Multi-zone and individual lamp control in a lamp head

Abstract

A method and apparatus for processing a semiconductor substrate are described. A substrate processing apparatus is disclosed that includes a processing chamber, a substrate support disposed within the processing chamber, a plurality of lamps arranged in a lamp head and positioned proximate to the substrate support, a gas source for providing a purge gas in a lateral flow path across the substrate support, and a controller that differentially adjusts power provided to individual lamps of the plurality of lamps based on a direction of the flow path.

Description

[0001] This application is a divisional application of the invention patent application filed on August 2, 2019, with application number 201910711874.0 and invention title "Multi-zone lamp control and individual lamp control in lamp holder". Technical Field

[0002] This document discloses methods and apparatus for semiconductor processing. More specifically, the embodiments disclosed herein relate to methods and apparatus for controlling particulate contamination in epitaxial processes. Background Technology

[0003] Epitaxy is a widely used semiconductor processing technique to form very thin layers of material on a semiconductor substrate. These layers typically define some of the smallest features of a semiconductor device and can have high-quality crystal structures if the electrical properties of the crystalline material are desired. To form these layers, a deposition precursor is provided to a processing chamber having a pedestal on which a substrate is disposed, and the substrate is heated to a temperature favorable for the growth of a material layer with the desired properties. Due to the small feature size of the semiconductor device formed on the substrate, the amount of particles on the substrate must be kept to a minimum.

[0004] However, particles may adhere to the substrate during transport into the processing chamber. For example, in a process where processing gas is supplied to one side of the substrate to flow over its surface, the gas flowing into the chamber during transport of the substrate may generate particles that fall onto it. These particles can detach from the chamber walls and be entrained in the airflow. Additionally, the substrate temperature may be uneven, causing the substrate to warp upon initial contact with the substrate. The retention area for particles on the substrate can be larger or smaller, depending on the orientation of the substrate's warp profile relative to the airflow direction. If the substrate has a warped shape with a large cross-section within the gas flow path, particle deposition on the substrate is greater than when the substrate has a shape with a small cross-section within the gas flow path.

[0005] Methods and apparatus for preventing or minimizing particulate contamination of substrates to be treated. Summary of the Invention

[0006] A method and apparatus for processing a semiconductor substrate are described. In one embodiment, a substrate processing apparatus is disclosed, comprising: a processing chamber; a substrate support disposed within the processing chamber; a plurality of lamps arranged in lamp heads and positioned proximate to the substrate support; a gas source for providing purge gas in a lateral flow path across the substrate support; and a controller that differentially adjusts the power supplied to individual lamps among the plurality of lamps based on the direction of the flow path.

[0007] In another embodiment, a substrate processing apparatus is disclosed, comprising: a processing chamber; a substrate support disposed within the processing chamber; a lamp array arranged in lamp heads and positioned close to the substrate support, the lamp array including at least an internal partition, a central partition, and an external partition, the external partition corresponding to the periphery of the substrate support; a gas source for providing purified gas in a lateral flow path across the substrate support; and a controller for adjusting the power of the lamps provided to the external partition based on the direction of the flow path.

[0008] In another embodiment, a method for processing a substrate is disclosed, comprising: heating a base in a processing chamber using a lamp array, the lamp array including a plurality of lamps positioned below the base, the plurality of lamps including an inner partition and an outer partition, the outer partition corresponding to the periphery of the base; causing a purge gas to flow in a lateral flow path across the base, wherein the heating includes providing power to one or more of the plurality of lamps in the outer partition of the lamp array, but not to the other lamps in the outer partition, the one or more lamps being positioned at a leading or trailing edge of the base based on the flow path; and conveying the substrate to the base after the heating step. Attached Figure Description

[0009] Therefore, in order to understand in detail the above-described features of this disclosure, a more specific description of the disclosure briefly outlined above can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate typical embodiments of this disclosure and should therefore not be considered as limiting the scope of this disclosure, as other equally effective embodiments are permissible.

[0010] Figure 1 This is a schematic cross-sectional view of a processing chamber according to one embodiment.

[0011] Figure 2A and 2B It is an exploded isometric view of the base and the substrate to be treated, showing the warping of the substrate to be treated.

[0012] Figure 2C and 2D They are rotated 90 degrees respectively Figure 2A and 2B A side view of the base and the substrate to be processed.

[0013] Figure 3A This is an isometric view of the base and lamp head, showing one embodiment of differential heating of the base.

[0014] Figure 3B This is an isometric view of the base and lamp head, showing another implementation of differential heating of the base.

[0015] For ease of understanding, the same reference numerals are used where possible to denote common elements in the figures. It is contemplated that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description. Detailed Implementation

[0016] A method and apparatus for preventing or minimizing particulate contamination of a substrate to be treated are provided. In one embodiment, a processing chamber is disclosed, comprising: a base disposed adjacent to a lamp holder. The lamp holder includes a plurality of energy sources, such as lamps, which direct electromagnetic energy to a surface of the base, thereby heating the base. The lamp holder includes a plurality of concentric zones, and one or more of these zones include lamps that can be individually controlled. Individual control of one or more lamps provides enhanced temperature control of the base.

[0017] Figure 1 This is a schematic cross-sectional view of a processing chamber 100 according to one embodiment. The processing chamber 100 can be used to process one or more substrates, including processes for depositing material on the upper surface of a substrate 108. The processing chamber 100 generally includes an energy module 102 for heating the back surface 104 of a substrate support or base 107 disposed within the processing chamber 100, and other components. The base 107 can be a circular, disc-shaped (e.g., disk-shaped) substrate support as shown. The base 107 is located within the processing chamber 100, between the upper housing 128 and the lower housing 114 of the chamber 100. A substrate 108 (not to scale) can be brought into the processing chamber 100 through a loading port 103 and placed on the base 107.

[0018] The base 107, connected to the central shaft 132, is shown in an elevated processing position, but is repositioned to a loading position below the processing position by an actuator (not shown) coupled to the central shaft 132. A substrate to be processed, such as substrate 108, is conveyed through the loading port 103 into the processing chamber 100 and placed on a lifting rod 105. The lifting rod 105 is coupled to a shaft disposed around the central shaft 132 and passes through a through-hole in the base 107 when the base 107 is in the loading position. The base 107 can then be actuated upward in the axial direction 134 to the processing position to contact the substrate 108 on the front side 110 of the base 107, wherein the device side 116 of the substrate 108 faces upward.

[0019] When in the processing position, the base 107 divides the internal volume of the processing chamber 100 into a processing gas region 156 (above the substrate) and a purging gas region 158 (below the base 107). During processing, the base 107 rotates via a central shaft 132 connected to it to minimize the effects of precursor depletion within the processing chamber 100 and abnormal heat and processing gas flow space, thereby promoting uniform processing of the substrate 108. The base 107 is supported by the central shaft 132, which also moves the substrate 108 in the axial direction 134 during loading and unloading, and in some cases during processing. The base 107 is typically formed of a material with low thermal mass or low heat capacity, allowing for rapid heating and cooling. Here, the base 107 is formed of silicon carbide or graphite coated with silicon carbide to absorb radiant energy from the energy module 102 and heat the substrate 108.

[0020] Gas can be supplied from gas source 123 to gas inlet 121. Gas source 123 can provide purified gas and precursor gas flowing to the device side 116 of substrate 108. The gas is generally supplied to the outlet port 127 of the chamber along a flow path 125 that crosses the device side 116 of substrate 108. The gas is discharged through the outlet port 127 via pump 129.

[0021] However, the gas flowing along the flow path 125 may contain particles entrained therein. For example, the purge gas flowing into the chamber during the transport of the substrate to be processed may carry particles that have fallen onto the substrate. These particles may detach from the chamber walls and become entrained in the flow path 125. Furthermore, the temperature of the substrate can cause the substrate 108 to warp upon initial contact with the substrate. Depending on the orientation of the warping relative to the flow path 125, the particle retention area may be larger or smaller. If the substrate 108 adopts a shape with a large cross-section within the flow path 125, then particle deposition is greater than if the substrate 108 adopts a shape with a small cross-section within the flow path 125.

[0022] Generally, the upper housing 128 and the lower housing 114 are typically formed of a substantially optically transparent material (such as quartz). These materials allow electromagnetic energy from the energy module 102 to pass through and reach the processing gas region 156.

[0023] Energy module 102 includes one or more lamps 141, or other electromagnetic radiation sources such as lasers, LEDs, and VCSELs disposed within housing 145. Energy module 102 is disposed adjacent to and below lower housing 114 to heat substrate 108 as process gas passes over substrate 105, thereby promoting a reaction that results in material deposition onto device side 116 of substrate 108. Figure 1In this configuration, one or more lamps 109 are disposed above the upper housing 128 to provide electromagnetic energy to the device side 116 of the substrate 108, but the upper lamps are optional. A central axis 132 passes through the energy module 102 and extends to the outside of the processing chamber 100.

[0024] Figure 1 The energy module 102 heats the substrate 108 to temperatures ranging from about 200 degrees Celsius to about 1200 degrees Celsius, such as from about 300 degrees Celsius to about 950 degrees Celsius. The energy module 102 may include an optional reflector 143 surrounding the lamp 141. The energy module 102 includes a housing 145 that houses the lamp 141 and can be cooled during or after processing by, for example, introducing cooling fluid into channels located between the lamps 141. In some cases, the housing 145 may contact a lower housing 114. The controller 160 controls the power supplied to each lamp 141 of the energy module 102.

[0025] A circular shielding element 167 may optionally be disposed around the base 107 and coupled to the sidewall of the chamber body 101. The shielding element 167 prevents or minimizes heat and / or light leakage from the energy module 102 to the device side 116 of the substrate 108. Additionally, the shielding element 167 absorbs electromagnetic energy from the energy module 102, which heats the shielding element 167 and preheats the process gas passing over it. The shielding element 167 may be made of CVD SiC-coated sintered graphite, SiC, or similar opaque materials that are resistant to the chemical decomposition of the process and cleaning gases.

[0026] Reflector 122 may optionally be placed outside the upper housing 128 to reflect infrared light radiated from substrate 108 back to substrate 108. Based on the reflected infrared light, the heating efficiency of substrate 108 is improved by reflecting electromagnetic energy that would otherwise not be used to heat substrate 108. Multiple thermal radiation sensors 140, which can function as pyrometers, are disposed in the processing chamber 100 to monitor the temperature of substrate 108. Sensors 140 are typically disposed at different locations within the processing chamber 100. Some sensors may be disposed in housing 145 to monitor the thermal state of base 107, while others may be disposed in reflector 122 to directly monitor the thermal state of substrate 108. Sensors disposed in housing 145 are typically located between lamps and benefit from the cooling applied to housing 145. The thermal sensors transmit data to controller 160, which can then modulate the lamp power based on the data to control the processing.

[0027] The energy module 102 is used to heat the base 107 before the substrate is placed on the base 107. For example, the energy module 102 provides heat to the back surface 104 of the base 107 before the substrate to be processed is positioned on the base 107. The inventors have discovered that heating the base 107 with the energy module 102 before the substrate to be processed is transferred to the base 107 causes the substrate to warp upon contact with the base 107.

[0028] Warpage is primarily caused by uneven heating and the resulting uneven thermal expansion on the substrate. Differential or preferential localized heating from lamp power management can adjust the thermal expansion within the substrate and cause it to exhibit certain warpage shapes, making the substrate more susceptible to particle addition and other issues.

[0029] As discussed above, warping leads to particle contamination of the substrate, depending on the orientation of the warping relative to the flow path 125. For example, the particle retention area can be larger or smaller, depending on the orientation of the warping relative to the flow path 125. If the substrate 108 adopts a shape with a large cross-section within the flow path 125, then particle deposition is greater than when the substrate 108 adopts a shape with a small cross-section within the flow path 125. Differential heating of the substrate 107 can counteract the thermal gradient in the substrate 107 that causes undesirable warping, thereby minimizing or controlling the deformation of the substrate to be treated.

[0030] The lamps 141 of the energy module 102 can be divided into radial partitions, such as an outer partition 170, a central partition 172, and an inner partition 174. Although it can be divided into three partitions 170, 172, and 174, the energy module 102 may also include only two partitions, such as an inner partition 174 and an outer partition 170. One or more individual lamps 141 within each of the outer partition 170, the central partition 172, and / or the inner partition 174 are individually controlled.

[0031] In one implementation, a first power supply 162 controls the power applied to each of the inner partition 174 and the central partition 172. For example, all lamps 141 in the inner partition 174 and the central partition 172 are controlled by the first power supply 162, while a second power supply 164 is used to independently control each of the lamps 141 in the outer partition 170. Here, the second power supply 164 includes a plurality of thyristors 176, such as silicon controlled rectifiers (SCRs). Each thyristor 176 is dedicated to a lamp 141 to independently control the power supplied to each lamp 141 in the outer partition 170 in order to control the heating of the periphery 178 of the base 107. Similarly, a third power supply 166 can be used to control the power applied to lamps 109.

[0032] Figures 2A-2D This is an exploded view of the base 107 and the substrate to be processed, showing various warping profiles of the substrate to be processed. Figure 2A and 2B This is an exploded isometric view of the base 107 and the substrate to be processed. Figure 2C and 2D They are rotated 90 degrees respectively Figure 2A and 2B A side view of the base 107 and the substrate to be processed. The substrate to be processed is in... Figure 2A and 2C The substrate 200A shown in the image is warped, and... Figure 2B and 2D The substrate 200B is shown as warped. The airflow direction 205 is... Figure 2A and 2B The arrow indicates the middle, and is related to Figure 1 The flow path 125 shown and described is the same. Figure 2C and 2D The airflow direction is not shown because the airflow direction points into the plane of the paper due to view rotation. The airflow may be a purified gas flowing during substrate transfer processing. Figure 2A and 2B The warping of the substrate to be processed is caused by variations in the temperature distribution of the base 107. Additionally, variations in the transfer process (including switching of the substrate to be processed and tilting of the base 107), as well as the position and / or mass of the lamp 141, can cause the substrate to warp into any shape or orientation. As explained in more detail below, this warping presents a profile relative to the airflow direction 205, which provides a larger surface area for particles entrained in the airflow to adhere to the substrate to be processed. The shape and / or orientation of the warping can result in a larger or smaller surface area for particles to adhere to the substrate to be processed, depending on the orientation of the substrate to be processed relative to the airflow direction 205.

[0033] exist Figure 2A and 2B In this process, the substrate to be processed (e.g., a warped substrate 200A or a warped substrate 200B) warps, forming a midpoint of curvature (indicated by the dashed line 207). Figure 2A In this process chamber 100, substrate 200A is oriented such that the midpoint of curvature 207 is oriented in a direction substantially perpendicular to the airflow direction 205. Figure 2B In the middle, the midpoint of curvature 207 is oriented in a direction that is substantially parallel to the airflow direction 205.

[0034] While warping is undesirable, the orientation of the warped substrate 200B presents a profile relative to the airflow direction 205 that is less likely to be contaminated by particles entrained in the airflow. For example, in the case of the warped substrate 200A, the profile 210 facing the airflow direction 205 is larger than the profile 215 facing the airflow direction 205 of the warped substrate 200B due to the warping relative to the gas orientation. Thus, differential heating of the base 107, as disclosed herein, is provided to minimize warping, such that the substrate to be processed does not warp (or warps are greatly reduced). Alternatively, differential heating of the base 107, as disclosed herein, is provided to control warping to present profile 215 (opposite to profile 210 of the warped substrate 200A).

[0035] Figure 3A This is an isometric view of base 107, which has an energy module 102 positioned below it. Leading edge lamp 300 and trailing edge lamp 305 (relative to airflow direction 205) and other lamps 310 in outer section 170 are shown. For clarity, inner section 174 and center section 172 are not shown. In this embodiment, leading edge lamp 300 and trailing edge lamp 305 are powered by a second power supply 164, while the other lamps 310 are powered at a lower energy level. Alternatively or additionally, the lamps 310 in inner section 174 and center section 172 are powered uniformly (e.g., at the same power level). Therefore, base 107 is heated non-uniformly, which heats the leading edge 315 and trailing edge 320 of the periphery 178 of base 107 relative to airflow direction 205 to a temperature greater than the rest of the periphery 178 of base 107. This differential heating reduces, minimizes, or controls warping of the substrate to be processed positioned on the base 107.

[0036] Figure 3B This is an isometric view of base 107, which has an energy module 102 positioned below it. One or more leading edge lamps 300 (relative to airflow direction 205) and other lamps 310 in the outer partition 170 of lamp head 145 are shown. For clarity, inner partition 174 and center partition 172 are not shown. In this embodiment, one or more leading edge lamps 300 are powered by a second power supply 164, while the other lamps 310 are not powered at a lower energy level. Alternatively or additionally, the lamps 310 in inner partition 174 and center partition 172 are powered uniformly (e.g., at the same power level). As a result, base 107 is heated non-uniformly, which heats the leading edge 315 of the periphery 178 of base 107 to a temperature greater than that of the rest of the periphery 178. This differential heating reduces, minimizes, or controls warpage of the substrate to be processed positioned on base 107.

[0037] The above embodiments relate to controlling anisotropy in a heated substrate to minimize, prevent, or control warpage of the substrate. In some embodiments, controlled warpage provided by the methods and apparatus disclosed herein provides a uniform shape, profile, and / or warpage orientation in the substrate to be treated, thereby minimizing particle adhesion to the substrate. The above embodiments of differential heating of the base 107 may be provided only for a period of at most about 10 seconds to about 40 seconds before the substrate to be treated contacts the base 107, after which the substrate to be treated flattens and / or uniformly contacts the base 107.

[0038] While the foregoing describes embodiments of the present invention, other and further embodiments of the invention may be conceived without departing from the basic scope of the invention, and the scope of the invention is defined by the appended claims.

Claims

1. A substrate processing apparatus, comprising: Processing chamber; A substrate support member is disposed within the processing chamber; Multiple lamps are arranged in lamp heads and positioned below the substrate support, and the lamps are positioned in concentric partitions; An airflow inlet and an airflow outlet are arranged to allow the process gas to flow laterally across the substrate support. as well as A controller that differentially adjusts the power supplied to the individual lamps among the plurality of lamps before placing the substrate onto the substrate support to counteract the thermal gradient in the substrate support that causes undesirable substrate warping due to an increased surface area of ​​the substrate being exposed to the process gases.

2. The substrate processing apparatus of claim 1, wherein each of the concentric partitions comprises two or more lamps.

3. The substrate processing apparatus of claim 2, wherein the concentric partitions include an inner partition, a central partition, and an outer partition, the outer partition corresponding to the periphery of the substrate support.

4. The substrate processing apparatus of claim 2, further comprising a plurality of upper lamps positioned above the substrate support.

5. The substrate processing apparatus of claim 4, wherein the upper lamp is positioned horizontally.

6. The substrate processing apparatus of claim 4, wherein the upper lamp is positioned parallel to the substrate support.

7. The substrate processing apparatus of claim 6, wherein the plurality of lamps in the lamp head are oriented in a direction different from that of the upper lamp.

8. A substrate processing apparatus, comprising: Processing chamber; A substrate support member disposed within the processing chamber and configured to support the substrate during processing; Multiple lamps are arranged in lamp heads and positioned below a base plate support, and the multiple lamps are positioned in a partition. An airflow inlet and an airflow outlet are arranged to allow the process gas to flow laterally across the substrate support. as well as A controller that differentially adjusts the power supplied to individual lamps among the plurality of lamps before placing the substrate onto the substrate support to induce bending in the substrate upon initial contact with the substrate support, thereby reducing the surface area of ​​the substrate exposed to the process gas when the substrate is bent.

9. The substrate processing apparatus of claim 8, wherein the airflow inlet and the airflow outlet define the leading edge and trailing edge of the substrate support.

10. The substrate processing apparatus of claim 9, wherein the substrate is bent in a direction substantially perpendicular to the gas flow direction of the processing gas.

11. The substrate processing apparatus of claim 8, wherein inducing bending in the substrate includes unevenly heating the substrate support.

12. A method for processing a substrate, the method comprising: Before placing the substrate into a substrate support in a processing chamber, the substrate support is heated using a lamp array comprising multiple zones, the heating step including differential power supply to selected lamps in the lamp array; Gas flows in a lateral flow path across the substrate support; and After the heating step, the substrate is positioned onto the substrate support. The positioning step includes inducing a predetermined oriented bend in the substrate to reduce the surface area of ​​the substrate exposed to the process gas.

13. The method of claim 12, wherein the substrate is bent in a direction substantially perpendicular to the gas flow direction of the gas.

14. The method of claim 12, wherein inducing bending in the substrate includes unevenly heating the substrate support.

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