Radiation Isolation System

Abstract

The present disclosure generally relates to a lamp-heated apparatus for thermally processing substrates. In particular, embodiments of the present disclosure relate to isolating heating zones in a rapid thermal processing (RTP) chamber using a substrate and a shield. In one implementation, a method of processing a substrate includes placing a substrate on multiple lift pins in a processing chamber, lifting the substrate using the multiple lift pins to a preheat position flush with a flange of a radiation shield, preheating the substrate at the preheat position with heat from multiple lamps positioned above the substrate, lowering the substrate using the lift pins to a substrate support after preheating, processing the substrate on the substrate support, and removing the substrate from the processing chamber.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure generally relate to lamp-heated apparatus for thermally processing substrates. In particular, embodiments of the present disclosure relate to using substrate and shields to separate heating zones in a rapid thermal processing (RTP) chamber. [Background technology]

[0002]

[0002] During rapid thermal processing of a substrate, the substrate is transferred in and out of the RTP chamber. Temperature differences between the substrate entering the RTP chamber and the RTP chamber itself can cause thermal stresses in the substrate and uneven heating of the substrate.

[0003] Therefore, what is needed in the art is an improved rapid thermal process. Summary of the Invention

[0004]

[0004] The present disclosure relates generally to lamp-heated apparatus for thermally processing substrates. In particular, embodiments of the present disclosure relate to isolating heating zones in a rapid thermal processing (RTP) chamber using a substrate and a shield.

[0005]

[0005] In one implementation, a substrate processing method includes placing a substrate on a plurality of lift pins in a processing chamber, using the plurality of lift pins to lift the substrate to a preheat position flush with a flange of a radiation shield, preheating the substrate at the preheat position with heat from a plurality of lamps positioned above the substrate, lowering the substrate to a substrate support using the lift pins after preheating, processing the substrate on the substrate support, and removing the substrate from the processing chamber.

[0006]

[0006] In one implementation, a processing chamber applicable for use in semiconductor manufacturing includes a chamber body, a window disposed on the chamber body, a substrate support disposed within the chamber body, a plurality of lamps disposed above the window for directing thermal energy toward the substrate support, and a radiation shield disposed between the window and the substrate support, the radiation shield including a cylindrical body including an opaque material and a flange including an optically transparent material, the flange being coupled to the cylindrical body.

[0007]

[0007] In one implementation, a radiation shield suitable for placement within a processing chamber includes a cylindrical body comprising an opaque material and a flange extending from the distal end of the cylindrical body, the flange comprising a transparent material and positioned in a plane perpendicular to the central axis of the cylindrical body.

[0008]

[0008] In order that the above-described features of the present disclosure may be understood in detail, the above-summarized disclosure will be more particularly described by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings depict only exemplary embodiments and therefore should not be considered limiting in scope, as the present disclosure may admit of other equally effective embodiments. [Brief explanation of the drawings]

[0009] [Figure 1A] 1 is a schematic cross-sectional view of a processing chamber with a substrate in a preheating position according to an embodiment of the present disclosure. [Figure 1B] 1 is a schematic cross-sectional view of a processing chamber with a substrate in a processing position according to an embodiment of the present disclosure. [Figure 1C] 1 is a schematic cross-sectional view of a processing chamber with a substrate in a processing position according to another embodiment of the present disclosure. [Figure 2A] FIG. 1 is a schematic isometric view of a radiation shield according to an embodiment of the present disclosure. [Figure 2B] 2B is a cross-sectional view of the radiation shield taken along the cross-sectional line 2B-2B shown in FIG. 2A. [Figure 3]1 is a schematic block diagram of a substrate processing method according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0015] To facilitate understanding, wherever possible, the same reference numerals have been used to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0011]

[0016] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to rapid thermal processing (RTP) chambers or other lamp-heated thermal processing chambers, and more particularly to shields used therein. As used herein, the term "about" should be understood to refer to a range of ±5% of the stated value.

[0012]

[0017] 1A and 1B are schematic cross-sectional views of a processing chamber 100 according to embodiments of the present disclosure. In some embodiments, the processing chamber 100 is an RTP chamber. In other embodiments, the processing chamber is any chamber applicable for use in semiconductor manufacturing. FIG. 1A illustrates the processing chamber 100 with a substrate 110 positioned in a preheating position, and FIG. 1B illustrates the processing chamber 100 with the substrate 110 positioned in a processing position. The processing chamber 100 includes a sidewall 102, a chamber bottom 104 coupled to the sidewall 102, and a window 106 disposed on the sidewall 102. In some embodiments, the window 106 is made of quartz. The sidewall 102 and the chamber bottom 104 form a chamber body. The sidewall 102, the chamber bottom 104, and the window 106 define an upper region 108 and a lower region 109 for processing the substrate 110 therein. The upper region 108 is fluidly coupled to the lower region 109 and is generally bounded from the lower region 109 by a plane defined by the lower or bottom edge of the radiation shield 160 .

[0013]

[0018] A slit valve door 116 is formed through the sidewall 102 for transferring the substrate 110 therethrough. The processing chamber 100 is connected by a conduit 119 to a gas source 118. The gas source 118 is configured to supply one or more process gases to the upper region 108 during processing. A vacuum pump 120 is connected to the processing chamber 100 for evacuating the upper region 108.

[0014]

[0019] A substrate positioning assembly 122 is disposed in the lower region 109 and is configured to support, position, and / or rotate the substrate 110 during processing. The substrate positioning assembly 122 includes a substrate support 155, which may be a contact support such as a pedestal or a non-contact substrate support device that utilizes fluid flow, for supporting, positioning, and / or rotating the substrate 110. The substrate positioning assembly 122 also includes an edge support 124 that supports an edge of the substrate 110 when the substrate 110 is in the processing position. The substrate positioning assembly 122 facilitates supporting the substrate 110 on the substrate support 155 and edge supports 124 located in the lower region 109 prior to the start of processing (e.g., rapid thermal annealing). The substrate positioning assembly 122 includes a plurality of lift pins 150 (two shown) disposed on lift pin supports 151 a. The lift pins 150 lift the substrate 110 from the substrate support 155 to facilitate loading and unloading of the substrate 110 through the slit valve door 116, and to facilitate transition of the substrate 110 from a preheating position (lifted from the substrate support 155) to a processing position (supported by the substrate support 155).

[0015]

[0020] Heating assembly 112 is disposed above window 106 and is configured to direct thermal energy through window 106 toward upper region 108. Heating assembly 112 includes a plurality of lamps 114, such as high-voltage tungsten halogen lamps, arranged in a hexagonal pattern and zone-controllable to provide controlled heating to different zones of upper region 108. Each of the plurality of lamps 114 is inserted into a heating assembly base 117 for electrical connection to a power source (not shown).

[0016]

[0021] The radiation shield 160 is coupled to the sidewall 102 of the processing chamber 100 and secured thereto via one or more optional mounts 161. The radiation shield 160 includes a cylindrical body 162 defining a central opening and a flange 163 extending radially outward from the bottom edge of the cylindrical body 162. The inner diameter of the cylindrical body 162 is larger than the substrate 110, e.g., capable of receiving the substrate 110 within the central opening defined by the body, as shown in FIG. 1A. In some embodiments, the lateral clearance between the substrate 110 and the inner diameter of the cylindrical body 162 is 0.1 mm to 2 mm, e.g., 0.3 mm to 1.1 mm, e.g., about 1 mm. When the substrate 110 is flush with the bottom of the radiation shield 160 (e.g., flush with the flange 163), the upper region 108 is separated from the lower region 109. In one example, the cylindrical body 162 is in contact with the window 106.

[0017]

[0022] FIG. 1A shows the substrate 110 in a preheat (e.g., upper) position in the processing chamber 100. In the preheat position, the substrate 110 is lifted from and positioned above the substrate support 155 by the lift pins 150. The preheat position is above (e.g., higher than) both the processing position and the transfer position (i.e., the vertical height at which the substrate 110 is transferred into the processing chamber 100) of FIG. 1B. The transfer height is indicated by plane 167. In the preheat position, the substrate 110 is flush with the flange 163 of the radiation shield 160. In this position, the lamps 114 of the heating assembly 112 preheat the substrate 110 while shielding the substrate support 155 from direct heating by the lamp radiation. For example, the flange 163 can be constructed of a material that absorbs radiation from the lamps 114. Similarly, the substrate 110 can be configured to absorb radiation from the lamps 114. Thus, when the substrate 110 is flush with the flange 163, radiation from the lamps 114 is substantially prevented from directly irradiating the substrate positioning assembly 122, and in particular the substrate support 155 of the substrate positioning assembly 122. Thus, it is possible to increase the temperature of the substrate 110 while reducing the thermal impact on the substrate support 155. In some embodiments, the substrate 110 in the preheat position is located about 3 mm to about 50 mm, e.g., about 5 mm to about 20 mm, e.g., about 5 mm to about 10 mm, from the window 106.

[0018]

[0023] 1B shows the substrate 110 in a processing (e.g., lower) position of the processing chamber 100. In the processing position, the lift pins 150 are lowered and retracted into lift pin supports 151 a so that the substrate 110 is supported by the substrate supports 155 and edge supports 124. The processing position is generally below the transfer height of the substrate 110 during transfer through the slit valve door 116. In the processing position, the substrate 110 undergoes a thermal treatment process, such as rapid thermal annealing. During thermal treatment, radiant energy from lamps 114 heats the substrate to a predetermined temperature. A controller 130 operably coupled to the processing chamber 100 controls one or more aspects of the thermal treatment process and movement of the substrate, including movement between the transfer position, preheat position, and processing position, as well as other aspects of the processing chamber 100.

[0019]

[0024] Controller 130 includes a central processing unit (CPU), memory containing instructions, and support circuitry for the CPU. Controller 130 controls various items directly or through other computers and / or controllers. In one or more embodiments, controller 130 is communicatively coupled to a dedicated controller, with controller 130 functioning as a central controller.

[0020]

[0025] The controller 130 is any form of general-purpose computer processor used in industrial environments to control various substrate processing chambers and equipment, as well as sub-processors thereon or therein. The memory, or non-transitory computer-readable medium, is one or more of readily available memory such as random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.), read-only memory (ROM), floppy disk, hard disk, flash drive, or any other form of digital storage (local or remote). The support circuitry of the controller 130 controls the CPU (processor). The controller 130 is coupled to a CPU to support the process. Support circuits include cache, power supplies, clock circuits, input / output circuits and subsystems, etc. Operating parameters (such as the temperature of the substrate 110 and power to the lamps 114) are stored in memory as software routines that are executed or invoked to cause the controller 130 to function as a special-purpose controller that controls the operation of the various chambers / modules described herein. The controller 130 is configured to perform any of the steps described herein. The instructions stored in the memory, when executed, cause one or more steps of the method 300 (described below) to be performed.

[0021]

[0026] 1C is a schematic cross-sectional view of a processing chamber with a substrate in a processing position according to another embodiment of the present disclosure. FIG. 1C is similar to FIG. 1B, except that the substrate support 155 and substrate positioning assembly 122 are replaced with an edge support 124. The edge support 124 is rotated by a rotation system 125. A reflector plate 156 is positioned below the substrate 110. The reflector plate 156 is attached to both lift pin supports 151c. The reflector plate 156 reflects radiation from the lamps 114.

[0022]

[0027] FIG. 2A is an isometric view of a radiation shield 160 according to an embodiment of the present disclosure. FIG. 2B is a cross-sectional view of the radiation shield 160 taken along section line 2B-2B shown in FIG. 2A. The radiation shield 160 includes a cylindrical body 162 and a flange 163 disposed in a plane perpendicular to a central axis 280 of the cylindrical body 162. The cylindrical body 162 is made of an opaque material such as opaque quartz, black quartz, polysilicon, tungsten, titanium, or silicon carbide. The opacity of the cylindrical body 162 reduces the transmission of thermal radiation from the lamps 114 (shown in FIGS. 1A and 1B). The cylindrical body 162 has an outer radius of 180 mm to 200 mm, e.g., 185 mm to 195 mm, e.g., approximately 190 mm, to accommodate multiple lamps. The cylindrical body 162 has an inner radius of 140 mm to 160 mm, for example 145 mm to 155 mm, for example about 150 mm, to accommodate the substrate 110. The flange 163 is made of an optically transparent material such as quartz, sapphire, or fused silica, and transmits a majority of the radiation from the lamp 114. The flange 163 has a thickness of 1 mm to 5 mm, for example 2 mm to 4 mm, for example about 3 mm. The cylindrical body 162 is connected to the flange 163. The flange 163 extends from the distal end of the cylindrical body 162.

[0023]

[0028] 3 is a schematic block diagram of a substrate processing method 300 according to one implementation. While FIG. 3 is described with reference to FIGS. 1A and 1B for ease of understanding, it is contemplated that the methods herein are applicable to other processing chambers besides processing chamber 100. In step 301, substrate 110 is placed on lift pins 150 in processing chamber 100. The substrate is loaded into the chamber at a low temperature (e.g., a temperature lower than the temperature of the interior region of the processing chamber, including the substrate support 155).

[0024]

[0029] In step 303, the substrate 110 is lifted by the lift pins 150. The lift pins 150 raise the substrate 110 to a preheat position where it is flush with the flange 163 of the radiation shield 160. This separates the processing chamber 100 into an upper region 108 and a lower region 109. The substrate is preheated before contacting the substrate support 155.

[0025]

[0030] In step 305, the substrate 110 is preheated. During preheating, the lamps 114 irradiate the substrate 110, raising the temperature of the substrate 110 to a preheating temperature. The preheating temperature is 290°C to 310°C, e.g., 295°C to 305°C, e.g., about 300°C. Preheating takes 10 to 20 seconds. The substrate 110 heats at a rate of about 30°C / sec. Radiation emitted from the lamps is blocked by the substrate and radiation shield 160 from reaching the underlying region and the substrate support 155, preventing it from reaching the substrate support 155. Therefore, the temperature rise of the substrate support is minimized. During preheating, heating of the substrate support 155 is substantially prevented.

[0026]

[0031] The radiation shield 160 includes a cylindrical body 162 formed from an opaque material. This opaque material reduces thermal radiation from lamps located within the inner diameter of the radiation shield from passing through the cylindrical body to the radially outer side of the cylindrical body (and into the lower part of the processing chamber). Therefore, heat from the lamps 114 is directed toward the substrate 110 rather than toward the processing chamber 100 components. Reducing thermal radiation toward the chamber components during the preheating step reduces unwanted or unintended temperature increases, improving temperature control and uniformity and subsequent thermal processing. In such instances, the processing temperature is more easily maintained at a predetermined target temperature, improving substrate-to-substrate uniformity. In such instances, it is contemplated that a controller may shut off power to lamps located outside the outer diameter of the cylindrical body 162 to further reduce unintended heating of processing chamber components.

[0027]

[0032] In step 307, the preheated substrate is lowered from the preheat position. The lift pins 150 lower the substrate to a processing position on the substrate support 155. The preheat step reduces the temperature difference between the substrate 110 and the substrate support 155. The temperature difference between the substrate 110 and the substrate support 155 is less than 50° C. The reduced temperature difference between the substrate 110 and the substrate support 155 reduces thermal shock to the substrate 110 and reduces undesired heat transfer between the substrate 110 (which is at a high temperature due to preheating) and the substrate support 155 (which is at a high temperature due to a previous thermal process performed in the processing chamber 100).

[0028]

[0033] In step 309, the substrate 110 is processed, for example, in a rapid thermal annealing process. One or more process gases may be supplied inside the processing chamber, and one or more lamps 114 may be turned on to deliver thermal radiation to the substrate 110 to facilitate its processing. The substrate 110 is processed on a substrate support 155.

[0029]

[0034] The presence of the radiation shield 160 does not substantially interfere with uniform processing of the substrate 110. Due to the relative height and thickness of the cylindrical body 162 and the relative spacing between the substrate 110 and the lamps 114 and / or window 106, the radiation blocked by the cylindrical body 162 is minimal. Even if any portion of the window 106 is blocked by the cylindrical body 162, the irradiated area of ​​the adjacent (uncovered) lamps 114 compensates for the blocked radiation. Furthermore, because the flange 163 is generally transparent to radiation from the lamps 114, the flange 163 does not substantially interfere with the thermal radiation from the lamps 114.

[0030]

[0035] After completing step 309, in step 311, the substrate 110 is detached from the substrate support 155 and removed from the process chamber 100. Due to the thermal process performed during step 309, the substrate support 155 remains hot relative to the incoming substrate 110. By repeating the above process for the incoming substrate 110, the thermal shock to the incoming substrate 110 can be reduced.

[0031]

[0036] Advantages of the present disclosure include isolating the substrate support 155 from radiation and preventing it from overheating. Because the substrate 110 enters the processing chamber 100 cold, direct contact with the hot substrate support causes thermal stress and warpage. Preheating the substrate 110 allows the substrate to heat faster and more uniformly, including better edge uniformity. Radiation shields can be used in various embodiments where the substrate 110 is on the substrate support 155 to achieve various optical properties. The present disclosure can be retrofitted to existing RTP and other chambers. The simple design allows for low-cost implementation.

[0032]

[0037] It is contemplated that one or more aspects disclosed herein may be combined. By way of example, it is possible to combine one or more aspects, features, components, operations, and / or characteristics of the processing chamber 100, the substrate support 155, the substrate 110, the upper region 108, the lower region 109, the lift pins 150, the heating assembly 112, the lamps 114, the radiation shield 160, the cylindrical body 162, the flange 163, and / or the method 300. Furthermore, it is contemplated that one or more aspects disclosed herein may include some or all of the advantages described above.

[0033]

[0038] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof as determined by the following claims.

Claims

1. A substrate processing method, comprising: placing a substrate on a plurality of lift pins within a processing chamber; lifting the substrate using the plurality of lift pins to a preheated position flush with a flange of a radiation shield; preheating the substrate at the preheat position with heat from a plurality of lamps positioned above the substrate; after the preheating, lowering the substrate onto a substrate support using the lift pins; processing the substrate on the substrate support; removing the substrate from the processing chamber; A method comprising:

2. 10. The method of claim 1, wherein the preheat location is about 5 mm to about 20 mm from a window that defines a processing region of the processing chamber.

3. The radiation shield is Cylindrical body containing an opaque material the cylindrical body is connected to the flange; The method of claim 1 , wherein the flange comprises an optically transparent material.

4. 4. The substrate processing method of claim 3, wherein the opaque material comprises opaque quartz, black quartz, polysilicon, tungsten, titanium, or silicon carbide, and the optically transparent material comprises quartz, sapphire, or fused silica.

5. 2. The method of claim 1, wherein the temperature difference between the substrate support and the substrate is less than 50[deg.] C. while the substrate is being lowered onto the substrate support.

6. The substrate processing method of claim 1 , wherein the preheating position is located at a position higher than a loading or unloading height of the substrate.

7. 10. The method of claim 1, wherein the substrate is preheated before contacting the substrate support in the processing chamber.

8. 1. A processing chamber applicable for use in semiconductor manufacturing, comprising: a chamber body; a window disposed on the chamber body; a substrate support disposed within the chamber body; a plurality of lamps positioned above the window to direct thermal energy toward the substrate support; a radiation shield disposed between the window and the substrate support, the radiation shield including a cylindrical body including an opaque material and a flange including an optically transparent material, the flange coupled to the cylindrical body; and A processing chamber comprising:

9. The processing chamber of claim 8 , wherein the cylindrical body comprises black quartz.

10. The processing chamber of claim 8 , wherein the cylindrical body comprises opaque quartz.

11. The processing chamber of claim 8 , wherein the flange comprises clear quartz.

12. and a plurality of lift pins configured to position the substrate in at least three positions, the at least three positions comprising: a preheating position flush with the flange of the radiation shield; a transfer position flush with a slit valve door formed in the chamber body; a processing position above the substrate support; The processing chamber of claim 8 , comprising:

13. The processing chamber of claim 12 , wherein the preheat position is above the transfer position and the processing position.

14. The processing chamber of claim 8 , wherein the cylindrical body has an outer radius of 180 mm to 200 mm.

15. 9. The processing chamber of claim 8, wherein the cylindrical body has an inner radius of 140 mm to 160 mm.

16. The processing chamber of claim 8 , wherein the flange has a thickness of 1 mm to 5 mm.

17. 1. A radiation shield adaptable for placement within a processing chamber, comprising: a cylindrical body including an opaque material; a flange extending from a distal end of the cylindrical body, the flange comprising an optically transparent material and positioned in a plane perpendicular to a central axis of the cylindrical body; A radiation shield comprising:

18. 18. The radiation shield of claim 17, wherein the opaque material of the cylindrical body comprises opaque quartz, black quartz, polysilicon, tungsten, titanium, or silicon carbide.

19. The radiation shield of claim 17 , wherein the optically transparent material of the flange comprises clear quartz, sapphire, or fused silica.

20. 18. The radiation shield of claim 17, wherein the cylindrical body has an outer radius of 180 mm to 200 mm and an inner radius of 140 mm to 160 mm.

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