Facet, 1038 Vacuum transfer module, 1040 Atmospheric transfer module, 1042 Load port module, 1044 Aligner

Claims

1. Processing chamber and A substrate support configured to support a semiconductor substrate within the processing chamber, A gas distributor that is in fluid communication with the processing chamber, A gas source that is in fluid communication with the gas distributor, wherein the gas source is configured to supply one or more reaction gases to the gas distributor, A light source configured to emit radiation to generate at least one photon-activated species of the reaction gas, A semiconductor processing device equipped with the following features.

2. The semiconductor apparatus according to claim 1, wherein the light source is adjusted to emit radiation having (1) a selected intensity and (2) a selected wavelength or wavelength range in order to obtain a desired energy distribution of the photon-activated species.

3. The semiconductor apparatus according to claim 2, wherein the light source is adjusted according to the selected wavelength or wavelength range to achieve a target etching rate and selectivity of one or more materials to be etched on the semiconductor substrate.

4. The semiconductor apparatus according to claim 2, wherein the light source is adjusted according to the selected intensity to achieve a target etching rate and selectivity of one or more materials to be etched on the semiconductor substrate.

5. The semiconductor apparatus according to claim 2, wherein the one or more reaction gases comprises a mixture of reaction gases, and the light source is tuned according to the selected wavelength or wavelength range to selectively generate one photon-activated species of the reaction gases in the mixture relative to the rest of the reaction gases in the mixture.

6. An optical cavity optically coupled to a light source to receive the radiation from the light source, wherein at least one of the reaction gases is converted into the photon-activating species within the optical cavity. The semiconductor processing apparatus according to claim 1, further comprising:

7. The semiconductor apparatus according to claim 6, wherein the optical cavity comprises a gas cell through which the one or more reaction gases flow, and an optical cell surrounding the gas cell or located above the gas cell, and the light source is positioned on one or more surfaces of the optical cell to emit the radiation through the gas cell.

8. The semiconductor processing apparatus according to claim 7, wherein the optical cell has a geometric shape different from that of the gas cell.

9. The semiconductor processing apparatus according to claim 7, wherein the optical cell has a cylindrical, rectangular, or octagonal geometric shape.

10. The semiconductor apparatus according to claim 7, wherein the optical cell includes one or more mirrors or reflective materials for reflecting the radiation emitted from the light source.

11. The semiconductor apparatus according to claim 7, wherein the gas cell includes one or more mirrors or reflective materials for reflecting the radiation emitted from the light source.

12. The semiconductor apparatus according to claim 7, wherein the material of the gas cell is transparent or substantially transparent to the radiation emitted from the light source.

13. The semiconductor processing apparatus according to claim 7, wherein the optical cell comprises a window located above the gas cell, and the light source comprises a plurality of light-emitting diodes (LEDs) arranged on the window and emitting radiation into the gas cell.

14. The semiconductor processing apparatus according to claim 7, wherein the optical cell comprises a ring surrounding the gas cell, and the light source comprises a plurality of LEDs arranged on the ring and emitting radiation into the gas cell.

15. The semiconductor processing apparatus according to claim 6, wherein the optical cavity includes one or more mirrors or reflective surfaces.

16. The semiconductor processing apparatus according to claim 6, wherein the optical cavity does not include a mirror or a reflective surface.

17. The semiconductor processing apparatus according to claim 1, wherein the light source includes a laser.

18. The semiconductor processing apparatus according to claim 1, wherein the light source includes a flash lamp.

19. The semiconductor processing apparatus according to claim 1, wherein the light source includes a plurality of LEDs.

20. The semiconductor apparatus according to claim 19, wherein the plurality of LEDs comprises a first LED configured to emit radiation of a first wavelength and a second LED configured to emit radiation of a second wavelength different from the first wavelength.

21. The semiconductor apparatus according to claim 1, wherein the light source is further configured to expose the semiconductor substrate to the emitted radiation in order to promote or inhibit a surface reaction on the semiconductor substrate.

22. The semiconductor apparatus according to claim 21, wherein the light source comprises a plurality of LEDs arranged above the gas distributor, and the gas distributor is transparent or substantially transparent to the emitted radiation.

23. The semiconductor apparatus according to claim 1, wherein the optical cavity is arranged between the gas distributor and the gas source such that photon activation occurs before the gas distributor.

24. The semiconductor apparatus according to claim 1, wherein the optical cavity is arranged in the gas distributor such that photon activation occurs within the gas distributor.

25. The semiconductor apparatus according to claim 1, wherein the optical cavity is arranged in the processing chamber such that photon activation occurs within the processing chamber.

26. The semiconductor apparatus according to claim 1, wherein the one or more reaction gases include halogen gas, hydrogen halide, oxidizing gas, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or a combination thereof.

27. The semiconductor apparatus according to claim 1, wherein the at least one photon-activated species of the reaction gas includes a molecular radical in the ground state or an excited state, an atomic radical in the ground state or an excited state, and / or an energy-imparted reaction gas in an excited vibrational state.

28. Processing chamber and A substrate support configured to support the semiconductor substrate in the semiconductor processing chamber, A gas distributor that is in fluid communication with the semiconductor processing chamber, A gas source that is in fluid communication with the gas distributor, wherein the gas source is configured to supply one or more reaction gases in a ground state to the gas distributor, A light source configured to emit radiation and to be adjusted to (1) a selected intensity and (2) a selected wavelength or wavelength range, An optical cavity disposed between the gas source and the gas distributor, wherein the optical cavity is configured to receive radiation from the light source and convert one or more reaction gases into photon-activated species within the optical cavity. A semiconductor processing device equipped with the following features.

29. Semiconductor processing chamber and A substrate support configured to support the semiconductor substrate in the semiconductor processing chamber, A gas distributor that is in fluid communication with the semiconductor processing chamber, A gas source that is in fluid communication with the gas distributor, wherein the gas source is configured to supply one or more reaction gases in a ground state to the gas distributor, A light source configured to emit radiation, which is tuned to (1) a selected intensity and (2) a selected wavelength or wavelength range. Equipped with, The gas divider functions as an optical cavity configured to receive radiation from the light source and convert one or more reaction gases into photon-activated species within the gas divider. Semiconductor processing unit.

30. Processing chamber and A substrate support configured to support the semiconductor substrate in the processing chamber, A gas distributor that is in fluid communication with the processing chamber, A gas source that is in fluid communication with the gas distributor, wherein the gas source is configured to supply one or more reaction gases in a ground state to the gas distributor, A light source configured to emit radiation, which is tuned to (1) a selected intensity and (2) a selected wavelength or wavelength range. Equipped with, The processing chamber functions as an optical cavity configured to receive radiation from the light source and convert one or more reaction gases into photon-activated species within the processing chamber. Semiconductor processing unit.

31. A method for generating photon-activated species for use in a processing chamber, wherein the method is The steps include flowing one or more reaction gases toward a gas distributor for distributing one or more reaction gases into the processing chamber, (1) Emitting radiation from a light source at a selected intensity and (2) at a selected wavelength or wavelength range, The steps include: exposing one or more reaction gases to the radiation emitted from the light source to generate at least one photon-activated species of the reaction gas in an optical cavity; Methods that include...

32. The step of etching one or more materials on the semiconductor substrate in the processing chamber by exposing the semiconductor substrate to the photon-activated species. The method according to claim 31, further comprising:

33. The method according to claim 32, wherein the one or more materials are etched with an etching rate and selectivity that is at least partially based on (1) the selected intensity and (2) the selected wavelength or wavelength range, or both.

34. The method according to claim 32, wherein the step of etching one or more materials includes etching silicon oxide rather than silicon and / or silicon nitride, and the photon-activated species includes radicals of an oxygen-containing gas and / or a hydrogen-containing gas.

35. The method according to claim 32, wherein the step of etching one or more materials includes etching silicon more than silicon oxide and / or silicon nitride, and the photon-activated species includes a radical of a halogen gas and / or methane gas.

36. The method according to claim 32, wherein the step of etching one or more materials includes etching silicon more than silicon germanium, silicon oxide, silicon nitride, or a combination thereof, and the photon-activated species includes a radical of a nitrogen-containing gas mixed with a fluorine-containing gas and / or a hydrogen-containing gas.

37. The method according to claim 32, wherein the step of etching one or more materials includes etching silicon nitride rather than silicon oxide, silicon, silicon germanium, or a combination thereof, and the photon-activating species includes radicals of a fluorine-containing gas and / or a nitrogen-containing gas.

38. The method according to claim 32, wherein the step of etching one or more materials includes a step of etching a metal or metal oxide, and the photon-activating species includes a radical of a fluorine-containing gas.

39. The step of processing the surface of the semiconductor substrate by exposing the semiconductor substrate to the photon-activated species and desorbing etching by-products from the surface of the semiconductor substrate. The method according to claim 32, further comprising:

40. The method according to claim 32, wherein the step of etching one or more materials includes etching silicon germanium rather than silicon, and the photon-activating species includes radicals of a fluorine-containing species and / or a chlorine-containing species.

41. The method according to claim 32, wherein the concentration of the photon-activating species for etching one or more materials is adjustable by controlling (1) the selected intensity of the emitted radiation and (2) the selected wavelength of the emitted radiation.

42. The step of processing the surface of the semiconductor substrate in the processing chamber by exposing the semiconductor substrate to the photon-activated species. The method according to claim 31, further comprising:

43. The step of cleaning the inner surface of the processing chamber by exposing the inner surface to the photon-activated species. The method according to claim 31, further comprising:

44. The method according to claim 31, wherein the optical cavity is located upstream of the gas distributor and is integrated with the gas distributor, or is integrated with the processing chamber.

45. The method according to claim 31, wherein the optical cavity comprises one or more mirrors or reflective materials configured to reflect the radiation emitted from the light source within the optical cavity.

46. The method according to claim 31, wherein the light source includes a plurality of LEDs, and the plurality of LEDs emit light at the same wavelength or a combination of different wavelengths.

47. The method according to claim 31, wherein the photon-activating species is generated independently from any of the plasmas.

48. The method according to claim 31, wherein the photon-activated species includes a molecular radical in the ground state or an excited state, an atomic radical in the ground state or an excited state, and / or an energy-conjugated reaction gas in an excited vibrational state.

49. The method according to claim 31, wherein the one or more reaction gases include halogen gases, hydrogen halides, oxidizing gases, nitrogen trifluoride, nitrous oxide, nitric oxide, nitrogen dioxide, methane, fluoromethane, trifluoromethane, ammonia, hydrogen gas, sulfur hexafluoride, silicon tetrafluoride, or a combination thereof.

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