Substrate processing apparatus

Abstract

A substrate processing device is provided, and the substrate processing device comprises a reaction chamber (110) defining a processing volume (115) for processing a stack of substrates (120) — the reaction chamber (110) includes a downwardly tapered lower portion (130), and the lower portion (130) is arranged to tapered toward an exhaust outlet (150) — and a heating system outside the processing volume (115), the heating system includes inclined heating elements (320), the inclined heating elements (320) are inclined from the vertical, and the lower portions of the inclined heating elements (320) are arranged inwardly toward the exhaust outlet (150) to heat the tapered lower portion (130) of the reaction chamber.

Description

Technology Field

[0001] The present disclosure generally relates to substrate processing. The present disclosure relates to temperature control of substrate processing devices, such as a substrate processing device including a heating system, although not exclusively. Background Technology

[0002] This section illustrates useful background information without acknowledging that any technology described in this specification represents the latest technology.

[0003] In substrate processing such as ALD (atomic layer deposition), uniform processing conditions are required to produce high-quality, uniform coatings. Temperature is one of the critical conditions that must be controlled. For example, in hot wall ALD reactors, the walls of the processing chamber can be heated to the same temperature as the substrates to be processed.

[0004] Processing quality may suffer from poor temperature control. For example, suboptimal reaction temperatures, temperature differences within and between substrates, or cold spots inside the processing chamber or on the substrates tend to result in reduced processing uniformity, for example, due to reduced reaction efficiency or undesirable reaction chamber contamination. Therefore, solutions are required to minimize undesirable temperature gradients and cold spots and to provide more accurate and homogeneous temperature control of the processing chamber.

[0005] The object of the present invention is to provide a substrate processing apparatus having improved temperature control, or at least an alternative to existing solutions. In particular, the object is to provide a substrate processing apparatus for processing a batch of substrates having improved temperature control.

[0006] The appended claims define the scope of protection. Any examples and technical descriptions of devices, products, and / or methods in the description and / or drawings that are not covered by the claims are presented not as embodiments of the invention, but as examples useful for understanding the background art or the invention.

[0007] According to a first exemplary aspect, a substrate processing device is provided, and the substrate processing device is:

[0008] A reaction chamber defining a processing volume for processing a stack of substrates ― the reaction chamber includes a downwardly tapered bottom, and the bottom is arranged to tapere (narrow down) toward an exhaust outlet ―; and

[0009] The heating system includes a heating system outside (around) the processing volume, and the heating system includes inclined heating elements, the inclined heating elements are inclined from the vertical, and the lower ends of the inclined heating elements are arranged inwardly toward the exhaust outlet to heat the bottom of the tapering reaction chamber.

[0010] Advantageously, heating of the reaction chamber and the bottom of the reaction chamber can be improved, thereby reducing temperature non-uniformity in the reaction chamber. Cooling points near the exhaust outlet can also be avoided. Consequently, reaction conditions and processing quality can be improved.

[0011] In certain embodiments, the tapering at the bottom comprises gradually narrowing the horizontal cross-section of the reaction chamber along only one horizontal dimension, namely the first horizontal dimension, as approaching the exhaust outlet. Advantageously, improved flow guiding may be enabled while the stack of substrates can be positioned closer to the bottom of the reaction chamber for processing. Accordingly, the empty space within the reaction chamber may be reduced and processing efficiency may be improved.

[0012] In certain embodiments, inclined heating elements are symmetrically arranged on opposite sides of the processing volume. In certain embodiments, inclined heating elements are arranged to follow the tapering of the bottom of the reaction chamber. Advantageously, the uniformity of heating can be improved.

[0013] In certain embodiments, the heating system further includes vertical heating elements arranged outside the processing volume parallel to the vertical sidewalls of the reaction chamber. Advantageously, a heating system including differently oriented heating elements can better conform to the shape of the reaction chamber. Additionally, heating uniformity and efficiency can be improved.

[0014] In certain embodiments, the heating system includes lateral heating elements configured to connect adjacent inclined heating elements and / or vertical heating elements. Advantageously, the size of the heating, heating efficiency, and targeting can be improved.

[0015] In certain embodiments, the heating system is arranged around the processing volume. In certain embodiments, the inclined heating elements, vertical heating elements, and lateral heating elements of the heating system are connected to each other to form a continuous heating element around the processing volume. Advantageously, since there is only one continuous heating element, the control and connections of the heating system can be simplified.

[0016] In certain embodiments, the inclined heating elements include at least one bent section to at least partially define the inclination angle of the inclined heating elements. In certain embodiments, the bent section is configured to further guide the lower end of the inclined heating element toward the narrowing underside of the lowest end. In certain embodiments, the bent section includes a kink or a curve. Advantageously, the distance of the inclined heating elements placed outside the reaction chamber from the lowest end of the reaction chamber can be controlled more precisely. Additionally, temperature control of the lowest end of the reaction chamber can be further improved.

[0017] In certain embodiments, the substrate processing device includes an outer chamber that at least partially surrounds the reaction chamber, and the heating elements of the heating system are located outside the reaction chamber within the outer chamber. Advantageously, the heating system can be protected from external disturbances and controlled more precisely. Additionally, temperature control of the reaction chamber can be improved.

[0018] In certain embodiments, the heating elements of the heating system are embedded within the walls of the reaction chamber. In certain embodiments, the heating elements of the heating system are embedded within the side walls and the bottom of the reaction chamber. Advantageously, faster and more effective heating of the reaction chamber may be possible. The direction of thermal energy can also be better controlled.

[0019] In certain embodiments, the substrate processing device is configured to accommodate a stack of substrates within a processing volume as a horizontal stack of vertically aligned substrates. In certain embodiments, the height direction of the stack is aligned parallel to a second horizontal dimension, and the second horizontal dimension is parallel to a first horizontal direction. Advantageously, the substrate stack can be accommodated close to the bottom of the tapering reaction chamber. Thus, empty space within the processing volume can be minimized. Additionally, temperature control of the substrates can be improved.

[0020] In certain embodiments, inclined heating elements are positioned transversely to the height direction of the stack of substrates at opposite ends of the (horizontally aligned) stack. Advantageously, the uniformity of heating of the substrate stack can be improved, and in particular, heating of substrates located in the middle of the stack can be improved.

[0021] In certain embodiments, each end of a horizontal stack of substrates is aligned (orthogonally) toward one or more vertical heating elements. In certain embodiments, the heating system surrounds the horizontal stack of substrates in a plane defined by the height axis of the horizontal stack of substrates. Advantageously, heating of the ends of the substrate stack can be improved. Additionally, temperature non-uniformity within the substrate stack can be reduced.

[0022] In certain embodiments, the bottom (of the reaction chamber) is configured to match the shape (curvature) of the horizontal stack of substrates. Advantageously, the substrates within the reaction chamber may be positioned closer to the bottom of the reaction chamber. Consequently, processing flow conditions and gas usage may be improved. Furthermore, heating of the substrates by a heating system outside the processing volume may be improved.

[0023] In certain embodiments, the reaction chamber has a rectangular horizontal cross-section. Advantageously, an arrangement of substrates having a rectangular horizontal cross-section, such as a stack of horizontally aligned substrates, can be accommodated snugly within the reaction chamber. Thus, empty space within the reaction chamber can be minimized and gas usage can be optimized. Furthermore, the distance between the reaction chamber walls and heaters outside the walls and the substrates can be minimized, thereby improving the heating of the substrates.

[0024] In certain embodiments, the substrate processing device includes a heating collar arranged to heat the exhaust outlet. Advantageously, temperature control of the exhaust outlet and the reaction chamber can be further improved and temperature non-uniformity can be reduced.

[0025] In certain embodiments, the height of the heating system is at least 90% of the height of the reaction chamber. Advantageously, the temperature of the reaction chamber can be controlled accurately and uniformly over the height of the reaction chamber.

[0026] According to a second exemplary aspect, a reaction chamber is provided comprising heating elements embedded within the walls of the reaction chamber. In certain embodiments, the heating elements are configured to follow the shape of the walls of the processing volume. In certain embodiments, the heating elements are configured to control the temperature of the processing volume within the reaction chamber.

[0027] Different non-restrictive exemplary aspects and embodiments have been illustrated in the foregoing. The embodiments in the foregoing are used merely to describe selected aspects or steps that may be utilized in different implementations. Some embodiments may be presented by reference only to specific exemplary aspects. It should be recognized that corresponding embodiments may also apply to other exemplary aspects. Brief explanation of the drawing

[0028] Some exemplary embodiments will be described with reference to the accompanying drawings, in which: FIG. 1 schematically illustrates a side cross-sectional view of a substrate processing apparatus according to specific embodiments; FIG. 2 schematically illustrates a side cross-sectional view of another substrate processing apparatus according to specific embodiments; FIG. 3 schematically illustrates another substrate processing apparatus according to specific embodiments; FIG. 4 schematically illustrates a heating collar according to specific embodiments; FIG. 5 schematically illustrates an exemplary cross-sectional view of vertical heating elements arranged within the sidewalls of a reaction chamber according to specific embodiments; and, FIG. 6 schematically illustrates a side cross-sectional view of another substrate processing device according to specific embodiments. Specific details for implementing the invention

[0029] In the following description, the same reference numerals represent the same elements or steps.

[0030] In certain embodiments described herein, a substrate processing apparatus (100) including a heating system is provided. Exemplary substrate processing apparatuses (100) are illustrated in FIGS. 1 through 3 and FIG. 6.

[0031] In certain embodiments, the substrate processing device (100) includes a reaction chamber (110) that defines a processing volume (115) for processing a batch of substrates (120). In certain embodiments, the reaction chamber (110) includes a downwardly tapered bottom section (130). In certain embodiments, the bottom section (130) is arranged to tapere (downwardly) toward an exhaust outlet (150). In certain embodiments, the substrate processing device (100) includes a heating system outside the processing volume (115). In certain embodiments, the heating system includes inclined heating elements (320). In certain embodiments, the inclined heating elements (320) are arranged outside the processing volume (115). In certain embodiments, the inclined heating elements (320) are inclined (away from) the vertical, so that the lower portions of the inclined heating elements (320) are arranged inward toward the exhaust outlet (150) to heat the bottom portion (130) of the tapered reaction chamber. Advantageously, since the inclined heating elements are positioned closer to the bottom portion (130) and arranged to follow the shape of the reaction chamber (110) and the tapered bottom portion (130), temperature control of the reaction chamber (110), particularly the bottom portion (130) and the exhaust outlet (150), can be improved. Consequently, temperature uniformity within the reaction chamber (110) can be improved. Additionally, since the lower surface of the bottom portion (130) can be effectively heated, undesirable cooling points at the bottom portion of the reaction chamber (100) can be reduced.

[0032] In certain embodiments, the heating system is configured to control the temperature of the reaction chamber (110) and the processing volume (115) within the reaction chamber (110). In certain embodiments, the heating system is configured to maintain the reaction chamber (110) and the substrates (120) within the reaction chamber (110) at a homogeneous temperature. In certain embodiments, the heating system includes resistive heating elements. Advantageously, stable processing conditions can be achieved. Consequently, the processing quality can be improved. Additionally, the film growth rate can be improved due to more stable conditions throughout the reaction chamber (110).

[0033] In certain embodiments, the heating system is arranged around the processing volume.

[0034] In certain embodiments, the heating system (heating elements of the heating system) is arranged around the reaction chamber (110). In certain embodiments, the heating system is arranged outside the reaction chamber (110) near the side walls (160) of the reaction chamber (110). In certain embodiments, the heating elements of the heating system do not come into direct (physical) contact with the reaction chamber (110). Accordingly, in certain embodiments, the heating system is configured to heat the reaction chamber by radiation. Advantageously, more uniform heating can be achieved.

[0035] In certain embodiments, the substrate processing apparatus (100) comprises a reaction chamber (110) for processing a stack of substrates (120) — the reaction chamber (110) comprises a downwardly tapered bottom portion (130), the bottom portion (130) arranged to taper toward an exhaust outlet (150) — and a heating system outside the reaction chamber (110), the heating system comprises inclined heating elements (320) arranged near the side walls (160) of the reaction chamber (110), the inclined heating elements (320) being inclined from the vertical, so that the lower portions of the inclined heating elements (320) are arranged inwardly toward the lower surface of the tapered bottom portion (130) of the reaction chamber. Schematic examples of such a substrate processing apparatus are shown in FIGS. 1, FIGS. 2, and FIGS. 3.

[0036] In certain embodiments, the heating elements (310, 320, 330) of the heating system are embedded within the reaction chamber sidewalls and the bottom (130). That is, in certain embodiments, the heating system is in direct physical contact with the reaction chamber (110). Advantageously, faster heating is possible and thermal energy can be directed more accurately.

[0037] In certain embodiments, a substrate processing device (100) comprises a reaction chamber (110) for processing a stack of substrates (120), and the device (100) comprises heating elements (310, 320, 330) embedded within the walls of the reaction chamber (110) to control the temperature of a processing volume (115) within the reaction chamber (110). A schematic example of such a device (100) is illustrated in FIG. 6. Advantageously, the temperature control of the processing volume can be improved and made more homogeneous. In certain embodiments, the shape of the heating elements (310, 320, 330) is configured to follow the shape of the walls of the reaction chamber (110).

[0038] In the context of the present disclosure, substrate processing devices or surface deposition devices are configured to utilize the principles of vapor-deposition-based technologies. In preferred embodiments, the substrate processing device is an ALD device. As used herein, the term ALD includes all applicable ALD-based technologies and any equivalent or closely related technologies, such as, for example, the following ALD subtypes: MLD (Molecular Layer Deposition), plasma-assisted ALD, such as PEALD (Plasma Enhanced Atomic Layer Deposition), and photon-enhanced atomic layer deposition (also known as flash-enhanced ALD).

[0039] Those skilled in the art are aware of the principles of ALD. In ALD, at least one substrate is typically exposed to time-separated precursor pulses within a reaction vessel to deposit material onto substrate surfaces via sequential self-saturating surface reactions. ALD advantageously enables the fabrication of uniform, dense, and pinhole-free thin films.

[0040] In certain embodiments, the substrate processing device is applied to other deposition technologies such as PVD (physical vapor deposition), CVD (chemical vapor deposition), and PECVD (plasma-enhanced chemical vapor deposition).

[0041] In certain embodiments, the substrate processing device is an atomic layer etching (ALE) device. In certain embodiments, the substrate processing device (100) includes a vertical flow reaction chamber (110), and the reaction flow direction is directed (downward) from the top (part) of the reaction chamber (110) to an exhaust outlet (150) located at the bottom (130) of the reaction chamber (110).

[0042] As used herein, fluid may refer to a liquid or a gas. However, in the context of this disclosure, fluids are preferably gaseous materials including precursor chemical(s), (inert) carrier gas(s), and purging gas(s) used in substrate processing. Fluid may also refer to a mixture of two or more gases.

[0043] Structural features of a substrate processing device (100) according to specific embodiments are described below in connection with FIGS. 1 to 3 and FIG. 6. Directional indicators, or coordinate axes, labeled herein as a first horizontal dimension (H1), a second horizontal dimension (H2), and a vertical dimension (V) are shown in FIGS. 1 to 3 and FIG. 6 for the reader's assistance. The first horizontal dimension (H1), the second horizontal dimension (H2), and the vertical dimension (V) are orthogonal to each other. Note that in FIGS. 1, 2, and 6, the second horizontal dimension (H2) is orthogonal to the drawing page and is therefore not visible.

[0044] In certain embodiments, the substrate processing device (100) is an ALD device. In certain embodiments, the substrate processing device (100) is a CVD device. Advantageously, uniform thin films can be manufactured.

[0045] In certain embodiments, the substrate processing device (100) includes a reaction chamber (110). The reaction chamber (110) defines a processing volume (115) within the reaction chamber (110). One or more substrates (120) may be processed within the processing volume (115). In certain embodiments, the reaction chamber (110) is configured to process a batch of substrates (120). In certain embodiments, the reaction chamber (110) is configured to process a stack of substrates (120).

[0046] In certain embodiments, the reaction chamber (110) is a vertical flow reaction chamber. In certain embodiments, the flow of reaction chemicals within the vertical flow reaction chamber proceeds vertically from the top to the bottom. The direction of vertical fluid flow within the reaction chamber (110) according to certain embodiments is schematically depicted by dashed arrows in FIG. 1.

[0047] In certain embodiments, the substrate processing device (100) is configured to accommodate a batch of substrates (120) within a processing volume (115). The batch of substrates (120) comprises a plurality of substrates (120). In certain embodiments, the batch (stack) of substrates comprises 6 to 35 substrates (120). In certain embodiments, the batch (stack) of substrates (120) comprises more than 30 substrates (120). In certain embodiments, the substrates (120) are circular wafers.

[0048] In certain embodiments, the substrates (120) are arranged as a stack of substrates (120) for processing. In certain embodiments, the substrates (120) in the stack are arranged on top of each other, and the planar surfaces of the substrates (120) are spaced apart from each other so that fluid flow is possible through the stack and between adjacent planar surfaces. In certain embodiments, the stack of substrates (120) has a cylindrical shape.

[0049] A stack of substrates (120) has a height axis or height direction orthogonal to the planar substrate surfaces within the stack. The length of the stack along the height axis defines the height of the stack. In certain embodiments, the height axis of the stack is parallel to or corresponds to the longitudinal dimension of the stack. In certain embodiments, the diameter of the substrates (120) within the stack corresponds to the width of the stack.

[0050] In certain embodiments, the substrate processing device (100) is configured to accommodate a stack of substrates (120) within a reaction chamber (110) as a horizontal stack of vertically aligned substrates (120). That is, the height direction of the stack of substrates (120) is arranged parallel to the horizontal direction, while the planar surfaces of the substrates (120) are arranged vertically perpendicular to the bottom (130). For example, in FIGS. 1 through 3 and FIG. 6, the height direction of the substrate stack within the reaction chamber (110) is arranged parallel to the second horizontal direction (H2). Advantageously, since the individual substrates within the stack are vertically aligned, a more homogeneous vertical fluid flow through the stack of substrates (120) may be made possible. As a result, processing quality and uniformity may be improved.

[0051] In certain embodiments, the substrate processing device (100) includes a substrate holder (or cassette) (125) for holding a stack of substrates (120) within a reaction chamber (110). In certain embodiments, the device (100) includes a loading arm for transferring the substrate holder (125) to or from a processing volume (115). Advantageously, the stack of substrates (120) can be processed and handled more effectively as a single unit.

[0052] In certain embodiments, a stack of substrates (120) is loaded into the reaction chamber through the top (140) of the reaction chamber. In certain embodiments, a stack of substrates (120) is unloaded from the reaction chamber (110) through the top (140) of the reaction chamber (110).

[0053] In certain embodiments, the reaction chamber (100) includes an exhaust outlet (150). Processing fluids can be removed from the reaction chamber (110) through the exhaust outlet (150). In certain embodiments, the exhaust outlet (150) is located at the bottom (130) of the reaction chamber (110). In certain embodiments, the exhaust outlet (150) is located at the lowest part of the bottom (130) of the reaction chamber. In certain embodiments, the exhaust outlet (150) is located centrally at the bottom (130). Advantageously, a more uniform vertical flow within the processing volume (115) can be enabled and facilitated.

[0054] In certain embodiments, the exhaust outlet (150) is connected to an exhaust line (155). In certain embodiments, the exhaust outlet (150) is connected to an exhaust line (155) outside the reaction chamber (110). In certain embodiments, the exhaust outlet (150) is connected to a vacuum pump through the exhaust line (155). Advantageously, the removal of processing fluids from the processing volume (115) can be improved.

[0055] In certain embodiments, the reaction chamber (110) includes a bottom section (130). In certain embodiments, the reaction chamber (110) includes a top wall (140). The top wall (140) is located opposite the processing volume (115) and facing the bottom section (130). In certain embodiments, the reaction chamber (110) includes side walls (160). In certain embodiments, the side walls (160) connect the bottom section (130) to the top wall (140). In certain embodiments, the processing volume (115) is defined by the bottom section (130), the top wall (140), and the vertical side walls (160) (inside).

[0056] In certain embodiments, the bottom section (130) is configured to form the bottom wall of the reaction chamber (110). In certain embodiments, the bottom section (130) is a downwardly tapering bottom section (130), and the bottom section (130) is arranged to tapere downward toward the exhaust outlet (150). That is, the horizontal cross section of the bottom section (130) is configured to become narrower as the cross section is located closer to the exhaust outlet (150). Advantageously, fluid flow within the reaction chamber can be effectively guided toward the exhaust outlet (150). As a result, homogeneous flow conditions within the reaction chamber (110) can be improved. Additionally, as a result, processing quality can be improved.

[0057] In certain embodiments, the tapering of the bottom section (130) involves gradually narrowing the horizontal cross section of the reaction chamber (110) only along one horizontal dimension, the first horizontal dimension (H1), as it approaches the exhaust outlet (150) (vertically). That is, the cross section dimension of the reaction chamber (110) parallel to the second horizontal dimension (H2), which is orthogonal to the first horizontal cross section, remains unchanged. In certain embodiments, the bottom section (130) is arranged to gradually narrow from the first horizontal dimension (H1) as it approaches the exhaust opening (150) of the reaction chamber (110) vertically. Advantageously, since the bottom section (130) gradually narrows along only one horizontal dimension, a horizontal stack of vertically aligned substrates, with the height direction parallel to the second horizontal dimension, can still be positioned close to the bottom of the reaction chamber (110). Consequently, the amount of empty space between the stack of substrates (120) and the bottom (130) of the reaction chamber (110) can be minimized. As a result, the use and flow of reaction gases and processing efficiency can be improved. Additionally, when the substrates are positioned close to the walls of the reaction chamber, the temperature of the substrates (120) can be better controlled by a heating system located outside the reaction chamber (100).

[0058] The bottom portion (130) of the reaction chamber (110) is not horizontally flat but has a three-dimensional shape. Accordingly, the bottom portion (130) may be tapered, inclined, or curved toward the exhaust outlet. Thus, the horizontal cross-section of the reaction chamber (110) narrows in at least one horizontal direction (i.e., the width or depth of the reaction chamber (110)) as it approaches the exhaust outlet (150) in the vertical direction (when the cross-section is at least partially defined by the bottom portion (130) at the bottom of the reaction chamber (110). Advantageously, the (vertical) fluid flow can be directed more effectively toward the exhaust outlet (150). Accordingly, a more uniform fluid flow within the reaction chamber (110) can be achieved.

[0059] In certain embodiments, the horizontal cross section of the reaction chamber (110) — the cross section is at least partially defined by the bottom (130) — is arranged to gradually narrow from at least one horizontal dimension, namely the first horizontal dimension (H1), as it approaches the exhaust outlet (150) in the vertical direction. In certain embodiments, the horizontal cross section of the reaction chamber (110) — the cross section is at least partially defined by the bottom (130) — is arranged to gradually narrow only in the direction parallel to the first horizontal dimension. In certain embodiments, the horizontal cross section of the reaction chamber (110) — the cross section is at least partially defined by the bottom (130) — is arranged to gradually narrow from the first horizontal dimension, and the first horizontal dimension is parallel to the side wall of the reaction chamber (110) which is parallel to the planar surfaces of the substrates (120) arranged in the reaction chamber (110) for processing.

[0060] In certain embodiments, the bottom section (130) is a curved wall. In certain embodiments, the bottom section (130) includes at least two straight or curved wall sections inclined toward the exhaust outlet (150). In certain embodiments, the bottom section (130) includes two inclined straight or inwardly curved wall sections that are mirror images of each other. In certain embodiments, the bottom section (130) includes two straight or curved wall sections inclined toward the exhaust outlet (150), and the exhaust outlet (150) is located between the two inclined wall sections. In certain embodiments, the bottom section (130) has a funnel-shaped vertical cross section (when viewed from at least one horizontal direction parallel to at least one vertical side wall). In certain embodiments, the bottom section (130) has a semi-cylindrical shape.

[0061] In certain embodiments, the bottom portion (130) is configured to match the shape of a stack of substrates (120) arranged within the reaction chamber (110). In certain embodiments, the bottom portion (130) is configured to match the curvature of a cylindrical stack of substrates (120) arranged within the reaction chamber (110), and the stack of substrates (120) is a horizontal stack of vertically arranged substrates (120) (i.e., the height direction of the stack (120) is arranged parallel to the horizontal direction and the planar surfaces of the substrates (120) are orthogonal to the bottom portion (130). Advantageously, the empty space within the reaction chamber (110) between the bottom portion (130) and the stack of substrates (120) can be minimized. Additionally, temperature control of the substrates (120) by heating elements (310, 320, 330) located outside the reaction chamber (110) can be improved.

[0062] In certain embodiments, the top wall (140) of the reaction chamber (110) includes an openable lid for loading and unloading a stack of substrates (120). In certain embodiments, the top wall (140) is formed by the lid. Accordingly, a stack of substrates (120) can be loaded and unloaded through the top of the reaction chamber (110). In certain embodiments, the lid forming the top wall (140) is sealable. In certain embodiments, a horizontal stack of substrates (120) is loaded into or unloaded from the reaction chamber (110) through the top wall (140), respectively.

[0063] In certain embodiments, the top wall (140) includes one or more processing fluid inlets (145) for providing processing fluid flow into the reaction chamber (110). Advantageously, vertical fluid flow may be provided from the top (140). The processing fluid may include reaction precursors, a mixture of reaction precursors and an inert carrier gas, plasma or plasma precursors, or a purge gas. One or more fluid inlets (145) are connected via suitable fluid lines to one or more fluid sources located outside the substrate processing device (100) (fluid lines or sources are omitted in FIG. 1 through 3 and FIG. 6).

[0064] In certain embodiments, the reaction chamber (110) includes four side walls (160). In certain embodiments, the reaction chamber (110) includes vertical side walls (160). In certain embodiments, the reaction chamber (110) includes four vertical side walls (160). Advantageously, the reaction chamber (110) may have a horizontal cross-sectional shape that closely corresponds to the dimensions of a horizontal stack of vertically aligned substrates (120). As a result, empty space within the processing volume (115) can be minimized. Additionally, temperature control of the substrates (120) by heating elements located outside the reaction chamber walls can be improved. Additionally, processing quality and efficiency can be improved.

[0065] In certain embodiments, the reaction chamber (110) has a rectangular horizontal cross section defined by four vertical side walls (160). In certain embodiments, the reaction chamber (110) is arranged to have a rectangular horizontal cross section configured to match the rectangular shape of a horizontal stack of vertically aligned substrates (120) arranged within the reaction chamber (110). In certain embodiments, the reaction chamber (110) has a rectangular horizontal cross section configured to accommodate a horizontal stack of vertically aligned substrates (120). Advantageously, the empty space around the stack of substrates (120) within the reaction chamber (110) can be minimized. Accordingly, fluid flow through the stack of substrates (120) can be improved, and consequently, processing quality can be improved. Additionally, more precise temperature control between the substrates (120) and the reaction chamber walls can be established. Furthermore, undesirable temperature gradients can be minimized. Furthermore, when the substrates are aligned parallel to the vertical flow, homogeneous, or even laminar, flow conditions within the reaction chamber can be improved.

[0066] The substrate processing device (100) includes a heating system outside the processing volume (115). In certain embodiments, the substrate processing device (100) includes a heating system around the processing volume (115). The heating system is configured to control the temperature of the reaction chamber (110) and the processing volume (115).

[0067] In certain embodiments, the substrate processing device (100) includes a heating system outside the reaction chamber (110) near the reaction chamber sidewalls (160). Exemplary substrate processing devices (100) including such a heating system are schematically depicted in FIGS. 1 through 3. In certain embodiments, the substrate processing device (100) includes a heating system arranged around the reaction chamber (110). In certain embodiments, the heating system is arranged to extend around the reaction chamber (110) along a horizontal plane. In certain embodiments, the heating system is arranged as a fence surrounding the reaction chamber (110), comprising inclined heating elements (320) arranged near the sidewalls (160) of the reaction chamber (110). That is, in certain embodiments, the heating system surrounds the sidewalls (160) of the reaction chamber (110).

[0068] In certain embodiments, the heating system is arranged as a circular fence around the reaction chamber (110) as depicted in FIG. 3. In certain embodiments, the heating system is arranged as a rectangular fence around the reaction chamber (110) so that the heating system corresponds to the cross-sectional shape of the reaction chamber (110). Advantageously, the heating of the side walls (160) can be controlled by the shape and arrangement of the heating system.

[0069] In certain embodiments, the device (100) includes heating elements embedded within the walls of the reaction chamber (110) (i.e., around the processing volume (115)). In certain embodiments, the device (100) includes heating elements of a heating system embedded within the side walls (160) of the reaction chamber (110). In certain embodiments, the device (100) includes heating elements of a heating system embedded within the bottom (130) of the reaction chamber (110). In certain embodiments, the device (100) includes heating elements of a heating system embedded within the side walls (160) and the bottom (130) of the reaction chamber (110). That is, in certain embodiments, there is direct heat conduction contact between the reaction chamber (110) and the heating elements (310, 320, 330) of the heating system. A hot-wall reaction chamber having a heating system embedded in this way can be obtained. Advantageously, faster heating of the processing volume may be possible. An exemplary arrangement of vertical heating elements (310) arranged within curved sidewalls (160) is shown in FIG. 5. FIG. 6 schematically illustrates a cross-sectional view of an exemplary substrate processing apparatus including heating elements embedded within sidewalls (160) and a downward tapering bottom section (130).

[0070] In certain embodiments, heating elements of different shapes and sizes are embedded within the walls of the reaction chamber (110). Advantageously, reaction chamber walls of different shapes and orientations can be effectively heated.

[0071] In certain embodiments, heating elements embedded within the walls of the reaction chamber (110) are arranged to form a continuous heating element around the processing volume. Advantageously, since the heating elements are interconnected, the control of the heating system can be simplified.

[0072] In certain embodiments, the reaction chamber sidewalls (160) and / or bottom (130) having embedded heating elements (310, 320, 330) are manufactured by hot isostatic pressing (HIP). In certain embodiments, the reaction chamber sidewalls (160) and / or bottom (130) having embedded heating elements (310, 320, 330) are manufactured by casting. In certain embodiments, the sidewalls (160) and / or bottom (130) of the reaction chamber (110) are made of metal. Advantageously, the reaction chamber sidewalls (160) and / or bottom (130) may be manufactured such that zero clearance is maintained between the heating elements and the bulk material of the sidewalls (160) and / or bottom (130). As a result, the transfer of thermal energy from the heating elements to the reaction chamber can be improved and the heating time can be reduced.

[0073] In certain embodiments, the height of the heating system is at least 90% of the height of the reaction chamber (100). In certain embodiments, the height of the inclined heating elements (320) is at least 90%, preferably at least 95%, of the height of the reaction chamber (100). In certain embodiments, the height of the heating system is defined as the (vertical) height difference from the highest part of the heating system (heating elements) to the lowest part of the heating system (heating elements). In certain embodiments, the height of the reaction chamber (110) is defined as the distance from the lowest part of the bottom (130) to the highest part of the top wall (140). In certain embodiments, the height of the heating system (measured as the height difference between the highest part and the lowest part of the heating system) is at least equal to the height of the processing volume (115) (i.e., the internal volume of the reaction chamber (110) measured from the lowest part (130) to the top wall (140) within the reaction chamber (110). Advantageously, the reaction chamber (110) can be heated effectively and uniformly over the entire height of the reaction chamber (110).

[0074] In certain embodiments, the height of the heating system around the reaction chamber (110) is not constant. Advantageously, the heating system may include heating elements of different heights, and its geometry may be adjusted to take into account and not damage structural details of the substrate processing device (100), such as the locations of important fluid inlets (145).

[0075] In certain embodiments, the heating system comprises one or more vertically aligned vertical heating elements (310). In certain embodiments, the vertical heating elements are arranged near the vertical reaction chamber sidewalls (160) outside the reaction chamber (110). In certain alternative embodiments, the vertical heating elements (310) are embedded within the reaction chamber sidewalls (160).

[0076] In certain embodiments, the vertical heating element (310) includes an upper and lower portion, and the upper and lower portions of the vertical heating element (310) are located equally far from the vertical central axis of the reaction chamber (110). In certain embodiments, each of one or more vertical heating elements (310) is parallel to the vertical side walls (160) of the reaction chamber (110). In certain embodiments, each of one or more vertical heating elements (310) is parallel to the vertical central axis of the reaction chamber (110). Advantageously, the vertical side walls (160) of the reaction chamber (110) can be heated effectively and evenly by the vertical heating elements (310).

[0077] In certain embodiments, the heating system comprises at least two inclined heating elements (320). In certain embodiments, the inclined heating elements (320) are arranged near the vertical reaction chamber sidewalls (160) outside the reaction chamber (110). In certain alternative embodiments, the inclined heating elements (320) are embedded within the bottom portion (130) of the reaction chamber (110). In certain embodiments, the inclined heating elements (320) are embedded within the walls of the reaction chamber (110). In certain embodiments, the device (100) comprises two to ten inclined heating elements. However, the optimal number of heating elements depends on the dimensions and size of the reaction chamber (100) to be heated, as well as the shape and size of the heating elements and the heating efficiency of the heating elements.

[0078] In certain embodiments, the inclined heating element (320) is a straight member, and the bottom end of the straight member is arranged to deviate from the vertical toward the reaction chamber (110). In certain embodiments, the inclined heating elements (320) are inclined away from the vertical so that the bottom end of the inclined heating elements (320) is arranged inward toward the lower surface of the tapered reaction chamber bottom (130). Advantageously, temperature control of the reaction chamber bottom can be improved.

[0079] In certain embodiments, inclined heating elements (320) are arranged opposite sides of the processing volume (115). In certain embodiments, inclined heating elements (320) are arranged symmetrically opposite sides of the processing volume (115). In certain embodiments, inclined heating elements (320) are arranged near the widest side walls (160) of the reaction chamber (110). Advantageously, more uniform heating of the reaction chamber (110) can be provided.

[0080] In certain embodiments, the substrate processing device (100) includes inclined heating elements (320) located on at least the sides of the reaction chamber (110), with the bottom (130) gradually narrowing toward the exhaust outlet (150). An exemplary positioning of these inclined heating elements (320) is clearly depicted in the perspective view of FIG. 3, and the reaction chamber (110) and the stack of substrates (120) within the reaction chamber (110) are indicated by dashed outlines within the outer chamber (210) and are surrounded by a heating system.

[0081] In certain embodiments, inclined heating elements (320) are positioned transversely with respect to the height axis of the stack of substrates (120), and the stack is accommodated in a reaction chamber as a horizontal stack of vertically aligned substrates (120). In certain embodiments, inclined heating elements (320) are positioned transversely with respect to the height axis of the stack of substrates (120) at opposite ends of the stack.

[0082] In certain embodiments, each of the inclined heating elements (320) includes a top portion and a bottom portion, and the bottom portion is arranged inward toward the bottom portion (130) such that the bottom portion is closer to the vertical central axis of the reaction chamber (110) than the top portion. In certain embodiments, the bottom portion of each of the inclined heating elements (320) is arranged toward the bottom portion (130). In certain embodiments, the inclined heating elements (320) are arranged to follow (at least partially) the angle, tangent, or curvature of the bottom portion (130). In certain embodiments, the inclined heating elements (320) deviate from the vertical by 1 to 40 degrees, preferably 5 to 30 degrees. However, the optimal inclination depends on the dimensions of the reaction chamber (110) and the shape of the bottom portion (130). Advantageously, since the distance between the tapered bottom (130) and the heating elements (320) is not allowed to be too large, temperature control of the bottom of the reaction chamber can be improved. Cooling points at the bottom of the reaction chamber can be minimized. As a result, reaction efficiency can be improved and undesirable reaction chamber contamination can be reduced.

[0083] In certain embodiments, the uppermost portions of the vertical heating elements (310) and the uppermost portions of the inclined heating elements (320) are located equally far from the vertical central axis of the reaction chamber (110). In certain embodiments, the uppermost portions of the vertical heating elements (310) and the uppermost portions of the inclined heating elements (320) are located equally far from the side wall (160) of the reaction chamber (110) where each heating element (310, 320) is located nearby. Advantageously, uniform heating can be provided to the uppermost portion of the reaction chamber that is not tapered.

[0084] Advantageously, temperature control and heating of the inner curved or inclined lower section (130) can be improved by inclined heating elements. Additionally, temperature control and heating of the lower section (130) of the reaction chamber near the exhaust outlet (150) can be improved. Accordingly, more targeted heating of the lower section (130) of the reaction chamber (110) can be provided, and the magnitude of temperature gradients at the lower section of the reaction chamber can be reduced. Furthermore, bending elements (340) provide more improved targeted temperature control of the reaction chamber (110) and the lower section (130).

[0085] In certain embodiments, at least one of the inclined heating elements (320) includes a bending section (or bending element) (340). A substrate processing device (110) in which the heating system includes the bending sections (340) is illustrated in FIG. 2. In certain embodiments, the bending section (340) includes a bend (or kink) or a curved shape. In certain embodiments, the bending section (340) is configured to at least partially define the angle of inclination of the inclined heating element (320). In certain embodiments, the bending section (340) is configured to guide the lower end of the inclined heating element (320) closer to the bottom (130). In certain embodiments, the bending section (340) includes a gradual curvature of the inclined heating element (320) (toward the reaction chamber (110)) to further guide the lower end of the inclined heating element (320) closer to the bottom (130). Advantageously, further improved targeted temperature control of the reaction chamber (110) and the bottom (130) can be provided. As a result, temperature gradients within the reaction chamber (110) can be minimized.

[0086] In certain embodiments, the vertical and inclined heating elements (310, 320) are shaped as rods, tubes, beams, wires, or plates. In certain embodiments, the vertical and inclined heating elements (310, 320) are shaped as linear rods, tubes, beams, wires, or plates.

[0087] In certain embodiments, the heating system comprises a mixture of vertical and inclined heating elements (310, 320). In certain embodiments, the heating system comprises vertical heating elements (310) and inclined heating elements (320), wherein the alignment of the vertical heating elements (310) differs from the alignment of the inclined heating elements (320) with respect to the vertical dimension (V). In certain embodiments, the vertical heating elements (310) are parallel to the vertical dimension (V). In certain embodiments, the inclined heating elements (320) are offset from the vertical dimension (V).

[0088] In certain embodiments, the heating system includes one or more lateral heating elements (330). In certain embodiments, the lateral heating elements (330) are arranged to connect adjacent vertical (310) and / or inclined (320) heating elements to one another. In certain embodiments, the lateral heating elements (330) are straight. In certain embodiments, the lateral heating elements (330) are curved. Advantageously, the heating dimensions and heating efficiency of the heating system can be improved.

[0089] In certain embodiments, vertical (310), inclined (320), and lateral heating elements (330) are connected to each other to form a single continuous heating element around the reaction chamber (110). In certain embodiments, the continuous heating element has a (vertical) serpentine shape. Advantageously, since the heating elements (310, 320, 330) form a single integrated heating element to be operated and controlled, heating system controls and connections can be simplified.

[0090] In certain embodiments, vertical, inclined, or lateral heating elements (310, 320, 330) are shaped into rods, tubes, beams, wires, or plates. Advantageously, heating elements having different shapes and sizes may be used to optimize the heating system according to the dimensions of the reaction chamber (110).

[0091] In certain embodiments, the heating elements (310, 320, 330) do not come into direct contact with the reaction chamber (110). Advantageously, abrupt temperature gradients and sudden temperature differences caused by direct contact can be avoided. Accordingly, more uniform temperature control and heating of the reaction chamber (110) can be achieved.

[0092] In certain embodiments, when the reaction chamber (110) is arranged to accommodate a horizontal stack of vertically aligned substrates (120), the heating system is configured to surround the reaction chamber along a horizontal plane parallel to the horizontally aligned height axis of the stack of substrates (120), so that both ends of the stack of substrates (120) are aligned toward a section of the heating system containing vertical heating elements (310). In certain embodiments, the ends of the horizontal stack of substrates (120) are aligned toward one or more vertical heating elements (310). In certain embodiments, the height axis of the horizontal stack of substrates (120) is aligned orthogonally toward one or more vertical heating elements (310). That is, the height axis of the stack of substrates (120) points toward the vertical heating elements (310). Consequently, the heating system can also effectively heat the ends of the stack of substrates (120). Advantageously, the ends of the stack of substrates (120), as well as the sides of the stack of substrates, can also be surrounded by a heating system and effectively heated. Accordingly, the temperature difference between the ends and the middle portions of the stack of substrates (120) can be minimized. As a result, the stack of substrates (120) can be heated more uniformly.

[0093] In certain embodiments, the heating system is arranged to heat the ends of a stack of substrates (120) arranged within a reaction chamber (110) for processing. In certain embodiments, the heating system is arranged to heat the ends of a stack of substrates (120) arranged horizontally within a reaction chamber (110). Advantageously, the heating of the distal substrates (120) of the stack can be improved.

[0094] In certain embodiments, the substrate processing device (100) includes an outer chamber (210) that at least partially surrounds the reaction chamber (110). The space (volume) between the interior of the outer chamber (210) and the exterior of the reaction chamber (110) is defined as an intermediate space (215). In certain embodiments, a heating system is located within the outer chamber (210) in the intermediate space (215). Advantageously, the heating system can be better protected from external disturbances and thus controlled more accurately. Accordingly, temperature control of the reaction chamber (110) can be improved.

[0095] In certain embodiments, heating elements (310, 320, 330) enter the intermediate space through the bottom of the outer chamber (210) or the side walls (160). Advantageously, connection and control means for controlling the heating system can be accommodated outside the outer chamber (210). As a result, maintenance and control of the heating system can be facilitated.

[0096] In certain embodiments, the pressure and / or gas composition within the intermediate space (215) is controlled during substrate processing.

[0097] In certain embodiments, the outer chamber (210) includes an openable top portion (230), such as a lid. The lid enables loading and unloading a stack of substrates (120) into and from a reaction chamber (110) located within the outer chamber (210) through the top portion.

[0098] In certain embodiments, the exhaust outlet (150) extends from the bottom of the reaction chamber (111) through the bottom of the outer chamber (210). In certain embodiments, the exhaust outlet (150) is connected to an exhaust line (155) outside the outer chamber (210).

[0099] In certain embodiments, the substrate processing device (100) includes a heating collar (400) arranged to heat the exhaust outlet (150). In certain embodiments, the heating collar includes resistive heating elements. An exemplary heating collar (400) is depicted in FIG. 4. In certain embodiments, the heating collar (400) may be attached around the exhaust outlet (150) outside the reaction chamber (110). In certain embodiments, the heating collar (400) may be attached around the exhaust outlet (150) outside the outer chamber (210). In certain embodiments, the heating collar (400) is attached around the point where the exhaust outlet (150) is connected to the exhaust line (155). Advantageously, the formation of a cooling point and abrupt temperature gradients at the exhaust outlet (150) can be further minimized.

[0100] In certain embodiments, the heating collar comprises a first portion (410) and a second portion (420). In certain embodiments, the first portion (410) and the second portion are separable from each other to enable attachment and removal of the heating collar (400) around the exhaust outlet (150). In certain embodiments, the heating collar comprises connection means (430) for attaching connectors and cables to the heating collar (400) to operate the heating collar (400).

[0101] Without limiting the scope and / or interpretation of the claims, specific technical effects and / or advantages of one or more of the exemplary embodiments disclosed herein are listed below. An advantage is improved temperature control of the substrate processing apparatus. In particular, temperature non-uniformity within the reaction chamber, within the substrate, and between the substrates in the arrangement of substrates can be reduced. Another advantage is that processing conditions, processing quality, and reaction efficiency can be improved. An additional advantage is that heating efficiency can be improved and heating time can be reduced. Additionally, the direction and transfer of thermal energy can be better controlled and targeted. Yet another advantage is an improved thin film growth rate. One or more advantages can be realized due to improved temperature control and more stable and uniform processing conditions.

[0102] Various embodiments have been presented. It should be recognized that in this document, the words *comprise*, *include*, and *contain* are used as open expressions without intended exclusivity.

[0103] The foregoing description has provided a complete and informative description of the best mode currently considered by the inventors for carrying out the invention, through non-limiting examples of specific implementations and embodiments. However, it will be clear to those skilled in the art that the invention is not limited to the details of the embodiments presented in the foregoing description, but may be embodied in other embodiments using equivalent means or in different combinations of embodiments without departing from the characteristics of the invention.

[0104] Furthermore, some of the features of the exemplary embodiments disclosed above may be used advantageously without corresponding use of other features. As such, the foregoing description should be considered merely as an example of the principles of the invention and is not a limitation thereon. Accordingly, the scope of the invention is limited only by the appended claims.

Claims

Claim 1 A substrate processing device (100), comprising: a reaction chamber (110) defining a processing volume (115) for processing a stack of substrates (120) — said reaction chamber (110) comprises a downwardly tapered lower portion (130), said lower portion (130) arranged to tapered toward an exhaust outlet (150); and a heating system outside the processing volume (115), said heating system comprising inclined heating elements (320), said inclined heating elements (320) inclined from vertical, said lower portions of said inclined heating elements (320) arranged inwardly toward the exhaust outlet (150) to heat the tapered lower portion (130) of the reaction chamber. Claim 2 A substrate processing apparatus (100), wherein the tapering of the lowermost portion (130) comprises gradually narrowing down the horizontal cross-section of the reaction chamber (110) only along one horizontal dimension, namely the first horizontal dimension (H1), as it approaches the exhaust outlet (150). Claim 3 In claim 1 or 2, the inclined heating elements (320) are symmetrically arranged opposite the processing volume (115), in a substrate processing device (100). Claim 4 A substrate processing device (100) according to any one of claims 1 to 3, wherein the heating system further comprises vertical heating elements (310) arranged outside the processing volume (115) parallel to the vertical side walls (160) of the reaction chamber (110). Claim 5 A substrate processing device (100) according to any one of claims 1 to 4, wherein the heating system comprises lateral heating elements (330) configured to connect adjacent inclined heating elements (320) and / or vertical heating elements (310) to each other. Claim 6 In claim 5, the inclined heating elements (320), vertical heating elements (310) and lateral heating elements (330) are connected to each other to form continuous heating elements around the processing volume (115), in a substrate processing device (100). Claim 7 A substrate processing device (100) according to any one of claims 1 to 6, wherein the inclined heating elements (320) include at least one bent section (340) to partially define the inclination angle of the inclined heating elements (320). Claim 8 A substrate processing device (100) according to any one of claims 1 to 7, comprising an outer chamber (210) that at least partially surrounds the reaction chamber (110), wherein heating elements (310, 320, 330) of the heating system are located outside the reaction chamber (110) within the outer chamber (210). Claim 9 A substrate processing device (100), wherein, in any one of claims 1 to 7, the heating elements (310, 320, 330) of the heating system are embedded within the side walls (160) and the bottom (130) of the reaction chamber (110). Claim 10 A substrate processing device (100) configured to accommodate a stack of substrates (120) within a processing volume (115) as a horizontal stack of vertically aligned substrates (120) in any one of claims 1 to 9. Claim 11 In claim 10, the inclined heating element (320) is positioned transversely with respect to the height direction of the stack of substrates (120) at opposite sides of the stack, in a substrate processing device (100). Claim 12 A substrate processing device (100) according to claim 10 or 11, wherein each end of the horizontal stack of the substrates (120) is aligned toward one or more vertical heating elements (310). Claim 13 A substrate processing device (100), wherein, in any one of claims 10 to 12, the lowermost portion (130) is configured to conform to the shape of the horizontal stack of the substrates (120). Claim 14 In any one of claims 1 to 13, the reaction chamber (110) has a rectangular horizontal cross-section, the substrate processing device (100). Claim 15 A substrate processing device (100) comprising a heating collar (400) arranged to heat the exhaust outlet (150) in any one of claims 1 to 14. Claim 16 A substrate processing apparatus (100) according to any one of claims 1 to 15, wherein the height of the heating system is at least 90% of the height of the reaction chamber (110).

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