Atomic layer etching system for selective etching using halogen-based compounds

Abstract

To provide a substrate processing system.SOLUTION: A substrate processing system 100 includes a processing chamber 108, a substrate support 110, a heat source 126, a gas delivery system 160 and a controller 180. The substrate support is disposed in the processing chamber and supports a substrate. The heat source heats the substrate. The gas delivery system supplies a process gas to the processing chamber. The controller controls the gas delivery system and the heat source to iteratively perform isotropic atomic layer etching processing. The isotropic atomic layer etching processing includes the steps of: during the iteration, performing pretreatment, atomistic adsorption, and pulsed thermal annealing; during the atomistic adsorption, exposing a surface of the substrate to a first process gas including a halogen species that is selectively adsorbed onto an exposed material of the substrate to form a modified material; and during the pulsed thermal annealing, pulsing the heat source multiple times within a predetermined period to expose and remove the modified material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This disclosure claims the benefit of U.S. Provisional Patent Application No. 62 / 767,564, filed November 15, 2018. The disclosures of the above-identified applications are incorporated herein by reference in their entireties.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to substrate etching and deposition processes, and more particularly to atomic layer etching and deposition. [Background technology]

[0003] The background description provided herein is intended to generally indicate the relevance of the present disclosure. To the extent described in this Background section, neither the works of the inventors named herein, nor aspects of the description that may not otherwise be considered prior art at the time of submission, are admitted, expressly or impliedly, as prior art to the present disclosure.

[0004] During atomic layer etching (ALE) of a substrate, such as a semiconductor wafer, reactants (e.g., chlorine (Cl) gas) are introduced into a processing chamber to modify the surface of the substrate. Often, silicon (Si), germanium (Ge), and metal oxides (MO) are used. x A chlorine-based gas is used during ALE of silicon chloride (SiCl) to provide a chlorine-implanted top layer. As an example, chlorine gas is introduced to convert the top portion of a silicon substrate formed from silicon chloride (SiCl). x ) layer on the top portion of the silicon substrate, where x is 1, 2, 3, or 4. After surface modification, the chamber is purged of chlorine gas. An argon (Ar) plasma is provided to perform ion bombardment and actively remove the silicon chloride reaction layer, followed by purging of by-products. Summary of the Invention

[0005] A substrate processing system is provided, the substrate processing system including a process chamber, a substrate support, a heat source, a gas delivery system, and a controller. The substrate support is disposed in the process chamber and configured to support a substrate. The heat source is configured to heat the substrate. The gas delivery system is configured to supply a first process gas to the process chamber. The controller is configured to control the gas delivery system and the heat source to repeatedly perform an isotropic atomic layer etching process, the isotropic atomic layer etching process including, during the repetitions, performing pretreatment, atomic level adsorption, and pulsed thermal annealing; exposing a surface of the substrate to a first process gas including a halogen species that selectively adsorbs onto the exposed material of the substrate during atomic level adsorption to form a modified material; and pulsing the heat source on and off multiple times within a predetermined period of time to expose and remove the modified material during the pulsed thermal annealing.

[0006] In other features, the controller is configured to allow the modified material to cool between successive thermal energy pulses of the heat source during the repetitions of pulsed thermal annealing. In other features, the heat source includes a flash lamp. In other features, the substrate processing system further includes a capacitive discharge circuit configured to discharge the flash lamp for each of the multiple thermal energy pulses of the heat source. In other features, the heat source includes a reflective surface having radially reflective portions for each of the multiple flash lamps. In other features, the flash lamps include corresponding cooling jackets.

[0007] In other features, the substrate processing system further includes a cone-shaped reflective surface that directs thermal energy from the plurality of flash lamps to the substrate. In other features, the controller is configured to pulse the plurality of flash lamps to be on for a pulse duration of less than 4 milliseconds during at least one iteration of the pulsed thermal annealing.

[0008] In other features, the controller is configured to heat the modified substrate material via the heat source during at least some of the repetitions of the pulsed thermal annealing such that the modified substrate material cools to a temperature less than 25° C. in less than 0.5 seconds after the heat source is turned off.

[0009] In other features, the heat source includes a laser. The laser is configured to generate a laser beam directed at the substrate. In other features, the substrate processing system further includes a mirror and a motor. The controller is configured to direct the laser beam to spread across the substrate by moving the mirror with the motor. In other features, the substrate has a diameter of 300 mm. The substrate includes dies. The controller is configured to spread across the dies and heat each of the dies within a predetermined period of time.

[0010] In other features, the predetermined period is 1 second. The controller is configured to individually heat each of the plurality of dies a second predetermined number of times. In other features, the substrate processing system further includes a lens circuit configured to shape and direct the laser beam. In other features, the lens circuit includes beam shaping optics to convert the laser beam from a round shaped laser beam to a square shaped laser beam.

[0011] In other features, the lens circuit includes a flat-top optic for converting the laser beam from a round-shaped laser beam to a flat-top shaped laser beam, and a diffractive optic for converting the flat-top shaped laser beam to a square-shaped laser beam.

[0012] In other features, the substrate processing system further includes a mirror module including a first mirror, a second mirror, a first motor, and a second motor, and the controller is configured to move the first mirror and the second mirror via the first motor and the second motor to adjust the position of the laser beam on the substrate.

[0013] In other features, the substrate processing system further includes a telecentric lens assembly including a plurality of lenses configured to direct the laser beam in a direction normal to the surface of the substrate.

[0014] In other features, the substrate processing system further includes a mirror module including a first mirror, a second mirror, a first motor, and a second motor. The laser beam is directed onto the first mirror. The laser beam is directed from the first mirror to the second mirror. The laser beam is directed from the second mirror through a telecentric lens assembly to the substrate. The controller is configured to move the first mirror and the second mirror via the first motor and the second motor to adjust the position of the laser beam on the substrate.

[0015] In other features, the processing chamber is an inductively coupled plasma chamber or a remote plasma source connected chamber. The telecentric lens assembly is positioned above a dielectric window of the processing chamber.

[0016] In other features, the substrate processing system further includes a beam size adjustment module configured to adjust a size of the laser beam before it is received by the substrate. In other features, the processing chamber is free of plasma during pulsed thermal annealing.

[0017] In other features, the controller is configured to set a temperature inside the processing chamber to less than or equal to 20° C. or to ambient temperature during one or more iterations of atomic level adsorption. In other features, the controller is configured to control the heat source to generate multiple thermal energy pulses that heat the modified material of the substrate without heating at least one of a base portion or a bulk portion of the substrate.

[0018] In other features, the controller is configured to supply a first process gas to the processing chamber to effect atomic-level adsorption on exposed material of the substrate during each successive pair of thermal energy pulses of the heat source. In other features, the controller is configured to modify the substrate by exposing the substrate to a second process gas during pre-processing. In other features, the controller is configured to pulse the heat source to generate multiple thermal energy pulses within one second.

[0019] In other features, the pre-treatment includes introducing a second process gas. The second process gas includes hydrogen. The halogen species includes oxygen. The pulsed thermal annealing includes removing a monolayer from the substrate. The monolayer includes germanium.

[0020] In other features, the pre-treatment includes introducing a second process gas, the second process gas including hydrogen, the halogen species including chlorine, and the pulsed thermal annealing includes removing a monolayer from the substrate, the monolayer including germanium.

[0021] In other features, the pre-treatment includes introducing a second process gas. The second process gas includes hydrogen. The halogen species includes iodine. The pulsed thermal annealing includes removing a monolayer from the substrate. The monolayer includes silicon. In other features, the pulsed thermal annealing includes selectively removing silicon without removing germanium.

[0022] In other features, the pre-treatment includes introducing a second process gas comprising hydrogen or oxygen. The halogen species includes chlorine. The pulsed thermal annealing includes removing a monolayer from the substrate. The monolayer includes titanium.

[0023] In other features, the pre-treatment includes introducing a second process gas. The second process gas includes hydrogen or ammonia. The halogen species includes fluorine. The pulsed thermal annealing includes removing a monolayer from the substrate. The monolayer includes silicon dioxide.

[0024] In another feature, a method for operating a substrate processing system is provided. The method includes depositing a substrate on a substrate support in a processing chamber and repeatedly performing a first atomic layer etching (ALE) process. The first ALE process is a sequential isotropic process that includes performing a pretreatment process including supplying a first process gas to the processing chamber to modify a first exposed portion of the substrate, an atomic level adsorption process including exposing the first exposed portion to a second process gas including a halogen species that selectively adsorbs onto the first exposed portion and modifies the first exposed portion, and a pulsed thermal annealing process including controlling a heat source to generate thermal energy pulses to expose and remove the modified first exposed portion. The method further includes determining whether a predetermined number of cycles of the first ALE process have been performed, and ceasing to perform the first ALE process if the predetermined number of cycles have been performed.

[0025] In other features, the method further includes purging the processing chamber after performing the atomic level adsorption and before performing the pulsed thermal annealing. In other features, the method further includes purging the processing chamber after performing each iteration of the pulsed rapid thermal annealing. In other features, the method further includes performing the first ALE process multiple times within one second.

[0026] In another feature, the method further includes determining whether to perform a second ALE process, changing parameters set for the first ALE process to updated parameters for the second ALE process, and repeatedly performing the second ALE process within the process chamber, wherein the second ALE process includes performing a pre-treatment including supplying a first process gas or a third process gas to the process chamber to modify the first exposed portion or the second exposed portion of the substrate, performing atomic-level adsorption including exposing the first exposed portion or the second exposed portion to a second gas or a fourth gas including a halogen species, and performing pulsed rapid thermal annealing including controlling a heat source to generate thermal energy pulses to heat the first exposed portion or the second exposed portion.

[0027] In other features, the method further includes determining whether to perform a second ALE process when performing the first ALE process on the first die of the substrate, and performing the second ALE process on the second die of the substrate. In other features, the method further includes, for rapid thermal annealing, charging a capacitor and discharging the capacitor to provide power to the plurality of flash lamps.

[0028] In other features, the method further comprises, for rapid thermal annealing, generating a laser beam; converting the laser beam into a flat-top beam; converting the flat-top beam into a square beam; reflecting the square beam off a mirror to a telecentric lens assembly; and passing the square beam through the telecentric lens assembly in a direction perpendicular to the substrate to the substrate.

[0029] In other features, the method further includes, for rapid thermal annealing, adjusting the size of the square beam to be equal to or greater than the size of the die on the substrate.In other features, the method further includes, for rapid thermal annealing, directing the laser beam by moving a mirror to spread across the entire surface of a substrate including the die, where the substrate has a diameter of 300 mm, and to heat each of the die within a predetermined period of time.

[0030] In other features, the predetermined period is 1 second, and each of the dies is individually heated the predetermined number of times. In other features, the first gas includes hydrogen. The halogen species includes oxygen. The pulsed thermal annealing includes removing a monolayer from the substrate. The monolayer includes germanium.

[0031] In other features, the first gas comprises hydrogen, the halogen species comprises chlorine, and the pulsed thermal annealing comprises removing a monolayer from the substrate, the monolayer comprising germanium.

[0032] In other features, the first gas comprises hydrogen. The halogen species comprises iodine. The pulsed thermal annealing comprises removing a monolayer from the substrate. The monolayer comprises silicon. In other features, the pulsed thermal annealing comprises selective removal of silicon and does not include removal of germanium.

[0033] In other features, the first gas comprises hydrogen or oxygen. The halogen species comprises chlorine. The pulsed thermal annealing comprises removing a monolayer from the substrate. The monolayer comprises titanium.

[0034] In other features, the first gas comprises hydrogen or ammonia. The halogen species comprises fluorine. The pulsed thermal annealing comprises removing a monolayer from the substrate. The monolayer comprises silicon dioxide.

[0035] Areas of applicability of the present disclosure will become more apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0036] The present disclosure will become more fully understood from the detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a functional block diagram of an example substrate processing system incorporating a flash lamp and a rapid heat pulse controller for performing rapid heat pulse operation during ALE and atomic layer deposition (ALD) in accordance with the present disclosure.

[0038] [Figure 2] FIG. 1 is a functional block diagram of an example substrate processing system incorporating a laser, lens circuitry, and a rapid heat pulse controller for performing rapid heat pulse operations during ALE and ALD in accordance with the present disclosure.

[0039] [Figure 3] 3 is a cross-sectional side view of a mirror and telecentric lens assembly incorporated into the lens circuit of FIG. 2.

[0040] [Figure 4] 1 is a time-dependent temperature profile illustrating an example of a heating-up period and a cooling period associated with a conventional continuous wave mode of operation.

[0041] [Figure 5] 1 is an example of a time-dependent temperature profile illustrating an example of a rapid heat pulse according to the present disclosure.

[0042] [Figure 6] FIG. 1 is an ALE processing diagram according to the present disclosure.

[0043] [Figure 7] 1 is an example signal diagram illustrating temperature change over time for a single rapid heat pulse provided in accordance with the present disclosure.

[0044] [Figure 8]1 is an example plot of etch rate versus laser fluence for ALE performed in accordance with the present disclosure.

[0045] [Figure 9] 1 is an example plot of the amount of germanium removed versus the number of processing cycles for ALE performed in accordance with the present disclosure.

[0046] [Figure 10] 10 is an example of a film thickness plot illustrating implementation of different material removal amounts as a reference, pulsed laser heating without chlorine adsorption, chlorine adsorption without pulsed laser heating, and a combination of chlorine adsorption and pulsed laser heating.

[0047] [Figure 11] 1 is an example plot of estimated temperature and lamp power ranges for certain processes.

[0048] [Figure 12] 1 is an example plot illustrating the rate of change of surface temperature during a flash lamp cycle performed in accordance with the present disclosure, and a corresponding example plot of the rate of change of surface temperature during a corresponding cool-down period after the flash lamp cycle.

[0049] [Figure 13] 1 is an example plot of flash lamp power level and repetition rate versus pulse duration for a flash lamp cycle according to the present disclosure.

[0050] [Figure 14] 1A-1C illustrate repeated rapid heat pulse cycles performed to remove portions of a dielectric layer in accordance with the present disclosure.

[0051] [Figure 15] 1 illustrates an ALE method according to the present disclosure.

[0052] [Figure 16]1 is an example plot of etch rate versus substrate surface temperature during an ALE process performed in accordance with the present disclosure.

[0053] [Figure 17] 1 is a plot showing examples of heating rate versus cooling rate for different heat sources.

[0054] [Figure 18] 1A-1C are block diagrams illustrating two example ALE methods for removing a titanium nitride layer according to the present disclosure.

[0055] [Figure 19] 1 is an example plot of titanium nitride film thickness for different energy levels.

[0056] [Figure 20] 1 is an example plot of titanium nitride film thickness for different numbers of ALE cycles performed in accordance with the present disclosure.

[0057] [Figure 21] 10 is an example plot of titanium nitride film thickness illustrating different amounts of material removal for different operations performed.

[0058] [Figure 22] 1 is an example ALE process diagram illustrating iodine gas introduction and silicon removal without germanium removal according to an embodiment of the present disclosure.

[0059] [Figure 23] 1 is an example plot of silicon layer thickness versus etch rate for different substrate support temperatures.

[0060] [Figure 24] 10 is an example graph of etch depth range and surface roughness associated with measurements of samples taken before heating, after flash lamp heating for different energy levels, and after substrate support heating.

[0061] [Figure 25] 1 is an example plot of silicon etch rate and germanium deposition rate due to iodine gas introduction and a heated substrate support.

[0062] [Figure 26] 1 is an example plot of etch rate versus heat pulse energy for silicon and germanium using iodine gas.

[0063] [Figure 27] 10 is an example plot of etch depth and surface roughness for heated substrate support mounting and laser mounting.

[0064] [Figure 28] 10 is an example plot of etch rate and surface roughness versus pulse number for substrate heating via a laser, according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0065] In the drawings, reference numbers may be reused to identify similar and / or identical elements.

[0066] Fabricating devices smaller than 7 nanometers (nm) requires isotropic removal of material from substrates with nanoscale control. At the nanoscale level, conventional dry and wet etching can cause roughness and / or damage to the substrate surface. In addition, ALE has limitations in isotropic removal due to the directionality of ions. For example, to remove an upper portion of a substrate, the upper portion may be modified to provide an upper volatile layer. The upper volatile layer may then be removed by heating it via a lamp. Conventional lamps (e.g., infrared lamps) may heat a portion of the substrate at rates ranging from 40°C / s to 250°C / s. The time it takes for the lamp to heat the upper volatile layer and for the upper volatile layer to cool can take several minutes. The time required to heat and cool the substrate can depend on the heating and cooling rates of the substrate support, such as an electrostatic chuck. The heating and cooling times of the substrate and substrate support can take tens of minutes.

[0067] Due to the lengthy heating period, the entire substrate is typically heated, including the base or bulk portion of the substrate. As a result, conventional heating by turning on heat lamps for extended periods of time has thermal balance issues due to heating not only the upper and / or surface portion of the substrate but also the bulk portion of the substrate. This type of heating has limited application to certain etching processes. Thermal balance refers to the amount of time a substrate can be exposed to a particular temperature without degrading the substrate's material and / or structure, adversely affecting the performance and / or operation of die components on the substrate, and / or causing interdiffusion problems in which molecules and / or atoms from one seed layer diffuse into another seed layer. The higher the temperature and the longer the exposure, the greater the likelihood and prevalence of thermal balance problems. In one example using conventional heat lamps, a thermal cycle providing a temperature rise of more than 200°C can result in Si diffusion into Ge, while a thermal cycle with a temperature rise of 40°C may not result in Si diffusion into Ge. Thermal balance issues limit the processing that can be performed on a substrate, particularly within a single processing chamber. It may be necessary to remove the substrate between processing chambers to quickly perform different processes, avoiding waiting for the substrate support to cool down.

[0068] Examples provided herein include an RTP system for performing rapid thermal pulsing (RTP) cycles via a heat source to rapidly increase the temperature of an upper portion of a substrate. By rapidly heating the upper portion of the substrate and not heating the base or bulk portion of the substrate, the upper portion of the substrate may rapidly decrease in temperature after deactivating the heat source. As described below, multiple heating and cooling cycles may be performed in a matter of seconds. RTP is provided, which avoids thermal balance issues. In other words, heating is provided without heating the lower bulk portion of the substrate and / or minimizing the amount of heating of the lower bulk portion of the substrate. This allows the surface and / or upper portion of the substrate to be rapidly heated and cooled, enabling multiple processing cycles and / or multiple different processes to be rapidly performed within a single processing chamber. In one example, the upper portion may be several hundred nanometers thick (or the heating depth extends several hundred nanometers into the substrate) as measured from the heated substrate surface.

[0069] RTP operations also enable the performance of processes that have not previously been performed due to their sensitivity to thermal budget issues. As an example, isotropic and selective removal of certain film materials from a substrate may be performed. Film materials that may be removed include silicon, germanium, metal oxides such as aluminum oxide, titanium oxide, zirconium oxide, and other materials such as titanium nitride.

[0070] Referring now to FIG. 1 , an example of a substrate processing system 100 that can be used is shown. The substrate processing system 100 includes an inductively coupled plasma (ICP) source, although other types of processing chambers and / or plasma sources (e.g., remote plasma sources) may be used. An optional remote plasma source may be provided to utilize radicals. An example of another processing chamber is a remote plasma source-coupled chamber (or first chamber) connected to another processing chamber (or second chamber). The substrate processing system 100 includes an RTP system 106 and a processing chamber 108. The processing chamber 108 includes a substrate support 110 for supporting a substrate 112. The RTP system 106 rapidly and repeatedly heats a surface and / or a portion of the substrate 112. In some examples, the substrate support 110 includes an electrostatic chuck or a vacuum chuck. In some examples, the substrate support 110 is temperature controlled. For example, the substrate support 110 may include fluid channels 114 and / or heaters 116, which may be arranged in one or more zones. The substrate support 110 may further include an electrode 118.

[0071] One or more sensors 119, such as temperature and / or pressure sensors, may be arranged within the processing chamber 108 to sense the temperature and / or pressure, respectively. A valve 122 and a pump 124 may be used to control the pressure within the processing chamber 108 and / or to evacuate reactants from the processing chamber 108.

[0072] The RTP system 106 includes a heat source 126 that performs rapid thermal annealing of the substrate 112. This includes RTP via flash lamps 128. Another example of a laser-based RTP system is shown in FIG. 2. A window assembly 130 may be disposed between the heat source 126 and the processing chamber 108. The window assembly 130 includes a first (or dielectric) window 132, a reflective surface 134, a coupling member 136, and a second window 138. The first window 132 may be a quartz window. The reflective surface 134 may be formed from stainless steel and may have a conical shape to direct thermal energy generated by the flash lamps 128 toward the substrate 112. The second window 138 may be a sapphire window. The coupling member 136 connects the reflective surface 134 to the processing chamber 108. In one embodiment, the reflective surface 134 is not included, and the first window 132 is attached to the coupling member 136. The flash lamps 128 may be cylindrical in shape and may include corresponding cooling jackets 140 through which water and / or other cooling fluid may be circulated to cool the flash lamps 128. A reflective surface 142 having radially reflective portions 144 may be disposed on the first window 132. The reflective surface 142 may be formed from aluminum. Each flash lamp 128 is disposed within the radially reflective portions 144 between the reflective surface 142 and the first window 132.

[0073] A temperature control system 150 may be used to control the temperature of the substrate support 110 and the substrate 112. The temperature control system 150 may control the supply of fluid from a fluid source 152 via a pump 154 ​​connected to the fluid channel 114. The temperature control system 150 may also control the operation of the heater 116. The temperature control system 150 may include one or more temperature sensors 156 that sense the temperature of one or more locations or zones of the substrate support 110.

[0074] The gas delivery system 160 includes one or more gas sources 164, one or more valves 105, one or more mass flow controllers 168, and a mixing manifold 170. The gas delivery system 160 selectively supplies a plasma gas mixture, a carrier and / or inert gas, and / or a purge gas mixture to the processing chamber 108 during pre-treatment, doping, passivation, annealing, and / or purging.

[0075] The RF generator 120-1 includes an RF source 123 and a matching network 125 that outputs RF power to a coil 127 that surrounds the outer wall of the processing chamber 108. The RF generator 120-1 creates a magnetic field within the processing chamber 108 that impinges on the plasma. Another RF generator 120-2 may be used to provide an RF bias to the electrode 118 in the substrate support 110. A controller 180 communicates with one or more sensors 119, valves 122 and pumps 124, temperature control system 150, heat source 126, RF generators 120-1 and / or 120-2, and gas delivery system 160 to control the processing being performed.

[0076] The controller 180 may include an RTP controller 182 that controls a capacitive discharge circuit 184 to pulse the flash lamp 128. The capacitive discharge circuit 184 may receive power from a power supply 186 and a control signal from the RTP controller 182. The capacitive discharge circuit 184 may charge a capacitor (represented by box 187) when in idle mode and may discharge the capacitor upon receiving a discharge signal from the RTP controller 182. The RTP controller 182 may perform RTP operations during ALE and / or ALD processes.

[0077] 2 shows an example of a substrate processing system 200 incorporating an RTP system 202 including a laser 204, a lens circuit 206, and a controller 208 with an RTP controller 210. The substrate processing system 200 operates similarly to the substrate processing system 100 of FIG. 1 and includes portions of the substrate processing system 100 not shown in FIG. 2. The substrate processing system 200 includes a laser 204, a lens circuit 206, and a controller 208 instead of the heat source 126, the controller 180, and the capacitive discharge circuit 184. The laser 204 is a heat source that may be pulsed (or modulated) by the RTP controller 210 during RTP operation based on control signals received from the RTP controller 210. This may be done during ALE and ALD processes.

[0078] The lens circuit 206 includes a beam shaping optic 212, a Galvano mirror circuit 213 including a first mirror 214 and a second mirror 216, and a telecentric lens assembly 218. The beam shaping optic 212 may include a flat-top (or first beam shaping) optic 220 and a diffractive (or second beam shaping) optic 222. The flat-top optic 220 is used to convert the laser beam received from the laser 204, which has a Gaussian distribution, into a flat-top beam (e.g., a 2 centimeter (cm) × 2 cm flat-top beam). The temperature profile of the laser beam is also Gaussian. An example of a flat-top optic is a "flywheel" optic.

[0079] The diffractive optic 222 converts the flat-top circular beam obtained from the flat-top optic 220 into a square beam. The square beam has a corresponding uniform temperature distribution on the substrate. This allows for a uniform thermal response and / or etch rate across the portion of the substrate (e.g., substrate 112) exposed to the square beam. Providing a square beam also provides a beam having a shape that matches the shape of the die being heated. The square beam may uniformly heat the surface or upper portion of a selected die. The substrate 112 may be positioned on a substrate support within the process chamber 108.

[0080] A beam size adjustment device 226 may be disposed between the beam shaping optics 212 and the first mirror 214. The beam size adjustment device 226 may adjust the size of the square beam to be equal to or greater than the size of the die on the substrate 112. The beam size adjustment device 226 may be motorized and may include a beam expander 227. The beam expander 227 may perform expansion to increase the size of the laser beam.

[0081] RTP Controller 210 and Galvano Mirror Circuit 213 may operate as an XY galvanometer scanning system. A first mirror 214 may be used to move the laser beam across the surface of the substrate 112 in a first (or X) direction. A second mirror 216 may be used to move the laser beam across the surface of the substrate in a second (or Y) direction. The controller 208 and / or the RTP controller 210 may move the mirrors 214, 216 via motors 230, 232.

[0082] The telecentric lens assembly 218, sometimes referred to as a collimating assembly, includes a series of plano-convex lenses 240, 242, 244, and 246. While a specific number of plano-convex lenses is shown, a different number of plano-convex lenses may be included. The diameters of the plano-convex lenses 240, 242, 244, and 246 increase as the plano-convex lenses are closer to the window assembly 130, such that the diameter of lens 242 is larger than that of lens 240, the diameter of lens 244 is larger than that of lens 242, and the diameter of lens 246 is larger than that of lens 244. The plano-convex lenses 240, 242, 244, and 246 are vertically aligned to share a common centerline 248. The plano-convex lenses 240, 242, 244, and 246 are held within a mold 250 in a fixed relationship. Plano-convex lenses 240, 242, 244, 246 direct the laser beam received from second mirror 216 perpendicular to the surface of substrate 112. As the laser beam moves across the surface of substrate 112, telecentric lens assembly 218 maintains the laser beam in an orthogonal relationship with the surface of substrate 112.

[0083] As an example, the laser beam generated by laser 204 may be 355 nm in diameter and pulsed every 80 picoseconds (ps). RTP controller 210 may move mirrors 214, 216 to perform a 150 hertz (Hz) scan across the surface of substrate 112.

[0084] The substrate processing system 200 may include a temperature control system 150 that may be used to control the temperature of the substrate support 110 and the substrate 112. The temperature control system 150 may include one or more temperature sensors 156 that sense the temperature of one or more locations or zones of the substrate support 110.

[0085] FIG. 3 shows a side cross-sectional view of mirrors 214, 216 and telecentric lens assembly 218 of FIG. 2. Mirrors 214, 216 are shown directing a laser beam 300 through telecentric lens assembly 218. Laser beam 300 travels through lenses 240, 242, 244, and 246 from smallest lens 240 to largest lens 246. Laser beam 300 is circular and has a Gaussian distribution represented by curve 302 at image plane 304 or the surface of substrate 112 when it does not pass through beam shaping optics 212 of FIG. 2. When laser beam 300 passes through beam shaping optics 212, it is square-shaped, having a spot with side S.

[0086] The galvanometer mirror circuit 213 in FIG. 2 provides a two-mirror system for scanning the entire field-of-view (FOV). In one example, the FOV may be greater than 300 mm by 300 mm. In one embodiment, the lenses 240, 242, 244, and 246 collectively have a low numerical aperture (smaller than a predetermined numerical aperture) and a focal column parameter (or beam squareness parameter) within a predetermined range perpendicular to the image plane 304. The laser beam is provided perpendicular to the image plane without beam distortion at the image plane while maintaining beam uniformity and intensity. The laser beam may be focused to the image plane 304. In one embodiment, the pupil aperture, or the size of the beam spot side S, is limited to 10 mm to 12 mm. The beam size adjustment device 226 in FIG. 2 may increase the beam spot size, resulting in S being 20 mm to 22 mm.

[0087] The flange focal length (FFL) and back focal length (BFL) are shown. The FFL may be (i) the end of the flange 305 and / or the point 307 where the lens 246 begins to bend and protrude outward toward the image plane 304 and (ii) the distance from the image plane 304. The BFL may refer to (i) the point 309 on the lens 246 that is closest to the image plane 304 and (ii) the distance from the image plane 304.

[0088] The examples of Figures 1-3 above provide examples of flash lamps and laser beams. The flash lamp may be modulated (pulsed) every predetermined number of microseconds (e.g., every 300 μs), and the laser beam may be modulated (pulsed) every predetermined number of picoseconds (e.g., every 80 ps). These examples allow for continuous thermal ALE or thermal ALD processes to be performed. In one example, a 100 μs pulsed light source may be used, with a 1 Hz cycle for 1000 sq cm (cm). 2) provides a lamp power of 8 Joules (J) per cycle. More than 50 cycles may be performed for a single recipe within a single processing chamber. ALE processes, including atomic-level material removal and isotropic material removal, may be performed. These processes are performed efficiently while controlling the substrate temperature without temperature balance issues.

[0089] Figure 4 shows a time-dependent temperature profile illustrating an example of a heating-up period and a cooling period associated with a conventional continuous wave mode of operation. As shown, a heat lamp operating in a conventional continuous wave mode may heat a substrate from 20°C to 100°C-600°C in x seconds. The heat lamp may be on for t minutes. The substrate may be cooled in y seconds.

[0090] FIG. 5 shows an example temperature profile over time illustrating an example of a rapid thermal pulse. For illustrative purposes, FIG. 5 shows cold and hot pulses. In one example, cold pulses may be provided to increase the temperature of a portion of the substrate by 80° C. per cycle. The hot pulses may increase the temperature of a portion of the substrate by 600° C. per cycle. In one embodiment, the cold pulses increase the temperature of a portion of the substrate by 20° C. to 80° C. In one embodiment, the hot pulses increase the temperature of a portion of the substrate by 100° C. to 600° C. In another embodiment, no cold pulses are provided. Between each successive pair of cold and / or hot pulses, the portion of the heated substrate is cooled, for example, to a reference temperature (e.g., 20° C.). Multiple cold and / or hot pulses may be provided, and the portion of the heated substrate may be cooled between successive pulses over a predetermined number of seconds (denoted x seconds). In one example, multiple cold and hot pulses may be provided over a long period of time, such as 3 to 10 seconds.

[0091] The RTP described herein increases the substrate surface temperature, allowing for control of the substrate surface temperature. It provides heating to a predetermined depth of the substrate in a controlled and tunable manner, while providing atomic-level reaction control. This may be achieved by controlling the number, length, intensity, and frequency of pulses of the light (e.g., flash lamp or laser) being generated. In one embodiment, a series of high-temperature pulses is provided. In another embodiment, a series of low-temperature pulses is provided. In another embodiment, a combination of low-temperature and high-temperature pulses is provided, and the pulse duration, intensity (or power level), and frequency are controlled to provide a temperature depth profile across at least a portion of the surface of the substrate. By having multiple flash lamps, as in the embodiment of FIG. 1, different temperature zones may be created by operating the flash lamps differently. For example, a first one or more of the flash lamps may be operated to provide a first series of pulses having a first set of one or more durations, one or more intensity levels (or power levels), and one or more frequencies, and a second one or more of the flash lamps may be operated to provide a second series of pulses having a second set of one or more durations, one or more intensity levels (or power levels), and one or more frequencies.

[0092] FIG. 6 shows an ALE process diagram illustrating a thermal ALE process performed in accordance with the present disclosure. The thermal ALE process may include repeatedly performing pretreatment, atomic-level adsorption (or condensation), RTP (or thermal removal), and substrate refresh (or purge) operations. RTP may be used to remove films isotropically at the atomic level without thermal budget issues compared to conventional continuous wave (CW) heating approaches. In one embodiment, the heat pulse duration is less than 3 ms in duration, increasing the surface substrate temperature to approximately 500°C to avoid thermal budget issues. For example, this type of RTP may be performed when etching silicon (Si) to avoid Si diffusion into germanium (Ge).

[0093] During pretreatment (or a first surface modification operation), a plasma may be provided to modify the surface and / or portion of the substrate while hydrogen H, ammonia NH, and / or other gases are supplied to the surface and / or portion of the substrate. During atomic level adsorption (or a second surface modification operation), oxygen, a halogen gas (e.g., chlorine Cl, iodine I, fluorine F, or other halogen gas), nitrogen trifluoride NF, and / or other reactants are provided and adsorbed into the surface and / or portion of the substrate. The portion of the substrate undergoing atomic level adsorption may be, for example, a metal oxide MO, such as aluminum oxide (Al)AlO, titanium oxide (Ti)TiO, or zirconium oxide (Zr). x From or silicon nitride SiN x The adsorption may be performed on the surface of the substrate, for example, on a surface of a silicon dioxide (SiO2), a silicon dioxide (Si), a silicon dioxide (Ge), a silicon nitride (TiN), or a hafnium oxide (HfO2). After adsorption on the atomic level, the removed portion may be formed from, for example, an oxide or halide with or without a ligand, MCl. x (F x ), aluminum fluoride AlF3, titanium oxide TiO2, ammonium silicofluoride (NH4)2SiF6, or other modified materials.

[0094] In some embodiments, a predetermined number of cycles are performed to remove a predetermined amount of one or more layers of the substrate. As an example, each cycle of the thermal ALE process may remove a 1-nm-thick layer of the top portion of the substrate. During the rapid thermal operation, a flash lamp assembly or laser may be used, as shown in FIGS. 1 and 2. Table 1 provides five examples (one per row) of thermal ALE processes being performed on different types of substrates. The columns indicate a) the substrate material being removed, b) the type of plasma provided during the pretreatment (PT), c) the gas provided during the atomic adsorption (AA) operation, and d) the flash lamp or laser that may be activated for the rapid thermal (RT) heating operation and the purge gas provided during the surface refresh (SR) operation. [Table 1]

[0095] The thermal ALE process disclosed herein may be performed on other types of substrates. Thermal ALE processes may be performed to remove films of interest, including, for example, germanium (Ge), metal nitrides (e.g., TiN), Si—SiGe-containing compounds, and / or metal oxides (e.g., Al2O3 or HfO2). By-products of interest that may be removed include germanium oxide (GeO), titanium oxychloride (TiOCl), titanium oxyfluoride (TiOF), silicon chlorine (Si—Cl), silicon fluorine (Si—F), germanium chlorine (Ge—Cl), germanium fluoride (Ge—F), aluminum acetylacetonate (Al(acac)4), and hafnium acetylacetonate (Hf(acac)4).

[0096] The substrate may be cooled during the surface refresh operation. In one embodiment, active cooling is provided to cryogenically cool the substrate. This reduces the time it takes to cool the substrate, allowing more cycles to be performed in a reduced period of time. Active cooling provides rapid recovery without adversely affecting the base (or bulk) portion of the substrate.

[0097] FIG. 7 shows an example signal diagram illustrating the temperature change pattern over time for a single rapid heat pulse 700 provided. A pulsed heat source may be used to control the surface reaction of a substrate over a predetermined number of milliseconds during ALE or ALD processing. In one implementation, a plasma may be generated by turning on source power (represented by pulse 701 of curve 702) and supplying gas to the processing chamber (represented by pulse 703 of curve 704). A pump (e.g., pump 124 of FIG. 1) may be turned on to perform a purge operation (represented by pulse 707 of curve 708) to clean the circuitry of the substrate. A surface modification and atomic-level adsorption (or condensation) operation may then be performed, represented by pulse 706, followed by heating, represented by pulse 700. The processing chamber may then be purged, as represented by pulse 710 of curve 712 and pulse 713 of curve 708. Optionally, bias power may be provided, as represented by pulse 714 of curve 716. The pump may then be activated to perform a purge, as represented by pulse 718.

[0098] FIG. 8 shows an example plot of etch rate versus laser fluence for a performed ALE, illustrating the differences for Ge plasma surface modification without H plasma, Ge plasma surface modification with H plasma, p-type Si plasma surface modification with H plasma, and p-type Si plasma surface modification without H plasma.

[0099] Selective removal of portions of a Si or Ge layer of a substrate having both Si and Ge layers can be challenging for nanowire fabrication processes due to the similarity of by-products formed from etching the Si and Ge layers during plasma processing. An example implementation disclosed herein enables selective removal of a Si or Ge layer of a substrate having both Si and Ge layers. This example implementation includes RTP to raise the surface temperature of the substrate during certain processing time windows. A H plasma treatment for surface modification is performed, and the reaction time is controlled to selectively etch the Si or Ge layer. This process avoids thermal budget issues, unlike conventional heated substrate supports, which can experience thermal budget issues due to interdiffusion.

[0100] The following Figures 9 and 10 illustrate the difference between using O2 and Cl2 for atomic-level adsorption during thermal ALE of Ge and TiN. The removal rates of Ge and TiN increase linearly with increasing number of process cycles. Selectivity is controlled by the pretreatment chemistry and thermal energy provided. Figure 9 shows a plot of the amount of Ge removed versus the number of process cycles for the ALE performed. Ge is removed at ambient (or room) temperature. Figure 10 shows film thicknesses illustrating different amounts of TiN material removal for the reference, laser RTP (laser pulsed heating) without pretreatment and chlorine adsorption, pretreatment and chlorine adsorption without laser RTP, and the combination of pretreatment, chlorine adsorption, and laser RTP. The reference implementation refers to when laser pulsed heating and chlorine adsorption are not performed. Film thickness ranges 1002, 1004, 1006, 1008 are shown providing example ranges for thickness for a reference implementation, a laser heating implementation without pretreatment and chlorine adsorption, a pretreatment and chlorine adsorption implementation without laser RTP, and a combined implementation of pretreatment, chlorine adsorption, and laser RTP. Chlorine adsorption with laser RTP removes material at a rate, for example, 10 times faster than without chlorine adsorption and laser RTP.

[0101] Figure 11 shows estimated temperature and lamp power ranges for certain processes, including ALE processes for Si or SiO removal, as represented by range 1102, Ge removal processes, as represented by 1104, and annealing processes, including RTP, as represented by 1106. At approximately 500°C, 27 J / cm 2 4 shows Ge removal as performed using a lamp power per unit area of ​​1000 .mu.m.

[0102] FIG. 12 shows an example of a plot of the surface temperature change rate during a flash lamp cycle performed in accordance with the present disclosure, as well as the surface temperature change rate during the corresponding cooling period after the flash lamp cycle. A rapid heat pulse duration of less than 0.3 ms may be provided for heating to achieve a surface temperature of 600°C. Curves 1202, 1204, 1206, 1208, 1210, 1212, and 1214 illustrate the temperature change for depths of the surface (i.e., less than 1 μm), 5 μm, 50 μm, 100 μm, 200 μm, 400 μm, and 800 μm, respectively. Curves 1202, 1204, 1206, 1208, 1210, 1212, and 1214 are shown for a 4 ms period. Curve 1220 is shown to illustrate the time it takes for the surface of the substrate to cool to ambient (or room) temperature without active cooling after a 4 ms period. As shown, the cooling time may be 0.5 seconds. As the noted curve illustrates, multiple cycles may be performed without increasing the temperature of the base (or bulk) portion of the substrate. Shorter pulse times and / or active cooling can further reduce recovery time and also avoid thermal balance issues from occurring.

[0103] Figure 13 shows flash lamp power levels and repetition rates versus pulse duration for a flash lamp cycle. Flash lamp power levels and repetition rates are provided for certain rapid heat pulse durations. Repetition rate refers to the number of pulses per second (e.g., 2 pulses per second is 2 Hertz). The maximum flash lamp power is 80 J / cm. 2and the maximum pulse duration may be 6000 μs. In one example, the rapid thermal process may be 30 J / cm for a duration of less than 3 ms. 2 As another example, it may include less than 20 J / cm 2 may be provided to increase the surface temperature of the substrate by 400 to 500°C.

[0104] FIG. 14 shows a diagram illustrating repeated rapid thermal pulse cycles performed to remove a portion of a dielectric layer from a portion of a substrate. A layer stack 1400 is shown, with a portion of the dielectric layer 1404 being removed during each cycle. The layer stack 1400 is positioned between two trenches (represented by arrows 1405), which allow etching access to the sides of the dielectric layer 1404. The substrate may be previously etched or cut to provide the trenches. The layer stack 1400 includes a mask layer 1402, a dielectric layer 1404 (e.g., a layer formed from Si), and a conductive layer 1406 (e.g., a conductive element or wiring formed from SiGe). A portion of the dielectric layer 1404 is removed during each cycle of the corresponding RTP process. For example, a portion 1408 is removed during the first cycle. The portion 1408 may be a single layer of the corresponding dielectric layer 1404.

[0105] Conventionally, portions of Si or Ge layers have been removed by (i) anisotropic plasma etching processes or (ii) isotropic digital etching processes, which include oxidation (or wet) and removal (or wet or dry) operations. Anisotropic plasma etching processes can cause layer damage, and isotropic digital etching processes (or wet processes) can result in layer pattern collapse, for example, in the central region of multiple layers due to tension caused by using wet chemicals. Dry processes can be performed instead of wet processes; however, dry processes carry the risk of correspondingly damaging layers. These concerns are widely recognized in nanoscale (or nanowire) applications. For example, a stack of Si nanowires extending over a given distance can be 60 nm thick and spaced 20 nm apart. When wet etching is performed, the central region between the ends of the Si nanowires can collapse, resulting in the gap between the Si nanowires being reduced to the point where they touch each other.

[0106] The disclosed examples provide isotropic ALE with RTP to remove portions of layers without layer damage and / or pattern collapse. In one embodiment, multiple cycles of oxidation and removal of portions of a Si layer are performed, for example, using RTP, to provide a gate-all-around (GAA) field effect transistor (FET) formed from an initial stack of layers. This process is dry and allows for atomic-level etch rate control of high aspect ratios (HARs) without damage.

[0107] The systems disclosed herein may be operated using numerous methods, examples of which are illustrated in Figure 15. Figure 15 shows an ALE method of implementing RTP as described herein. The following operations are described primarily with respect to the implementations of Figures 1 and 2, but the operations may be easily modified to apply to other implementations of the present disclosure. The operations may be performed iteratively.

[0108] The method begins at 1500. At 1502, a substrate (e.g., substrate 112 of FIGS. 1 and 2 and / or a 300 mm diameter substrate) is arranged in a processing chamber. At 1504, chamber operating parameters such as substrate support temperature, chamber pressure, RF and bias power levels, and gas flow rates are set.

[0109] At 1506, the surface of the substrate is cleaned. As an example, the substrate may include a Ge layer disposed on a Si layer. The top surface of the Ge layer may be cleaned.

[0110] At 1508, pre-treatment may be performed, including exposing the surface of the substrate to, for example, H plasma or NH plasma for dechlorination and surface activation. As an example, a plasma gas mixture containing hydrogen H gas or ammonia NH gas species is supplied to the processing chamber. In one embodiment, surface modification is performed without plasma, but by using gases with pre-selected chemistries.

[0111] At 1510, atomic level adsorption is performed. This may be performed at low temperatures (e.g., 20° C. or below) and may include exposing the surface of the substrate to O, Cl, I, NF, or other reactants. In one embodiment, atomic level adsorption is performed below room (or ambient) temperature. As an example, a non-plasma flow of Cl may be provided. At 1512, gases are purged from the corresponding process chamber.

[0112] At 1514, pulsed rapid thermal annealing is performed, for example, using a flash lamp, laser, or other suitable lamp (e.g., infrared lamp) that can be rapidly pulsed as described herein. At least operations 1508-1515, including adjusting the surface (or upper portion) temperature of the substrate, may be performed repeatedly. The temperature of the surface (or upper portion) may be adjusted multiple times in as little as one second. At 1514, pulsed rapid thermal annealing is performed for desorption / removal purposes. This may include generating one or more pulses of thermal energy that heat the modified portion of the substrate. The increased temperature may cause evaporation of certain molecules.

[0113] During operation 1514, the base and / or bulk of the substrate is maintained at a predetermined temperature (e.g., 20°C or below). GeCl begins to sublime above 260°C. SiCl begins to sublime above 650°C. By applying a laser or flash lamp pulse of appropriate energy, Ge can be selectively etched with infinite selectivity without etching Si in applications where a layer of Ge is deposited over a layer of Si. RTP allows one processing chamber configuration to be used for high throughput. Multiple processing operations may be performed in a single processing chamber. Figure 16 shows a plot of etch rates for Ge and Si versus substrate surface temperature during an ALE process performed as described. As another example, the pulse may be 0.1 ms long and may raise the surface and / or portion of the substrate up to 1000°C.

[0114] In some examples, each of the flash lamp pulses is 10 J / cm 2 (i.e., energy per unit area of ​​the substrate) ~80J / cm 2 In some examples, each of the laser pulses provides an output of 10 mJ / cm 2 ~80mJ / cm 2In some examples, the annealing is performed for a predetermined period of time ranging from 0.1 ms to 20 ms. In one embodiment, a surface or upper portion of the substrate is heated from an initial temperature to above 500°C using a flash lamp with a pulse duration of 1 ms or a laser with a pulse duration of 1 ps, and then cooled back to the initial temperature in less than 1 s.

[0115] Operations 1508, 1510, and 1514 allow for controllable atomic by atomic removal of the top layer of the substrate modified during operations 1508 and 1510. The rapid heating performed in 1514 provides an isotropic reaction without the use of plasma. In addition, the claimed heating allows for rapid cooling, thereby further avoiding heat balance issues. FIG. 17 shows examples of heating rates versus cooling rates for different heat sources and corresponding methods. FIG. 17 shows that the disclosed flash lamp and laser heating methods provide more rapid heating and cooling rates compared to other furnace, IR lamp, electron (E) beam, and spike methods.

[0116] At 1515, the surface of the substrate may be refreshed by purging the processing chamber with a purge gas (e.g., argon (Ar) gas) to perform ion bombardment and remove one or more modified portions of the substrate. In one embodiment, the processing chamber is purged between one or more successive pairs of applied rapid thermal pulses. In some embodiments, gas is purged from the processing chamber between each successive pair of pulses. This allows for multiple plasma and / or gas phase processes to be performed within the processing chamber. In some embodiments, substrate support cooling is provided during and / or after pulsed rapid thermal annealing to help maintain the base and / or bulk temperature of the substrate during pulsed rapid thermal annealing and to help rapidly cool the substrate after pulsed rapid thermal annealing is performed.

[0117] At 1516, the controller 180 or 208 and / or the rapid thermal pulse controller 182 or 210 determines whether N cycles have been completed. If N cycles have been completed, operation 1518 is performed; if not, operation 1508 is performed. At 1518, the controller 180 or 210 may optionally perform a second (or subsequent) annealing operation. At 1519, the controller 180 or 210 may determine whether another process should be performed on the current die, and / or whether the current process should be modified and / or repeated multiple times. If another process should be performed, operation 1504 may be performed; otherwise, operation 1520 may be performed if a laser and lens circuit is utilized as in the embodiment of FIG. 2. If a flash lamp is used as in the embodiment of FIG. 1, if another process or modification of the current process is not to be performed, the method may end at 1522. If processing is to be performed on another die, operation 1524 may be performed; otherwise, the method may end at 1522 .

[0118] At 1524, the controller 208 moves the mirrors 214, 216 to change the image plane position of the laser beam so that it is over a different die on the substrate 112. As an example, a 2 cm x 2 cm laser beam may be moved from over a first die to over a second die. The described method may be performed iteratively to scan the laser beam over tens to hundreds of dies on a substrate. The movement of the mirrors 214, 216 may be synchronized with the pulsing repetition rate of the laser 204 to provide one or more shots per die.

[0119] The above-described operations are meant to be illustrative examples. Depending on the application, the operations may be performed sequentially, synchronously, simultaneously, consecutively, or in a different order during overlapping periods. Also, none of the operations may be performed or omitted depending on the implementation and / or chronological order.

[0120] While the method of FIG. 15 was described with respect to performing ALE using the systems of FIGS. 1 and 2, ALD may also be performed using the systems of FIGS. 1 and 2. Heat sources such as flash lamps and lasers may be used to grow a monolayer on a substrate. For example, RTP may be provided before and / or during a deposition operation to deposit (grow) material rather than remove it. During ALD, different gases may be provided and maintained in the corresponding process chambers to allow the monolayer to grow.

[0121] Figure 18 is a block diagram showing two examples of the ALE method for removing a single layer of TiN. The systems of Figures 1 and 2 may be used to perform the method of Figure 18. The first method involves providing a H plasma as a pre-treatment operation to modify the upper portion of the TiN layer or substrate, providing a weakly bonded TiN layer 1800 on the remaining portion 1802 of the TiN layer or substrate. Then, a Cl plasma is provided to perform atomic level adsorption to convert the weakly bonded TiN layer 1800 into TiCl. x N y Converting to layer 1804. TiCl x N y is a volatile complex compound. RTP is then carried out to remove TiCl x N y Layer 1804 is removed.

[0122] As an example, a cycle may include providing H plasma for 13 seconds, including providing H gas and Ar gas at a flow rate of 90 sccm (standard cubic centimeter) and a pressure of 180 milliTorr (mT), providing Cl plasma for 25 seconds, including providing Cl at a flow rate of 100 sccm and a pressure of 400 mT, and performing a 30-second purge operation after the atomic level adsorption operation and before the RTP operation, each at x mJ / cm. 2and performing an RTP operation including providing five pulses at 1000 . In one embodiment, x is 21. In one embodiment, this cycle is performed a predetermined number of times (e.g., 30 times). Table 2 below provides example film thicknesses for this method before performing atomic-level adsorption with Cl2 and / or performing RTP, as well as example film thicknesses resulting from performing atomic-level adsorption with Cl2 and / or RTP. [Table 2]

[0123] Figure 19 shows an example plot of TiN film thickness for different energy levels. Etching is at 20 mJ / cm 2 Therefore, etching is performed with a laser energy of 21 mJ / cm 2 , and range 1906 is below ranges 1900, 1902, and 1904.

[0124] Referring again to FIG. 18, the second method provides an O2 plasma as a pre-treatment operation to reduce nitric oxide (NO x ) and modify the upper portion of the TiN layer or substrate by removing nitrogen, and deposit TiO on the remaining portion 1812 of the TiN layer or substrate. x The step of providing a layer 1810 includes providing a Cl plasma to achieve atomic level adsorption to form a TiO x Layer 1810 is made of titanium sub-oxychloride (TiOCl x ) layer 1814. TiOCl x is a volatile complex compound. Then, RTP is carried out to obtain TiOCl xTo remove layer 1814, for example, a cycle may include providing O and Ar gases at a flow rate of 90 sccm and a pressure of 180 milliTorr (mT), providing an O plasma for 5 seconds, providing Cl plasma for 25 seconds, providing Cl at a flow rate of 100 sccm and a pressure of 400 mT, and performing a 30-second purge after the atomic level adsorption operation and before the RTP operation, each at x mJ / cm. 2 and performing an RTP operation, including providing five pulses at 100 . As an example, for the second method, an example film thickness is 93 nm before performing the second method and 79.6 nm after performing 100 cycles of the second method. The corresponding etch rate may be 1.32 Å per cycle. FIG. 20 shows an example plot of TiN film thickness for different numbers of ALE cycles performed. As an example, the ranges 2000, 2002, and 2004 are shown for 0, 50, and 100 cycles performed.

[0125] The two mentioned methods are isotropic ALE processes. In one embodiment, these methods provide an etch rate of 1.5 Å to 2.0 Å per cycle. An etch rate of 2.0 Å per cycle is 10 times faster than an oxidation-fluorination etch process for TiN. The etch depth may be controlled by controlling the number of cycles of the mentioned methods performed and / or the plasma power level. The two methods described above include optical radiation / pulsed heat sources that enable isotropic removal during the ALE process. The two methods may be modified to perform two anisotropic ALE processes by applying a plasma during RTP and introducing a bias voltage through one or more electrodes in the substrate support. For example, a bias voltage may be provided through electrode 118 of the substrate support 110 in FIG. 1 . In addition, the bias power applied to one or more electrodes in the substrate support may be controlled to control the directionality of the ions, enabling isotropic control.

[0126] 21 is an example plot of TiN film thickness ranges illustrating different amounts of material removal for different operations performed. TiN film thickness ranges 2100, 2102, 2104, 2106, 2108, 2110, and 2112 are shown for the baseline, laser RTP without pretreatment and atomic-level adsorption (or "laser only"), Cl pretreatment and atomic-level adsorption without laser RTP, H plasma pretreatment and laser RTP, O plasma pretreatment and laser RTP, H plasma pretreatment with flash lamp RTP, and O plasma pretreatment with flash lamp RTP, respectively. As an example, for 30 cycles, the TiN etch rates for H plasma pretreatment and laser RTP, O plasma pretreatment and laser RTP, H plasma pretreatment with flash lamp RTP, and O plasma pretreatment with flash lamp RTP may be 3.9 Å per cycle, 1.4 Å per cycle, 2.0 Å per cycle, and 2.4 Å per cycle, respectively.

[0127] 22 shows an ALE process diagram 2500 illustrating iodine gas introduction and silicon removal without germanium removal. The illustrated ALE process is similar to the ALE process described above with respect to FIG. 22 The ALE process shown in Figure 1 includes starting with layers of silicon and germanium, which may be stacked or arranged side-by-side as shown, that have formed bonds with hydroxide OH. A hydrogen H2 plasma is then introduced during pre-treatment to remove elemental oxygen as shown. After pre-treatment, a halogen (e.g., iodine gas) is introduced. The silicon and germanium layers are then used to form halogen species (or iodine) bonds (e.g., Si-I and Ge-I molecules). Alternatively, a hydrocarbon (e.g., CH3) may be introduced instead of iodine.

[0128] After forming the Si-halogen or Si-hydrocarbon molecules, the temperature of the silicon and germanium layers is increased to remove the Si-halogen or Si-hydrocarbon molecules. This may be done by (i) heating the substrate containing the silicon and germanium layers by heating the corresponding substrate support, and / or (ii) heating the substrate using a laser or heat lamp as described herein. x Sublimation of GeI occurs at approximately 110°C. x Sublimation of SiI begins at approximately 350°C. Therefore, the silicon and germanium layers are heated to approximately 100°C to 130°C to selectively convert SiI x Remove the molecule and remove GeI x The molecules may not be removed. Heating may include RTP heating as described herein. After removing the Si-halogen or Si-hydrocarbon molecules, hydrogen plasma may be reintroduced and the cycle may be repeated.

[0129] Figure 23 shows a plot of silicon layer thickness versus etch rate for different substrate support temperatures. x 1 shows a plot for etching of molecules. As can be seen from the plot, the peak etch rate varies with the temperature of the substrate support and therefore with the SiI x This occurs when the temperature of the substrate bearing the molecule-containing layer is approximately 110° C. The amount of material removed is greatest at this temperature. As an example, the plot of FIG. 23 is provided for an ALE process cycle that includes the introduction of hydrogen followed by the introduction of iodine gas (or iodine plasma), followed by a purge using, for example, argon gas. 23 The plots of are also based on heating the substrate by heating the substrate support using, for example, heater 116 of Figure 1. No laser and / or flash lamp was used to heat the substrate.

[0130] FIG. 24 shows graphs of etch depth range and surface roughness associated with measurements of samples taken before heating (referred to as "before" Si), after flash lamp heating for different energy levels (referred to as "SiCl"), and after substrate support heating. As shown, the Z range (or the distance between the highest and lowest physical points on the Si layer) and surface roughness Rq are lowest before etching. However, when the substrate support is heated and iodine is introduced, for example via heating element 116 of FIG. 1, the Z range and surface roughness Rq are significantly higher than when chlorine etching is performed using a flash lamp to heat the substrate. Two sets of bar graphs are shown for two tests of chlorine etching using a flash lamp; the first test was performed for 0.3 ms with greater thermal energy than the second test, which was performed for 3 ms with less thermal energy. The difference between these two sets of bar graphs is negligible. As an example, a bar graph for Si-I2 is provided for an ALE process cycle that includes the introduction of hydrogen followed by the introduction of iodine gas (or iodine plasma), followed by purging using, for example, argon gas.

[0131] FIG. 25 shows a plot of silicon etch rate and germanium deposition rate resulting from iodine plasma introduction with a heated substrate support. As can be seen from the plot, the silicon etch rate is maximized when the substrate support and / or substrate are approximately 110° C. Although not shown in the plot, the germanium etch rate may increase as the temperature of the substrate support increases to approximately 300° C. or higher. Depending on the temperature of the substrate, there may be a 10:1 selectivity ratio between the silicon etch rate and the germanium etch rate. In the plot, the germanium etch rate is shown for when the substrate support is at room temperature and is approximately zero. Germanium deposition begins at approximately 70° C. or higher.

[0132] The ALE process described above, using flash lamp or laser heating and introducing iodine as the halogen, provides a highly selective ALE that removes silicon at high throughput and does not remove germanium. This ALE process improves thickness control compared to plasma etching and is compatible with high aspect ratio (HAR) etching. In one embodiment, pulsed thermal flash lamp or laser heating is provided to elevate the substrate temperature to 100°C-290°C or higher, desorbing Si-I bonds while leaving Ge-I bonds. Desorption of Ge-I bonds does not occur until the substrate temperature reaches 300°C-440°C or higher. A few examples of species that may be introduced in place of iodine are CH3I, CH3I3, C2H5I, CH2I2, and other C x H y I z It is a molecule.

[0133] Figure 26 shows a plot of etch rate versus heat pulse energy for silicon and germanium using an iodine plasma. As shown, the etch rate for silicon begins at 15 millijoules (mJ) and increases, such that activation occurs at approximately 18 mJ. As shown, the etch rate for germanium is zero for energy levels below 45 mJ. This etching method is self-limiting in that after a certain number of rapid heat pulses, all or most of the surface modified during adsorption has been removed during desorption.

[0134] FIG. 27 shows plots of etch depth and surface roughness for heated and laser-mounted substrate support implementations. A first surface roughness curve 3000 is shown for heating the substrate support via heating element 116, e.g., FIG. 1 . A second surface roughness curve 3002 is shown for laser heating of the substrate support, as described herein. Both curves 3000 and 3002, and therefore etch rate curve 3004, are shown for heating via an internal heating element in the substrate support or heating the substrate via a laser. As shown, roughness is significantly greater using an internal heating element or other internal heating method, such as heating a fluid circulating through an internal heating channel in the substrate support, than when heating the substrate using a laser. Additionally, laser heating removes a high percentage of the modified layer (e.g., Si—I bonds) after approximately 10 cycles, each cycle comprising 11 mJ of energy and 5 pulses.

[0135] Figure 28 shows plots of etch rate and surface roughness versus pulse number for laser-mediated substrate heating. As shown, the etch rate decreases as the pulse number increases until it reaches approximately 5 pulses. As shown, the surface roughness decreases with increasing pulse number and has minimal change after a certain number of pulses (e.g., 10 pulses). This is because a high percentage of the modified material is removed after a given number of pulses. Removing modified material using a pulsed laser is a self-limiting process, resulting in all of the modified material being removed after a certain number of pulses. For the example shown, the substrate support was at room temperature and therefore not heated. The laser pulse energy was set to 11 mJ.

[0136] The above examples include selective etching of silicon over germanium. Examples provide high-throughput, highly selective ALE with improved layer thickness control. Pulsed laser operation enables in-situ plasma or gas-phase processing. Perform multiple cycles of surface modification and isotropic removal with nanoscale selectivity with short processing times. Perform rapid pulsed thermal ALE in a single processing chamber without thermal budget issues.

[0137] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its field of application, or uses. The broad teachings of the present disclosure can be implemented in a variety of forms. Thus, while the present disclosure includes specific examples, the true scope of the disclosure should not be limited to those examples, as other modifications will become apparent upon study of the drawings, the specification, and the following claims. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in and / or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitution of one or more embodiments for another remains within the scope of the present disclosure.

[0138] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless expressly described as "direct," when the above disclosure describes a relationship between a first element and a second element, the relationship can be a direct relationship where no other intervening elements exist between the first and second elements, or it can be an indirect relationship where one or more intervening elements (spatial or functional) exist between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical non-exclusive OR (A OR B OR C), and not to mean "at least one of A, at least one of B, and at least one of C."

[0139] In some implementations, the controller is part of a system, which may be part of the examples described above. Such a system may comprise semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (such as wafer pedals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a "controller," which may control various components or subdivisions of one or more systems. Depending on the processing requirements and / or type of system, the controller may be programmed to control any of the processes disclosed herein, including delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and motion settings, wafer transfer into and out of tools and other transfer tools, and / or load locks connected to or interfaced with specific systems.

[0140] Broadly speaking, a controller may be defined as an electronic circuit having various integrated circuits, logic circuits, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute the program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files) that define operational parameters for performing specific processes on or for a semiconductor wafer or for a system. The operational parameters, in some embodiments, may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon oxides, surfaces, circuits, and / or die of a wafer.

[0141] In some implementations, the controller may be part of or coupled to a computer that is integrated with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or part of a semiconductor fab’s host computer system, thereby enabling remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a fabrication operation, examine the history of past fabrication operations, examine trends or performance indicators from multiple fabrication operations, modify parameters of a current process, configure processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data specifying parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by having one or more separate controllers networked together that operate toward a common purpose, such as the process and control described herein. One example of a distributed controller for such purposes is one or more integrated circuits on the chamber that are in communication with one or more remotely located integrated circuits (e.g., at the platform level or as part of a remote computer) that combine to control the process on the chamber.

[0142] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0143] As noted above, depending on the processing step or steps to be performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, nearby tools, adjacent tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to transport containers of wafers to and from tool locations and / or load ports within a semiconductor fabrication factory. [Form 1] a heat source configured to heat a substrate, a gas delivery system configured to supply a first process gas to the processing chamber; a controller configured to control the gas delivery system and the heat source to repeatedly perform an isotropic atomic layer etching process; and The isotropic atomic layer etching process comprises: performing pretreatment, atomic level adsorption, and pulsed thermal annealing during the iterations of the isotropic atomic layer etching process; exposing the surface of the substrate to a first process gas comprising a halogen species that selectively adsorbs onto the exposed material of the substrate to form a modified material during the atomic level adsorption; during the pulsed thermal annealing, pulsing the heat source on and off multiple times within a predetermined period of time to expose and remove the modified material; A heat source including. [Form 2] A substrate processing system as described in claim 1, wherein the controller is configured to allow the modified material to cool between successive pulses of thermal energy from the heat source during repetition of the pulsed thermal annealing. [Form 3] 2. The substrate processing system according to claim 1, wherein the heat source includes a plurality of flash lamps. [Form 4] 4. The substrate processing system of claim 3, further comprising a capacitive discharge circuit configured to discharge the plurality of flash lamps for each of a plurality of thermal energy pulses of the heat source. [Form 5] 4. The substrate processing system according to claim 3, wherein the heat source includes a reflective surface having radial reflective portions for each of the plurality of flash lamps. [Form 6] 4. The substrate processing system according to claim 3, wherein the plurality of flash lamps each include a corresponding cooling jacket. [Form 7] 4. The substrate processing system according to claim 3, further comprising a conical reflective surface that directs thermal energy from the plurality of flash lamps toward the substrate. [Form 8] 4. A substrate processing system as described in claim 3, wherein the controller is configured to pulse the plurality of flash lamps to be on for a pulse duration of less than 4 milliseconds during at least one iteration of the pulsed thermal annealing. [Form 9] A substrate processing system as described in form 1, wherein the controller is configured to heat the modified material of the substrate via the heat source during at least some of the repetitions of the pulsed thermal annealing so that the modified material of the substrate cools to a temperature of less than 25°C in less than 0.5 seconds after the heat source is turned off. [Form 10] The substrate processing system according to aspect 1, the heat source includes a laser; The laser is configured to generate a laser beam that is directed toward the substrate. [Form 11] 11. The substrate processing system according to claim 10, Multiple mirrors and Multiple motors and Furthermore, The controller is configured to direct a laser beam by moving the mirror via the plurality of motors to spread across the substrate. [Form 12] 12. The substrate processing system according to claim 11, The substrate has a diameter of 300 mm; the substrate includes a plurality of dies; The substrate processing system, wherein the controller is configured to heat each of the plurality of dies spread across each of the plurality of dies within the predetermined period of time. [Form 13] 13. The substrate processing system according to claim 12, the predetermined period is 1 second; The substrate processing system, wherein the controller is configured to individually heat each of the plurality of dies a second predetermined number of times. [Form 14] 11. A substrate processing system according to claim 10, further comprising a lens circuit configured to shape and direct the laser beam. [Form 15] A substrate processing system as described in claim 14, wherein the lens circuit includes a beam shaping optical component for converting the laser beam from a round-shaped laser beam to a square-shaped laser beam. [Form 16] 15. The substrate processing system according to claim 14, wherein the lens circuit comprises: the laser beam Circle a flat-top optic for converting a flat-top laser beam into a flat-top laser beam; The flat-topped laser beam Correct A diffractive optical element that converts the laser beam into a square shape. A substrate processing system comprising: [Form 17] 11. The substrate processing system according to claim 10, further comprising a mirror module including a first mirror, a second mirror, a first motor, and a second motor; The substrate processing system is configured such that the controller moves the first mirror and the second mirror via the first motor and the second motor to adjust the position of the laser beam on the substrate. [Form 18] A substrate processing system as described in aspect 10, further comprising a telecentric lens assembly comprising a plurality of lenses configured to direct the laser beam in a direction perpendicular to the surface of the substrate. [Form 19] 19. The substrate processing system according to claim 18, further comprising a mirror module including a first mirror, a second mirror, a first motor, and a second motor; the laser beam is directed towards the first mirror; the laser beam is directed from the first mirror to the second mirror; the laser beam is directed from the second mirror through the telecentric lens assembly to the substrate; The substrate processing system is configured such that the controller moves the first mirror and the second mirror via the first motor and the second motor to adjust the position of the laser beam on the substrate. [Form 20] A substrate processing system according to aspect 19, the processing chamber is an inductively coupled plasma chamber or a remote plasma source connected chamber; The substrate processing system, wherein the telecentric lens assembly is positioned above a dielectric window of the processing chamber. [Form 21] 11. A substrate processing system as described in claim 10, further comprising a beam size adjustment module configured to adjust the size of the laser beam before it is received by the substrate. [Form 22] 2. The substrate processing system of claim 1, wherein the processing chamber is plasma-free during the pulsed thermal annealing. [Form 23] A substrate processing system as described in form 1, wherein the controller is configured to set the temperature inside the processing chamber to 20°C or less or equal to ambient temperature during one or more repetitions of the atomic level adsorption. [Form 24] A substrate processing system as described in form 1, wherein the controller is configured to control the heat source to generate multiple thermal energy pulses that heat the modified material of the substrate without heating at least one of a base portion or a bulk portion of the substrate. [Form 25] A substrate processing system as described in claim 1, wherein the controller is configured to supply the first processing gas to the processing chamber to perform atomic-level adsorption on the exposed material of the substrate between each successive pair of thermal energy pulses of the heat source. [Form 26] 26. A substrate processing system according to claim 25, wherein the controller is configured to modify the substrate by exposing the substrate to a second process gas during the pre-processing. [Form 27] 2. A substrate processing system according to claim 1, wherein the controller is configured to pulse the heat source to generate multiple pulses of thermal energy within one second. [Form 28] The substrate processing system according to aspect 1, the pre-treatment includes introducing a second treatment gas; the second process gas comprises hydrogen; the halogen species comprises oxygen; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises germanium. [Form 29] The substrate processing system according to aspect 1, the pre-treatment includes introducing a second treatment gas; the second process gas comprises hydrogen; the halogen species comprises chlorine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises germanium. [Form 30] The substrate processing system according to aspect 1, the pre-treatment includes introducing a second treatment gas; the second process gas comprises hydrogen; the halogen species includes iodine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises silicon. [Form 31] 31. The substrate processing system of claim 30, wherein the pulsed thermal annealing comprises selectively removing silicon without removing germanium. [Form 32] The substrate processing system according to aspect 1, the pre-treatment includes introducing a second process gas containing hydrogen or oxygen; the halogen species comprises chlorine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises titanium. [Form 33] The substrate processing system according to aspect 1, the pre-treatment includes introducing a second treatment gas; the second process gas comprises hydrogen or ammonia; the halogen species comprises fluorine; the pulsed thermal annealing comprises removing a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises silicon dioxide. [Form 34] 1. A method of operating a substrate processing system, comprising: placing a substrate on a substrate support in a processing chamber; repeatedly performing a first atomic layer deposition (ALE) process, the first ALE process being a sequential isotropic process; a pre-treatment step including supplying a first process gas to the processing chamber to modify a first exposed portion of the substrate; atomic level adsorption, including exposing the first exposed portion to a second process gas comprising a halogen species that selectively adsorbs onto the first exposed portion to modify the first exposed portion; and pulsed thermal annealing, which includes controlling a heat source to generate pulses of thermal energy to expose and remove the modified first exposed portion. and determining whether a predetermined number of cycles of the first ALE process have been performed; when the predetermined number of cycles has been performed, the first ALE process is no longer performed; A method for providing the above. [Form 35] 35. The method of claim 34, further comprising purging the processing chamber after performing the atomic level adsorption and before performing the pulsed thermal annealing. [Form 36] 35. The method of claim 34, further comprising purging the processing chamber after performing each iteration of the pulsed rapid thermal annealing. [Form 37] 35. A method according to claim 34, further comprising the step of performing the first ALE process multiple times within one second. [Form 38] 35. The method of claim 34, determining whether a second ALE process should be performed; changing the parameters set for the first ALE process to updated parameters for the second ALE process; Within the processing chamber: performing a pre-processing step including supplying the first process gas or the third process gas to the processing chamber to modify the first exposed portion or the second exposed portion of the substrate; performing atomic level adsorption, including exposing the first exposed portion or the second exposed portion to the second gas or a fourth gas comprising a halogen species; and performing pulsed rapid thermal annealing, including controlling the heat source to generate pulses of thermal energy to heat the first exposed portion or the second exposed portion; repeatedly performing the second ALE, including A method further comprising: [Form 39] 35. The method of claim 34, determining whether to perform a second ALE process, wherein the first ALE process is performed on a first die of the substrate; performing the second ALE process on a second die of the substrate; A method further comprising: [Form 40] 35. The method of claim 34, further comprising: charging a plurality of capacitors; discharging the plurality of capacitors to provide power to a plurality of flash lamps; A method further comprising: [Form 41] 35. The method of claim 34, further comprising: generating a laser beam; converting the laser beam into a flat-top beam; converting the flat-top beam into a square beam; reflecting the square beam off a plurality of mirrors to a telecentric lens assembly; passing the square beam through the telecentric lens assembly to the substrate in a direction perpendicular to the substrate; A method further comprising: [Form 42] 42. The method of claim 41, further comprising adjusting the size of the square beam for the rapid thermal annealing to be equal to or greater than the size of the die of the substrate. [Form 43] 35. The method of claim 34, further comprising: to extend across the substrate, which is 300 mm in diameter and contains multiple dies; and spreading across each of the plurality of dies within a predetermined period of time to heat each of the plurality of dies; directing the laser beam by moving a mirror A method further comprising: [Form 44] 44. The method of claim 43, the predetermined period is 1 second; Each of the plurality of dies is individually heated a predetermined number of times. [Form 45] 35. The method of claim 34, the first gas comprises hydrogen; the halogen species comprises oxygen; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises germanium. [Form 46] 35. The method of claim 34, the first gas comprises hydrogen; the halogen species comprises chlorine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises germanium. [Form 47] 35. The method of claim 34, the first gas comprises hydrogen; the halogen species includes iodine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises silicon. [Form 48] 48. The method of claim 47, wherein the pulsed thermal annealing comprises selective removal of silicon and does not comprise removal of germanium. [Form 49] 35. The method of claim 34, the first gas comprises hydrogen or oxygen; the halogen species comprises chlorine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises titanium. [Form 50] 35. The method of claim 34, the first gas comprises hydrogen or ammonia; the halogen species comprises fluorine; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises silicon dioxide.

Claims

1. 1. A method of operating a substrate processing system, comprising: placing a substrate on a substrate support in a processing chamber; repeatedly performing a first atomic layer deposition (ALE) process, the first ALE process being a sequential isotropic process; a pretreatment to modify a first exposed portion of the substrate; atomic level adsorption, including exposing the first exposed portion to a process gas including a halogen gas that selectively adsorbs onto the first exposed portion to modify the first exposed portion; a pulsed thermal annealing step to remove the modified first exposed portion; and A method comprising:

2. 10. The method of claim 1, The method, wherein performing the pre-treatment includes supplying another process gas to the processing chamber to modify the first exposed portion of the substrate.

3. 10. The method of claim 1, The method, wherein the pulsed thermal annealing comprises pulsing a heat source to generate a pulse of thermal energy to remove the modified first exposed portion.

4. 10. The method of claim 1, The method, wherein the pulsed thermal annealing comprises pulsing a heat source on and off multiple times to remove the modified first exposed portion.

5. 10. The method of claim 1, determining whether a predetermined number of cycles of the first ALE process have been performed; When the predetermined number of cycles has been performed, the first ALE process is not performed; The method further comprises:

6. 10. The method of claim 1, The method, wherein the first exposed portion comprises at least one of silicon and germanium.

7. 10. The method of claim 1, The method, wherein the first exposed portion comprises silicon and germanium.

8. 10. The method of claim 1, The method further comprising allowing the first exposed portion to cool between successive thermal energy pulses during the repetitions of the pulsed thermal annealing.

9. 10. The method of claim 1, determining whether a second ALE process should be performed; changing the parameters set for the first ALE process to updated parameters for the second ALE process; Repeating the second ALE process within the processing chamber, the second ALE process comprising: performing a pre-treatment to modify the first exposed portion or the second exposed portion of the substrate; performing atomic level adsorption, which includes exposing the first exposed portion or the second exposed portion to the halogen gas or another halogen gas; performing pulsed rapid thermal annealing to heat the first exposed portion or the second exposed portion; The method further comprises:

10. 10. The method of claim 1, determining whether to perform a second ALE process, the first ALE process being performed on a first die of the substrate; performing the second ALE process on a second die of the substrate; The method further comprises:

11. 10. The method of claim 1, For the pulsed thermal annealing, charging a plurality of capacitors; discharging the plurality of capacitors to provide power to a plurality of flash lamps; A method further comprising:

12. 10. The method of claim 1, further comprising: generating a laser beam; converting the laser beam into a flat-top beam; converting the flat-top beam into a square beam; reflecting the square beam off a plurality of mirrors to a telecentric lens assembly; passing the square beam through the telecentric lens assembly in a direction perpendicular to the substrate to the substrate; The method further comprises:

13. 13. The method of claim 12, further comprising adjusting the size of the square beam for the pulsed thermal annealing to be equal to or greater than the size of a die of the substrate.

14. 13. The method of claim 12, further comprising: for the pulsed thermal annealing: to extend over the entire substrate containing the plurality of dies, the substrate being 300 mm in diameter; and spreading across each of the plurality of dies within a predetermined period of time to heat each of the plurality of dies; The method further comprising the step of directing the laser beam by moving a mirror.

15. 15. The method of claim 14, the predetermined period is 1 second; A method wherein each of the plurality of dies is individually heated a predetermined number of times.

16. 10. The method of claim 1, the processing gas contains at least one of hydrogen and oxygen; the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises germanium.

17. 10. The method of claim 1, the process gas comprises hydrogen; the halogen gas contains chlorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises germanium.

18. 10. The method of claim 1, the process gas comprises hydrogen; the halogen gas contains iodine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises silicon.

19. 20. The method of claim 18, A method wherein said pulsed thermal annealing includes selective removal of silicon and does not include removal of germanium.

20. 10. The method of claim 1, the process gas comprises hydrogen or oxygen; the halogen gas contains chlorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises titanium.

21. 10. The method of claim 1, the process gas comprises hydrogen or ammonia; the halogen gas contains fluorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The method wherein the monolayer comprises silicon dioxide.

22. 1. A substrate processing system, comprising: a heat source configured to heat a substrate on the substrate support within the processing chamber; a gas delivery system configured to supply process gases to process the substrate; a controller configured to control the gas delivery system and the heat source to perform an iterative isotropic atomic layer etching process; The isotropic atomic layer etching process comprises: performing pretreatment, atomic level adsorption, and pulsed thermal annealing during the iterations of the isotropic atomic layer etching process; exposing the surface of the substrate to the process gas comprising a halogen gas that selectively adsorbs onto the exposed material of the substrate to form a modified material during the atomic level adsorption; pulsing the heat source during the pulsed thermal annealing to remove the modified material; A substrate processing system comprising:

23. 23. The substrate processing system of claim 22, The substrate processing system, wherein the controller is configured to pulse the heat source on and off multiple times during the pulsed thermal annealing to remove the modified material.

24. 23. The substrate processing system of claim 22, wherein the controller is configured to allow the modified material to cool between successive thermal energy pulses during the repetitions of the pulsed thermal annealing.

25. 23. The substrate processing system of claim 22, further comprising a capacitive discharge circuit configured to discharge a plurality of flash lamps for each of a plurality of thermal energy pulses during the repetitions of the pulsed thermal annealing, wherein the heat source comprises the plurality of flash lamps.

26. 26. The substrate processing system of claim 25, wherein the heat source comprises: a reflecting surface having radial reflecting portions for each of the plurality of flash lamps; a cooling jacket for the plurality of flash lamps; a cone-shaped reflective surface that directs thermal energy from the plurality of flash lamps toward the substrate; A substrate processing system comprising:

27. 26. The substrate processing system of claim 25, wherein the controller is configured to pulse the plurality of flash lamps to be on for a pulse duration of less than 4 milliseconds during at least one iteration of the pulsed thermal annealing.

28. 23. The substrate processing system of claim 22, wherein the controller is configured to heat the modified material of the substrate via the heat source during at least some of the repetitions of the pulsed thermal annealing such that the modified material of the substrate cools to a temperature of less than 25°C in less than 0.5 seconds after the heat source is turned off.

29. 23. The substrate processing system of claim 22, the heat source includes a laser; The substrate processing system, wherein the laser is configured to generate a laser beam that is directed toward the substrate.

30. 30. The substrate processing system of claim 29, Multiple mirrors and a plurality of motors; The controller is configured to direct a laser beam by moving the mirror via the plurality of motors to spread across the substrate.

31. 30. The substrate processing system of claim 29, The diameter of the substrate is 300 mm; the substrate includes a plurality of dies; The controller is configured to extend over and heat each of the plurality of dies.

32. 32. The substrate processing system of claim 31, the controller is configured to pulse the heat source on and off multiple times during the pulsed thermal annealing for one second to heat each of the plurality of dies in a spread across each of the plurality of dies; The controller is configured to individually heat each of the plurality of dies a second predetermined number of times.

33. 30. The substrate processing system of claim 29, further comprising a lens circuit configured to shape and direct the laser beam.

34. 34. The substrate processing system of claim 33, wherein the lens circuit includes beam shaping optics for converting the laser beam from a round shaped laser beam to a square shaped laser beam.

35. 34. The substrate processing system of claim 33, wherein the lens circuit comprises: a flat-top optic that converts the laser beam from a round-shaped laser beam to a flat-top shaped laser beam; a diffractive optical element that converts the flat-topped laser beam into a square-topped laser beam; A substrate processing system comprising:

36. 30. The substrate processing system of claim 29, further comprising a mirror module comprising a first mirror, a second mirror, a first motor, and a second motor; The substrate processing system, wherein the controller is configured to move the first mirror and the second mirror via the first motor and the second motor to adjust a position of the laser beam on the substrate.

37. 30. The substrate processing system of claim 29, further comprising a telecentric lens assembly comprising a plurality of lenses configured to direct the laser beam in a direction normal to the surface of the substrate.

38. 38. The substrate processing system of claim 37, further comprising a mirror module comprising a first mirror, a second mirror, a first motor, and a second motor; the laser beam is directed towards the first mirror; the laser beam is directed from the first mirror to the second mirror; the laser beam is directed from the second mirror through the telecentric lens assembly to the substrate; The substrate processing system, wherein the controller is configured to move the first mirror and the second mirror via the first motor and the second motor to adjust a position of the laser beam on the substrate.

39. 30. The substrate processing system of claim 29, further comprising a beam size adjustment module configured to adjust a size of the laser beam before it is received by the substrate.

40. 23. The substrate processing system of claim 22, wherein the controller is configured to set a temperature inside the processing chamber to 20° C. or less or equal to ambient temperature during one or more iterations of the atomic level adsorption.

41. 23. The substrate processing system of claim 22, wherein the controller is configured to control the heat source to generate a plurality of thermal energy pulses that heat the modified material of the substrate without heating at least one of a base portion or a bulk portion of the substrate.

42. 23. The substrate processing system of claim 22, wherein the controller is configured to supply the process gas to the processing chamber to perform the atomic level adsorption on the exposed material of the substrate during each successive pair of thermal energy pulses of the heat source.

43. 43. The substrate processing system of claim 42, wherein the controller is configured to modify the substrate by exposing the substrate to a second process gas during the pre-processing.

44. 23. The substrate processing system of claim 22, wherein the controller is configured to pulse the heat source to generate multiple pulses of thermal energy within one second.

45. 23. The substrate processing system of claim 22, the pre-treatment includes the introduction of a separate treatment gas; the other process gas comprises hydrogen; the halogen gas contains oxygen, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises germanium.

46. 23. The substrate processing system of claim 22, the pre-treatment includes the introduction of a separate treatment gas; the other process gas comprises hydrogen; the halogen gas contains chlorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises germanium.

47. 23. The substrate processing system of claim 22, the pre-treatment includes the introduction of a separate treatment gas; the other process gas comprises hydrogen; the halogen gas contains iodine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises silicon.

48. 48. The substrate processing system of claim 47, wherein the pulsed thermal annealing comprises selectively removing silicon without removing germanium.

49. 23. The substrate processing system of claim 22, the pre-treatment includes the introduction of another process gas, the other process gas including hydrogen or oxygen; the halogen gas contains chlorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises titanium.

50. 23. The substrate processing system of claim 22, the pre-treatment includes the introduction of a separate treatment gas; the other process gas comprises hydrogen or ammonia; the halogen gas contains fluorine, the pulsed thermal annealing comprises the removal of a monolayer from the substrate; The substrate processing system, wherein the monolayer comprises silicon dioxide.

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