Semiconductor processing chamber with filament lamp having non-uniform heat output

Abstract

An arrangement of linear heating lamps is provided that allows for local control of temperature non-uniformity in a substrate during semiconductor processing. The reactor includes a substrate holder positioned between a top array and a bottom array of linear heating lamps. At least one lamp of the lamp set includes a filament having a varying density and power output along the length of the lamp. In particular, at least one lamp of the lamp set includes a filament having a higher filament winding density within a central portion of the lamp relative to a peripheral portion of the lamp. In some embodiments, at least one lamp is a central lamp that extends across a central portion of a substrate heated by the lamps. Further, at least one lamp of the lamp set has a higher power output within a central portion of the lamp than at a peripheral portion of the lamp.

Description

[0001] This application is a divisional application of Chinese invention patent application filed on January 21, 2021 (application number: 202110078438.1, applicant: ASM IP Holdings Limited, invention title: semiconductor processing chamber with filament lamp having uneven heat output). Technical Field

[0002] This disclosure relates generally to semiconductor processing equipment, including equipment for heating semiconductor substrates. More specifically, embodiments thereof relate to semiconductor processing equipment having heating lamps for providing non-uniform heat output to a semiconductor substrate. Background Technology

[0003] In semiconductor processing, many processes, including deposition, etching, and masking, involve heating the substrate. For example, chemical vapor deposition (CVD) is a process used to form thin films of material on a substrate, such as a silicon substrate. In a CVD process, gaseous molecules of the material to be deposited are provided to the substrate to form a thin film of that material on the substrate through a chemical reaction. Such films can be polycrystalline, amorphous, or epitaxial. Typically, CVD processes are performed at elevated temperatures to accelerate the chemical reactions and produce high-quality films. Some processes, such as epitaxial silicon deposition, are performed at extremely high temperatures (e.g., >450°C). O C、<1220 O It was carried out at point C).

[0004] During a CVD process, one or more substrates are placed on a substrate support inside the semiconductor processing reaction chamber. For example, the substrate can be a substrate itself, and the substrate support can be a pedestal. The substrate, and typically the support, are heated to a desired temperature. In a typical substrate processing step, reactant gases are passed through the heated substrate, causing a thin layer of the desired material to be deposited on the substrate by chemical vapor deposition (CVD). If the deposited layer has the same crystallographic structure as the underlying silicon substrate, it is called an epitaxial layer. Deposited layers are sometimes also called single-crystal layers because they have only one crystal structure. Through subsequent processes, these layers are fabricated into integrated circuits, resulting in integrated devices ranging from tens to millions, depending on the size of the substrate and the complexity of the circuitry.

[0005] When forming semiconductor devices, it is crucial to deposit materials of uniform thickness and with uniform properties on the substrate. For example, in very large-scale integrated circuit (VLSI) and ultra-large-scale integrated circuit (ULSI) technologies, the substrate is divided into individual chips on which integrated circuits are mounted. If the CVD process steps produce a deposited layer with non-uniformity, devices formed on the substrate or in different regions of the individual chips, or chips formed in different regions of the substrate, may have inconsistent operating characteristics or may fail completely.

[0006] To deposit uniform layers, sophisticated systems have been used to heat semiconductor substrates, aiming to provide a uniform temperature across the entire substrate. Unrestricted by theory, a uniform temperature across the substrate is believed to provide a uniform deposition result. On the other hand, non-uniformity or instability of temperature across the substrate during other thermal processes is believed to adversely affect the uniformity of the resulting structure. Other processes where temperature control may also be crucial include oxidation, nitriding, doping diffusion, sputtering deposition, photolithography, dry etching, plasma processing, and high-temperature annealing.

[0007] Substrates can be heated using resistance heating, induction heating, or radiation heating. Radiation heating is the most efficient technique and is therefore the preferred method for certain types of CVD. Radiation heating involves placing an infrared lamp inside a high-temperature furnace, called a reactor (or reaction chamber), where the substrate is processed. Unfortunately, due to the use of localized radiation sources and associated focusing and interference effects, radiation tends to produce a non-uniform temperature distribution, including "hot spots."

[0008] To mitigate these effects, the infrared lamps within the reactor are positioned to facilitate control of the temperature gradient throughout the reaction chamber. For example, in some configurations, the infrared lamps are designed to be linear and arranged in a pair of cross arrays. The grid created by this cross array configuration helps control the temperature uniformity of the substrate by adjusting the power delivered to any particular lamp or group of lamps; however, since high temperatures and high temperature uniformity are typically required, it can be difficult to properly configure the lamp array to provide such uniformity.

[0009] To provide even more uniform temperature distribution across the entire substrate, reflectors have been installed behind the lamps to provide indirect illumination. The reflector (or baffle) shields a portion of the lamp in the localized area of ​​interest, thus resulting in a more balanced temperature distribution throughout the reaction chamber. These reflectors are typically made of base metals and often plated with metal to increase their reflectivity. However, planar reflective surfaces still tend to induce hot spots on the heated substrate. Furthermore, while reflectors can improve temperature distribution, integrating them into production facilities has always been challenging from both an assembly and energy efficiency perspective. Once configured, modifying the reflector to provide different temperature distributions can be both tricky and time-consuming due to the need to address various production and design parameters.

[0010] Therefore, there has always been a need for a simple system to achieve uniform temperature across the entire semiconductor substrate during processing. Summary of the Invention

[0011] Some aspects of this document relate to a semiconductor processing system including a reaction chamber comprising: a substrate holder configured to support a semiconductor substrate; and a top array of linear heating lamps, wherein at least one lamp in the top array of linear heating lamps is configured to provide a power output varying over the entire length of the at least one lamp, and wherein the power output in a central portion is higher than the power output in a peripheral portion of the at least one lamp. In some embodiments, the semiconductor processing system includes a bottom array of linear heating lamps below the substrate holder. In some embodiments, the length of the central portion is 30 mm. In some embodiments, the power output ratio of the central portion to the power output of the peripheral portion is between 15 and 200. In some embodiments, the power output of the central portion is 2000 W. In some embodiments, each lamp in the top array of linear heating lamps extends substantially parallel to each other lamp in the top array of heating lamps. In some embodiments, at least one lamp in the top array of linear heating lamps includes a central lamp of the top array. In some embodiments, the top array of linear heating lamps includes eleven lamps. In some embodiments, at least one lamp is the sixth lamp counting from the edge of the top array. In some embodiments, the reaction chamber also includes a parabolic reflector.

[0012] Some aspects of this document relate to a semiconductor processing system including a reaction chamber comprising: a substrate holder configured to support a semiconductor substrate; and a top array of linear heating lamps, wherein at least one lamp in the top array of linear heating lamps includes a filament having a varying density over the entire length of the at least one lamp, and wherein the density in a central portion is higher than the density in a peripheral portion of the at least one lamp. In some embodiments, the filament of the at least one lamp includes a wound portion in the central portion and a substantially linear portion in the peripheral portion. In some embodiments, the semiconductor processing system includes a bottom array of linear heating lamps, wherein the substrate holder is located between the bottom array of linear heating lamps and the top array of linear heating lamps. In some embodiments, the length of the central portion is between 15 mm and 30 mm. In some embodiments, the ratio of the filament density in the central portion to the filament density in the peripheral portion is between 5 and 200. In some embodiments, each lamp in the top array of linear heating lamps extends substantially parallel to each other lamp in the top array of heating lamps. In some embodiments, at least one lamp in the top array of the linear heating lamps includes a central lamp in the top array. In some embodiments, the top array of the linear heating lamps includes eleven lamps. In some embodiments, at least one lamp is the sixth lamp counting from the edge of the top array.

[0013] Some aspects of this document relate to a method of heating a semiconductor substrate, the method comprising: placing the substrate on a substrate holder configured to support the semiconductor substrate; and heating the substrate with a top array of linear heating lamps covering the semiconductor substrate, wherein at least one lamp in the top array of linear heating lamps includes a filament having a varying winding density over the entire length of the at least one lamp, and wherein the winding density in a central portion is higher than the density in a peripheral portion of the at least one lamp. In some embodiments, the method comprises heating the substrate with a bottom array of linear heating lamps while simultaneously heating the substrate with the top array of linear heating lamps, and wherein the substrate holder is located between the bottom array and the top array of linear heating lamps. In some embodiments, the ratio of the winding density in the central portion to the winding density in the peripheral portion is between 5 and 200. In some embodiments, the length of the central portion is 30 mm. In some embodiments, each lamp in the top array of linear heating lamps extends substantially parallel to each other lamp in the top array of heating lamps. In some embodiments, at least one lamp in the top array of linear heating lamps includes a central lamp of the top array. In some implementations, the top array of linear heating lamps includes eleven lamps.

[0014] Some aspects relate to methods for heating a semiconductor substrate, the method comprising: placing the substrate on a substrate holder configured to support the semiconductor substrate; heating the substrate with a top array of linear heating lamps covering the semiconductor substrate, wherein at least one lamp in the top array of linear heating lamps includes a power output varying over the entire length of the at least one lamp, and wherein the power output in a central portion is higher than the power output in a peripheral portion of the at least one lamp. In some embodiments, the method comprises heating the substrate with a bottom array of linear heating lamps while simultaneously heating the substrate with the top array of linear heating lamps, and wherein the substrate holder is located between the bottom array and the top array of linear heating lamps. In some embodiments, the ratio of the power output of the central portion to the power output of the peripheral portion is between 5 and 200. In some embodiments, the length of the central portion is 30 mm. In some embodiments, the power output of the central portion is 2000 W. In some embodiments, each lamp in the top array of linear heating lamps extends substantially parallel to each other lamp in the top array of heating lamps. In some embodiments, at least one lamp in the top array of the linear heating lamps includes a central lamp in the top array. In some embodiments, the top array of the linear heating lamps includes eleven lamps. Attached Figure Description

[0015] Figure 1A is a cross-sectional view of the top and bottom arrays of a conventional reaction chamber together with heating lamps, wherein the substrate is supported on a substrate holder in the reaction chamber.

[0016] Figure 1B is a top plan view of a conventional substrate holder.

[0017] Figure 1C is a partial cross-sectional view of the substrate holder of Figure 1B taken along line 1C-1C of Figure 1B.

[0018] Figure 1D is a partial cross-sectional view of the substrate holder of Figures 1B and 1C, showing the state in which the substrate is held.

[0019] Figures 2A and 2B are schematic top and bottom plan views (2A and 2B) showing the conventional arrangement of lamps in the top (2A) and bottom (2B) arrays of the reactor.

[0020] Figures 3A and 3B are schematic top and bottom plan views (3A and 3B) showing alternative arrangements of lamps in the top and bottom arrays (3A and 3B) of the reactor.

[0021] Figure 4 is a schematic top plan view of a portion of the processing system environment, showing an array of radiant heating lamps positioned above and below an exemplary substrate.

[0022] Figure 5A is a top view of a single linear radiant heating lamp.

[0023] Figure 5B is a side view of the linear lamp in Figure 5A.

[0024] Figure 6 shows the deposition thickness curves, which compare the thickness of the deposited film across the entire surface of the substrate relative to the center.

[0025] Figure 7A is a top plan view of an example of a single linear radiant heating lamp according to some of the embodiments disclosed herein.

[0026] Figure 7B is a top plan view of another example of a single linear radiant heating lamp according to some of the embodiments disclosed herein.

[0027] Figure 8 is a schematic top plan view of a portion of the processing system environment, showing an array of radiant heating lamps positioned above and below an exemplary substrate according to some embodiments disclosed herein. Detailed Implementation

[0028] Reactors used in semiconductor processing (including CVD reactors) typically employ radiant heating lamps positioned around the reaction chamber to achieve the desired high temperatures within the substrate. Unfortunately, as discussed herein, due to the use of localized radiant energy sources, radiant energy tends to produce non-uniform temperature distributions, including “hot spots” and “cold spots.” The increased surface area of ​​the substrate and substrate holder near their outer edges also causes convective heat losses, resulting in further temperature non-uniformity. Other temperature non-uniformity may also be due to heat losses from the support disks supporting the substrate or from heat losses caused by the use of purge gas beneath the substrate. Advantageously, some embodiments described herein can overcome temperature non-uniformity caused by “cold spots” in the central portion of the semiconductor substrate. Temperature non-uniformity leads to undesirable processing non-uniformities in the substrate, such as variations in the thickness of the deposited film and variations in the electrical properties of the deposited layer throughout the substrate.

[0029] Many systems have been proposed to provide uniform heating to substrates. For example, to promote uniform substrate temperature during processing, some reactors include lamps grouped in separately controllable heating zones to allow different levels of power to be supplied to each individual zone. In some cases, different lamps extending partially or fully across the substrate can be controlled separately to provide different amounts of heat to the substrate. However, such systems may be overly complex and / or fail to provide the desired control over substrate heating, which is undesirable.

[0030] Some embodiments disclosed herein include a lamp having a central portion configured to provide a high level of heat energy to a substrate, and a peripheral portion on either side of the central portion providing a low level of heat energy to the substrate. Preferably, the lamp extends over the entire width of the substrate to be heated by the lamp. In some embodiments, the central portion has a radius of about 5.0 mm to about 30.0 mm, including a radius of about 7.5 mm to about 15.0 mm, and can provide a heat output of about 1000 W to about 2000 W. In some embodiments, the power output density in the central portion 242 can be about 60 W / mm to about 125 W / mm, while the power output in the peripheral portion is about 0 W / mm to about 10 W / mm. In some embodiments, the higher heat output in the central portion is provided by a higher filament winding density in the central portion relative to the peripheral portion. For example, the central portion may have a wound filament, while the peripheral portion has an unwound linear filament. In other embodiments, both the central and peripheral portions have wound filaments, but the winding density in the central portion is higher than that in the peripheral portion.

[0031] Advantageously, by providing lamps with higher heat output in the central section, a simple mechanism is provided to address the cold spot in the central section without requiring extensive redesign of the reaction chamber. Instead, the central section can be customized to the desired size of the central cold spot in the substrate to be heated by the lamps, taking into account the increased heat output and the required size. Furthermore, this customization can be achieved in the reaction chamber with simple modifications by swapping the lamps. This avoids, for example, the need to redesign auxiliary features, such as reflectors for radiative heat, which can be both difficult and time-consuming to reconfigure.

[0032] Referring now to the accompanying drawings, the same numbers always denote the same parts.

[0033] Figures 1A to 1D illustrate reactor 10, which can be used for CVD processing and in which some embodiments of the present invention can be implemented. As can be seen from Figure 1A, reactor 10 includes a horizontally flowing reaction chamber 12 formed of a thermally permeable material, such as quartz. Gas flows into and out of reaction chamber 12 in a generally horizontal flow pattern in the directions indicated by arrows 40 (inlet) and 42 (outlet).

[0034] Reactor 10 is shown with heating lamps 14 arranged in a top array 36 above reaction chamber 12 and a bottom array 38 below reaction chamber 12. Alternatively, only one such array of lamps may be provided; for example, reactor 12 may consist only of top array 36. Arrays 36 and 38 are supported outside reaction chamber 12 to provide heat to reaction chamber 12 through the chamber walls, which preferably are not significantly absorbed by the chamber walls. Reactor 10 includes a substrate support structure 20 with a substrate holder 1 on which a semiconductor substrate 16 may rest. A support disk 22 may be provided to support the holder 1. The support disk 22 may be made of a transparent material. The material may also be non-metallic to reduce the risk of contamination. The support disk 22 may be mounted to a shaft 24 that extends downward through a tube 26 suspended from the lower wall of reaction chamber 12. During substrate processing, shaft 24, support disk 22 and retainer 1 are configured to rotate uniformly about the vertical central axis of retainer 1.

[0035] While this disclosure is not limited to any particular theory, in some configurations of reactor 10, undesirable temperature nonuniformity is believed to be due to radiative heat loss from the substrate holder 1 and / or support structure 20 to the support disk 22 and / or shaft 24 (which may comprise quartz). Although quartz has a relatively low thermal conductivity, and although many parts of the reactor are also made of quartz and even with heat supplied to the central region of the substrate using a spotlight below, it is believed that significant differences in heat loss through the support structure 20 to the support disk 22 and / or shaft 24 still exist due to the high processing temperatures employed during ultra-high temperature deposition. For example, in some embodiments, the processing temperatures for such ultra-high temperature deposition can range from about 1000°C to 1200°C. In some embodiments, as disclosed herein, the width of the central portion of the filament with a higher winding density can roughly correspond to the width of the support disk 22.

[0036] Figures 1B to 1D further illustrate examples of the substrate holder 1 of the reactor 10. The holder 1 may have a generally circular shape and includes a recess 3 configured to receive the substrate 16. During substrate processing, the substrate holder 1 can be heated by radiant heating lamps 14 surrounding the reaction chamber 12. Figure 1A The substrate holder 1 absorbs heat. It can also dissipate heat to the surrounding environment (e.g., to a room wall that is not typically totally reflective). Some of this heat can be radiated away from the holder 1, while the remainder can be lost due to convection and conduction. Referring to Figure 1D, the holder 1 loses heat from its upper surfaces 3 and 5, side surfaces 6, and bottom surface 7, and the substrate 16 loses heat from its upper surface 9 and its edge 8. Arrow HT schematically illustrates the heat loss at upper surfaces 3, 5, and 9. Similarly, arrows HS and HB schematically illustrate the heat loss at side surface 6 and bottom surface 7, respectively. In most areas of the holder / substrate assembly, the heat losses HT and HB are generally compensated for by the uniform heat input from the lamp 14 across the entire surface of the assembly. However, there is an additional heat loss HS at the outer radial edges of the holder / substrate assembly that receive less direct radiation. In addition, local temperature non-uniformity may also be due to conductive heat loss to the support disk 22 or convective heat loss caused by introducing purge gas through holes in the substrate holder 1 below the substrate 16.

[0037] Without localized control of the power output to the heating lamp 14, these temperature non-uniformities may be undercompensated or overcompensated. Therefore, the lamp may cause a degree of processing non-uniformity in the substrate being processed, potentially rendering some portions of the substrate unusable. For example, the area near the outer radial edge 8 of the substrate 16 is often referred to as an "exclusion region" because this area cannot be used to manufacture a satisfactory chip.

[0038] Referring again to Figure 1A, the exemplary reactor 10 includes a central temperature sensor or thermocouple 28 that extends through the shaft 24 and the support disk 22 near the substrate holder 1. Additional peripheral thermocouples 30 may also be housed within a slip ring or temperature compensation ring 32 that may surround the substrate holder 1 and the substrate 16. Thermocouples 28, 30 may be connected to a temperature controller (not shown) that can selectively set the power of the various heating elements 14 in response to readings from the thermocouples 28, 30.

[0039] Various heating schemes using lamps have been proposed to provide uniform temperature across the entire substrate. Some of these heating schemes will now be discussed further.

[0040] Referring now to Figures 2A and 2B, an example of the arrangement of the heating lamps 14 is further illustrated. This arrangement includes elongated lamps 14 that span at least the diameter of the substrate holder 1. As shown in the figures, the lamps 14 in the top array 36 can be arranged parallel to each other and perpendicular to the lamps 14 in the bottom array 38. Although Figure 1A shows a top array 36 with lamps 14 oriented parallel to the direction of gas flow through the reaction chamber 12 and a bottom array 38 with lamps 14 oriented perpendicular to the direction of gas flow, it should be understood that these orientations can be reversed. That is, the top array 36 can be perpendicular to the direction of gas flow through the reaction chamber 12, while the bottom array 38 can be parallel to the direction of gas flow through the chamber 12. Alternatively, in some embodiments, the two lamp groups 36, 38 can be oriented in the same direction. Furthermore, the lamps 14 do not necessarily need to be arranged collinearly; instead, they can be offset from each other laterally or vertically. Furthermore, these lights do not have to be arranged parallel to each other; instead, they can be set at an angle relative to each other, depending on the requirements of a specific application.

[0041] Although the lamps 14 are arranged in a uniform pattern, temperature non-uniformity may still occur in the substrate. The arrangement of long lamps 14 may make local temperature control difficult, which is undesirable because the power reaching the entire lamp 14 must be adjusted to overcome local non-uniformity.

[0042] Referring now to Figures 3A and 3B, alternative recommended arrangements of the lamps are shown. The top array 36 and bottom array 38 may include linear heating lamps 54, 56, each shorter than the diameter of the substantially circular substrate holder 1. Lamps 54, 56 may also be shorter than the diameter of the recess 3. For example, lamp 56 may be approximately half the diameter of the substrate holder 1; lamp 54 may be approximately half the length of lamp 56. As shown in the figures, lamps 54, 56 in each array 36, 38 may be arranged in a repeating pattern of substantially parallel rows. Lamps 54, 56 in the top array 36 may be positioned substantially perpendicular to lamps 54, 56 in the bottom array 38. Lamps 54, 56 in the top array 36 may be suspended from or attached to a top plate or frame (not shown) mounted in the reactor 10. Similarly, lamps 54, 56 in the bottom array may be attached to a bottom plate or frame (not shown) mounted in the reactor 10. In addition, shorter lamps allow for control of the incident power over a smaller portion of the substrate, thus allowing for temperature regulation in a smaller area without affecting the temperature of adjacent areas. However, shorter lamps may introduce additional complexity in terms of installation, manufacturing, and control, potentially requiring a simpler arrangement of the heating lamps in some implementations.

[0043] Referring now to Figure 4, a grid of heating lamps consisting of a top lamp array 36 and a bottom lamp array 38 is shown. In this illustrated arrangement, the substrate is positioned within the reaction chamber 12 generally between the top lamp array 36 and the bottom lamp array 38. It should be noted that in some chambers, the top and bottom arrays may be constructed differently. For example, the bottom array 38 may typically house spotlights, a rotation shaft 24, and a gas supply pipe. Therefore, the central region of the bottom array may not allow fully linear lamps to reach from one side to the other. Conversely, in this configuration, the top array will not have such an obstacle and can easily accommodate and enable fully linear lamps to reach from one side to the other. It should be understood that fewer or more lamps may be used and / or other heating devices may be used to supplement the heat provided by the lamps. For example, in some embodiments, the bottom lamp array 38 may include additional linear lamps (not shown) forming the heating region 23 and / or one or more spotlights (not shown) forming the heating region 24 to guide heat from the underside of the substrate to the central portion of the substrate.

[0044] Referring again to Figure 4, in one arrangement of the grid, the lamps are linear, and eleven lamps constitute each of the top and bottom arrays. It should be noted that other numbers of lamps may also be used. The lamps 36 of the top array preferably extend substantially perpendicular to the lamps 38 of the bottom array. Generally, lamps 36 and 38 can receive different power levels to overcome end effects and other phenomena that may alter the temperature gradient across the entire substrate. Different power levels create multiple regions. In the arrangement shown, six regions (i.e., regions 1 to 11) are provided in the top array, while nine regions (i.e., regions 12 to 22) are provided in the bottom array. In some embodiments, additional lamps are added to the lamps of the bottom array 38 to provide region 23. These regions can receive different power levels so that the temperature gradient across the entire substrate can be substantially uniform across all portions of the substrate surface. Lamps 36 and 38 can be controlled individually or in groups or regions as shown. Each region can be associated with the temperature control module based on feedback from temperature sensors (e.g., thermocouples 28 and 30 in Figure 1A).

[0045] Referring now to Figures 5A and 5B, lamp 230 is shown. The lamp 230 typically includes two connectors 232 and 234, positioned at opposite ends of tube 236. Filament 238 (schematically shown in Figures 5A and 5B) extends through tube 236 and is electrically connected to each of the end connectors 232 and 234. Therefore, when a power source is connected across end connectors 232 and 234, filament 238 receives current and dissipates heat.

[0046] Lamp 230 may have dimensions that vary depending on the application and desired size. For example, the lamp may have a length extending between connectors 232, 234 at opposite ends of tube 236. In some embodiments, the lamp length may be about 420 mm. In some embodiments, the lamp length may be from about 100 mm to about 1200 mm. For example, in some embodiments, the length of the lamp can be approximately 100 mm, approximately 120 mm, approximately 140 mm, approximately 160 mm, approximately 180 mm, approximately 200 mm, approximately 220 mm, approximately 240 mm, approximately 260 mm, approximately 280 mm, approximately 300 mm, approximately 320 mm, approximately 340 mm, approximately 360 mm, approximately 380 mm, approximately 400 mm, approximately 420 mm, approximately 440 mm, approximately 460 mm, approximately 480 mm, approximately 500 mm, approximately 520 mm, approximately 540 mm, approximately 560 mm, approximately 580 mm, approximately 600 mm, approximately 620 mm, approximately 640 mm, approximately 660 mm, approximately 680 mm, approximately 700 mm, approximately 720 mm, approximately 740 mm, approximately 760 mm, approximately 780 mm, approximately 800 mm, approximately 820 mm, approximately 840 mm, approximately 860 mm, approximately 8 ... mm, approximately 900 mm, approximately 920 mm, approximately 940 mm, approximately 960 mm, approximately 980 mm, approximately 1000 mm, approximately 1020 mm, approximately 1040 mm, approximately 1060 mm, approximately 1080 mm, approximately 1100 mm, approximately 1120 mm, approximately 1140 mm, approximately 1160 mm, approximately 1180 mm, approximately 1200 mm, or between any of the aforementioned values.

[0047] Even with advancements in localized temperature control mechanisms, spotlights, and / or rotating base technologies, achieving uniform heat distribution across the entire substrate surface can still present challenges. For example, in some cases, the central portion of the substrate's top surface may exhibit a sudden drop in temperature across the entire substrate.

[0048] Region-based heating schemes have consistently failed to address this temperature drop, which is undesirable. Referring to Figure 6, even with region heating, a sharp drop in deposition thickness across the entire substrate surface has been observed at the center of the substrate (i.e., at 0 along the x-axis of the curve). This drop could, for example, occur during silicon deposition (e.g., epitaxial silicon).

[0049] Advantageously, lamp configurations according to some embodiments can mitigate or eliminate this temperature drop at the center of the substrate in the thickness distribution. While in some cases reflector modifications can be used to direct and focus heat energy to the center of the substrate to increase the temperature there, these changes require significant alterations to the reactor and lamp design and may be time-consuming and undesirable to implement. However, some embodiments described herein can mitigate or eliminate the temperature drop at the center of the substrate with simple, minor modifications to the substrate heating system, thereby enabling a more uniform deposition thickness across the entire substrate. For example, the embodiments described herein can be implemented without altering the arrangement of the linear lamp array or the housing and form factor of the lamps typically used in reactors. In some embodiments, lamp configurations according to certain embodiments can reduce the central temperature drop, thereby enhancing temperature uniformity in the semiconductor processing system.

[0050] In some embodiments, the lamp configuration according to some embodiments can reduce, mitigate, or eliminate abrupt drops or decreases in temperature distribution at a central portion of the substrate surface. In some embodiments, the central portion may include a substantially circular portion of the surface concentrically positioned with respect to the substrate. In some embodiments, the substantially circular portion may have a radius of about 7.5 mm to about 15.0 mm. In some embodiments, the substantially circular portion may have a radius of about 5.0 mm to about 30.0 mm. In some embodiments, the substantially circular portion may have the following radii: about 5 mm, about 7.5 mm, about 10 mm, about 12.5 mm, about 15 mm, about 17.5 mm, about 20 mm, about 22.5 mm, about 25 mm, about 27.5 mm, about 30 mm, about 32.5 mm, about 35 mm, about 37.5 mm, about 40 mm, about 42.5 mm, about 45 mm, about 47.5 mm, about 50 mm, or between any of the foregoing values.

[0051] Referring to Figures 7A and 7B, exemplary lamp constructions according to various embodiments are illustrated. In some embodiments, lamp 230 includes a distinct peripheral portion 240 and a central portion 242. In some embodiments, the central portion has a relatively higher density of conductive wound filament compared to the peripheral portion, resulting in a higher heat output at the center of the lamp compared to the periphery. In some embodiments, such as the one shown in Figure 7A, the peripheral portion 240 may include a straight conductor extending from end connectors 232, 234 to the central portion. In those embodiments, the conductor may have linear contact with the filament at an attachment or junction point between the conductor in the peripheral portion 240 and the conductive filament in the central portion 242.

[0052] Depending on the lamp's rated power and distribution, the configuration of Figure 7A may result in an unsuitable high-temperature gradient between the linear filament in the peripheral portion 240 and the wound or coiled filament in the central portion 242. For example, an excessive gradient could damage the mechanical integrity of the wires, filament, or lamp housing due to baking, melting, or bubbling. Therefore, in other embodiments (such as the one shown in Figure 7B), both the peripheral portion 240 and the central portion 242 can include conductive wound filaments. However, the winding density of the conductive filament in the central portion 242 can be relatively higher than that in the peripheral portion 240.

[0053] In either of the configurations in Figure 7A or Figure 7B, the central portion 242 of the lamp may have a length of about 15 mm to about 30 mm, which may correspond to a cold spot on the substrate to be heated by the lamp. In some embodiments, the central portion 242 of the lamp may have a length of about 15 mm. In some embodiments, the central portion 242 of the lamp may have a length of about 30 mm. In some embodiments, the central portion 242 of the lamp may have the following lengths: approximately 5 mm, approximately 5.5 mm, approximately 6 mm, approximately 6.5 mm, approximately 7 mm, approximately 7.5 mm, approximately 8 mm, approximately 8.5 mm, approximately 9 mm, approximately 9.5 mm, approximately 10 mm, approximately 10.5 mm, approximately 11 mm, approximately 11.5 mm, approximately 12 mm, approximately 12.5 mm, approximately 13 mm, approximately 13.5 mm, approximately 14 mm, approximately 14.5 mm, approximately 15 mm, approximately 15.5 mm, approximately 16 mm, approximately 16.5 mm, approximately 17 mm, approximately 17.5 mm, approximately 18 mm, approximately 18.5 mm, approximately 19 mm, approximately 19.5 mm, approximately 20 mm, approximately 20.5 mm, approximately 21 mm, approximately 21.5 mm, approximately 22 mm, approximately 22.5 mm, approximately 23 mm, approximately 23.5 mm, approximately 24 mm, approximately 24.5 mm. mm, approximately 25 mm, approximately 25.5 mm, approximately 26 mm, approximately 26.5 mm, approximately 27 mm, approximately 27.5 mm, approximately 28 mm, approximately 28.5 mm, approximately 29 mm, approximately 29.5 mm, approximately 30 mm, approximately 30.5 mm, approximately 31 mm, approximately 31.5 mm, approximately 32 mm, approximately 32.5 mm, approximately 33 mm, approximately 33.5 mm, approximately 34 mm, approximately 34.5 mm, approximately 35 mm, approximately 35.5 mm, approximately 36 mm, approximately 36.5 mm, approximately 37 mm, approximately 37.5 mm, approximately 38 mm, approximately 38.5 mm, approximately 39 mm, approximately 39.5 mm, approximately 40 mm, approximately 40.5 mm, approximately 41 mm, approximately 41.5 mm, approximately 42 mm, approximately 42.5 mm, approximately 43 mm, approximately 43.5 mm, approximately 44 mm, approximately 44.5 mm, approximately 45 mm mm, approximately 45.5 mm, approximately 46 mm, approximately 46.5 mm, approximately 47 mm, approximately 47.5 mm, approximately 48 mm, approximately 48.5 mm, approximately 49 mm, approximately 49.5 mm, approximately 50 mm, or between any of the aforementioned values.In some embodiments, the length of the central portion and the higher-density wound filament therein can be configured to match the diameter of the central portion of the substrate. In some embodiments, the shorter central portion 242 will provide more targeted heat transfer compared to the longer central portion 242.

[0054] Providing a high-density wound filament in the central portion 242 and incorporating wires or a lower-density wound filament in the peripheral portion 240 of the lamp 230 may concentrate the lamp's power output in the central portion. In some embodiments, for a lamp with a rated power of 4200 W, the central portion may have a power output of approximately 1000 W to approximately 2000 W. For example, a lamp with a central portion 242 of 30 mm in length may have a power output of approximately 1000 W in the central portion. In another example, a lamp with a central portion 242 of 15 mm in length may have a power output of approximately 2000 W in the central portion. In some implementations, the power output at the central section can be approximately 1000 W, approximately 1025 W, approximately 1050 W, approximately 1075 W, approximately 1100 W, approximately 1125 W, approximately 1150 W, approximately 1175 W, approximately 1200 W, approximately 1225 W, approximately 1250 W, approximately 1275 W, approximately 1300 W, approximately 1325 W, approximately 1350 W, approximately 1375 W, approximately 1400 W, approximately 1425 W, approximately 1450 W, approximately 1475 W, approximately 1500 W, approximately 1525 W, approximately 1550 W, approximately 1575 W, approximately 1600 W, approximately 1625 W, approximately 1650 W, approximately 1675 W, approximately 1700 W, approximately 1725 W, approximately 1750 W, approximately 1775 W, approximately 1800 W, approximately 1825 W. W, approximately 1850 W, approximately 1875 W, approximately 1900 W, approximately 1925 W, approximately 1950 W, approximately 1975 W, approximately 2000 W, or between any of the foregoing values. Those skilled in the art will understand that the power output at the central portion 242 can vary depending on the rated power of the lamp 238.

[0055] Because the length of the central portion 242 is smaller than the total length of the lamp 230, the power output density of the central portion 242 can be relatively higher than that of the peripheral portion 240. In some embodiments, the power output density in the central portion 242 can be from about 60 W / mm to about 125 W / mm. For example, the power output density in the central section 242 can be approximately 60 W / mm, approximately 62.5 W / mm, approximately 65 W / mm, approximately 67.5 W / mm, approximately 70 W / mm, approximately 72.5 W / mm, approximately 75 W / mm, approximately 77.5 W / mm, approximately 80 W / mm, approximately 82.5 W / mm, approximately 85 W / mm, approximately 87.5 W / mm, approximately 90 W / mm, approximately 92.5 W / mm, approximately 95 W / mm, approximately 97.5 W / mm, approximately 100 W / mm, approximately 102.5 W / mm, approximately 105 W / mm, approximately 107.5 W / mm, approximately 110 W / mm, approximately 112.5 W / mm, approximately 115 W / mm, approximately 117.5 W / mm, approximately 120 W / mm, approximately 122.5 W / mm, approximately 12 ... W / mm, or any of the values ​​mentioned above.

[0056] The power output density in the peripheral portion 240 can be relatively low. In some embodiments, the power output density in the peripheral portion 240 can be from about 0 W / mm to about 10 W / mm. For example, the power output density in the peripheral portion 240 can be approximately 0.00 W / mm, approximately 0.25 W / mm, approximately 0.5 W / mm, approximately 0.75 W / mm, approximately 1 W / mm, approximately 1.25 W / mm, approximately 1.5 W / mm, approximately 1.75 W / mm, approximately 2 W / mm, approximately 2.25 W / mm, approximately 2.5 W / mm, approximately 2.75 W / mm, approximately 3 W / mm, approximately 3.25 W / mm, approximately 3.5 W / mm, approximately 3.75 W / mm, approximately 4 W / mm, approximately 4.25 W / mm, approximately 4.5 W / mm, approximately 4.75 W / mm, approximately 5 W / mm, approximately 5.25 W / mm, approximately 5.5 W / mm, approximately 5.75 W / mm, approximately 6 W / mm, approximately 6.25 W / mm, approximately 6.5 W / mm, approximately 6.75 W / mm, approximately 7 W / mm, about 7.25 W / mm, about 7.5 W / mm, about 7.75 W / mm, about 8 W / mm, about 8.25 W / mm, about 8.5 W / mm, about 8.75 W / mm, about 9 W / mm, about 9.25 W / mm, about 9.5 W / mm, about 9.75 W / mm, about 10 W / mm, or between any of the aforementioned values.

[0057] In some implementations, the ratio between the power output in the central portion 242 and the power output in the peripheral portion 240 can be in the range of about 5 to about 200. For example, in some embodiments, the ratio between the power output in the central portion 242 and the power output in the peripheral portion 240 may be about 5, about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, about 90, about 95, about 100, about 105, about 110, about 115, about 120, about 125, about 130, about 135, about 140, about 145, about 150, about 155, about 160, about 165, about 170, about 175, about 180, about 185, about 190, about 195, about 200, or between any of the aforementioned values.

[0058] In some embodiments, the ratio between the filament winding density in the central portion 242 and the filament winding density in the peripheral portion 240 can be in the range of about 5 to about 200. For example, in some embodiments, the ratio between the filament winding density in the central portion 242 and the filament winding density in the peripheral portion 240 may be about 5, about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, about 90, about 95, about 100, about 105, about 110, about 115, about 120, about 125, about 130, about 135, about 140, about 145, about 150, about 155, about 160, about 165, about 170, about 175, about 180, about 185, about 190, about 195, about 200, or between any of the aforementioned values.

[0059] In some embodiments, the lamp configurations of Figures 7A and 7B can be used as one or more lamps in a cross array, including one or more lamps in the exemplary lamp array shown in Figure 4. For example, in some embodiments, according to Figure 7A The lamp configuration of Figure 7B can replace the lamps in region 6 of the top lamp array 36 of Figure 4. In some embodiments, only the lamps in region 6 of the top array can be replaced. This lamp configuration is shown in Figure 8. The remaining lamps in the top lamp array 36 can be similar to each other (e.g., they can have a constant filament winding density over their entire length). However, as those skilled in the art will understand, the lamp configurations of Figure 7A and / or Figure 7B can be used to replace any one or more lamps in the top lamp array 36 of Figure 4 or any one or more lamps in the bottom lamp array 38 of that figure. Furthermore, it should be understood that the lamp configurations of Figure 7A or Figure 7B can also be used in alternative lamp configurations, including non-linear arrays, shortened or segmented lamp arrays, or any other configurations discussed above. In addition, the lamp configuration can be added as an additional or supplementary lamp to any array described herein (i.e., without removing any conventional lamps). For example, lamp configurations can be added near, above, or below any of the lamps shown in Figure 4 to provide additional localized thermal control at specific locations on the substrate.

[0060] The lamp configuration in Figure 8 can mitigate or eliminate the temperature drop at the center of the semiconductor substrate. The high power output of the central portion of the lamp in region 6 can reduce, mitigate, or eliminate the temperature drop in the semiconductor substrate located between the top and bottom lamp arrays in Figure 8. For example, referring again to Figure 6, it has been advantageously found that using lamps according to various embodiments results in a concentrated increase in the thickness of the deposited silicon film, and this increase is concentrated in the desired central portion of the substrate, as shown by the top curve (a curve that extends higher at the zero point). This top curve illustrates the deposition of a lamp configuration with a high-winding-density central portion according to the embodiments described herein, while the bottom curve illustrates the deposition of a lamp configuration with a conventionally wound filament distributed throughout the lamp. As shown, the lamp configuration according to the embodiments described herein effectively increases the deposition thickness at the center of the semiconductor substrate while also reducing the magnitude of the central thickness drop.

[0061] Various embodiments have been described in the foregoing description. However, it will be apparent that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

[0062] In fact, it should be understood that the systems and methods disclosed herein each have several innovative aspects, and no single aspect is solely responsible for or required to achieve the desired properties disclosed herein. The various features and processes described above can be used independently of each other or combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of this disclosure.

[0063] Furthermore, while the lamps disclosed herein advantageously avoid complex redesigns of reflectors used to guide the heat emitted by the lamp, it should be understood that the lamps remain compatible with such reflectors. Therefore, in some embodiments, the processing system may include a lamp with a relatively high heat output and winding density in the central portion of the lamp, along with a reflector designed to preferentially guide radiant heat from the lamp of the processing system toward the central region of the substrate. For example, these reflectors may be curved to focus radiant heat toward the central region of the substrate.

[0064] Some features described in the context of individual embodiments in this specification may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, although features may be described above as functioning in certain combinations and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and the claimed combination may involve sub-combinations or variations thereof. For each embodiment, no single feature or group of features is necessary or indispensable.

[0065] It should be understood that the conditional language used herein, such as “can,” “may,” “may,” “may,” “for example,” etc., unless otherwise expressly stated or understood otherwise in the context in which they are used, is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not include these features, elements, and / or steps. Therefore, such conditional language is not generally intended to imply that features, elements, and / or steps are necessary in any way for one or more embodiments, or that one or more embodiments must include logic for determining, with or without author input or prompting, whether such features, elements, and / or steps are included in any particular embodiment or will be performed in any particular embodiment. The terms “comprising,” “including,” “having,” etc., are synonyms and are used inclusively in a manner that can be broadly interpreted, and do not exclude additional elements, features, actions, operations, etc. Furthermore, the term “or” is used in its inclusive sense (rather than in its exclusive sense), and therefore, when used, for example, to connect a list of elements, the term “or” indicates one, some, or all of the elements in that list. Furthermore, the articles “a,” “an,” and “the” used in this application and the appended claims should be understood to mean “one or more” or “at least one”, unless otherwise specified. Similarly, although operations may be depicted in the drawings in a specific order, it should be understood that such operations do not need to be performed in the specific order shown or sequentially, or that all the illustrated operations need not be performed to obtain the desired result. Additionally, the drawings may schematically depict one or more exemplary processes in the form of flowcharts. However, other operations not depicted may be combined with the exemplary methods and processes schematically shown. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. Furthermore, in other embodiments, these operations may be rearranged or reordered. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the above embodiments should not be construed as requiring such separation in all embodiments, but rather it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Furthermore, other embodiments are within the scope of the following claims. In some cases, the actions described in the claims can be performed in a different order and still achieve the desired result.

[0066] Therefore, the claims are not intended to be limited to the embodiments described herein, but should be given the broadest scope consistent with this disclosure, principles and novel features disclosed herein.

Claims

1. A method for heating a semiconductor substrate, the method comprising: The substrate is placed on a substrate holder configured to support the semiconductor substrate; as well as The substrate is heated by a top array of linear heating lamps, the top array of which covers the semiconductor substrate. At least one lamp in the top array of the linear heating lamps includes a filament having a varying winding density along the entire length of the at least one lamp. The winding density in the central portion of the at least one lamp is greater than the winding density in the peripheral portion.

2. The method of claim 1, further comprising heating the substrate with a bottom array of linear heating lamps while simultaneously heating the substrate with a top array of the linear heating lamps, wherein... The substrate holder is located between the bottom array of the linear heating lamps and the top array of the linear heating lamps.

3. The method of claim 1, wherein the ratio of the winding density of the central portion to the winding density of the peripheral portion is between 5:1 and 200:

1.

4. The method of claim 1, wherein the length of the central portion is 30 mm.

5. The method of claim 1, wherein each lamp in the top array of the linear heating lamps extends parallel to each other lamp in the top array of the heating lamps.

6. The method of claim 1, wherein the at least one lamp in the top array of the linear heating lamps includes a central lamp of the top array of the linear heating lamps, wherein the length of the central portion of the at least one lamp is less than the length of the peripheral portion of the at least one lamp.

7. The method of claim 1, wherein the top array of the linear heating lamps comprises eleven lamps.

8. A method for heating a semiconductor substrate, the method comprising: The substrate is placed on a substrate holder configured to support the semiconductor substrate; as well as The substrate is heated by a top array of linear heating lamps, the top array of which covers the semiconductor substrate. At least one lamp in the top array of the linear heating lamps includes a power output that varies along the entire length of the at least one lamp. The power output in the central portion of the at least one lamp is higher than the power output in the peripheral portion of the at least one lamp.

9. The method of claim 8, further comprising heating the substrate with a bottom array of linear heating lamps while simultaneously heating the substrate with a top array of linear heating lamps, wherein the substrate holder is located between the bottom array of linear heating lamps and the top array of linear heating lamps.

10. The method of claim 8, wherein the power output ratio of the central portion to the power output ratio of the peripheral portion is between 5:1 and 200:

1.

11. The method of claim 8, wherein the length of the central portion is 30 mm.

12. The method of claim 8, wherein the power output of the central portion is 2000 W.

13. The method of claim 8, wherein each lamp in the top array of the linear heating lamps extends parallel to each other lamp in the top array of the heating lamps.

14. The method of claim 8, wherein the at least one lamp in the top array of the linear heating lamps includes a central lamp of the top array, wherein the length of the central portion of the at least one lamp is less than the length of the peripheral portion of the at least one lamp.

15. The method of claim 8, wherein the top array of the linear heating lamps comprises eleven lamps.

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