Integrated epitaxy and pre-cleaning system

Abstract

The embodiments of the present disclosure generally relate to an integrated substrate processing system for cleaning a substrate surface and subsequently performing an epitaxial deposition process thereon. The processing system includes a film formation chamber, a transfer chamber coupled to the film formation chamber, and an oxide removal chamber coupled to the transfer chamber and having a substrate support. The processing system includes a controller configured to introduce into the oxide removal chamber a process gas mixture including a fluorine-containing gas and a vapor including at least one of water, an alcohol, an organic acid, and combinations thereof. The controller is configured to expose a substrate positioned on the substrate support to the process gas mixture to remove an oxide film from the substrate.

Description

[Technical field]

[0001]

[0001] Embodiments of the present disclosure generally relate to an apparatus and method for cleaning a surface of a substrate. More particularly, embodiments disclosed herein relate to an integrated substrate processing system for cleaning a substrate surface and subsequently performing an epitaxial deposition process thereon. [Background technology]

[0002]

[0002] Integrated circuits are formed in and on silicon and other semiconductor substrates. In the case of single crystal silicon, the substrate is produced by growing an ingot from a solution of molten silicon and then sawing the solidified ingot into multiple substrates. An epitaxial silicon layer can then be formed on the single crystal silicon substrate to form a defect-free silicon layer, which may be doped or undoped. From this epitaxial silicon layer, semiconductor devices such as transistors can be fabricated. The electrical properties of the formed epitaxial silicon layer are generally superior to those of the single crystal silicon substrate.

[0003]

[0003] The surfaces of single crystal silicon and epitaxial silicon layers are susceptible to contamination when exposed to the ambient conditions of a typical substrate fabrication facility. For example, a native oxide layer may form on the single crystal silicon surface prior to deposition of the epitaxial layer due to handling of the substrate and / or exposure to the ambient environment of the substrate processing facility. In addition, extraneous contaminants such as carbon and oxygen species present in the ambient environment may also deposit on the single crystal surface. The presence of a native oxide layer or contaminants on the single crystal silicon surface adversely affects the quality of the epitaxial layer subsequently formed on the single crystal surface. Conventional pre-cleaning processes are often performed in one or more stand-alone vacuum process chambers, which may result in extended substrate handling times and increased exposure of the substrate to the ambient environment.

[0004]

[0004] Therefore, there is a need in the art to provide an improved substrate processing system for cleaning a substrate surface prior to performing an epitaxial deposition process that minimizes substrate handling time and exposure to the ambient environment. Summary of the Invention

[0005]

[0005] This disclosure describes a processing system including a film formation chamber, a transfer chamber coupled to the film formation chamber, and an oxide removal chamber coupled to the transfer chamber and having a substrate support. The processing system includes a controller configured to introduce into the oxide removal chamber a process gas mixture including a fluorine-containing gas and a vapor including at least one of water, an alcohol, an organic acid, and combinations thereof. The controller is configured to expose a substrate positioned on the substrate support to the process gas mixture to remove an oxide film from the substrate.

[0006] Also described herein is a method of treating a substrate, comprising removing oxides from a substrate disposed in a first process chamber by exposing the substrate to a process gas mixture comprising a fluorine-containing gas and a vapor comprising at least one of water, an alcohol, an organic acid, and combinations thereof, The method includes transferring the substrate from the first process chamber to a second process chamber under vacuum or an inert environment, and forming a film on the substrate disposed in the second process chamber.

[0007] Also described herein is a processing system including a film formation chamber, a first transfer chamber coupled to the film formation chamber, a pass station coupled to the first transfer chamber, a second transfer chamber coupled to the pass station, a first oxide removal chamber coupled to the second transfer chamber, and a load lock chamber coupled to the first oxide removal chamber. The first oxide removal chamber, the second transfer chamber, the pass station, the first transfer chamber, and the film formation chamber are maintained under a vacuum or an inert environment. The first oxide removal chamber includes a first substrate support. The system includes a computer readable medium having stored thereon instructions that, when executed by a processor of the processing system, cause the system to remove oxide from a first substrate disposed in the first oxide removal chamber by exposing the first substrate to a process gas mixture including a fluorine-containing gas and a vapor including at least one of water, an alcohol, an organic acid, and combinations thereof.

[0008]

[0008] The embodiments of the present disclosure summarized above and described in more detail below can be understood by referring to the exemplary embodiments of the present disclosure shown in the attached drawings. However, it should be noted that the attached drawings merely illustrate typical embodiments of the present disclosure and therefore should not be considered as limiting its scope, as the present disclosure may admit of other equally effective embodiments. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates a processing method according to a particular embodiment. [Diagram 2] 2 is a cross-sectional view of a processing chamber used to perform at least a portion of the cleaning process of FIG. 1, according to certain embodiments. [Diagram 3] 1 is a schematic cross-sectional view of a process chamber for performing an epitaxial deposition process, in accordance with certain embodiments. [Figure 4]FIG. 1 illustrates an exemplary integrated vacuum processing system for performing the cleaning and deposition processes described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010]

[0013] To facilitate understanding, the same reference numbers have been used, wherever possible, to designate identical elements common to the drawings. The drawings are not drawn to scale and may be simplified for clarity. It is believed that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011]

[0014] SUMMARY OF THE DISCLOSURE Embodiments disclosed herein relate to an integrated substrate processing system for cleaning a substrate surface and subsequently performing an epitaxial deposition process thereon.

[0012]

[0015] Certain embodiments disclosed herein provide for the removal of surface oxides by exposing a substrate to a mixture of a fluorine-containing gas and a vapor containing water, an alcohol, and / or an organic acid. The gas-phase mixture disclosed herein avoids the formation of solid by-products characteristic of reactions with conventional process gas mixtures containing ammonia (NH3). For example, the presence of NH3 in a fluorine-containing process gas results in the formation of solid ammonium salts (e.g., (NH4)2SiF6, or ammonium silicofluoride). The ammonium silicofluoride forms solid crystals and deposits within features formed on the substrate surface. Integrated systems are designed such that the substrate is maintained under a vacuum or inert environment to reduce or prevent the growth of native oxides, such as silicon oxide (e.g., SiO2), on the substrate surface. However, the formation of solid crystals with conventional process gases negates many of the efficiency gains that would be obtained by using such systems. Beneficially, certain embodiments disclosed herein enable the removal of surface oxides without the formation of solid by-products, such as salts.

[0013]

[0016] Removal of solid by-products from within features formed on a substrate surface may require thermal treatment (e.g., heating to decompose salt crystals), which increases processing time and complexity. For smaller feature sizes (e.g., having a critical dimension of about 25 nm or less, such as about 10 nm to about 25 nm, or having an aspect ratio (i.e., the ratio of depth to width) of about 25 or less, such as about 10 to about 25), removal of solid by-products presents even greater challenges that may not be addressed by conventional techniques. The process gas mixture disclosed herein can completely avoid the formation of solid by-products, avoiding the need for thermal treatment and improving cleaning efficiency and throughput.

[0014]

[0017] The particular process gas mixtures and process parameters disclosed herein, with or without plasma formation, improve etch selectivity compared to conventional fluorine and ammonia containing process gases, particularly for enhanced removal of native oxide compared to other materials such as low-k dielectric materials, silicon, silicon germanium, and silicon nitride (e.g., SiN).

[0015]

[0018] FIG. 1 illustrates a processing method 100 according to certain embodiments. In step 102, oxide is removed from a surface of a semiconductor substrate using a cleaning process. The removal of oxide in step 102 may also be referred to as "pre-cleaning" or "etching." The substrate may include a silicon-containing material, and the surface may include materials such as silicon (Si), germanium (Ge), or silicon germanium alloy (SiGe). In some instances, the Si, Ge, or SiGe surface may have an oxide layer, such as a native oxide layer, and contaminants disposed thereon. Because epitaxial deposition processes are sensitive to contaminants, such as oxides and carbon-containing contaminants, surface contamination resulting from exposure to a clean room environment for several hours may be significant enough that the accumulated oxides and contaminants affect the quality of the subsequently formed epitaxial layer.

[0016]

[0019] The substrate surface may be cleaned by performing an oxide removal process and a contaminant removal process. In one example, oxides are removed from the surface of the substrate using a cleaning process (step 102) and contaminants, such as carbon-containing contaminants, are removed from the surface of the substrate using a reduction process. The cleaning process may include steam. In some examples, the cleaning process may be performed without forming a plasma and / or exposing the substrate to radicals or radical species. In some examples, the process gas may not include ammonia. The process gas may include a fluorine-containing gas mixed with steam. In some examples, the process gas may further include one or more purge gases or carrier gases (e.g., hydrogen, helium, and / or argon).

[0017]

[0020] In some examples, the fluorine-containing gas may include hydrogen fluoride (e.g., HF), anhydrous hydrogen fluoride, fluorine (F2), nitrogen fluoride (e.g., nitrogen trifluoride (NF3)), carbon fluoride (e.g., carbon tetrafluoride (CF4), hexafluoroethane (C2F6), trifluoromethane (CHF3), difluoromethane (CH2F2), octofluoropropane (C3F8), octofluorocyclobutane (C4F8), octofluoro[1-]butane (C4F8), octofluoro[2-]butane (C4F8), or octofluoroisobutylene (C4F8)), sulfur fluoride (e.g., sulfur hexafluoride (SF6)), or combinations thereof. In some examples, the flow rate of the fluorine-containing gas may be about 50 sccm to about 500 sccm for a 300 mm substrate. In some examples, the concentration of the fluorine-containing gas in the processing chamber (e.g., in contact with the substrate surface) is about 5% of the total process gas mixture including all other components (e.g., carrier gas or purge gas). weight% From about 75 weight% It may be.

[0018]

[0021] In some examples, the vapor may include water (e.g., distilled water), a primary alcohol (e.g., methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, or isobutyl alcohol), a secondary alcohol (e.g., isopropyl alcohol or sec-butyl alcohol), a tertiary alcohol (e.g., tert-butyl alcohol), a cyclic alcohol (e.g., cyclohexyl alcohol), a complex alcohol (e.g., 4-ethyl-3-hexanol), a C1 alcohol, a C2 alcohol, a C3 alcohol, a C1-C2 alcohol, a C1-C3 alcohol, a C1-C4 alcohol, an organic acid, or a combination thereof. In some examples, the vapor may increase the reaction rate between the fluorine-containing gas and the surface oxide. In some examples, an alcohol with a lower carbon number may increase the reaction rate to a greater extent compared to an alcohol with a higher carbon number (e.g., the relative reaction rate may be C1 alcohol>C2 alcohol>C3 alcohol). In some examples, the flow rate of the vapor may be about 5 sccm to about 500 sccm for a 300 mm substrate. In some examples, the flow ratio of fluorine-containing gas to steam may be from about 10:1 to about 1:10. In some examples, the concentration of steam is about 5% of the total process gas mixture, including all other components (e.g., carrier gas or purge gas). weight% From about 75 weight% It may be.

[0019]

[0022] During the process, the fluorine-containing gas can be mixed with the vapor to fill the process chamber. In some other examples, the gases can be delivered to the process chamber through different paths (i.e., separately) and mixed after arriving at the process chamber before contacting the substrate. The mixture of gases can be spatially separated from the processing region in which the substrate is placed. The term "spatially separated" as used herein can refer to a mixing region that is separated from the substrate processing region by one or more chamber components or even a conduit between the mixing chamber and the substrate processing chamber. In some examples, the processing temperature, which can refer to the temperature of the mixed process gas in the processing chamber (e.g., the temperature of the mixed process gas in contact with the substrate surface), can be about 0° C. or less, such as about −50° C. to about −40° C. In some examples, the pressure of the processing chamber can be in the range of about 0.5 Torr to about 20 Torr.

[0020]

[0023] The pre-cleaning process is largely conformal and selective to oxide layers, so it does not readily etch silicon (e.g., low-k spacers or other dielectric materials), germanium, or nitride layers, whether the layers are amorphous, crystalline, or polycrystalline. The selectivity of the process gas for oxide compared to silicon or germanium is at least about 3:1, such as about 5:1 or more, such as about 10:1 or more. The process gas also has a high selectivity for oxide compared to nitride. The selectivity of the process gas compared to nitride is at least about 3:1, such as about 5:1 or more, such as about 10:1 or more.

[0021]

[0024] In some embodiments, either during or after the pre-cleaning process, thermal energy may be applied to the processed substrate to aid in the removal of any by-products that are generated. In some embodiments, the thermal energy is provided via radiative, convective and / or conductive heat transfer processes that sublimate the unwanted by-products found on the substrate surface.

[0022]

[0025] In optional step 104, a second cleaning process may be performed by removing carbon contaminants from the surface of the substrate. Although step 104 is shown after step 102, in some other embodiments, step 104 may precede step 102. The cleaning process may include a plasma process performed in a plasma cleaning chamber. The plasma process may use a plasma formed from gases including hydrogen (H2), helium (He), ammonia (NH3), a fluorine-containing gas, or combinations thereof. The plasma may be inductively or capacitively coupled, and the plasma may be formed by a microwave source in the processing chamber, or the plasma may be formed by a remote plasma source.

[0023]

[0026] In step 106, an epitaxial layer is formed on the surface of the substrate. As discussed above, the pre-cleaning ensures that the substrate surface is uniformly oxidized and free of contaminants, improving the quality of the layers subsequently formed on the substrate surface. An exemplary epitaxial process may be a selective epitaxial process carried out at a temperature below about 800° C., for example, from about 450° C. to about 650° C. The epitaxial layer may be formed using a high temperature chemical vapor deposition (CVD) process. The epitaxial layer may be any suitable semiconductor material, such as crystalline silicon, germanium, silicon germanium, or III-V or II-VI compounds. In one exemplary thermal CVD process, chlorosilane SiH x Cl 4-x (mono, di, tri, tetra), silane Si x H 2X+2 (Silane, disilane, trisilane, etc.), Germanium Ge x H 2x+2Process gases such as fluorine (germane, digermane, etc.), hydrogen chloride HCl, chlorine gas (Cl2), or combinations thereof are used. The process temperature is less than 800° C., such as about 300° C. to about 600° C., such as about 450° C., and the process pressure is in the range of about 5 Torr to about 600 Torr. An exemplary process chamber that can be used to perform the epitaxial deposition process is the Centura™ Epi chamber available from Applied Materials, Inc., Santa Clara, Calif. Chambers from other manufacturers can also be used.

[0024]

[0027] Steps 102, 104 and 106 may be performed in one processing system, such as the processing system illustrated in Figure 4 and further described below. An optional heat treatment may also be performed between or after steps 102 and 104 to remove any residual by-products or contaminants and to anneal the surface to remove any surface defects before performing the layer formation process of 106. Such an anneal may be performed under a hydrogen atmosphere, optionally containing an inert gas such as argon or helium, at a temperature of about 400°C to about 800°C and a pressure of about 1 Torr to about 300 Torr.

[0025]

[0028] FIG. 2 is a cross-sectional view of a processing chamber 200 adapted to perform at least a portion of the cleaning process of step 102, thereby configuring to remove contaminants such as oxides from the surface of the substrate.

[0026]

[0029] The processing chamber 200 may be particularly useful for performing a gas-phase cleaning process. The processing chamber 200 generally includes a chamber body 202, a lid assembly 204, and a support assembly 206. The lid assembly 204 is disposed at an upper end of the chamber body 202, and the support assembly 206 is disposed at least partially within the chamber body 202. A vacuum system may be used to remove gases from the processing chamber 200. The vacuum system includes a vacuum pump 208 coupled to a vacuum port 210 disposed in the chamber body 202.

[0027]

[0030] The lid assembly 204 includes multiple stacked components configured to supply gas to the processing region 212 in the chamber 200. The lid assembly 204 is connected to a first gas source 214 and a second gas source 216. Gases from the first gas source 214 and the second gas source 216 are introduced to the lid assembly 204 through a gas port 218. In some examples, the first gas source 214 can supply at least a first portion of a process gas (e.g., a fluorine-containing component of the process gas described above with respect to step 102 of FIG. 1). In some examples, the second gas source 216 can supply a second portion of a process gas (e.g., a vapor component of the process gas described above with respect to step 102 of FIG. 1). In some examples, one or more purge gases or carrier gases can also be supplied to the processing region 212 from the first gas source 214, the second gas source 216, or from another gas source.

[0028]

[0031] The lid assembly 204 generally includes a first plate 220, a second plate 222 below the first plate 220, and a showerhead 224 below the second plate 222 and above the processing region 212. The first plate 220, the second plate 222, and the showerhead 224 each include a plurality of apertures formed therethrough that connect the gas regions above and below each respective component. Thus, gases introduced into the lid assembly 204 through the gas ports 218 flow through each component of the lid assembly 204 in that order. In the embodiment shown in FIG. 2, the showerhead 224 is a dual channel showerhead having a first set of channels 228 and a second set of channels 230. A dual channel showerhead can be particularly advantageous for improving the mixing of different gases coming from the first gas source 214 and the second gas source 216.

[0029]

[0032] The support assembly 206 (also referred to as a "pedestal") includes a substrate support 232 for supporting a substrate thereon during processing. The substrate support 232 has a flat or substantially flat substrate support surface. As shown, the substrate support 232 includes two independent temperature control zones (referred to as "dual zones") that control the substrate temperature for center-to-edge processing uniformity and tuning. In the example shown in FIG. 2, the substrate support 232 includes an inner zone 232i and an outer zone 232o that surrounds the inner zone 232i. In some other examples, the substrate support 232 may have more than two independent temperature control zones (referred to as "multi-zones").

[0030]

[0033] The substrate support 232 is coupled to an actuator 234 by a stem 236 that extends through a centrally located opening formed in the bottom of the chamber body 202. The actuator 234 is flexibly sealed to the chamber body 202 by a bellows 238 that prevents vacuum leakage around the stem 236. The actuator 234 can vertically move the substrate support 232 within the chamber body 202 between a processing position and a loading position. The loading position is slightly below a substrate opening 240 formed in a sidewall of the chamber body 202.

[0031]

[0034] The processing chamber 200 also includes an ultra-low temperature kit 242 for reducing the temperature of the substrate being processed, which can improve selectivity of oxide removal (e.g., native oxide removal), especially compared to other materials such as low-k dielectric materials and silicon nitride (e.g., SiN). In some examples, the temperature of the substrate being processed and / or the temperature of the substrate support 232 can be reduced from about -30°C to about 10°C. The ultra-low temperature kit 242 provides a continuous flow of ultra-low temperature coolant to the substrate support 232, which cools the substrate support 232 to a desired temperature. In some examples, the ultra-low temperature coolant can include a perfluorinated inert polyether fluid (e.g., Galden® fluid). In the example shown in FIG. 2, the ultra-low temperature coolant is provided to the inner zone 232i and the outer zone 232o of the substrate support 232 through an inner coolant channel 244i and an outer coolant channel 244o, respectively. The coolant channels are depicted in FIG. 2 diagrammatically and may have different arrangements than shown. For example, each coolant channel may be in a loop.

[0032]

[0035] A system controller 250, such as a programmable computer, is coupled to the process chamber 200 for controlling the process chamber 200 or its components. For example, the system controller 250 may control the operation of the process chamber 200 using direct control of the support assembly 206, the vacuum pump 208, the first gas source 214, the second gas source 216, the actuator 234, and / or the ultra-low temperature kit 242, or using indirect control of other controllers associated therewith. In operation, the system controller 250 enables data collection and feedback from each component to regulate processing in the process chamber 200.

[0033]

[0036] The system controller 250 includes a programmable central processing unit (CPU) 252 operable with memory 254 (e.g., non-volatile memory) and support circuits 256. The support circuits 256 are conventionally coupled to the CPU 252 and include cache, clock circuits, input / output subsystems, power supplies, etc., and combinations thereof coupled to the various components of the processing chamber 200.

[0034]

[0037] In some embodiments, CPU 252 is one of any form of general-purpose computer processor used in industrial environments, such as a programmable logic controller (PLC), for controlling various monitoring system components and sub-processors. Memory 254 coupled to CPU 252 is non-transitory and is typically one or more of readily available memory, such as random access memory (RAM), read-only memory (ROM), a floppy disk drive, a hard disk, or any other form of digital storage, local or remote.

[0035]

[0038] As used herein, memory 254 is in the form of a computer-readable storage medium (e.g., non-volatile memory) that includes instructions that, when executed by CPU 252, facilitate operation of process chamber 200. The instructions in memory 254 are in the form of a program product, such as a program (e.g., a middleware application, an instrument software application, etc.) that implements the methods of the present disclosure. The program code may conform to any one of a number of different programming languages. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) of the program product define the functions of the embodiments, including the methods described herein.

[0036]

[0039] Exemplary computer-readable storage media include, but are not limited to, (i) non-writable storage media in which information is permanently stored (e.g., a read-only memory device in a computer such as a CD-ROM disk readable by a CD-ROM drive, a flash memory, a ROM chip, or any type of solid-state non-volatile semiconductor memory), and (ii) writable storage media in which information that can be changed is stored (e.g., a floppy disk in a diskette drive or hard disk drive, or any type of solid-state random access semiconductor memory). An embodiment of the present disclosure is such a computer-readable storage medium carrying computer-readable instructions that direct the functions of the methods described herein.

[0037]

[0040] 3 is a schematic cross-sectional view of a process chamber 300 for performing an epitaxial deposition process, according to certain embodiments. The process chamber 300 can be used to process one or more substrates, including depositing material on an upper surface of a substrate 325. The process chamber 300 includes, among other components, an array of radiant heat lamps 302 for heating a backside 304 of a substrate support 306 disposed within the process chamber 300. The substrate support 306 can be a disk-shaped substrate support 306 as shown, or a ring-shaped substrate support (with a central opening) that supports the substrate from its edge to facilitate exposure to the thermal radiation of the lamps 302.

[0038]

[0041] The substrate support 306 is positioned within the process chamber 300 between an upper dome 328 and a lower dome 314. The upper dome 328, the lower dome 314, and a base ring 336 disposed between the upper dome 328 and the lower dome 314 generally define an interior region of the process chamber 300. A substrate 325 (not to scale) is transferred into the process chamber 300 and positioned on the substrate support 306 through a loading port.

[0039]

[0042] The substrate support 306 is supported by a central stem 332 that moves the substrate 325 in a vertical direction 334 during loading and unloading, and possibly processing of the substrate 325. The substrate support 306 is shown in a raised processing position in FIG. 3, but can be traversed vertically to a loading position below the processing position by an actuator coupled to the central stem 332. When lowered below the processing position, lift pins can contact the substrate 325 and lift the substrate 325 off the substrate support 306. A robot can then enter the process chamber 300 and engage and remove the substrate 325 through a loading port. The substrate support 306 can then be actuated vertically to a processing position to place the substrate 325, device side 316 facing upward, on the front side 310 of the substrate support 306.

[0040]

[0043] While in the processing position, the substrate support 306 divides the interior volume of the process chamber 300 into a process gas region 356 above the substrate 325 and a purge gas region 358 below the substrate support 306. The substrate support 306 rotates during processing by a central stem 332 to minimize the effects of spatial anomalies in heat and process gas flow within the process chamber 300 and facilitate uniform processing of the substrate 325. The substrate support 306 is formed from silicon carbide or silicon carbide coated graphite and is capable of absorbing radiant energy from the lamps 302 and conducting the radiant energy to the substrate 325.

[0041]

[0044] Typically, the central window portion of the upper dome 328 and the bottom of the lower dome 314 are formed from an optically transparent material such as quartz. The thickness and degree of curvature of the upper dome 328 can be configured to provide a flatter geometry for uniform flow uniformity in the process chamber.

[0042]

[0045] An array of lamps 302 is disposed adjacent to and below lower dome 314 in a predetermined manner about central stem 332 to independently control the temperature at various regions of substrate 325 as process gases pass therethrough, thereby facilitating deposition of material on the upper surface of substrate 325. Although not described in detail herein, in some embodiments, the material deposited may include gallium arsenide, gallium nitride, or aluminum gallium nitride. In some embodiments, an array of radiant heat lamps, such as lamps 302, may be disposed above upper dome 328.

[0043]

[0046] The lamps 302 include bulbs configured to heat the substrate 325 to a temperature in the range of about 200° C. to about 1600° C. Each lamp 302 is connected to a power distribution board through which power is provided to the lamps. The lamps 302 are positioned within a lamp head 345 that is cooled during or after processing, for example, by a cooling fluid introduced into a channel 349 located between the lamps 302. The lamp head 345 conductively and radiatively cools the lower dome 314, in part due to the proximity of the lamp head 345 to the lower dome 314. The lamp head 345 may also cool the lamp wall and reflector wall surrounding the lamp. In some examples, the lower dome 314 may be cooled by convection. Depending on the application, the lamp head 345 may or may not be in contact with the lower dome 314.

[0044]

[0047] A circular shield 367 is disposed around the substrate support 306 and is surrounded by the liner assembly 363. The shield 367 prevents or minimizes thermal / light noise leakage from the lamps 302 to the device side 316 of the substrate 325 while providing a preheat zone for the process gases. The shield 367 may be made from CVD SiC, sintered graphite coated with SiC, grown SiC, opaque quartz, coated quartz, or other similar suitable material that is resistant to chemical attack by the process and purge gases.

[0045]

[0048] The liner assembly 363 is sized to nest within or be surrounded by the inner periphery of the base ring 336. The liner assembly 363 shields the processing volume (i.e., the process gas region 356 and the purge gas region 358) from the metal walls of the process chamber 300 that may react with precursors and cause contamination in the processing volume. Although the liner assembly 363 is shown as a unitary body, the liner assembly 363 may include one or more liners having different configurations.

[0046]

[0049] An optical pyrometer 318 can be used for temperature measurement and control. In the illustrated example, the optical pyrometer 318 is located above the upper dome 328 to measure the temperature of the device side 316 of the substrate 325. This positioning provides radiative sensing of the substrate 325, which conducts heat from the substrate support 306, and minimizes background radiation from the lamps 302 from reaching the optical pyrometer 318 directly. In other embodiments, the optical pyrometer can be located below the backside 304 of the substrate support 306 to measure the temperature of the backside 304.

[0047]

[0050] A reflector 322 is located outside the upper dome 328 and reflects light emitted from the substrate 325 back onto the substrate 325. The reflector 322 is secured to the upper dome 328 using a clamp ring 330. The reflector 322 may be made of a metal such as aluminum or stainless steel. The efficiency of the reflection may be improved by applying a highly reflective coating such as gold to the reflector area. The reflector 322 has a pair of channels 326 connected to a cooling source. The channels 326 connect to passages formed in the sides of the reflector 322 for cooling the reflector 322. The passages may carry a flow of a fluid such as water and may run horizontally along the sides of the reflector 322 in any desired pattern covering part or all of the reflector 322.

[0048]

[0051] Process gas supplied from a process gas source 372 is introduced into the process gas region 356 through a process gas inlet 374 formed in a sidewall of the base ring 336. The process gas inlet 374 is configured to direct the process gas generally radially inward. During a film formation process, the substrate support 306 may be located in a processing position adjacent to and at approximately the same height as the process gas inlet 374, allowing the process gas to flow up and around along a channel 373 across an upper surface of the substrate 325 in a laminar flow. The process gas exits the process gas region 356 through a gas outlet 378 (along a channel 375) located on an opposite side of the process chamber 300 from the process gas inlet 374. Removal of the process gas through the gas outlet 378 may be facilitated by a vacuum pump 380 coupled to the gas outlet 378. The process gas inlet 374 and the gas outlet 378 are aligned with each other and located at approximately the same height (e.g., coplanar). Such alignment, when combined with the flatter upper dome 328, allows for a generally planar and uniform gas flow across the substrate 325. Further radial uniformity can be obtained by rotation of the substrate 325 through the substrate support 306.

[0049]

[0052] Purge gas may be supplied to the purge gas region 358 from a purge gas source 362 through a purge gas inlet 364 (or process gas inlet 374) formed in a sidewall of the base ring 336. The purge gas inlet 364 is disposed at a lower elevation than the process gas inlet 374. A circular shield 367 is disposed between the process gas inlet 374 and the purge gas inlet 364. In some examples, a preheat ring may be disposed between the process gas inlet 374 and the purge gas inlet 364. The purge gas inlet 364 is configured to direct the purge gas generally radially inward. During a film formation process, the substrate support 306 may be positioned such that the purge gas flows down and around the channel 365 across the backside 304 of the substrate support 306 in a laminar flow. The flow of purge gas may prevent or substantially reduce the flow of process gas into the purge gas region 358 or may reduce diffusion of process gas entering the purge gas region 358 (i.e., the region below the substrate support 306). The purge gas exits the purge gas region 358 (along channel 366) and is exhausted outside the process chamber through a gas outlet 378 located on an opposite side of the process chamber 300 from the purge gas inlet 364. In some embodiments, a controller (e.g., controller 250 shown in FIG. 2 or another similar controller) may be coupled to the process chamber 300 to control the process chamber 300 or components thereof.

[0050]

[0053] FIG. 4 illustrates an exemplary integrated vacuum processing system 400 that may be used to complete the processing sequence 100 shown in FIG. 1, according to certain embodiments. The vacuum processing system 400 has an internal volume isolated from the ambient environment. As shown in FIG. 4, multiple processing chambers 402a, 402b, 402c, 402d are coupled to a first transfer chamber 404. The processing chambers 402a-402d may be used to perform any substrate-related process, such as annealing, chemical vapor deposition, physical vapor deposition, epitaxial processes, etching processes, thermal oxidation or thermal nitridation processes, degassing, etc. In an embodiment, the processing chamber 402a may be a vapor phase epitaxial deposition chamber capable of forming crystalline silicon or silicon germanium, such as a film formation chamber, such as an Epi chamber available from Applied Materials, Inc., Santa Clara, Calif. In some examples, the processing chamber 402a may be an epitaxial deposition chamber, such as the process chamber 300 described in FIG. 3.

[0051]

[0054] The processing chamber 402b may be a rapid thermal processing chamber (RTP). The processing chamber 402c may be a plasma etch chamber or a plasma clean chamber. The processing chamber 402d may be a degassing chamber. The first transfer chamber 404 is also coupled to at least one transition station, such as a pair of pass-through stations 406, 408. The pass-through stations 406, 408 maintain vacuum or inert environmental conditions while allowing substrates to be transferred between the first transfer chamber 404 and the second transfer chamber 410. The first transfer chamber 404 may include a robotic substrate handling mechanism for transferring substrates between the pass-through stations 406, 408 and any of the processing chambers 402a-402d. Although the illustrated processing chambers 402a-402d are arranged in a particular order in FIG. 4, the processing chambers 402a-402d may be arranged in any desired order.

[0052]

[0055] One end of the pass-through stations 406, 408 is coupled to a second transfer chamber 410. Thus, the first transfer chamber 404 and the second transfer chamber 410 are separated and connected by the pass-through stations 406, 408. The second transfer chamber 410 is coupled to a first pre-clean chamber 414 and a second pre-clean chamber 416, each of which may be an oxide removal chamber, such as the processing chamber 200 described in FIG. 2, adapted to perform at least a portion of the process of step 102 for removing oxide from the surface of a substrate. In one example, each of the first pre-clean chamber 414 and the second pre-clean chamber 416 may be a Siconi™ or Selectra™ chamber available from Applied Materials, Inc. of Santa Clara, Calif.

[0053]

[0056] In one example, at least one transition station, such as one of the pass-through stations 406, 408, may be a plasma cleaning chamber. Alternatively, a plasma cleaning chamber may be coupled to one of the pass-through stations 406, 408 to remove contaminants from the surface of the substrate. Thus, the processing system 400 may have a plasma cleaning chamber that is one of the pass-through stations 406, 408 or is coupled to one of the pass-through stations 406, 408. The plasma cleaning chamber may be adapted to perform at least a portion of the process of step 102 to remove contaminants from the surface of the substrate. In one example, a plasma cleaning chamber may be coupled to both of the pass-through stations 406, 408.

[0054]

[0057] The second transfer chamber 410 may also have a robotic substrate handling mechanism for transferring substrates between the set of load lock chambers 412 and the first pre-clean chamber 414 or the second pre-clean chamber 416. A factory interface 420 is connected to the second transfer chamber 410 by the load lock chambers 412. The factory interface 420 is connected to one or more pods 430 on the opposite side of the load lock chambers 412. The pods 430 may be front-opening unified pods (FOUPs) accessible from a clean room.

[0055]

[0058] Although two transfer chambers are shown, it is contemplated that either of the transfer chambers may be omitted. In one embodiment in which the second transfer chamber 410 is omitted, the first pre-clean chamber 414 and the second pre-clean chamber 416 may be disposed within or coupled to the first transfer chamber 404 in the positions currently shown occupied by the pass-through stations 406 and 408. The first transfer chamber 404 may be coupled to one or more processing chambers capable of forming crystalline silicon or silicon germanium, for example, an epitaxy chamber such as a Centura™ Epi chamber available from Applied Materials, Inc., Santa Clara, Calif. Alternatively, the first transfer chamber 404 may be omitted and the second transfer chamber 410 may be configured to be coupled to one or more processing chambers capable of forming crystalline silicon or silicon germanium.

[0056]

[0059] In operation, substrates are removed one at a time from the pod 430 and transferred to the vacuum processing system 400. Each substrate is first moved through a factory interface 420 coupled to the pod 430 and placed in one of the load lock chambers 412. A robotic transport mechanism in the second transfer chamber 410 transports the substrates one at a time from the load lock chamber 412 to the first pre-clean chamber 414 or the second pre-clean chamber 416 where a cleaning process, such as an oxide clean as described with respect to step 102, is performed to remove oxide from the surface of the substrate. Once the oxide is removed from the substrate surface, a robotic transport mechanism located in the second transfer chamber 410 transfers the substrate from the first pre-clean chamber 414 or the second pre-clean chamber 416 to the pass-through station 406. A robotic transport mechanism located in the first transfer chamber 404 then transfers the substrate from the pass-through station 406 to one or more of the processing chambers 402a-402d. One or more of the processing chambers 402a-402d may include an epitaxy process chamber in which a layer formation process, such as epitaxial deposition as described with respect to step 102, is performed.

[0057]

[0060] Upon completion of processing in one or more of the processing chambers 402a-402d, a robotic transport mechanism disposed in the first transfer chamber 404 transfers the substrate from any one of the processing chambers 402 to the pass-through station 408. The substrate is then removed from the pass-through station 408 by a robotic transport mechanism disposed in a second transfer chamber 410 and transferred to another load lock chamber 412 through which the substrate is removed from the vacuum processing system 400. The exemplary substrate transfer sequences described above are provided for illustrative purposes only and other substrate transfer sequences are contemplated.

[0058]

[0061] 1 are performed in the same vacuum processing system 400, the vacuum is not broken as the substrate is moved between chambers, reducing the chance of contamination and improving the quality of the deposited epitaxial film. In some examples, a controller (e.g., controller 250 shown in FIG. 2 or another similar controller) can be coupled to the vacuum processing system 400 to control the vacuum processing system 400 or its components. The controller can be used to schedule the movement of the substrate through the vacuum processing system 400 according to a desired sequence program, which can vary depending on the application.

[0059]

[0062] Advantages of the present disclosure include an improved vacuum processing system that integrates a pre-clean process chamber and an epitaxial process chamber on the same vacuum processing system. The integrated vacuum processing system allows the substrate to be maintained in a vacuum or inert environment between oxide removal and epitaxial deposition, reducing the amount of time the substrate is exposed to the environment and eliminating the need to pre-clean the substrate in a separate processing chamber or system.

[0060]

[0063] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. 1. A processing system comprising: a film formation chamber; a transfer chamber coupled to the film formation chamber; an oxide removal chamber coupled to the transfer chamber and having a substrate support, the oxide removal chamber configured to receive gases directly from a first gas source and a second gas source into a processing region of the oxide removal chamber; A controller for the processing system, flowing a first gas from the first gas source and a second gas from the second gas source into a mixing region of the oxide removal chamber to form a process gas mixture comprising a fluorine-containing gas and a vapor comprising at least one of water, an alcohol, an organic acid, and combinations thereof; flowing the process gas mixture into the processing region of the oxide removal chamber, wherein a concentration of the fluorine-containing gas is from about 5% to about 75% by weight of the process gas mixture; removing oxide from the substrate without the use of a plasma by exposing the substrate positioned on the substrate support to the process gas mixture; a controller configured to cause A processing system comprising:

2. The treatment system of claim 1 , wherein the alcohol comprises a primary alcohol.

3. 3. The treatment system of claim 2, wherein the alcohol comprises at least one of methyl alcohol and ethyl alcohol.

4. 2. The treatment system of claim 1, wherein said alcohol comprises a C1-C3 alcohol.

5. 10. The processing system of claim 1, wherein said fluorine containing gas comprises at least one of hydrogen fluoride, nitrogen fluoride, carbon fluoride, sulfur fluoride, and combinations thereof.

6. 10. The processing system of claim 1, wherein said process gas mixture is ammonia-free.

7. 10. The treatment system of claim 1, wherein a concentration of said vapor can be from about 5% to about 75% by weight of said total process gas mixture.

8. The processing system of claim 1 , wherein the substrate support includes two or more independent temperature control zones, each having a separate cooling channel.

9. 10. The processing system of claim 1, wherein the controller is configured to maintain a temperature of the substrate support at or below about 0 degrees Celsius during exposure of the substrate to the process gas mixture.

10. The processing system of claim 1 , wherein the controller is configured to form a film on a substrate disposed in the film formation chamber.

11. A method for processing a substrate, comprising the steps of: removing oxide from a substrate disposed in a processing region of a first process chamber without using a plasma; transferring the substrate from the first process chamber to a second process chamber under vacuum or an inert environment; forming a film on the substrate disposed in the second process chamber; Including, removing oxide without the use of said plasma; flowing a first gas from a first gas source and a second gas from a second gas source into a mixing region of the first process chamber to form a process gas mixture comprising a fluorine-containing gas and a vapor comprising at least one of water, an alcohol, an organic acid, and combinations thereof; flowing the process gas mixture into the processing region of the first process chamber; exposing the substrate to the process gas mixture; wherein the concentration of the fluorine-containing gas is 5% to 75% by weight of the process gas mixture. method.

12. The method of claim 11 , wherein the process gas mixture is ammonia-free.

13. The method of claim 11 , further comprising cooling the substrate to a temperature of about 0° C. or less during oxide removal.

14. 12. The method of claim 11, wherein the oxide is removed from the substrate by reaction with the process gas mixture without forming solid by-products.

15. separately supplying the fluorine-containing gas and the vapor to the first process chamber; mixing the fluorine-containing gas and the vapor upon arrival at the first process chamber; The method of claim 11 further comprising:

16. The method of claim 11 , wherein a flow ratio of the fluorine-containing gas to the vapor may be from about 1:10 to about 10:

1.

17. 1. A processing system comprising: a film formation chamber; a first transfer chamber coupled to the film formation chamber; a pass-through station coupled to the first transfer chamber; a second transfer chamber coupled to the passing station; a first oxide removal chamber coupled to the second transfer chamber, the first oxide removal chamber, the second transfer chamber, the pass-through station, the first transfer chamber, and the film formation chamber being maintained under a vacuum or an inert environment, the first oxide removal chamber including a first substrate support and configured to receive gases directly from a first gas source and a second gas source into a processing region of the first oxide removal chamber; A non-transitory computer readable medium, which when executed by a processor of the processing system, causes the processing system to: flowing a first gas from the first gas source and a second gas from the second gas source into a mixing region of the first oxide removal chamber to form a process gas mixture comprising a fluorine-containing gas and a vapor comprising at least one of water, an alcohol, an organic acid, and combinations thereof; a plasma-free oxide removal from a first substrate disposed in the processing region of the first oxide removal chamber, the oxide removal being performed by flowing the process gas mixture into the processing region and exposing the first substrate to the process gas mixture, the fluorine-containing gas having a concentration of about 5% to about 75% by weight of the process gas mixture; transferring the first substrate to the film formation chamber; forming a film on the first substrate disposed in the film formation chamber; A non-transitory computer readable medium having instructions stored thereon to cause a load lock chamber coupled to the first oxide removal chamber; A processing system comprising:

18. a second oxide removal chamber coupled to the second transfer chamber and maintained under a vacuum or an inert environment, the second oxide removal chamber including a second substrate support, the instructions stored on the non-transitory computer readable medium further comprising: removing oxide from a second substrate disposed in the second oxide removal chamber by exposing the second substrate to the process gas mixture. The processing system of claim 17 .

19. 20. The processing system of claim 17, wherein an interior volume of the processing system is isolated from an ambient environment.

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