Method for processing a substrate, substrate boat, and heat treatment system

Abstract

A method of processing a substrate, a substrate boat, and a heat treatment system. The substrate boat for heat treatment of semiconductor wafers includes support bars and fingers for supporting a substrate in a horizontal orientation in a processing tool such as a furnace. The substrate is supported in the substrate boat by a set of fingers located in a common horizontal plane. These fingers contact the substrate at the support positions on the back side of the substrate. These fingers have a plurality of different shapes and a non-contact area with the substrate surface.

Description

Technical Field

[0001] The present disclosure relates to a method for processing a substrate, a substrate boat, and a heat treatment system. Background Art

[0002] High-temperature heat treatment (annealing) of semiconductor wafers is typically used to achieve some desired characteristics. For example, such processes can be used to form a defect-free layer of silicon or to form a silicon nitride film on the wafer. Such high-temperature processes are typically carried out in a vertical furnace that subjects the wafer to high temperatures.

[0003] During such high-temperature heat treatment, the wafer should be properly supported to avoid sliding or deformation due to local gravity and thermal stress. In some processes, a vertical wafer boat is used to properly support the semiconductor wafer. Summary of the Invention

[0004] One embodiment described in the present disclosure is a method for processing a substrate, the method including supporting a substrate having a front side on a back side of a substrate boat. The substrate boat includes a top plate, a bottom plate, and a plurality of boat rods extending between the top plate and the bottom plate. Each of the plurality of boat rods includes a finger member that includes a lower side, a substrate contact surface, and a substrate non-contact region. The substrate contact surface contacts a lower side of the substrate supported by the substrate boat. The substrate non-contact region overlaps with the substrate located in the substrate boat. In one embodiment, the surface area of the substrate contact surface is less than the sum of the area of the substrate non-contact region and the surface area of the substrate contact surface. The method further includes forming a thin film on a back side of the substrate and patterning a front side of the substrate.

[0005] In another embodiment of the present disclosure, a substrate boat is provided, the substrate boat including a top plate, a bottom plate, and a plurality of boat rods extending between the top plate and the bottom plate. Each of the plurality of boat rods includes a finger member that includes a lower side surface, a plurality of substrate contact surfaces that contact a back side of the substrate in operation, and one or more substrate non-contact regions. The substrate non-contact regions overlap with the substrate and are located between adjacent ones of the plurality of substrate contact surfaces.

[0006] In another embodiment of the present disclosure, a heat treatment system is provided that includes a substrate boat. The substrate boat includes a top plate, a bottom plate, and a plurality of boat rods extending between the top plate and the bottom plate. Each of the plurality of boat rods includes a finger member that includes a lower side, a substrate contact surface (which contacts a lower side of the substrate inside the boat), and a substrate non-contact region that overlaps with the substrate. Brief Description of the Drawings

[0007] When associated with the accompanying Figure 1When starting to read, various aspects of this disclosure can be best understood according to the following detailed description. Note that, according to standard practices in the industry, various features are not drawn to scale. In fact, for the sake of clear discussion, the sizes of various features may be arbitrarily increased or decreased.

[0008] Figure 1 A cross-sectional view of a processing chamber including a wafer boat according to an embodiment of the present disclosure;

[0009] Figure 2 A schematic perspective view of a part of a wafer boat according to an embodiment of the present disclosure;

[0010] Figure 3 A top plan view of a boat finger according to an embodiment of the present disclosure;

[0011] Figure 4 A top plan view of a boat finger according to an embodiment of the present disclosure;

[0012] Figure 5 A top plan view of a boat finger according to an embodiment of the present disclosure;

[0013] Figure 6 A top plan view of a boat finger according to an embodiment of the present disclosure;

[0014] Figure 7 A top plan view of a boat finger according to an embodiment of the present disclosure;

[0015] Figure 8 A top plan view of a boat finger according to an embodiment of the present disclosure.

[0016]

Symbol Description

[0017] 1: Boat

[0018] 3: Support rod

[0019] 9: Central rod

[0020] 11: Front rod

[0021] 13: Finger

[0022] 15: Front side

[0023] 17: Lower side

[0024] 100: Chamber

[0025] 101: Chamber

[0026] 103: Exhaust bag

[0027] 104: Injector bag

[0028] 113: Chamber

[0029] 117: Processing area

[0030] 120: Substrate boat

[0031] 121: Substrate

[0032] 123: Dorsal side

[0033] 150: Injector assembly

[0034] 152: Panel

[0035] 153: Opening

[0036] 154: Seal

[0037] 155: Vertical channel

[0038] 156: Inlet channel

[0039] 158: Valve

[0040] 159: Gas source

[0041] 160: Diffuser

[0042] 170: Exhaust assembly

[0043] 173: Horizontal slot

[0044] 174: Seal

[0045] 175: Vertical compartment

[0046] 176: Exhaust port

[0047] 178: Valve

[0048] 179: Vacuum pump

[0049] 180: Power supply

[0050] 300: Boat finger

[0051] 302: Substrate non-contact surface

[0052] 304: Substrate contact surface

[0053] 306: Substrate contact finger

[0054] 308: Substrate non-contact area

[0055] 310: Dashed line

[0056] 400: Finger

[0057] 402: Substrate non-contact surface

[0058] 404: Substrate contact surface

[0059] 406: Substrate contact finger

[0060] 408: Substrate non-contact area

[0061] 410: Dotted line

[0062] 500: Boat finger

[0063] 502: Substrate non-contact surface

[0064] 504: Substrate contact surface

[0065] 506: Substrate contact finger

[0066] 508: Substrate non-contact area

[0067] 510: Dotted line

[0068] 520: Radial line

[0069] 600: Boat finger

[0070] 602: Substrate non-contact surface

[0071] 604: Substrate contact surface

[0072] 606: Substrate contact finger

[0073] 608: Substrate non-contact area

[0074] 610: Dotted line

[0075] 700: Boat finger

[0076] 702: Substrate non-contact surface

[0077] 704: Substrate contact surface

[0078] 706: Substrate contact finger

[0079] 708: Substrate non-contact area

[0080] 710: Dotted line

[0081] 800: Boat finger

[0082] 802: Substrate non-contact surface

[0083] 804: Substrate contact surface

[0084] 806: Substrate contact finger

[0085] 808: Substrate non-contact area Detailed implementation mode

[0086] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. For example, in the following description, the formation of a first feature on or above a second feature may include embodiments in which the first feature is formed in direct contact with the second feature, and may also include embodiments in which additional features are formed between the first feature and the second feature such that the first feature and the second feature may not be in direct contact. Additionally, the present disclosure may repeat reference numerals and / or letters in various instances. This repetition is for simplicity and clarity purposes and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0087] In addition, spatial relative terms such as "below", "beneath", "lower", "above", "upper", etc. may be used herein to facilitate the description of the relationship of one element or feature to another (s) element or feature as illustrated in the figures. In addition to the orientation depicted in the figures, the spatial relative terms are also intended to encompass different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein may be interpreted accordingly.

[0088] One embodiment described herein is a method for processing a substrate, the method including supporting a substrate having a front side on a back side of a substrate boat. The substrate boat includes a top plate, a bottom plate, and a plurality of boat rods extending between the top plate and the bottom plate. Each of the plurality of boat rods includes a finger that includes a lower side, a substrate contact surface, and a substrate non-contact region. The substrate contact surface contacts a lower side of the substrate supported by the substrate boat. The substrate non-contact region overlaps the substrate located in the substrate boat. In one embodiment, the surface area of the substrate contact surface is less than the sum of the area of the substrate non-contact region and the surface area of the substrate contact surface. The method further includes the steps of forming a thin film on the back side of the substrate and patterning the front side of the substrate. According to some embodiments of the present disclosure, the contact of the finger with the back side of the substrate does not result in the thickness of the thin film formed on the back side of the substrate being too thin such that when the substrate is subjected to subsequent patterning of the front side of the substrate, a "boat print" (due to the contact between the finger and the bottom side of the substrate) formed on the back side of the substrate causes irregularities to form in the front side surface of the substrate due to the force applied on the front side of the substrate during the subsequent patterning process. Other embodiments of the present disclosure are directed to a substrate boat including boat fingers as described herein and a heat treatment system including a substrate boat including fingers as described herein.

[0089] Typically, an excited state processing gas species can be generated to assist an atomic layer deposition (ALD) process as described herein. These species can be excited by plasma assistance, UV assistance (photoassistance), ion assistance (e.g., ions generated by an ion source), or a combination thereof. These species are excited in or near the processing region within the chamber enclosure to avoid relaxation of the excited state before the ions reach the processing region of the batch processing chamber. Embodiments of the present disclosure are described in the context of an ALD process being performed in a furnace; however, the present disclosure is not limited to embodiments where the ALD process is performed in a furnace. Embodiments of the present disclosure include other material deposition processes or heat treatment processes performed in a furnace and utilize a substrate (e.g., a wafer boat) to support the underside of the substrate within the furnace during a deposition process or heat treatment process of depositing a material on the underside of the substrate.

[0090] As used herein, "substrate" includes, but is not limited to, semiconductor wafers, semiconductor workpieces, and other workpieces such as optical plates, storage disks, etc. Embodiments of the present disclosure can be applied to any substantially flat workpiece on which a material has been deposited by the methods and using the apparatuses described herein.

[0091] The "vertical direction" and "horizontal direction" should be understood to indicate relative directions. Thus, the horizontal direction should be understood to be substantially perpendicular to the vertical direction, and vice versa. However, within the scope of the present disclosure, the described embodiments and aspects can be rotated as a whole such that the dimension referred to as the vertical direction is horizontally oriented, and at the same time, the dimension referred to as the horizontal direction is vertically oriented.

[0092] A batch processing chamber for ALD processing that can be used in the embodiments described herein includes a chamber, a heating system, a gas delivery system, and an exhaust system. Figure 1 An embodiment of a batch processing chamber is illustrated having an internal chamber 101 (e.g., a quartz chamber) and a controlled injector assembly 150 and an exhaust assembly 170 that are in fluid communication with the internal chamber 101. In some embodiments, the injector assembly 150 and the exhaust assembly 170 are temperature controlled to avoid condensation of the processing gas. Figure 1A side cross-sectional view of the batch processing chamber 100. The batch processing chamber 100 generally includes an internal chamber 101 that defines a processing area 117 configured to receive a batch of substrates 121 stacked in a substrate carrier 120. The substrates are disposed in the processing area to be processed by various deposition processes such as ALD processes. Typically, one or more heater blocks (not shown) are arranged around the internal chamber 101 and configured to heat the substrates 121 disposed in the processing area 117. In one embodiment, the internal chamber 101 may be, for example, a quartz chamber. An external chamber 113 is generally disposed around the internal chamber 101. One or more thermal insulators (not shown) may be provided between the external chamber 113 and any heaters to keep the external chamber cool.

[0093] Figure 1 The internal chamber 101, such as a quartz chamber, is shown. It generally includes a chamber body having an opening at the bottom, an injector pocket formed on one side of the chamber body, and an exhaust pocket formed on the chamber body on the opposite side of the injector pocket. The internal chamber 101 has a cylindrical shape similar to the substrate carrier 120. Thereby, the processing area 117 can be kept small. The reduced processing area can reduce the amount of processing gas per batch and shorten the residence time during batch processing.

[0094] In one embodiment, the exhaust pocket 103 and the injector pocket 104 may be welded in place using slots milled in the chamber body of the internal chamber 101. According to one embodiment, the injector pocket and the exhaust pocket are flat quartz tubes, one end of which is welded to the chamber body and one end of which is open. The injector pocket 104 and the exhaust pocket 103 are configured to receive an injector assembly 150 and an exhaust assembly 170. In some embodiments, the temperatures of the injector assembly 150 and the exhaust assembly 170 are controlled. Further, a support plate for supporting the internal (quartz) chamber is further connected to a load lock located below the bottom opening of the internal chamber 101. The substrate carrier 120 can be loaded and unloaded through the load lock. The substrate carrier 120 can be vertically translated between the processing area 117 and the load lock through an opening at the bottom of the internal chamber. Details of various embodiments of the substrate carrier 120 are described in more detail below.

[0095] Except for being close to the injector bag 104 and the exhaust bag 103, the heater block generally wraps around the outer periphery of the inner chamber 101. According to another embodiment (not shown), the heater block (not shown) may also wrap around the injector bag 104 and / or the exhaust bag 103. The substrate 121 is heated to an appropriate temperature by the heater block via the inner chamber 101. The heater is controlled to achieve uniform heating of the substrate. In one embodiment, the points on the substrate 121 in a batch reach the same set point temperature plus or minus 1 degree Celsius. The configuration of the batch processing chamber 100 improves the temperature uniformity in batch processing. For example, the cylindrical shape of the inner chamber 101 causes the edges of the substrate 121 to be evenly spaced from the inner chamber. The heater may have multiple controllable zones to adjust the temperature variation between the zones. The heater block may be made of a resistive heater arranged in multiple vertical zones. In one example, the heater block may be a ceramic resistive heater.

[0096] Figure 1 It is illustrated that the injector bag 104 can be welded to one side of the chamber body to define an injection volume communicating with the processing area 117. When the substrate boat is in the processing position, the injection volume generally extends along the entire height of the substrate boat 120. Therefore, the injector assembly 150 placed in the injector bag can provide a horizontal process gas flow to each substrate 121 within the substrate boat 120.

[0097] Recesses are formed to hold the wall of the injector bag 104. The injector assembly is thermally isolated, for example, by a seal 154. The seal 154 can be an O-ring or other suitable element, and also provides a vacuum seal to control the pressure in the inner chamber 101. Thermal isolation of the injector assembly may be required to independently control the temperature of the injector. Since the processing area 117 and the injection volume generally remain in a vacuum state during processing, the outer volume between the inner chamber 101 and the chamber 113 can also be evacuated. Maintaining the outer volume at a reduced pressure can reduce the pressure generated on the inner chamber 101. Additional vacuum seals, such as O-rings, can be placed between appropriate parts of the chamber 100 to control the pressure in the processing area 117, the vacuum / pressure stress applied to the inner chamber 101, and to control the flow of the inserted process gas to only flow to the processing area. In addition, one or more vacuum pumps can be directly connected to the inner chamber or via an additional exhaust chamber (not shown) to control the pressure in the inner chamber 101.

[0098] The temperatures of various components in a batch processing chamber can be controlled independently, especially when a deposition process is to be performed in the batch processing chamber. If the temperature of the injector assembly is too low, the injected gas may condense and remain on the surface of the injector assembly, which can generate particles and affect chamber processing. If the temperature of the injector assembly is high enough to cause gas-phase decomposition and / or surface decomposition, the paths in the injector assembly may become blocked. In some embodiments, the injector assembly of the batch processing chamber is heated to a temperature that is lower than the decomposition temperature of the injected gas and higher than the condensation temperature of the gas. The temperature of the injector assembly is typically different from the processing temperature in the processing region. In one example, the substrate can be heated to about 600 degrees Celsius during an atomic layer deposition process, while the temperature of the injector assembly is about 80 degrees Celsius. Thus, the temperature of the injector assembly is independently controlled.

[0099] Figure 1 It is illustrated that the exhaust bag 103 can be welded to one side of the chamber body to define an exhaust volume that communicates with the processing region 117. When the substrate boat is in the processing position, the exhaust volume generally covers the entire height of the substrate boat 120, such that the exhaust assembly 170 disposed in the exhaust bag can provide a horizontal process gas flow to each substrate 121. A recess is formed to hold the wall of the exhaust bag 103. The exhaust assembly is thermally isolated, for example, by a seal 174. The seal 174 can be an O-ring or other suitable element and also provides a vacuum seal to be able to control the pressure in the internal chamber 101. Thermal isolation of the exhaust assembly may be required to independently control the temperature of the exhaust.

[0100] Since the processing region 117 and the exhaust volume are generally maintained in a vacuum state during processing, the external space between the internal chamber 101 and the chamber 113 can also be evacuated. Maintaining the external volume in a vacuum state can reduce the pressure generated on the internal chamber 101. Additional vacuum seals (such as O-rings) can be placed between appropriate portions of the chamber 100 to control the pressure in the processing region 117, the vacuum / pressure stress applied to the internal chamber 101, and / or to control the flow of the inserted process gas to flow only to the processing region. In addition, one or more vacuum pumps can be connected directly or via an additional exhaust chamber (not shown) to the internal chamber to control the pressure in the internal chamber 101.

[0101] The temperatures of various components in a batch processing chamber can be controlled independently, especially when a deposition process is to be performed in the batch processing chamber. On the one hand, it is necessary to keep the temperature in the exhaust assembly lower than that in the processing chamber so that no deposition reaction occurs in the exhaust assembly. On the other hand, it is necessary to heat the exhaust assembly so that the processing gas passing through the exhaust assembly does not condense and remain on the surface, thereby causing particle contamination. If deposition of reaction by-products does occur on the exhaust assembly, the elevated temperature on the exhaust assembly can reduce the deposition of by-products strongly adhering to the components on the exhaust assembly. Therefore, the exhaust assembly can be heated independently of the processing area.

[0102] Figure 1 It is illustrated that a gas source 159 is additionally provided. The gas source 159 supplies a processing gas, such as a precursor gas or a deposition gas, a processing gas, a carrier gas, and a purge gas, to the vertical channel 155 of the injector assembly via a valve 158 and via an inlet channel 156. The vertical channel 155 can also be referred to as the vertical channel 155 of the gas chamber or the vertical channel 155 of the cavity. The processing gas enters the processing area 117 via an opening 153 of the injector assembly. The plate and the opening form a panel 152 to uniformly distribute the gas on the substrate 121 in the substrate boat 120.

[0103] Generally, carrier gases and purge gases that can be used as processing gases include N2, H2, Ar, He, combinations thereof, etc. In a pre-treatment step, H2, NH3, B2H6, Si2H4, SiH6, H2O, HF, HCl, O2, O3, or other known gases can be used as processing gases. In one embodiment, the deposition gas or the precursor gas can contain a nitrogen precursor, a hafnium precursor, a silicon precursor, or a combination thereof.

[0104] Although Figure 1 only one gas source is shown, in other embodiments, it will be understood that multiple gas sources (for example, one gas source for a first precursor, one gas source for a second precursor, and one gas source for the carrier and purge gases) can be coupled to the batch processing chamber 100. The gas flows from different gases can be opened or closed according to the required processing needs. Therefore, a three-way valve or a four-way valve can be used to supply different gases to the inlet channel 156. Alternatively, two, three, or more inlet channels 156 can be horizontally milled on the injector assembly 150, and several vertical channels 155 can be provided to insert different processing gases into the processing area.

[0105] At the end of the internal chamber 101 opposite the injector assembly 150, an exhaust bag 103 is provided in the chamber 101. The exhaust bag houses the exhaust assembly 170. An exhaust port 176 is formed horizontally across the exhaust assembly 170 near the central portion. The exhaust port 176 leads to a vertical compartment 175 formed in the central portion. The vertical compartment 175 is further connected to a plurality of horizontal slots 173, which lead to the processing area 117. When the processing area 117 is evacuated via the valve 178 by the vacuum pump 179, the processing gas first flows from the processing area 117 to the vertical compartment 175 via the plurality of horizontal slots 173. Then, the processing gas flows into the exhaust system via the exhaust port 176. In one aspect, the size of the horizontal slots 173 may vary depending on the distance between a particular horizontal slot 173 and the exhaust port 176 to provide a uniform draw from top to bottom across the entire susceptor 120.

[0106] Processing gases (such as precursor gases, deposition gases, processing gases, purge gases, or carrier gases), as described in more detail above, are delivered to or from the processing area 117 through the injector assembly and the exhaust assembly. A uniform gas flow is required across each substrate 121 and across all substrates vertically aligned in the susceptor 120.

[0107] The gas flow carries ionized processing gas species, such as precursor gases or carrier gases or purge gases. The uniformity of the gas flow further improves the uniformity of the ionized species, which are used to provide plasma-assisted, UV-assisted, or ion-assisted processes. Generally, processes assisted by plasma, UV, or ion generation can be characterized as exciting the introduced gas or ionizing the introduced gas. The components that provide the processing gas flow to the processing area 117 are configured to form a uniformly deposited material across each substrate and across the substrates in the susceptor.

[0108] The described embodiments provide an apparatus and method for processing semiconductor substrates in a batch processing tool.

[0109] Figure 1The embodiments described herein include a power supply 180 that generates plasma, which is connected to a panel 152 of a diffuser 160 and an injector assembly 150. Plasma is generated between the diffuser 160 and the panel 152 of the injector assembly 150. The injector face serves as an anode, and the diffuser serves as a cathode to generate plasma therebetween. The power used to generate the plasma can be adapted to the desired application and can depend on the energy required to ionize a particular species in the process gas flowing into the processing region. As a result, the plasma power can vary depending on the processing step currently being performed. For example, for a plasma-assisted ALD process, different powers can be applied during the gas flow of the first precursor, during purging or pumping to remove the first precursor, during the gas flow of the second precursor, and during purging or pumping to remove the second precursor. Alternatively, some processing steps can be performed with a similar plasma power or without plasma assistance. For example, the purge step can be performed with the same power or without power, and for the time of supplying the precursors to the processing region, plasma powers suitable for the first precursor and the second precursor are applied respectively.

[0110] As already described above, a barrier seal 154 is disposed between the injector pocket 104 and the injector assembly 150, and a barrier seal 174 is disposed between the exhaust pocket 103 and the exhaust assembly 170. Thereby, any unwanted areas of the batch processing chamber are prevented from being exposed to the processing chemicals. In addition, a vacuum seal for the quartz chamber can be provided by the seals 154, 174. Additionally, seals that can be provided in the form of O-rings or the like can electrically insulate different components within the chamber from each other. This has an increasing relevance as the power supplied by the power supply 180 increases. A higher voltage applied to an electrode (such as the injector assembly) may require improved electrical insulation of the injector assembly.

[0111] In Figure 1 the embodiment shown, the plasma can be confined between the surface of the injector assembly 150 and the diffuser 160. Thereby, the substrate can be prevented from being directly exposed to the plasma. In some embodiments, this will be desirable to prevent damage to the substrate surface by the plasma. Thus, the diffuser protects the substrate from the plasma. In reference Figure 1 to the embodiment described, the plasma is generated in the horizontal direction. The plasma extends along the vertical direction of the diffuser 160 and the injector assembly 150. Thus, the horizontal plasma extends along the vertical direction of the processing region 117. The substrates 121 in the substrate boat 120 are exposed to the plasma along the entire substrate stack. The previously described uniform gas flow provides a uniform distribution of the ionized species of the plasma over the wafers.

[0112] Figure 2A portion of an embodiment of a susceptor wafer boat according to the present disclosure is generally designated by reference numeral boat 1. The susceptor boat 1 includes spaced support rods 3 (boat rods) that are attached at their tops to a top plate (not shown) and at their bottoms to a bottom plate of the boat (not shown) to maintain the position of the rods relative to each other. When the wafer boat 1 is placed in a vertical processing chamber such as a furnace, the support rods 3 are generally vertical. In the illustrated embodiment, the wafer boat 1 has a central rod 9 and two front rods 11.

[0113] The support rods 3 support a plurality of laterally extending susceptor fingers 13. The fingers 13 may be integrally formed on the support rods 3. Alternatively, cuts or slots may be formed in the elongate single-piece structure of the support rods 3 to form slots for receiving the fingers 13 and securing them to the support rods 3. Each finger includes a top side (on which the underside of the substrate 121 rests when placed in the boat 1) and a bottom side 17 opposite the front side 15. The susceptor fingers 13 of the susceptor boat 1 are arranged in groups in different common generally horizontal planes along the vertical length of the support rods 3. The fingers 13 located in the same generally horizontal plane engage and support the same substrate 121. The fingers 13 in the same generally horizontal plane contact the back side 123 of the substrate 121. The entire susceptor boat 1 is made of quartz, silicon carbide material, or other suitable materials that are mechanically stable and chemically inert with respect to the processing conditions, including high temperatures.

[0114] In use, the susceptor boat 1 is prepared by placing substrates (e.g., wafers) into the boat 1 such that each wafer is placed on the top surfaces of three susceptor fingers located in the same horizontal plane. The wafers are loaded into the boat by a robotic arm. Once the boat 1 is loaded with a predetermined number of wafers, the boat is received in a processing chamber where a high-temperature heat treatment is performed. After the heat treatment and other processing, the wafers are unloaded from the boat 1, for example, using a robotic arm.

[0115] When high-temperature heat treatment involves depositing or forming a thin film (e.g., SiO2 or SiN) on the back side of a substrate, the thickness of the thin film on the back side of the substrate at the location where the boat finger contacts the back side of the substrate can be less than the thickness of the thin film at other locations on the back side of the substrate. Without being bound by any theory, the thinner film thickness at the location where the boat finger contacts the back side of the substrate (sometimes referred to as the "boat area") is due to reduced reaction of the substrate with the gas in the chamber and / or a lower substrate temperature at the location where the boat finger contacts the back side of the substrate. These areas where the thin film thickness is reduced on the back side of the substrate can adversely affect the subsequent patterning of the thin film or layer on the front side of the substrate, such as photolithographic patterning, especially in areas on the front side of the substrate that overlap with the areas on the back side of the substrate that include the thin film with reduced thickness. For example, photolithographic patterning of the thin film or layer on the front side of the substrate involves securing the back side of the substrate to an electrostatic chuck. The force applied by the electrostatic chuck on the back side of the substrate can cause deformation of the substrate and the layer or thin film on the front side of the substrate that overlaps with the areas on the back side of the substrate where the thin film thickness is reduced, resulting in local deformation on the front side surface of the substrate. For example, such local deformation can create depressions or other surface irregularities, resulting in an uneven surface on the front side of the substrate. When the surface of the front side of the substrate is uneven, the focus of the photolithography tool is impaired, which will result in less precise patterning of the features on the front side surface of the substrate. When the device includes multiple layers of thin films deposited or formed as described above, these adverse effects of the boat area on the back side of the substrate are exacerbated.

[0116] According to an embodiment of the present disclosure, a substrate boat finger is described. The substrate boat finger includes a lower side surface, a substrate contact surface, and a substrate non-contact area. The substrate boat finger according to an embodiment of the present disclosure includes a substrate contact surface, and the surface area of the substrate contact surface is less than the sum of the surface area of the substrate non-contact area and the surface area of the substrate contact area. The presence of the substrate non-contact area within the boat finger reduces the area where the finger contacts the lower side of the substrate. Reducing the area where the boat finger contacts the back side of the substrate can reduce the impact of the boat area on subsequent processing performed on the front side of the substrate.

[0117] Reference Figure 3 , a top plan view of the boat finger 300 according to an embodiment of the present disclosure is illustrated. The boat finger 300 includes a top side surface ( Figure 2 15 in Figure 2 ) and a bottom side surface ( Figure 3 17 in Figure 3 . In Figure 2 , the boat finger 300 includes a width "a" and a length "b". The top surface in Figure 2 includes a substrate non-contact surface 302, two substrate contact surfaces 304, and a substrate non-contact area 308. The substrate non-contact surface 302 corresponds to those portions of the boat finger 300 that do not contact the bottom side of the substrate 121 (see Figure 2 ). In Figure 3In [reference], the width "a" of the substrate non-contact surface 302 and the length are equal to the difference between "b" and "c" (the length of the substrate contact surface 304). Figure 3 The boat finger 300 in [reference] further includes two rectangular substrate contact sub-fingers 306, each of which includes a rectangular substrate contact surface 304 on its top side. The substrate contact sub-fingers 306 extend away from the boat rod ( Figure 2 3 in [reference]), and the substrate non-contact surface 302 extends toward the center of the supported substrate ( Figure 3 not shown in [reference]). In Figure 3 [reference], the corners of the substrate contact sub-fingers 306 at their distal ends are square, but in other embodiments, these corners are rounded or beveled. The substrate contact sub-fingers 306 have a width "d" and a length "c" that define the contact surface area of each substrate contact sub-finger 306. The boat finger 300 further includes a substrate non-contact region 308 between the two substrate contact sub-fingers. The substrate non-contact region 308 is the void space between the two substrate contact sub-fingers 306 and is further defined by Figure 3 the dashed line 310 in [reference]. The substrate non-contact region 308 has a width equal to "a" minus 2 times "d" and a length "c". The area of the substrate non-contact region 308 is defined by its width and length. According to Figure 3 an embodiment of [reference], the combined surface area of the two substrate contact surfaces 304 is less than the sum of the area of the substrate non-contact region 308 and the combined surface area of the two substrate contact surfaces 304.

[0118] Refer to Figure 4 , and a top plan view of the boat finger 400 according to an embodiment of the present disclosure is illustrated. The boat finger 400 includes a top side surface ( Figure 2 15 in [reference]) and a bottom side surface ( Figure 2 17 in [reference]). In Figure 4 [reference], the boat finger 400 includes a width "a" and a length "b". Figure 4 The top side surface in [reference] includes a substrate non-contact surface 402, three substrate contact surfaces 404, and two substrate non-contact regions 408. The substrate non-contact surface 402 corresponds to those portions of the boat finger 400 that do not contact the bottom side of the substrate 121 (see Figure 2 ). In Figure 4 [reference], the width "a" and the length of the substrate non-contact surface 402 are equal to the difference between "b" and "c" (the length of the substrate contact surface 404). Figure 4 The boat finger 400 in [reference] further includes three rectangular substrate contact sub-fingers 406, each of which includes a rectangular substrate contact surface 404 on its top side. The substrate contact sub-fingers 406 extend away from the boat rod ( Figure 2 3 in [reference]), and the substrate non-contact surface 402 extends toward the supported substrate ( Figure 3extends from the center (not shown in the figure). In Figure 4 In, the corners of the substrate contact finger 406 at its distal end are square, but in other embodiments, these corners are rounded or chamfered. The substrate contact finger 406 has a width "d" and a length "c" that define the contact surface area of each substrate contact finger 406. The boat finger 400 further includes a substrate non-contact area 408 between three substrate contact fingers. The substrate non-contact area 408 is the void space between the three substrate contact fingers 406 and is further defined by Figure 4 the dashed line 410 in. Each substrate non-contact area 408 has a width. In Figure 4 In, the sum of the widths of the two substrate non-contact areas 408 is equal to "a" minus 3 times "d". The length of the substrate non-contact area is "c". The total area of the two non-substrate non-contact areas 408 is defined by multiplying the sum of the widths of the two non-substrate non-contact areas 408 by their length. According to Figure 4 the embodiment of, the combined surface area of the two substrate contact surfaces 404 is less than the sum of the area of the two substrate non-contact areas 408 and the combined surface area of the three substrate contact surfaces 404. Although Figure 2 the embodiment of shows that the boat finger includes two substrate contact fingers 306 and one substrate non-contact area 308, and Figure 3 shows that the boat finger includes three substrate contact fingers 406 and two substrate non-contact areas 408, but the boat fingers included in the embodiments according to the present disclosure include a larger number of substrate contact fingers and a larger number of substrate non-contact areas. Additionally, Figure 3 and Figure 4 the substrate contact fingers in are illustrated as having a substantially rectangular shape. In other embodiments, two, three, or more substrate contact fingers have a non-rectangular shape, such as triangular, arcuate, or polygonal.

[0119] Referring to Figure 5 , a top plan view of a boat finger 500 according to an embodiment of the present disclosure is illustrated. The boat finger 500 includes a top side surface ( Figure 2 15 in) and a bottom side surface ( Figure 2 17 in). Figure 5 The top side surface in includes a substrate non-contact surface 502, two substrate contact surfaces 504, and one substrate non-contact area 508. The substrate non-contact surface 502 corresponds to those portions of the boat finger 500 that do not contact the bottom side of the substrate 121 (see Figure 2 ). In Figure 5 , the substrate non-contact surface 502 has a width "a" and a length "b". Figure 5The boat finger member 500 therein further includes two partially rectangular-shaped substrate contact finger members 506, each of which includes a partially rectangular-shaped substrate contact surface 504 on its top side. The substrate contact finger members 506 extend away from the boat rod ( Figure 2 the 3) therein, and the substrate non-contact surface 502 is angled θ with respect to a radial line 520 that passes through the vertical axial centerline of the boat ( Figure 2 the 1) therein and is offset in half of the substrate non-contact surface 502. In Figure 5 it, the corners of the substrate contact finger members 506 are square at their distal ends, but in other embodiments, the corners are rounded or chamfered. The substrate contact finger members 506 have a width "d" and a length "c", and the contact surface area of each substrate contact finger member 506 can be calculated therefrom depending on the value of θ. The boat finger member 500 further includes a substrate non-contact area 508 between the two substrate contact finger members 506. The substrate non-contact area 508 is the void space between the two substrate contact finger members 506 and is further delimited by Figure 5 the dashed line 510 in Figure 5 . The area of the substrate non-contact area 508 can be determined based on "c" and the angle θ. According to

[0120] the embodiment of Figure 6 , the combined surface area of the two substrate contact surfaces 504 is less than the sum of the area of the substrate non-contact area 508 and the combined surface area of the two substrate contact surfaces 504. Figure 2 the 15) and a bottom side surface ( Figure 2 the 17) in Figure 6 . In Figure 6 , the top side surface of the boat finger member 600 includes a substrate non-contact surface 602, a substrate contact surface 604, and a substrate non-contact area 608. The substrate non-contact surface 602 corresponds to those portions of the boat finger member 600 that do not contact the bottom side of the substrate 121 (see Figure 2 ). In Figure 6 , the width "a" and length of the substrate non-contact surface 602 are equal to the difference between "b" and "c" (the length of the substrate contact surface 604). Figure 6 The boat finger member 600 in Figure 2 the 3) therein and the substrate non-contact surface 602 faces the supported substrate ( Figure 3extends from the center (not shown in Figure 6 ). The susceptor contact finger 606 has a width "d" and a length "c", which define the contact surface area of the susceptor contact finger 606. The susceptor finger 600 further includes a susceptor non-contact area 608 around the susceptor contact finger 606. The susceptor non-contact area 608 is the void space around the susceptor contact finger 606, which is delimited by Figure 6 the dashed line 610 in

[0121] Reference Figure 7 , a top view plan view of a susceptor finger 700 according to an embodiment of the present disclosure is illustrated. The susceptor finger 700 includes a top side surface ( Figure 2 15 in Figure 2 ) and a bottom side surface ( Figure 7 17 in Figure 7 ). In Figure 2 , the top side surface of the susceptor finger 700 includes a susceptor non-contact surface 702, a susceptor contact surface 704, and a susceptor non-contact area 708. The susceptor non-contact surface 702 corresponds to those portions of the susceptor finger 700 that do not contact the bottom side of the substrate 121 (see Figure 7 ). In Figure 7 , the susceptor finger 700 further includes a susceptor contact finger 706, which has a triangular shape, i.e., an isosceles triangle, and includes a similarly shaped susceptor contact surface 704 on its top side. The susceptor contact finger 706 extends away from the susceptor stem ( Figure 2 3 in Figure 3 ), and the susceptor non-contact surface 702 extends towards the center of the supported substrate ( Figure 7The void space delimited by the dashed line 710 in. The dashed line 710 reflects an imaginary boundary defined by the length "b" of the boat finger 700 and the width "a" of the substrate non-contact surface 702. The area of the substrate non-contact region 708 is defined by its width and its length minus the area of the boat finger 700 occupied by the substrate contact surface 704 on the substrate contact sub-finger 706. According to Figure 7 In an embodiment, the surface area of the substrate contact surface 704 is less than the sum of the area of the substrate non-contact region 708 and the surface area of the substrate contact surface 704.

[0122] Reference Figure 8 , a top plan view of a boat finger 800 according to an embodiment of the present disclosure is illustrated. The boat finger 800 includes a top side surface ( Figure 2 15 in) and a bottom side surface ( Figure 2 17 in). In Figure 8 , the boat finger 800 includes a width "a" and a length "b". Figure 8 The top side surface in includes a substrate non-contact surface 802, a substrate contact surface 804, and a plurality of substrate non-contact regions 708, the substrate non-contact regions 708 being perforations that pass through the boat finger 800 from the top side surface to the bottom side surface, for example. The substrate non-contact surface 802 corresponds to those portions of the boat finger 800 that do not contact the bottom side of the substrate 121 (see Figure 2 ). In Figure 8 , the substrate non-contact surface 802 has a width "a" and a length equal to the difference between "b" and "c" (the length of the substrate contact surface 704). Figure 8 The boat finger 800 in further includes a substrate contact sub-finger 806 having a generally rectangular shape with rounded corners at the distal ends. The substrate contact sub-finger 806 includes a substrate contact surface 804 of a similar shape on its top side. The substrate contact sub-finger 806 extends away from the boat stem ( Figure 2 3 in) and the substrate non-contact surface 802 extends towards the center of the substrate to be supported ( Figure 3 not shown in). The substrate contact sub-finger 806 has a width equal to "a" and a length equal to "c" at its bottom. The boat finger 800 further includes a plurality of substrate non-contact regions 808 that extend in the form of perforations and that extend through the substrate contact sub-finger 806 for the top side surface to the bottom side surface. The substrate non-contact regions 808 are void spaces that pass through the substrate contact sub-finger 806. The area of the substrate non-contact region 808 is defined by the diameter of the circular perforation. According to Figure 8 In an embodiment, the surface area of the substrate contact surface 804 is less than the sum of the area of the substrate non-contact region 808 and the surface area of the substrate contact surface 804. Although the substrate non-contact region 808 is in Figure 8is described as a circular perforation in the figure, but the substrate non-contact area 808 is not limited to a circular perforation. In other embodiments, the perforation can be of different shapes, such as oval or polygonal.

[0123] According to some embodiments of the present disclosure, dimension "a" is 13 - 19 mm, dimension "b" is 15 - 19 mm, dimension "c" is 3 - 9 mm, dimension d is 3 - 9 mm, and angle θ is 30 to 90 degrees. The embodiments of the present disclosure are not limited to the aforementioned dimensions or angles. Other embodiments of the present disclosure include dimensions outside the above ranges and angles outside the above ranges.

[0124] In one embodiment of the present disclosure, a method for processing a substrate includes supporting a substrate having a front side on the back side of a substrate boat. The substrate boat includes a top plate, a bottom plate, and a plurality of boat rods extending between the top plate and the bottom plate. Each of the plurality of boat rods includes a finger member, and the finger member includes a lower side, a substrate contact surface, and a substrate non-contact area. The substrate contact surface contacts the lower side of the substrate supported by the substrate boat. The substrate non-contact area overlaps the substrate located in the substrate boat. In one embodiment, the surface area of the substrate contact surface is less than the sum of the area of the substrate non-contact area and the surface area of the substrate contact surface. The method further includes the steps of forming a thin film on the back side of the substrate and patterning the front side of the substrate. According to some embodiments of the present disclosure, the contact between the finger member and the back side of the substrate does not cause the thickness of the thin film formed on the back side of the substrate to be too thin such that when the substrate undergoes subsequent patterning of the front side of the substrate, the "wafer boat area" formed on the back side of the substrate (due to the contact between the finger member and the bottom side of the substrate) causes irregularities to form in the front side surface of the substrate due to the force applied on the front side of the substrate during the subsequent patterning process. In some embodiments of the present disclosure, the finger member further includes a substrate non-contact surface. In some embodiments of the present disclosure, the finger member includes two or more substrate contact surface sub-finger members, and the two or more substrate contact surface sub-finger members are spaced 3 to 8 mm apart. In some embodiments of the present disclosure, each of the two or more substrate contact surface sub-finger members has a rectangular shape. In some embodiments of the present disclosure, the patterning is photolithography patterning. In some embodiments of the present disclosure, the finger member of each of the plurality of boat rods is located in a common horizontal plane. In some embodiments of the present disclosure, the substrate contact surface has a triangular shape.

[0125] In another embodiment of the present disclosure, a susceptor is provided. The susceptor includes a top plate, a bottom plate, and a plurality of susceptor rods extending between the top plate and the bottom plate. Each of the plurality of susceptor rods includes a finger member. The finger member includes a lower side, a substrate contact surface (which contacts the lower side of the substrate inside the susceptor), and a substrate non-contact area overlapping the substrate. According to this embodiment, the surface area of the substrate contact surface is smaller than the sum of the area of the substrate non-contact area and the surface area of the substrate contact surface. In some embodiments of the present disclosure, the substrate non-contact area is located between adjacent ones of the substrate contact surfaces. In some embodiments of the present disclosure, the finger member further includes a substrate non-contact surface. In some embodiments of the present disclosure, the finger members of each of the plurality of susceptor rods are located in a common horizontal plane. In some embodiments of the present disclosure, each of the plurality of susceptor rods includes a plurality of the finger members. In some embodiments of the present disclosure, each of two or more substrate contact surface sub-finger members has a rectangular shape. In some embodiments of the present disclosure, the finger member includes two contact surface sub-finger members, and each of the two contact surface sub-finger members includes a longitudinal axis that is separated from each other by an angle between 30 degrees and 90 degrees. In some embodiments of the present disclosure, the surface area of the plurality of substrate contact surfaces is smaller than the sum of the area of the one or more substrate non-contact areas and the surface area of the plurality of substrate contact surfaces. In some embodiments of the present disclosure, the finger member includes one or more through holes extending from the lower side to the substrate contact surface.

[0126] In another embodiment of the present disclosure, a heat treatment system is provided, which includes the susceptor as described above. In some embodiments of the present disclosure, the susceptor includes a top plate, a bottom plate, and a plurality of susceptor rods extending between the top plate and the bottom plate. Each of the plurality of susceptor rods includes a finger member. The finger member includes a side surface, a substrate contact surface that contacts a back side of a substrate during operation, and a substrate non-contact area overlapping the substrate. In some embodiments of the present disclosure, the finger member includes two substrate contact surface sub-finger members. Each of the two substrate contact surface sub-finger members includes a longitudinal axis that is separated from each other by an angle between 30 degrees and 90 degrees. In some embodiments of the present disclosure, the substrate contact surface is triangular in shape. In some embodiments of the present disclosure, the finger member includes one or more through holes extending between the back side and the substrate contact surface.

[0127] The foregoing outlines the features of several embodiments, enabling those skilled in the art to better understand aspects of the present disclosure. Those skilled in the art should understand that the present disclosure can be readily used as a basis for designing or modifying other processes and structures to achieve the same purposes and / or advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent structures do not depart from the spirit and scope of the present disclosure, and various changes, substitutions, and alterations can be made without departing from the spirit and scope of the present disclosure.

Claims

1. A method for processing a substrate, characterized in that, comprising the following steps: supporting a substrate having a front side and a back side in a susceptor, the susceptor comprising: a top plate; a bottom plate; and a plurality of susceptor rods extending between the top plate and the bottom plate, each of the plurality of susceptor rods comprising a finger, the finger comprising: a first portion including an adjacent first end of the corresponding finger, the first portion extending inwardly from the corresponding susceptor rod towards a center of the susceptor, the first portion including a second end opposite the first end, and the first portion of the corresponding finger including a non-contact top surface that does not contact a back side of a substrate during operation; a plurality of second portions extending inwardly from the second end of the first portion towards the center of the susceptor, the plurality of second portions including a plurality of planar substrate contact surfaces that contact the back side of the substrate during operation; and one or more substrate non-contact regions overlapping the substrate, each of the one or more substrate non-contact regions including a gap space laterally located between adjacent ones of the plurality of second portions, the one or more substrate non-contact regions overlapping the substrate during operation; forming a thin film on the back side of the substrate; and patterning a front side of the substrate.

2. The method according to claim 1, characterized in that, The finger further comprises a lower side surface that does not contact the substrate during operation.

3. The method according to claim 1, characterized in that, The plurality of second portions are spaced 3 to 8 mm apart.

4. The method according to claim 3, characterized in that, Each of the plurality of second portions has a rectangular shape.

5. The method according to claim 1, characterized in that, The patterning is a photolithography patterning.

6. The method according to claim 1, characterized in that, The finger of each of the plurality of susceptor rods is located in a common horizontal plane.

7. The method according to claim 1, characterized in that, The plurality of second portions have a triangular shape.

8. A substrate boat, characterized in that, comprising: a top plate; a bottom plate; and a plurality of susceptor rods extending between the top plate and the bottom plate, each of the plurality of susceptor rods including at least one finger, the at least one finger comprising: a first portion including an adjacent first end of the corresponding finger, the first portion extending inwardly from the corresponding susceptor rod towards a center of the susceptor, the first portion including a second end opposite the first end, and the first portion of the corresponding finger including a non-contact top surface that does not contact a back side of a substrate during operation; a plurality of second portions extending inwardly from the second end of the first portion towards the center of the susceptor, the plurality of second portions including a plurality of corresponding planar substrate contact surfaces that contact the back side of the substrate during operation; and one or more substrate non-contact regions, each of the one or more substrate non-contact regions including a gap space laterally located between adjacent ones of the plurality of second portions, the one or more substrate non-contact regions overlapping the substrate during operation.

9. The substrate boat according to claim 8, characterized in that, The at least one finger further comprises a lower side surface that does not contact the substrate during operation.

10. The substrate boat according to claim 8, characterized in that, The finger of each of the plurality of susceptor rods is located in a common horizontal plane.

11. The substrate boat according to claim 10, characterized in that, Each of the plurality of susceptor rods includes a plurality of said fingers.

12. The substrate boat according to claim 8, characterized in that, The finger includes three or more second portions.

13. The substrate boat according to claim 12, characterized in that, Each of the three or more second portions has a rectangular shape.

14. The susceptor according to claim 8, wherein The finger includes two second portions, each of the two second portions occupying a common horizontal plane and including a longitudinal axis that is angled between 30 degrees and 90 degrees from each other.

15. The susceptor according to claim 8, wherein The surface area of one of the multiple planar substrate contact surfaces is smaller than the sum of the area of one or more substrate non-contact regions and the surface area of the multiple planar substrate contact surfaces.

16. The susceptor according to claim 8, wherein The finger includes one or more perforations from a lower surface to the planar substrate contact surface.

17. A heat treatment system, wherein Comprising: A substrate boat, the substrate boat includes: A top plate; A bottom plate; and A plurality of boat rods extending between the top plate and the bottom plate, each of the plurality of boat rods includes a finger, and the finger includes: A first portion, including a first end adjacent to the corresponding finger, the first portion extends inward from the corresponding boat rod to a center of the substrate boat, the first portion includes a second end opposite to the first end, and the first portion of the corresponding finger includes a non-contact top surface that does not contact a back side of a substrate during operation; A plurality of second portions, extending inward from the second end of the first portion to the center of the substrate boat, the plurality of second portions include a plurality of planar substrate contact surfaces that contact a back side of a substrate during operation; and One or more substrate non-contact regions, each of the one or more substrate non-contact regions includes a gap space laterally located between adjacent ones of the plurality of second portions, and the one or more substrate non-contact regions overlap the substrate during operation.

18. The heat treatment system according to claim 17, wherein The number of the second portions is two, and each of the two second portions includes a longitudinal axis with an angle between 30 degrees and 90 degrees separated from each other.

19. The heat treatment system according to claim 17, wherein The plurality of second portions are triangular in shape.

20. The heat treatment system according to claim 17, wherein The finger includes one or more perforations extending between the back side and the plurality of second portions.

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