Substrate carrier and method of manufacturing substrate carrier

Abstract

The present invention relates generally to a substrate or wafer carrier in a system for depositing thin films. According to a first aspect of the invention, a substrate carrier is provided in a system for growing an epitaxial layer on a semiconductor substrate, the substrate carrier being a disk having a first surface, including a plurality of regions defined as substrate support regions, arranged during use to accommodate the semiconductor substrate, and wherein the substrate carrier further includes a plurality of gas channels extending radially inward from the disk, each gas channel providing a gas connection between each substrate support and a radially inward portion of the substrate support toward the center of the disk, and wherein each gas channel includes drill holes arranged circumferentially from a wall surface of the substrate carrier, and provides a drill hole insert, characterized in that the drill hole insert includes a first component and a separate second component, wherein at least one segment of the first component has a shape that mates with the drill hole for press-fitting at least the segment of the first component into the drill hole, and the second component is provided with interlocking means, each drill hole having means corresponding to and arranged for receiving and mechanically retaining the interlocking means of the second component, and wherein the interlocking means of the drill hole is disposed at an angle relative to the longitudinal direction of the drill hole on the wall surface of the substrate carrier for blocking the first component.

Description

[Technical Field]

[0001] This invention relates generally to a substrate or wafer carrier system for depositing thin films on a substrate by chemical vapor deposition (CVD) or atomic layer deposition (ALD) to manufacture semiconductor devices. More specifically, this invention relates to a substrate carrier having one or more drill holes. [Previous Technology]

[0002] A substrate carrier is used for chemical vapor deposition (CVD) processes in the manufacture of semiconductor devices. In CVD or atomic layer deposition (ALD) processes, a stack of thin layers composed of materials such as alumina, aluminum nitride, or gallium nitride is grown or deposited on a semiconductor substrate (also called a wafer or chip substrate) such as silicon, gallium nitride, or sapphire, the semiconductor substrate being housed in a recessed pocket present on the deposition surface of the substrate carrier.

[0003] Such a circular substrate carrier may have a single recessed pouch, but typically has multiple recessed pouches, each for accommodating a single semiconductor substrate in the ALD processing chamber, as disclosed in, for example, US2017309512A1. In use, the recessed pouches for the semiconductor substrate to be processed are uniformly distributed on the first deposition surface side of the substrate carrier. This type of substrate carrier system is generally referred to as a pancake-type batch carrier system.

[0004] In CVD or ALD processing, the entire deposition surface of the substrate carrier, including the semiconductor substrate housed in the groove, is affected by the deposition gas, causing the semiconductor layer to be deposited on the exposed surface side of the semiconductor substrate, as well as on the remaining exposed area of ​​the substrate carrier on the deposition surface side adjacent to the pouch (and substrate).

[0005] Known wafer carrier arrangements provide gas channels to the bottom of the recessed wafer pouch. These channels, or gas distribution channels, can provide purge gas to the recessed wafer pouch where the wafer is located. In other designs, these gas channels can serve different or other purposes, such as providing vacuum channels. In any such design, the wafer carrier will provide a channel arranged to provide a gas or vacuum connection between the pouch and the system's supply or exhaust manifold.

[0006] Such gas channels within the wafer carrier are typically machined into the carrier in a series of manufacturing steps, including machining a first vertical channel section within each pouch on a plane perpendicular to the bottom of the pouch containing the wafer. Furthermore, a vertical channel section is provided or machined on the radially inner side of the pouch near the spindle or carrier hub to provide a channel inlet or outlet port exiting from or toward the first vertical channel section of the pouch. The final section of the channel, i.e., the horizontal channel section connecting the first and second vertical sections, is machined on a horizontal plane parallel to the main surface of the wafer carrier. Therefore, a deep-drilled gas channel borehole is provided, extending from the sidewall of the wafer carrier toward the first vertical channel section and then to the second vertical channel section, to provide gas or fluid connections between these first and second channel sections, thereby between the inlet / outlet on the pouch and the bottom component, at or near the center of the wafer carrier, and radially inner side of the pouch.

[0007] Because the gas supplied through this channel may escape to and from the openings on the sidewalls of the wafer carrier, it is necessary to seal these gases after drilling. Typically, these drill holes have a drill insert that is pushed into the gas channel, and its size can be maintained in place by a press-fit application. To ensure that the insert does not negatively affect the processing parameters of the CVD or ALD process, the insert must be pressed into the channel until it does not extend beyond the sidewalls or contours of the wafer carrier.

[0008] However, it has been found that these known plug-ins have drawbacks, including that they do change the CVD or ALD processing parameters, and most importantly, they tend to loosen before the recommended end of the wafer carrier's lifespan, which in turn may cause further damage to the CVD or ALD system.

[0009] Therefore, there is a need for an improved wafer carrier design in which gas channels provide gas connections between pouches and provide gas input / output at or near the center of the wafer carrier and on the radially inner side of the pouches. More specifically, there is a need for an improved wafer carrier design with an improved gas channel drilling insert that avoids at least some of the aforementioned problems. [Summary of the Invention]

[0010] According to a first aspect of the invention, a substrate carrier is provided in a system for growing an epitaxial layer on a semiconductor substrate. The substrate carrier is a disk having a first surface side, including a plurality of regions defined as substrate supports, arranged during use to accommodate the semiconductor substrate. The substrate carrier further includes a plurality of gas channels extending radially inward from the disk, each gas channel providing a gas connection between each substrate support and a radially inward portion of the disk toward the center of the substrate. Each gas channel includes drill holes arranged around a wall of the substrate carrier and provides a drill insertion insert. The drill insertion insert comprises a first component and a separate second component, wherein at least one segment of the first component has a shape that mates with the drill holes for press-fitting at least one segment of the first component into the drill holes, and the second component is provided with an interlocking device. Furthermore, each drill hole is provided with a device corresponding to and arranged for receiving and mechanically retaining the interlocking device of the second component, wherein the interlocking device of the drill hole is disposed at an angle relative to the longitudinal direction of the drill hole on the wall surface of the substrate carrier for blocking the insertion portion of the first drill hole.

[0011] It is known that wafer carriers or substrate carriers have long or deep drill holes that are machined or drilled into the carrier to obtain gas channels that extend radially through the substrate carrier. Each of these gas channels provides a gas connection between each substrate support, for example, a recessed wafer pouch portion and a central portion of the substrate carrier radially toward the interior of the substrate support.

[0012] Therefore, these gas channels begin from a central location and end at the deepest, innermost part of the substrate support, preferably near or at the center of the substrate support. The gas channels are arranged to provide purge gas and / or vacuum channels. In some embodiments, more common for MOCVD planetary systems, the gas propelling these channels will be increased, and in the case of pouches with a spiral pattern, the wafer is rotated or a disk supporting the wafer rotates within these pouches. Therefore, in all aspects and in all instances, the substrate support should be interpreted as a support for any type of substrate, wafer, or subcarrier, and thus includes, but is not limited to, substrate carriers having pouches for receiving substrates, or devices having a spiral pattern for suspending subcarriers in a planetary disk-type configuration. Those skilled in the art will understand that the disclosure of this invention applies to these and any other types of such disk-shaped carriers.

[0013] These gas channels or holes are drilled out from the outer diameter or surrounding wall of the substrate carrier and plugged with a drill plug.

[0014] However, it has been found that while conventionally known drill inserts, pressed into the drill holes, do provide a tight fit due to the use of a press-fit method and the precise dimensions of the drill holes and drill inserts, over time, the drill inserts may become loose. When the drill inserts detach, this can ultimately lead to substrate carrier failure or gas leakage, negatively impacting the processing parameters of CVD, ALD, or MOCVD processes.

[0015] The drill insert according to the invention comprises two parts, one of which is similar to a known drill insert and is arranged for press-fitting the part into a drill hole to ensure a hermetically sealed effect of the drill hole, while the second part is configured as an interlocking device, for example, in the form of a blocking or stopping element, to permanently lock the first part in position. The second drill insert part is a separate part, and unlike the first part, it is preferably not arranged for press-fitting only, but includes an interlocking mechanism, such as a bayonet or threaded section, which can be received in a pocket portion in the drill hole of the substrate carrier, the pocket portion having a corresponding interlocking device. Since the blocking or stopping element is provided at an angle relative to the drill hole and the first drill insert part, it will ensure that the first drill insert part does not fall off the wafer carrier or even loosen, thereby preventing gas leakage.

[0016] Using a second drill insert component has several advantages. For example, regarding the redesign of known press-fit drill inserts, at least a portion of the drill insert is kept press-fitted, which ensures the airtightness of the drill hole on the one hand, and prevents malfunctions due to loosening or detachment on the other hand. Furthermore, the second drill insert component is at least partially placed in the corresponding drill hole, its orientation not aligned with the gas pressure in the channel and the force generated by the first drill insert component being pressed into the drill hole. Because the second component is at an angle to the first component, it can withstand greater pressure than a single component or two (separate) components aligned with the drill hole. Moreover, the proposed drill insert requires only a few additional processing steps, requiring no additional equipment or tools beyond those needed for processing the original drill hole and known drill inserts. Furthermore, the drill hole and gas channel do not require modification, thus not affecting the processing parameters of CVD, ALD, or MOCVD processes. Finally, the proposed drill insert is also arranged to undergo post-processing of at least the second drill insert component to ensure that the drill insert is flush with the wall of the substrate carrier.

[0017] In one example, the wall of the substrate carrier is inclined to the second surface side of the substrate carrier, which is opposite to the first surface side.

[0018] In one example, the threads of the drilled hole are provided on the substrate carrier after at least the section of the first component is press-fitted into the drilled hole.

[0019] In one example, the second component of the drilling insert contacts the first component of the drilling insert after it is disposed in the drill hole.

[0020] In one example, the second part of the drilling insert has a head for receiving a tool for screwing the threaded section into the thread of the drill hole.

[0021] In one example, the head for receiving the tool includes a polygonal tool receiving section extending from the head, and the tool receiving section is preferably arranged after being disposed in a thread in a drilled hole, extending the wall of the substrate carrier.

[0022] In one example, the interlocking device includes one or more of the following: threaded fastening device, screw fastening device, press-fit fastening device, rotary fastening device, bayonet mounting fastening device, key or pin fastening device, and retraction fastening device.

[0023] In one example, the angle of the interlocking device of the borehole relative to the longitudinal direction of the borehole is approximately one or more of 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 135 degrees or 150 degrees.

[0024] In one example, the substrate carrier is composed of graphite.

[0025] In one example, the substrate carrier consists of a graphite core covered with a silicon carbide coating.

[0026] In one example, one or both of the first and second drilling insert components are made of graphite.

[0027] In a second aspect of the invention, a method for manufacturing a substrate carrier in a system for depositing a layer on a semiconductor substrate is provided, comprising the steps of: - providing a substrate carrier having a first surface, a portion of the first surface having a recessed wafer pouch portion for accommodating the semiconductor substrate during use; - machining a first drilled segment at least substantially perpendicular to the first surface side of the substrate carrier in each of the wafer pouch portions; - machining a second drilled segment extending radially through the substrate carrier from a peripheral wall surface of the substrate carrier for providing a gas connection between each of the first drilled segments in the recessed wafer pouch portions and a central portion of the substrate carrier radially toward the interior of the recessed wafer pouch portions; - pressing a first drilled insert component into the second drilled segment; - machining a pouch portion for the second drilled insert component on a wall surface of the substrate carrier, wherein the pouch portion is threaded and angled relative to the longitudinal direction of the drill; - screwing in a second drilled insert component, the component having at least a partially threaded section corresponding to the thread of the pouch portion for blocking the first drilled insert component.

[0028] In one example, the method further includes the following steps prior to the step of pressing the first drilled insert component: - machining a chamfer on the wall surface of the substrate carrier.

[0029] In one example, the second drilling insert component includes a polygonal tool receiving section extending from the head section, and the method further includes the step of: - machining the wall of the substrate carrier by removing the tool receiving section extending from the wall of the substrate carrier so that the second drilling insert component is flush with the wall of the substrate carrier.

[0030] In one example, after the step of screwing in the second drilling insert component, the method further includes the following steps: - providing a silicon carbide coating on at least the wall surface of the substrate carrier, particularly covering the entire substrate carrier.

[0031] In one example, one or both of the first and second drilling insert components are made of graphite.

[0032] The invention will now be described in more detail by way of specific embodiments, with reference to the accompanying drawings, wherein like or similar parts and / or components are represented by the same element symbols. The invention is not limited in any way to the disclosed embodiments.

Implementation Method

[0041] Figure 1 schematically shows a top view of a substrate carrier 1 in a system for growing an epitaxial layer on a semiconductor substrate. Figure 2 shows a cross-sectional view indicated by AA in Figure 1, wherein the enclosed portion in Figure 2 is shown in more detail by an isometric view in Figure 3. The substrate carrier 1 is a substrate carrier or (planetary) disk made of graphite, having a first surface side 3 and a second surface side 5. As shown in Figure 1, the first surface 3 is the top surface. The second surface 5 is located opposite the first surface 3. The peripheral surface 7 of the substrate carrier 1 is inclined toward the second surface 5 at an angle α relative to a plane parallel to the first surface 3 and the second surface 5 of the substrate carrier 1. Note that in Figures 3-7, for illustrative purposes, the first surface 3 and the second surface 5 are flipped relative to Figures 1 and 2. In the embodiment shown in Figure 1, the substrate carrier 1 includes six regions 9, which are defined as substrate supports and arranged during use to accommodate a semiconductor substrate.

[0042] The substrate carrier 1 also includes six internal gas channels 11. The gas channels 11 extend radially inward within the planetary disk. Each gas channel 11 provides a gas connection between each substrate support 9 and the central portion 13 of the planetary disk, with its central portion radially inward of the substrate support 9. Each gas channel 11 includes a first drilled section 11A, a second drilled section 11B, and a third drilled section 11C. Starting from each substrate support 9, the first section 11A extends perpendicularly to the first surface side 3 of the substrate carrier 1 into the substrate carrier 1, approximately reaching half the height h of the substrate carrier 1. Starting from the central portion 13, the third section 11C extends perpendicularly to the second surface 5 of the substrate carrier 1 into the substrate carrier 1, approximately reaching half the height h of the substrate carrier 1. The second section 11B of the gas channel 11 includes a circular drill hole extending radially inward from the wall 7 into the substrate carrier 1, thereby fluidly connecting the first section 11A and the third section 11C of each gas channel 11.

[0043] To close and seal the opening of the gas channel 11 on the wall surface 7 of the substrate carrier 1, a drilling insert is provided on the substrate carrier 1. The drilling insert includes a first component 15 and a separate second component 17, both made of graphite. The first component 15 has a shape that mates with the drilled hole of the gas channel 11, for press-fitting the first component 15 into the drilled hole. The first component 15 is inserted longitudinally into the gas channel 11, thereby closing and sealing the opening of the specific gas channel 11 on the wall surface of the substrate carrier 1. Due to the pressure of the gas present in the gas channel 11, the press-fitted first component 15 of the drilling insert can be pushed out of the gas channel 11 when the substrate carrier is in use. To prevent this, the drilling insert has a second component 17.

[0044] The second component 17 of the drilling insert includes a circular top section 19 and a circular interlocking section 21, wherein the diameter of the interlocking section 21 is smaller than the diameter of the top section 19. The interlocking section 21 has an interlocking function, preferably threaded. The top section 19 is provided with a polygonal head section 23 for receiving a suitable polygonal tool.

[0045] To interlock the second component 17 of the drilling insert with the substrate carrier 1, the substrate carrier 1 is provided with a pocket portion 25. The pocket portion 25 is machined into the substrate carrier 1, wherein the pocket portion 25 extends into the substrate carrier 1 perpendicular to the inclined wall portion 7. The depth and diameter of the pocket portion 25 correspond to the length and diameter of the individual top section 19 and the individual interlocking section 21 of the second component 17 of the drilling insert.

[0046] A section of the pouch 25 corresponding to the interlocking section 21 of the second component 17 of the drilling insert is provided with a corresponding and arranged means for receiving and mechanically retaining the interlocking section 21 of the second component 17 of the drilling insert. Preferably, this means includes a thread corresponding to the thread of the interlocking section 21 of the second component 17 of the drilling insert. As shown in Figures 4 and 5, the second component 17 of the drilling insert is screwed into the thread of the pouch 25 by rotating it clockwise relative to its central axis using a suitable polygonal tool.

[0047] Preferably, after the first component 15 of the drilling insert is press-fitted into the bore in the gas channel 11, the bag portion 25 is placed in the substrate carrier 1, such that the second component 17 of the drilling insert, after being placed in the bag portion 25, contacts the first component 15 accordingly, thereby preventing the first component 15 of the drilling insert from leaving its respective gas channel 11. When the second component 17 of the drilling insert is securely provided into the bag portion 25, the portion of the second component 17 protruding from the inclined wall section 7 is removed, and then the substrate carrier 1 is covered with a silicon carbide coating 27. As a result, the insert, which is not visible from the outside, is securely fixed in the gas channel 11 and will not be pushed out of its position.

[0048] Figure 8 illustrates a method 101 for manufacturing a substrate carrier 1 in a system for growing an epitaxial layer on a semiconductor substrate via chemical vapor deposition. In the first step 103 of method 1, the substrate carrier 1 is provided. A region 9 of the first surface side 3 of the substrate carrier 1 is provided with a substrate support for accommodating the semiconductor substrate during use.

[0049] In the second step 105 of method 101, a first drilled section 11A is processed on each substrate support, which is at least substantially perpendicular to the first surface side of the substrate carrier.

[0050] In the third step 107 of method 101, a second drilled section 11B is machined around the wall 7 of the substrate carrier 1. The second drilled section 11B extends radially through the substrate carrier 1 to provide a gas connection between each first drilled section 11A in the substrate support and the central portion 13 of the substrate carrier 1, the central portion of which extends radially toward the interior of the substrate support.

[0051] Furthermore, in the fourth step 109 of method 101, a chamfer is machined on the wall surface 7 of the substrate carrier 1.

[0052] In the fifth step 111 of method 101, the first drilling insert component 15 is press-fitted into the second drilling section 11B.

[0053] After the first drilling insert 15 is press-fitted into the second drilling section, during the fifth step 113 of method 101, the pocket portion 25 for the second inner drilling insert component 17 is processed onto the wall surface 7 of the substrate carrier 1, wherein the pocket portion 25 is provided with threads and is set at an angle relative to the longitudinal direction of the drilling.

[0054] During the sixth step 113 of method 101, the second drilling insert component 17 (which has at least partially threaded sections corresponding to the threads of the bag portion 25) is screwed into the bag portion 25 to block the first drilling insert component 15.

[0055] Finally, in the seventh step 115 of method 101, the wall 7 of the substrate carrier 1 is processed by removing the tool receiving section 23 extending from the wall 7 of the substrate carrier 1, so that the second drilling insert component 17 is flush with the wall 7 of the substrate carrier 1, thereby completing the substrate carrier 1.

[0056] In the final step 117 of method 101, a silicon carbide coating is provided to the substrate carrier 1.

[0057] Based on the above description, those skilled in the art can modify and supplement the disclosed methods and arrangements, and such modifications and supplements are all included within the scope of the appended patent application. [Simplified Explanation of the Diagram]

[0033] FIG1 schematically shows a top view of the components of a substrate carrier according to a first aspect of the present invention.

[0034] Figure 2 shows a cross-sectional side view of cross section AA in Figure 1.

[0035] Figure 3 shows in detail an isometric view of the enclosed section of Figure 2.

[0036] FIG4 schematically shows an isometric view of the cross-section of the substrate carrier section and the drilling plug according to the first aspect of the present invention.

[0037] Figure 5 schematically shows an isometric view of the cross-section of Figure 4, in which the plugged drill hole is connected to the substrate carrier.

[0038] FIG6 schematically shows an isometric view of the coating portion of a substrate carrier according to the first aspect of the present invention.

[0039] Figure 7 schematically shows a cross-sectional view of the coating portion of Figure 6.

[0040] Figure 8 shows an overall outline of a method for manufacturing a substrate carrier according to a second aspect of the present invention. [Biomaterial Storage]

[0059] None

Claims

1. A substrate carrier in a system for growing an epitaxial layer on a semiconductor substrate, the substrate carrier being a disk having a first surface, including a plurality of regions defined as substrate supports arranged in use to accommodate the semiconductor substrate, and wherein the substrate carrier further includes a plurality of gas channels extending radially inward toward the disk, each gas channel providing a gas connection between each substrate support and a central portion of the disk radially inward of the substrate support, and wherein each gas channel includes drill holes arranged around a wall of the substrate carrier and provides a drill hole insert, characterized in that: the drill hole insert includes a first component and a separate second component, wherein at least one segment of the first component has a shape that mates with the drill hole for press-fitting at least the segment of the first component into the drill hole, and wherein the second component is provided with an interlocking device, each drill hole having means corresponding to and arranged for receiving and mechanically retaining the interlocking device of the second component, and wherein the interlocking device of the drill hole is disposed at an angle relative to the longitudinal direction of the drill hole on the wall of the substrate carrier for blocking the first component.

2. The substrate carrier according to claim 1, wherein the wall surface of the substrate carrier is inclined toward a second surface side on the substrate carrier opposite to the first surface side.

3. The substrate carrier according to claim 1 or claim 2, wherein the thread of the drilled hole is provided on the substrate carrier after at least the section of the first component is press-fitted into the drilled hole.

4. The substrate carrier according to claim 1, wherein the second component of the drilling insert contacts the first component of the drilling insert after being disposed in the drill hole.

5. The substrate carrier according to claim 1, wherein the second part of the drilling insert has a head section for receiving a tool for screwing the section into or otherwise rotating it into the drill hole.

6. The substrate carrier according to claim 5, wherein the head section for receiving the tool includes a polygonal tool receiving section extending from the head section, and wherein the tool receiving section, after being disposed in the thread of the drilled hole, is arranged to extend the wall surface of the substrate carrier.

7. The substrate carrier according to claim 1, wherein, The interlocking device includes one or more of the following: threaded fastening device, screw fastening device, press-fit fastening device, rotary fastening device, bayonet fastening device, key or pin fastening device, and retraction fastening device.

8. The substrate carrier according to claim 1, wherein the included angle of the interlocking device of the drill hole with respect to the longitudinal direction of the drill hole is approximately one or more of 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees, 135 degrees or 150 degrees.

9. The substrate carrier according to claim 1, wherein the substrate carrier comprises graphite.

10. The substrate carrier according to claim 9, wherein the substrate carrier comprises a graphite core covered by a silicon carbide coating.

11. The substrate carrier according to claim 1, wherein the first component comprises graphite.

12. The substrate carrier according to claim 1, wherein the second component comprises graphite.

13. A method of manufacturing a substrate carrier in a system for growing a thin film layer on a semiconductor substrate via chemical vapor deposition, comprising the steps of: providing a substrate carrier having a first surface side, the area of ​​the first surface side being provided with a substrate support for accommodating the semiconductor substrate during use; machining a first drilled section at least substantially perpendicular to the first surface side of the substrate carrier on each of the substrate supports; machining a second drilled section extending radially through the substrate carrier from a peripheral wall surface of the substrate carrier for providing a gas connection between each first drilled section of the substrate support and a central portion of the substrate carrier radially inward relative to the substrate support; pressing a first component into the second drilled section; machining a pocket portion for the second component on the wall surface of the substrate carrier, wherein the pocket portion is threaded and configured to have an angle relative to the longitudinal direction of the drilled section; screwing in a second component, the component being at least partially provided with a threaded section corresponding to the thread of the pocket portion for blocking the first component.

14. The method of manufacturing a substrate carrier according to claim 13, wherein the method further comprises the step of: machining a chamfer on the wall surface of the substrate carrier before the step of pressing the first component.

15. A method of manufacturing a substrate carrier according to any one of claims 13 and 14, wherein the second component includes a head section including a polygonal tool receiving section extending from the head section, and wherein the method further includes the step of: processing the wall of the substrate carrier by removing the tool receiving section extending from the wall of the substrate carrier so that the second component is flush with the wall of the substrate carrier.

16. The method of manufacturing a substrate carrier according to claim 13, wherein after the step of screwing in the second component, the method further comprises the step of providing a silicon carbide coating on at least the wall surface of the substrate carrier, particularly covering the entire substrate carrier.

17. The method of manufacturing a substrate carrier according to claim 13, wherein one or both of the first component and the second component comprise graphite.

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