Method and apparatus for processing substrate

Abstract

Methods and apparatus for processing a substrate are provided. For example, the method includes obtaining a first measurement at a first point along a surface of a substrate prior to processing the substrate, the substrate being processed in a processing chamber in the presence of an electric field; after processing the substrate, a second measurement at the first point along the surface of the substrate is obtained, and whether substrate warping occurs is determined based on an analysis of the first measurement and the second measurement.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to methods and apparatus for processing substrates, and, for example, to methods and apparatus for real-time warpage monitoring of processed substrates. Background Art

[0002] Substrate level (wafer) warpage (e.g., upward or downward bending) can be a serious problem in high-volume production (deposition). For example, in advanced nodes, the feature density of chips on the chip and on the substrate continues to increase. Stress analysis and stress relief methods are critical to device function. Therefore, stress monitoring methods are extremely important. For example, real-time substrate warpage can be an excellent indicator of stress accumulation / change during a substrate process sequence. For example, a substrate sometimes experiences significant changes in substrate warpage after being heated (e.g., heated using degassing, plasma, high-temperature heaters, etc.). However, conventional methods and devices are not configured to monitor real-time substrate warpage. For example, it is usually necessary to cool the substrate before monitoring the substrate warpage, which increases the total processing time and reduces the processing volume (throughput). In addition, sometimes when cooling the substrate for monitoring, the warpage of the cooled substrate may be different from that of the hot substrate (e.g., inside a processing chamber). Therefore, it is difficult to obtain an accurate analysis of the warpage using ex-situ measurements, and ex-situ warpage measurements can only give the final result, but do not provide the user with information about how the substrate changes during processing.

[0003] Accordingly, the inventors herein describe improved methods and apparatus for real-time warpage monitoring of processed substrates. Summary of the invention

[0004] Methods and apparatus for processing substrates are provided herein. In some embodiments, a method for processing a substrate includes: obtaining a first measurement at a first point along a surface of the substrate before processing the substrate, processing the substrate in a processing chamber in the presence of an electric field; after processing the substrate, obtaining a second measurement at the first point along the surface of the substrate, and determining whether substrate warpage occurs based on an analysis of the first measurement and the second measurement.

[0005] According to at least some embodiments, a non-transitory computer-readable storage medium has instructions stored thereon, which, when executed by a processor, perform a method for processing a substrate, the method comprising: before processing the substrate, obtaining a first measurement value at a first point along a surface of the substrate, processing the substrate in a processing chamber in the presence of an electric field; after processing the substrate, obtaining a second measurement value at the first point along the surface of the substrate, and determining whether substrate warping occurs based on an analysis of the first measurement value and the second measurement value.

[0006] According to at least some embodiments, an apparatus for processing a substrate includes: a processing chamber, the processing chamber being configured to process a substrate; an apparatus, the apparatus being configured to obtain measurement values ​​along a surface of the substrate; and a controller, the controller being configured to: obtain a first measurement value at a first point along the surface of the substrate before processing the substrate; process the substrate in the presence of an electric field in the processing chamber; obtain a second measurement value at the first point along the surface of the substrate after processing the substrate; and determine whether substrate warping occurs based on analysis of the first measurement value and the second measurement value.

[0007] Other and further embodiments of the disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments of the present disclosure briefly summarized above and discussed in more detail below can be understood by referring to the exemplary embodiments of the present disclosure illustrated in the accompanying drawings. However, the accompanying drawings illustrate only typical embodiments of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure, as the present disclosure may allow other equally effective embodiments.

[0009] Figure 1 is a flow chart of a method for processing a substrate in accordance with at least some embodiments of the present disclosure.

[0010] Figure 2 According to at least some embodiments of the present disclosure, Figure 1 Schematic diagram of the apparatus of the method.

[0011] Figure 3 is configured to communicate with Figure 2 Schematic diagram of a displacement sensor used together with the device.

[0012] For ease of understanding, the same reference numerals are used to refer to common elements in the drawings where possible. For clarity, the drawings are not drawn to scale and may be simplified. Elements and features in one embodiment may be advantageously incorporated into other embodiments without further description. DETAILED DESCRIPTION

[0013] Embodiments of methods and apparatus for processing substrates are provided herein. For example, the methods and apparatus described herein use one or more sensors positioned (mounted) near a slit valve position of a processing chamber / platform (e.g., an integrated tool). In at least some embodiments, the displacement sensor can be configured to monitor substrate bending / warping using pre-measurement and post-measurement, for example, using triangulation. In at least some embodiments, pre-measurement and post-measurement can be obtained before and after physical vapor deposition (PVD). For example, given the known relative position of a laser emitter and a detector (e.g., an RS-CMOS detector) of a displacement sensor, the positioning of a target (e.g., the maximum (max) and minimum (min) of a processed substrate) can be calculated by determining the position of a reflected beam spot on the detector. At a sampling period of <1ms, the accuracy of the measured value can be <10μm.

[0014] Figure 1 is a flow chart of a method 100 for processing a substrate, and Figure 2 A tool 200 (or apparatus) may be used to implement the method 100 (eg, configured to process a substrate) in accordance with at least some embodiments of the present disclosure.

[0015] The method 100 may be performed in a tool 200, which may include any suitable processing chamber configured for physical vapor deposition (PVD), chemical vapor deposition (CVD), and / or atomic layer deposition (ALD), such as plasma-enhanced ALD or thermal ALD (e.g., without forming a plasma). Examples of processing systems that may be used to perform the inventive methods disclosed herein may include, but are not limited to, one or more processing chambers commercially available from Applied Materials, Inc. of Santa Clara, California. Other processing chambers, including those from other manufacturers, may also be used as appropriate in conjunction with the teachings provided herein.

[0016] The tool 200 may be embodied in individual processing chambers that may be configured in a standalone manner or as a cluster tool (as described below with respect to Figure 2 200)). Examples of integrated tools may include, but are not limited to, one or more processing chambers commercially available from Applied Materials, Inc. of Santa Clara, California. The methods described herein may be practiced using other cluster tools having suitable processing chambers coupled thereto or in other suitable processing chambers. For example, in some embodiments, the methods of the present invention discussed above may be performed in an integrated tool such that there are limited or no vacuum breaks between processing steps. For example, reducing vacuum breaks may limit or prevent contamination (e.g., oxidation) of one or more metal layers or other portions of the substrate.

[0017] The integrated tool includes a processing platform 201 (vacuum sealed processing platform), a factory interface 204, and a controller 202. The processing platform 201 includes a plurality of processing chambers (such as 214A, 214B, 214C, and 214D) operably coupled to a transfer chamber 203 (vacuum substrate transfer chamber) and processing chambers 214E and 214F operably coupled to a buffer chamber 208 (vacuum substrate buffer chamber).

[0018] The factory interface 204 is provided through one or more load lock chambers (two load lock chambers, such as Figure 2 206A and 206B) are operably coupled to the buffer chamber 208. In at least some embodiments, one of the buffer chamber 208 or the transfer chamber 203 of the tool 200 can be omitted. One or more modules or channels can be disposed between the buffer chamber 208 and the transfer chamber 203 and can be configured to receive one or more substrates from the buffer chamber 208 and / or the transfer chamber 203. In at least some embodiments, the module 218A and the module 218B are disposed between the buffer chamber 208 and the transfer chamber 203 and are configured to receive one or more substrates from the buffer chamber 208 and / or the transfer chamber 203 during operation, as will be described in more detail below. As described above, the module 218A and the module 218B can have a transparent cover.

[0019] In some embodiments, the factory interface 204 includes a docking station 207 and a factory interface robot 238 to facilitate the transfer of one or more semiconductor substrates (wafers). The docking station 207 is configured to receive one or more front opening unit (FOUP). Figure 2In the embodiment of FIG. 2 , four FOUPs are shown, such as 205A, 205B, 205C, and 205D. The factory interface robot 238 is configured to transfer substrates from the factory interface 204 to the processing platform 201 through the load lock chambers, such as 206A and 206B. Each of the load lock chambers 206A and 206B has a first port coupled to the factory interface 204 and a second port coupled to the transfer chamber 203. The load lock chambers 206A and 206B are coupled to a pressure control system (not shown) that pumps and exhausts the load lock chambers 206A and 206B to facilitate the transfer of substrates between the vacuum environment of the buffer chamber 208 and the substantially ambient (e.g., atmospheric) environment of the factory interface 204. In at least some embodiments, the buffer chamber 208 can be maintained in a substantially ambient environment. In embodiments where the buffer chamber 208 is not used, the load lock chambers 206A and 206B facilitate the transfer of substrates between the transfer chamber 203 and the factory interface 204. The buffer chamber 208 and the transfer chamber 203 each have a vacuum robot 242 positioned to transfer / receive one or more substrates. For example, the vacuum robot 242 of the buffer chamber 208 can receive / transfer substrates 221 between the load lock chambers 206A and 206B, the processing chambers 214E and 214F, and the modules 218A and 218F. Similarly, the vacuum robot 242 of the buffer chamber 203 can receive / transfer substrates 221 between the processing chambers 214A, 214B, 214C, and 214D, and the modules 218A and 218F.

[0020] In some embodiments, the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F may include at least an ALD chamber, a CVD chamber, a PVD chamber, an electron beam deposition chamber, and / or an electroplating chamber, an electroless plating (EEP) deposition chamber. Likewise, in some embodiments, one or more optional service chambers (shown as 216A and 216B) may be coupled to the buffer chamber 208. The service chambers 216A and 216B may be configured to perform other substrate processes such as degassing, bonding, chemical mechanical polishing (CMP), substrate cleaning (pre-cleaning), wafer cutting, etching, plasma cutting, orientation, substrate metrology, cooling, etc.

[0021] In at least some embodiments, one or more temperature measurement devices 215 can be mounted proximate to the process chambers 214A, 214B, 214C, 214D, 214E, and 214F, the service chambers 216A and 216B, the modules 218A and 218F, and / or the load lock chambers 206A and 206B using one or more suitable mounting devices (e.g., nuts, bolted joints, adhesives, etc.). The one or more temperature measurement devices 215 can be configured to obtain temperature measurements at a first point or a second point different from the first point, as will be described in more detail below.

[0022] In at least some embodiments, one or more displacement devices can be mounted proximate to the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F, the service chambers 216A and 216B, the modules 218A and 218F, and / or the load lock chambers 206A and 206B using one or more suitable mounting devices (e.g., nuts, bolted joints, adhesives, etc.). For example, the one or more displacement devices can be one or more laser displacement sensors, or other suitable devices capable of obtaining measurements along the surface of the substrate, as will be described in more detail below. The one or more displacement sensors 213 can include an emitter 302 and a detector 304. The emitter 302 is configured to direct a displacement of the substrate 221 or a plurality of substrates (e.g., Figure 3 2 and 3. Similarly, detector 304 is configured to detect one or more light beams 308 reflected from the surface of substrate 221. In at least some embodiments, one or more filters, lenses, or other optical devices 310 may be used in conjunction with emitter 302 and detector 304.

[0023] Additionally, one or more displacement sensors 213 may be mounted proximate an opening (e.g., a slit valve position) to any of the following: the process chambers 214A, 214B, 214C, 214D, 214E, and 214F, the service chambers 216A and 216B, the modules 218A and 218F, and / or the load lock chambers 206A and 206B. For example, in at least some embodiments, one or more displacement sensors 213 may be mounted proximate a slit valve (not shown) that opens to the following: the process chambers 214A, 214B, 214C, 214D, 214E, and 214F, the service chambers 216A and 216B, the modules 218A and 218F, and / or the load lock chambers 206A and 206B.

[0024] The controller 202 controls the operation of the tool 200 using direct control of the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F and the device 212 or by controlling a computer (or controller) associated with the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F, the device 212, and the tool 200. In operation, the controller 202 is capable of collecting and feeding back data from various chambers and systems to optimize the performance of the tool 200. The controller 202 typically includes a central processing unit 230, a memory 234, and support circuits 232. The central processing unit 230 can be any form of general-purpose computer processor that can be used in an industrial environment. The support circuits 232 are typically coupled to the central processing unit 230 and may include cache, clock circuits, input / output subsystems, power supplies, etc. Software routines (such as the processing methods described above) may be stored in memory 234 (e.g., non-transitory computer-readable storage having instructions stored thereon) and, when executed by central processing unit 230, transform central processing unit 230 into a special-purpose computer (e.g., controller 202). Software routines may also be stored and / or executed by a second controller (not shown) located remotely from tool 200.

[0025] Continue to refer Figure 1 Initially, one or more substrates, thermal module assemblies, etc. may be loaded into four FOUPs (such as 205A, 205B, 205C, and 205D ( Figure 2 )). For example, in at least some embodiments, substrate 221 (wafer) can be loaded into FOUP 205B. Substrate 300 can have a diameter of 150mm, 200mm, 300mm, etc. Substrate 221 can be formed of germanium, silicon, silicon carbide, silicon oxide, etc. In at least some embodiments, substrate 221 can have a diameter of 300mm and can be formed of silicon. In at least some embodiments, one or more metal layers can be deposited on substrate 221. For example, one or more metal layers can include aluminum, cobalt, copper, nitride, titanium, tantalum, etc. In at least some embodiments, substrate 221 can include a metal layer containing cobalt and tungsten.

[0026] Once loaded, the factory interface robot 238 may move the substrate 221 from the factory interface 204 to the processing platform 201 through, for example, the load lock chamber 206A. The vacuum robot 242 may move the substrate 221 from the load lock chamber 206A to one or more of the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F and / or the service chambers 216A and 216B.

[0027] For example, in at least some embodiments, the vacuum robot 242 can move the substrate 221 from the load lock chamber 206A to the service chamber 216A, where one or more of the following can be performed: degassing, bonding, chemical mechanical polishing (CMP), substrate cleaning (pre-cleaning), wafer cutting, etching, plasma cutting, orientation, substrate metrology, cooling. For example, in at least some embodiments, a pre-cleaning process can be performed on the substrate 221 to remove oxides that may have formed on the metal layer. In at least some embodiments, before or after the substrate 221 is processed in the service chamber 216A, one or more displacement sensors 213 can be used to obtain a first measurement and / or a second measurement at a first point along the substrate 221, as will be described in more detail below.

[0028] Next, the vacuum robot 242 of the buffer chamber 208 can move the substrate 221 from the service chamber 216A to one of the modules 218A and 218B (e.g., for cooling). Again, before or after the substrate 221 is moved to the modules 218A and 218B, one or more displacement sensors 213 can be used to obtain a first measurement and / or a second measurement at a first point along the substrate 221, as will be described in more detail below.

[0029] Next, at 102, the method 100 includes obtaining a first measurement at a first point along a surface of the substrate before processing the substrate. For example, before the vacuum robot 242 of the transfer chamber 203 transfers the substrate 221 from one of the modules 218A and 218B to one of the processing chambers 214A, 214B, 214C, and 214D (wherein one or more deposition processes may be performed on the substrate 221), under the control of the controller 202, the one or more displacement sensors 213 may obtain a first measurement at a first point along the substrate 221. For example, as described above, the emitter 302 of the laser displacement sensor is configured to emit a light beam 306 toward a surface of the substrate 221 (or multiple substrates). Similarly, the detector 304 is configured to detect one or more light beams 308 reflected from the surface of the substrate 221. In at least some embodiments, the first measurement can be based on the positioning of the emitter 302 relative to the substrate 221 and the positioning of the detector 304 relative to the substrate 221 and the location of one or more light beams 308 spots detected by the detector 304. One or more filters, lenses, or other optical devices 310 can be used in conjunction with the emitter 302 and the detector 304 of the laser displacement sensor.

[0030] Next, at 104, the method 100 includes: processing the substrate 221 in the presence of an electric field in a processing chamber. For example, the substrate 221 can be transferred to the processing chamber 214A, where physical vapor deposition can be performed on the substrate 221. For example, during the physical vapor deposition, one or more additional metal layers (e.g., relatively thick, highly uniform, low temperature films including at least one of aluminum nitride, aluminum oxide, gallium arsenide, germanium, indium tin oxide, lead zirconium titanate, scandium-doped aluminum nitride, silicon carbide, etc.) can be deposited on the metal layer previously deposited on the substrate 221. The additional metal layers can be used for one or more MTM (More than Moore) applications, such as power devices, MEMS, RF, photonics, and packaging technologies (e.g., through silicon vias (TSVs)).

[0031] Next, at 106, the method 100 includes: after processing the substrate, obtaining a second measurement at a first point along the surface of the substrate. For example, warping / bending may occur during physical vapor deposition, taking into account the electric fields present during the deposition process (e.g., physical vapor deposition or chemical vapor deposition). Accordingly, after the deposition process, under the control of the controller 202, as described above, the emitter 302 emits a light beam 306 to the surface of the substrate 221 (or multiple substrates), and the detector 304 detects one or more light beams reflected from the surface of the substrate 221 to obtain a second measurement, for example based on the positioning of the emitter 302 relative to the substrate 221 and the positioning of the detector 304 relative to the substrate 221 and the position of the one or more light beam 308 points detected by the detector 304.

[0032] Next, at 108, the method 100 includes determining whether substrate warpage has occurred based on an analysis of the first measurement and the second measurement. For example, in at least some embodiments, the controller 202 may compare the first measurement with the second measurement to determine the amount of warpage / bending. For example, using the controller 202 with a known relative positioning of the emitter 302 and the detector 304, the position (e.g., first position along the substrate), the amount of warpage / bending, the position of the target (e.g., the maximum and minimum of the processed substrate) may be calculated by determining the position of the reflected beam spot on the detector 304, the accuracy of the measurement may be about <10 μm at a sampling period of about <1 ms. For example, a comparison indicating an increase in the distance between the substrate 221, the emitter 302, and the detector 304 at a first point may indicate concave warpage / bending to the controller 202. Similarly, a comparison indicating a decrease in the distance between the substrate 221, the emitter 302, and the detector 304 at a first point may indicate convex warpage / bending to the controller 202. In at least some embodiments, the controller 202 can compare the change in distance to a predetermined amount (e.g., stored in the memory 234), which allows the controller 202 to determine whether a maximum (predetermined) amount of acceptable warping / bending has occurred. In at least some embodiments, the method 100 includes triggering a fault indication when the substrate is determined to be warped. For example, if the controller 202 determines that the amount of warping / bending equals or exceeds the predetermined amount, the controller 202 can trigger an alarm (visual / audio) and / or stop processing of the substrate 221.

[0033] In at least some embodiments, method 100 may include obtaining a temperature measurement at the first point or a second point different from the first point, wherein determining whether substrate warpage occurs is further based on analyzing the temperature measurement.

[0034] The method 100 including operations 102-108 may be repeated for each of the processing chambers 214A, 214B, 214C, 214D, 214E, and 214F and / or the service chambers 216A and 216B. The method 100 including operations 102-108 may also be used in a similar manner in conjunction with the modules 218A and 218F and / or the load lock chambers 206A and 206B, such as metrology.

[0035] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be conceived without departing from the basic scope thereof.

Claims

1. A method for processing a substrate, comprising: Prior to processing a substrate, obtaining a first measurement at a first point along a surface of the substrate; processing the substrate in the presence of an electric field in a processing chamber; after processing the substrate, obtaining a second measurement at the first point along the surface of the substrate; as well as Whether substrate warpage occurs is determined based on analysis of the first measurement value and the second measurement value.

2. The method of claim 1, wherein obtaining the first measurement and the second measurement is performed using a laser displacement sensor comprising an emitter and a detector.

3. The method of claim 2, wherein the first measurement value and the second measurement value are based on the positioning of the emitter relative to the substrate and the positioning of the detector relative to the substrate and the position of the reflected light beam spot detected by the detector.

4. The method of claim 2, wherein the laser displacement sensor is positioned adjacent to a slit valve on the processing chamber.

5. The method according to any one of claims 1 to 4, further comprising: A temperature measurement is obtained at the first point or a second point different from the first point, wherein determining whether substrate warpage occurs is further based on an analysis of the temperature measurement.

6. The method according to any one of claims 1 to 4, further comprising: When substrate warpage is determined, a fault indication is triggered.

7. The method of any one of claims 1 to 4, wherein the substrate comprises at least one of aluminum, copper, or tantalum.

8. A non-transitory computer readable storage medium having instructions stored thereon, which when executed by a processor, perform a method for processing a substrate, the method comprising: Prior to processing a substrate, obtaining a first measurement at a first point along a surface of the substrate; processing the substrate in a processing chamber in the presence of an electric field; after processing the substrate, obtaining a second measurement at the first point along the surface of the substrate; as well as Whether substrate warpage occurs is determined based on analysis of the first measurement value and the second measurement value.

9. The non-transitory computer readable storage medium of claim 8, wherein obtaining the first measurement and the second measurement is performed using a laser displacement sensor including an emitter and a detector.

10. The non-transitory computer-readable storage medium of claim 9, wherein the first measurement value and the second measurement value are based on a positioning of the emitter relative to the substrate and a positioning of the detector relative to the substrate and a position of a reflected light beam spot detected by the detector.

11. The non-transitory computer readable storage medium of claim 9, wherein the laser displacement sensor is positioned adjacent to a slit valve on the processing chamber.

12. The non-transitory computer-readable storage medium of any one of claims 8 to 11, further comprising: A temperature measurement is obtained at the first point or a second point different from the first point, wherein whether substrate warpage occurs is determined further based on an analysis of the temperature measurement.

13. The non-transitory computer-readable storage medium of any one of claims 8 to 11, further comprising: When substrate warpage is determined, a fault indication is triggered.

14. The non-transitory computer readable storage medium of any one of claims 8 to 11, wherein the substrate comprises at least one of aluminum, copper, or tantalum.

15. An apparatus for processing a substrate, comprising: a processing chamber configured to process a substrate; an apparatus configured to obtain measurements along a surface of the substrate; as well as A controller configured to: prior to processing the substrate, obtaining a first measurement at a first point along the surface of the substrate; processing the substrate in the processing chamber in the presence of an electric field; after processing the substrate, obtaining a second measurement at the first point along the surface of the substrate; as well as Whether substrate warpage occurs is determined based on analysis of the first measurement value and the second measurement value.

16. The apparatus of claim 15, wherein the means for obtaining measurements along the surface of the substrate is a laser displacement sensor comprising an emitter and a detector.

17. The apparatus of claim 16, wherein the first measurement and the second measurement are based on a positioning of the emitter relative to the substrate and a positioning of the detector relative to the substrate and a position of a reflected beam spot detected by the detector.

18. The apparatus of claim 16, wherein the laser displacement sensor is positioned adjacent to a slit valve on the processing chamber.

19. The apparatus of any one of claims 15 to 18, further comprising a temperature measuring device configured to obtain a temperature measurement value at the first point or a second point different from the first point, wherein the controller is further configured to determine whether substrate warpage occurs based on the temperature measurement value.

20. The apparatus of any one of claims 15 to 18, wherein the controller is further configured to trigger a fault indication when substrate warpage is detected.

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