Performance validation for impedance transformer in a microwave system

Abstract

Embodiments disclosed herein may include a method for testing a thermal break. In an embodiment, the method includes sweeping a frequency between a first frequency and a second frequency with a vector network analyzer (VNA) on a test bench that comprises a dielectric resonator antenna (DRA) and a thermal break electrically coupled to the VNA. In an embodiment, the method may further include detecting a resonant frequency of the DRA and an impedance at an input of the thermal break. The method may further include comparing the resonant frequency and the impedance to a reference resonant frequency and a reference impedance of a known good thermal break.

Description

[0001] PERFORMANCE VALIDATION FOR IMPEDANCE TRANSFORMER IN A MICROWAVE SYSTEM

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Patent Application No. 63 / 560,450, filed on March 1 , 2024, the entire contents of which are hereby incorporated by reference herein.

[0004] FIELD

[0005] Embodiments relate to the field of semiconductor manufacturing and, in particular, to processes for validating impedance across a thermal break in a microwave system.

[0006] DESCRIPTION OF RELATED ART

[0007] In some microwave systems, a thermal break (also referred to as a thermal breaker) is a fixed match that provides a reduction in reflected power in the system. In some instances, the thermal break can fail for various reasons. When the thermal break fails there is a large increase in the reflected power. This requires an immediate stop to the process and can result in damage to the power amplifier upstream from the thermal break.

[0008] In the case of semiconductor processing, the microwave system may include a dielectric resonator antenna (DRA) that is downstream of the thermal break. The DRA couples the microwave radiation to gasses within a processing chamber in order to ignite and / or sustain a plasma within the chamber. The plasma can be used in order to process a semiconductor substrate, such as a silicon wafer or the like. When the thermal break fails, the recipe that is currently being run is halted to protect the tool. This can result in improperly processed substrates, and (as a result) a decrease in yield or the need for rework on the substrate.

[0009] SUMMARY

[0010] Embodiments disclosed herein may include a method for testing a thermal break. In an embodiment, the method includes sweeping a frequency between a first frequency and a second frequency with a vector network analyzer (VNA) on a test bench that comprises a dielectric resonator antenna (DRA) and a thermal break electrically coupled to the VNA. In an embodiment, the method may further include detecting a resonant frequency of the DRA and an impedance at an input of the thermal break. The method may further include comparing the resonant frequency and the impedance to a reference resonant frequency and a reference impedance of a known good thermal break.

[0011] An embodiment may also include a test bench apparatus for testing thermal breaks. In an embodiment, the apparatus includes a dielectric resonator antenna (DRA), and a thermal break electrically coupled to the DRA. The apparatus may also include a vector network analyzer (VNA) electrically coupled to the thermal break, and a computer electrically coupled to the VNA.

[0012] Embodiments may also comprise method for testing a thermal break that includes sweeping a frequency between a first frequency and a second frequency with a vector network analyzer (VNA) on a test bench that comprises a dielectric resonator antenna (DRA) and a thermal break electrically coupled to the VNA. In an embodiment, the process may further include detecting a resonant frequency of the DRA, an impedance at an input of the thermal break, and an S 11 value, and comparing the resonant frequency, the impedance, and the S il value to a reference resonant frequency, a reference impedance, and a reference Si l value of a known good thermal break.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A is a cross-sectional illustration of a semiconductor processing tool for generating a microwave plasma using a plurality of dielectric resonator antennas (DRAs), in accordance with an embodiment.

[0015] Figure IB is a plan view illustration of a DRA array over a dielectric plate for use in a microwave plasma semiconductor processing tool, in accordance with an embodiment.

[0016] Figure 2 is a schematic illustrations of the microwave power delivery system of a semiconductor processing tool for generating a microwave plasma, in accordance with an embodiment.

[0017] Figure 3A is a plot of the forward power over time of a microwave power delivery system, in accordance with an embodiment.

[0018] Figure 3B is a plot of the reflected power over time of a microwave power delivery system with a defective thermal break, in accordance with an embodiment.

[0019] Figure 4 is a cross-sectional illustration of a portion of a thermal break, in accordance with an embodiment.

[0020] Figure 5 A is a schematic illustration of a test bench for diagnosing the performance of a thermal break, in accordance with an embodiment.

[0021] Figure 5B is an illustration of a test bench that includes a stand for holding the thermal break and a vector network analyzer (VNA) over the DRA, in accordance with an embodiment.

[0022] Figure 6A is a plot of the impedance of a known good thermal break and the impedance of a defective thermal break, in accordance with an embodiment.

[0023] Figure 6B is a plot of the Sn value of a known good thermal break and the Sn value of a defective thermal break, in accordance with an embodiment. Figure 7 is a process flow diagram of a process for testing the functionality of a thermal break with a test bench, in accordance with an embodiment.

[0024] Figure 8 illustrates a block diagram of an exemplary computer system that may be used in conjunction with a processing tool, in accordance with an embodiment.

[0025] DETAILED DESCRIPTION

[0026] Embodiments described herein include apparatuses and processes for validating impedance across a thermal break in a microwave system. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. It will be apparent to one skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known aspects are not described in detail in order to not unnecessarily obscure embodiments. Furthermore, it is to be understood that the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0027] Various embodiments or aspects of the disclosure are described herein. In some implementations, the different embodiments are practiced separately. However, embodiments are not limited to embodiments being practiced in isolation. For example, two or more different embodiments can be combined together in order to be practiced as a single device, process, structure, or the like. The entirety of various embodiments can be combined together in some instances. In other instances, portions of a first embodiment can be combined with portions of one or more different embodiments. For example, a portion of a first embodiment can be combined with a portion of a second embodiment, or a portion of a first embodiment can be combined with a portion of a second embodiment and a portion of a third embodiment.

[0028] The embodiments illustrated and discussed in relation to the figures included herein are provided for the purpose of explaining some of the basic principles of the disclosure. However, the scope of this disclosure covers all related, potential, and / or possible, embodiments, even those differing from the idealized and / or illustrative examples presented. This disclosure covers even those embodiments which incorporate and / or utilize modern, future, and / or as of the time of this writing unknown, components, devices, systems, etc., as replacements for the functionally equivalent, analogous, and / or similar, components, devices, systems, etc., used in the embodiments illustrated and / or discussed herein for the purpose of explanation, illustration, and example.

[0029] Microwave plasma sources have seen a growth in importance in semiconductor processing environments. This can be due, at least in part, to the improved plasma performance that is provided when a microwave power source is used. Compared to traditional RF based plasmas (e.g., a capacitively coupled plasma (CCP), inductively coupled plasmas (1CP), etc.), the flux of radicals provided to the substrate is higher for the microwave plasma. That is, a plasma density of the microwave plasma may be higher. At the same time, the ion energy at the substrate surface for a microwave plasma is lower than the ion energy at the substrate surface for a typical RF based plasma. More particularly, the ion energy is typically well below a general damage threshold of approximately 30eV.

[0030] Previous attempts to provide microwave power sources relied on magnetron solutions. The use of magnetrons results in bulky and hard to control systems. Accordingly, solid state solutions have been suggested for microwave power supplies. Solid state solutions provide enhanced control, while also shrinking the form factor of the power delivery system. One benefit of a reduced form factor is that a plurality of microwave supplies can be used for a single processing tool. Such a modular microwave plasma tool is shown in Figures 1 A.

[0031] Referring now to Figure 1 A, a cross-sectional illustration of a semiconductor processing tool 100 is shown, in accordance with an embodiment. The semiconductor processing tool 100 may be a tool that processes a substrate 101 with plasma 105 that is generated through the use of microwave power. In an embodiment, the tool 100 may be a plasma deposition tool (e.g., plasma enhanced chemical vapor deposition (PECVD), plasma enhanced atomic layer deposition (PEALD), etc.), a plasma etching tool, a plasma treatment tool, and / or the like. The substrate 101 may be any substrate suitable for fabricating semiconductor structures. For example, the substrate 101 may be a silicon wafer or any other semiconductor wafer. The substrate 101 may include any suitable form factor, such as a 300mm diameter, a 400mm diameter, or the like. In an embodiment, the substrate 101 may be supported on a pedestal 108. The pedestal may comprise a chucking device for securing the substrate 101 during processing. The chucking device may comprise an electrostatic chuck (ESC) or the like.

[0032] In an embodiment, the tool 100 may comprise a chamber 107. The chamber 107 may be suitable for supporting a vacuum environment within the chamber 107. The vacuum environment may be at a pressure suitable for the formation of the plasma 105. That is, a “vacuum environment” does not necessarily mean that a perfect vacuum environment is necessary. For example, the chamber 107 may support a rough vacuum (e.g., a pressure up to approximately 800Torr). Though, higher vacuum environments (i.e., lower pressures) may also be supported by the chamber 107. The low pressure environment may be provided through the use of an exhaust, a vacuum pump, and / or the like (not shown for simplicity). The chamber 107 may also include a slit valve (not shown) for passing the substrate 101 into and out of the chamber 107.

[0033] In an embodiment, the tool 100 may comprise a lid assembly 110. The lid assembly 110 may comprise a dielectric plate 112 that is provided opposite of the pedestal 108. The dielectric material of the dielectric plate 112 may comprise a ceramic in some embodiments. The dielectric plate 112 may comprise pathways, channels, holes, and / or the like (not shown) for distributing gasses into the chamber 107. In some instances, the dielectric plate 112 may be referred to as a showerhead. In an embodiment, a plurality of dielectric resonator antennas (DRAs) 115 may be distributed across the top surface of the dielectric plate 112. The DRAs 115 may each comprise a puck 1 16 and a pin 1 17 that is inserted into a hole into the top surface of the puck 116.

[0034] In an embodiment, the puck 116 is a dielectric material, such as a ceramic material or the like. The puck 116 may be the same dielectric material as the dielectric plate 112. Though, in other embodiments, the puck 116 and the dielectric plate 112 may be different materials. In an embodiment, the puck 116 is a cylindrical shaped object. Though, other axially symmetric shapes may also be used in some embodiments. The dimensions and material of the puck 116 may be chosen in order to set a desired resonant frequency for coupling microwave power into the plasma 105.

[0035] In an embodiment, the pin 117 is an electrically conductive pin (e.g., copper). The pin 117 may be inserted into the hole of the puck 116 to a desired depth. The depth into the puck 116 can be controlled in order to provide a desired response. In an embodiment, the opposite end of the pin 117 is coupled to a remainder of the microwave power supply system (which will be described in greater detail below). For example, the pin 117 may be coupled to a thermal break.

[0036] In the illustrated embodiment, the DR A 115 is shown as a bare dielectric material puck 116 with an electrically conductive pin 117. However, it is to be appreciated that the DRA 115 may comprise a housing that surrounds portions (or all of) the DRA 115. For example, an electrically conductive housing may be provided around the DRA 115. The electrically conductive housing may be grounded in some embodiments. In an embodiment, the housing may comprise aluminum or the like.

[0037] Referring now to Figure IB, a plan view illustration of a lid assembly 110 is shown, in accordance with an embodiment. In an embodiment, the lid assembly 110 may be similar to the lid assembly 110 described above with respect to Figure 1A. For example, the lid assembly 110 may comprise a dielectric plate 112. The dielectric plate 112 in Figure IB is shown as being circular. Though, in other embodiments, the dielectric plate 112 may have any shape. The dielectric plate 112 may comprise a ceramic material in some embodiments.

[0038] In an embodiment, a plurality of DRAs 115 may be distributed across the dielectric plate 112. The DRAs 115 may be similar to the DRAs 115 described above with respect to Figure 1 A. For example, each DRA 115 may comprise a puck and a pin. A housing may also surround the puck and pin of each DRA 115. In the illustrated embodiment, twenty five DRAs 115 are distributed across the dielectric plate 112. Though, it is to be appreciated that one or more DRAs 115 may be included in the lid assembly 110 in other embodiments. In a particular embodiment, nineteen DRAs 115 are provided on the dielectric plate 112.

[0039] In an embodiment, the layout of the plurality of DRAs 115 may include any suitable pattern. In a particular embodiment, the DRAs 115 may be provided in a symmetric pattern about the dielectric plate 112. Embodiments may also include a series of DRA 115 rings that are substantially concentric with each other, as shown in Figure IB. Other packing configurations may also be used in order to provide denser DRA 115 layouts.

[0040] The use of a plurality of DRAs 115 allows for greater control of the processing environment within the chamber 107. That is, the plasma 105 can be controlled with greater spatial variation. This allows for different plasma parameters to be applied to (for example) the center of the substrate 101 and the edge of the substrate 101. Variable control in this manner can lead to improved overall processing uniformity.

[0041] Referring now to Figure 2, a schematic illustration of a microwave power delivery system 220 is shown, in accordance with an embodiment. In an embodiment, the microwave power delivery system 220 may be coupled to a plasma processing tool similar to the tool 100 described in greater detail herein. The microwave power delivery system 220 may be a solid state microwave power delivery system 220. That is, the microwaves may be generated without the use of a magnetron or the like. Accordingly, a plurality of microwave lines 230 may be included within a reasonable form factor. In Figure 2, microwave lines 230A to 230N are provided as an example. The number of microwave lines 230 may be equal to the number of DRAs that are desired for the tool. For example, there may be one or more microwave lines 230, ten or more microwave lines 230, or twenty or more microwave lines 230. In a particular embodiment, there may be nineteen micro wave lines 230.

[0042] In an embodiment, the microwave power delivery system 220 may comprise a power supply 222. A single power supply 222 may supply power to each of the microwave lines 230. For example, coaxial cables 223 may electrically couple the power supply 222 to the plurality of microwave lines 230. The power supply 222 may be an AC / DC power supply in some embodiments. More particularly, the power supply 222 may be a solid state microwave power supply 222. While a single power supply 222 is shown in Figure 2, it is to be appreciated that two or more power supplies 222 may be used in the power delivery system 220 in other embodiments.

[0043] In an embodiment, the microwave lines 230 may each comprise a plurality of components that take the microwave power and deliver it to the plasma processing tool. In an embodiment, the microwave line 230 may comprise a microwave power amplifier 231. The microwave power amplifier may be electrically coupled to a thermal break 235 by a coaxial cable 224. The thermal break 235 may be a quarter-wavelength impedance transformer in some embodiments. A more detailed description of the thermal break 235 is provided in greater detail below. In an embodiment, the thermal break 235 is electrically coupled to the DRA 215. The DRA 215 may be similar to any of the DRAs described in greater detail herein. For example, the DRA 215 may comprise a puck 216 and a pin 217. The pin 217 may be coupled to the thermal break 235 by solder, a connector, or the like. The DRA 215 may be used to couple the microwave power to gasses within the chamber (not shown) in order to initiate and / or sustain a plasma within the chamber.

[0044] The thermal break 235 may be used to match an impedance of the DRA 215 to the impedance of the coaxial cable 224. This is done to reduce (or eliminate) reflected power in the system at a given frequency. For example, at an operating frequency of approximately 2,450MHz, the characteristic impedance of the coaxial cable 224 may be approximately 50 Ohms. However, when the thermal break 235 is damaged, the matching is sub-optimal and high reflected power is seen within the power delivery system.

[0045] An example of the effect of a damaged thermal break 235 is shown in Figures 3A and 3B. Figure 3A is a plot of the forward power in Watts over time, and Figure 3B is a plot of the reflected power in Watts over the same duration. As can be seen, for a given forward power, in each pulse there is a rapid increase in reflected power, as shown by the plurality of peaks 340. Ideally, the reflected power should be zero for each pulse of forward power. However, as shown in Figure 3B, the reflected power increases to a significant percentage of the forward power. In some instances, the reflected power may extend up to over 50% of the forward power. This can lead to multiple issues.

[0046] One problem is that the high reflected power can damage the microwave power delivery system 220. As such, when high values of reflected power are detected, the processing may be halted. This can occur in the middle of a processing recipe, and the substrates being processed may not be processed properly. The substrate may need to be scrapped or reworked. Therefore, yields and throughput are negatively impacted.

[0047] Alternatively, if the tool is not stopped in time, the reflected power can damage the microwave power amplifiers 231. This increases cost of ownership of the tool, as parts need to be replaced more frequently. Replacing components also results in down time for the tool, which can increase cost of ownership and reduce throughput. Accordingly, it is desirable to prevent or limit the failure of the thermal breaks 235.

[0048] Referring now to Figure 4, a cross-sectional illustration of a thermal break 435 is shown, in accordance with an embodiment. In an embodiment, the thermal break 435 may comprise a housing 445, such as an aluminum housing 445 or the like. An electrically conductive trace 441 may pass through the housing 445. In an embodiment, the trace 441 may be provided on a board (e.g., a printed circuit board (PCB)). The board is not shown in Figure 4 for simplicity. In an embodiment, stubs 442 may be provided along the trace 441 in order to modify an impedance of the trace 441 in order to allow for the proper impedance matching within the system.

[0049] In an embodiment, a pin 417 is electrically coupled to a first end of the trace 441. For example, a solder 446 or the like may be used to couple the pin 417 to the trace 441 . The pin 417 may be the pin 417 that is inserted into the DRA (not shown in Figure 4). In an embodiment, the opposite second end of the trace 441 may be electrically coupled to a connector 448 for receiving a coaxial cable (not shown). For example, the connector 448 may be an n-connector or the like. Generally, the thermal break 435 will fail in one of two modes. A first mode of failure includes the thermal break 435 failing at a solder 446 or 447 that couples the thermal break 435 to the pin 417 or the connector 448. This type of failure is typically easy to detect, as arcing at the solder joint causes burning of Teflon (not shown) at the interface with the connector 448 or the pin 417. This burning can be diagnosed visually. The other failure mode is not visually discernable. Instead, part of the copper trace 441 of the thermal break 435 is deformed by heat from the DRA (not shown) and / or was oxidized over time. This changes the characteristic impedance of the copper trace within the thermal break 435 and can lead to higher reflected power. One proposed test for the second type of failure is a high potential test (or hipot test). However, it has been shown that hipot testing also fails to detect such defects.

[0050] As noted above, failure of the thermal break 435 can lead to significant down time for the tool. However, in the case of the second mode of failure, there is no easily distinguishable way to diagnose that the thermal break 435 was the reason for the increase in reflected power. Accordingly, a time consuming investigation into the cause of the reflected power is needed in order to repair the tool and bring it back online. This can result in the need to replace multiple components (e.g., the thermal break 435 and / or the microwave power amplifier 231). Accordingly, it is desirable to know that only good thermal breaks 435 are integrated into the microwave line 230 at the outset. This requires a method of testing the individual thermal breaks 435 after manufacture. Additionally, when a defect is detected in the tool, an easy way to investigate the thermal break 435 allows for the tool to be repaired and brought back online faster.

[0051] Therefore, embodiments disclosed herein include a test bench apparatus that can be used to individually test the thermal breaks 435 after manufacture. The testing can be done for each thermal break 435 before it is integrated into a plasma processing tool. The test bench can also be provided at the fabrication facility in order to run rapid diagnostics on a tool that is operating out of specification. Embodiments disclosed herein include a method for using the test bench as well.

[0052] In an embodiment, the test bench may comprise a DRA that is coupled to the thermal break 435. The thermal break 435 is then electrically coupled to a vector network analyzer (VNA). By sweeping a voltage through the system, the VNA is able to determine the resonant frequency of the DRA and the impedance at the input of the thermal break 435. These two parameters (and the associated Si i value) can be compared to the performance of a known good device in order to determine if the thermal break 435 is within specification. Accordingly, only known good thermal breaks 435 can be integrated into the tool, or a determination of whether the thermal break 435 is damaged can be rapidly made.

[0053] Referring now to Figure 5 A, a schematic illustration of a thermal break test bench 550 is shown, in accordance with an embodiment. In an embodiment, the test bench 550 may comprise a DRA 515. The DRA 515 may be a single DRA 515. That is, there is no need to couple the thermal break (TB) 535 into a system that includes the plurality of DRAs 515 that will be present in a tool, such as the tools described in greater detail above. Accordingly, a more compact testing solution is provided. In an embodiment, the DRA 515 may be similar to the DRA 115 described in greater detail above.

[0054] In an embodiment, the thermal break 535 is electrically coupled to the DRA 515 and a VNA 552. The VNA 552 is configured to detect the impedance of the thermal break 535 and a resonant frequency of the DRA 515. The VNA 552 may also provide an Si i value for the thermal break 535. As will be described in greater detail herein, these parameters may be used in order to determine if the thermal break 535 is suitable for integration into a tool.

[0055] In an embodiment, the VNA 552 may be communicatively coupled to a computer 551. The computer 551 may comprise software for operating the VNA 552 and extracting the parameters of interest. The computer 551 may be a laptop in some embodiments in order to improve portability of the test bench 550. However, it is to be appreciated that the computer 551 may include any computing system, such as a desktop computer, a server, or the like.

[0056] Referring now to Figure 5B, a schematic illustration of the test bench 550 with the components more clearly illustrated is shown, in accordance with an embodiment. In an embodiment, the VNA 552, the thermal break 535, and the DRA 515 may be arranged in a vertical stack and supported by an underlying surface (e.g., the surface of a table or work bench (not shown)). The thermal break 535 may be electrically coupled to the DRA 515 by solder or the like. For example, the pin (not shown) of the DRA 515 may be soldered to an electrical trace (not shown) within the thermal break 535. In an embodiment, the DRA 515 may comprise a metallic housing (e.g., an aluminum housing) or the like. The DRA 515 may be similar to any of the DRAs described in greater detail herein. Similarly, the thermal break 535 may be similar to any of the thermal breaks described in greater detail herein.

[0057] In an embodiment, the VNA 552 may be directly coupled to the thermal break 535. Though, a coaxial cable may be provided between the VNA 552 and the thermal break 535 in other embodiments. In an embodiment, the VNA 552 may be coupled to the computer 551 through a data and / or electrical cable 557. For example, the cable 557 may comprise a USB cable in some embodiments.

[0058] Referring now to Figures 6A and 6B, a pair of plots are shown that illustrate the parameters of the thermal break that can be extracted by a test bench, such as test bench 550. The data obtained in plots similar to those shown in Figures 6A and 6B can be used to rapidly determine if the thermal break being tested is within specifications.

[0059] Figure 6A is an illustration of the impedance of the thermal break. For example, the impedance may be measured at an input of the thermal break. In Figure 6A, the line 662 illustrates the performance of a known good thermal break. As shown, the impedance peaks at 50 Ohms. This is ideal since it matches the impedance of the DRA to the characteristic impedance of coaxial cabling, and reduces (or eliminates) reflected power. The line 661 illustrates the performance of a thermal break under test. Here, the line 661 has a peak that is above the target of 50 Ohms. As such, there will be an impedance mismatch with the coaxial cable, and reflected power increases. Additionally, it is shown that the resonant frequency of the DRA when the known good thermal break is used is different than the resonant frequency of the DRA when the tested thermal break is used.

[0060] Figure 6B is a plot of the Si i value of the test bench. Line 664 is a plot of the Si i value of the known good thermal break, and line 663 is a plot of the Si i value of the thermal break that is being tested. As shown, the minimum of line 664 is deeper than the minimum of line 663. In the case of the S 11 value, a deeper trough indicates a reduction in reflected power. For example, the minimal value (deep trough) of Sil of line 664 is approximately -30 dB, which means the reflected power is 0W. While for line 663, the minimal value of its Si l is approximately -15dB, which indicates the power reflection is approximately 3%. Furthermore, a resonant frequency of the line 663 is below minimal operation frequency 2,400MHz. Accordingly, the thermal break being tested is out of specification.

[0061] In an embodiment, the determination of a thermal break being “out of specification”, “defective”, “damaged”, “underperforming”, and / or the like may be made in view of a comparison of one or more parameters to the similar parameters of a known good thermal break. These parameters may include one or more of an impedance of the thermal break, a resonant frequency of the DRA, or an Si i value. In the case of impedance, a target value for the impedance may be equal to the characteristic impedance of the coaxial cables used in the system. For example, the target impedance may be approximately 50 Ohms. Though, higher or lower targets may be set for the impedance in other embodiments. In an embodiment, a thermal break within specification may include an impedance that is within ±20% of the reference impedance, within ±10% of the reference impedance, within ±5% of the reference impedance, or within ±1% of the reference impedance. With respect to resonant frequency, the tested thermal break may be within specification when the resonant frequency of the DRA is within ±10MHz of the reference resonant frequency, within ±5MHz of the reference resonant frequency, or within ±lMHz of the reference resonant frequency. For example, the reference resonant frequency may be around 2,400MHz, or may be around 2450MHz in some embodiments. In an embodiment, the reference S 11 absolute value may be greater than 5, greater than 10, or greater than 15. If the Sn absolute value of the tested thermal break is lower than the reference Sn absolute value, then the thermal break may be considered out of specification.

[0062] Referring now to Figure 7, a process flow diagram of a process 770 for testing a thermal break in a test bench is shown, in accordance with an embodiment. In an embodiment, the thermal break may be similar to any of the thermal breaks described in greater detail herein. The test bench may also be similar to any of the test benches described in greater detail herein. In an embodiment, the process 770 may be implemented after the thermal break has been manufactured, but before integration into a tool. Accordingly, only known good thermal breaks will be integrated into the tool. In other embodiments, the process 770 is implemented to diagnose a potentially defective thermal break that is pulled from a tool. That is, the tool may indicate a high reflected power, and the process 770 is used to determine if the reflected power is attributable to damage of the thermal break.

[0063] In an embodiment, the process 770 may begin with operation 771, which comprises assembling a test bench for analysis of a thermal break. In an embodiment, the test bench comprises a DRA, a thermal break, a VNA, and a computer. The computer may be a laptop that comprises VNA software in order to implement the testing process.

[0064] In an embodiment, the process 770 continues with operation 772, which comprises sweeping a frequency between a start frequency and a stop frequency. The frequency sweep is applied to the thermal break and the DRA in order to determine how they react to the different frequencies. In an embodiment, the start frequency and the stop frequency may have any suitable range that includes an expected resonant frequency of the DRA. For example, when the expected resonant frequency is approximately 2,400MHz, the start may be 2,000MHz and the stop frequency may be 3,000MHz. Though, wider or narrower frequency sweeps may be used in other embodiments. In an embodiment, the process 770 may continue with operation 773, which comprises detecting a resonant frequency of the DRA and an impedance at an input of the thermal break. The resonant frequency and the impedance may be plotted on a graph similar to the graph shown in Figure 6A. The operation 773 may also comprise detecting an Sn value similar to the plot shown in the graph of Figure 6B.

[0065] In an embodiment, the process 770 may continue with operation 774, which comprises comparing the resonant frequency and the impedance to parameters of a known good thermal break. The S 11 value may also be compared in some embodiments. The parameters of the known good thermal break may be the ideal values of a perfect thermal break (i.e., a golden unit). That is, an ideal impedance, an ideal resonant frequency, and / or an ideal Sn value may be compared against the performance of the thermal break being tested.

[0066] In an embodiment, the comparison may result in a pass or fail of the thermal break under test. A passing result will occur when the parameters of the thermal break under test are all within a given threshold of the reference values of a known good unit (or a golden unit). For example, the thermal break may pass testing when the impedance is within a certain percentage of the reference impedance (e.g., 50 Ohms), the resonant frequency is within a particular range of the reference resonant frequency (e.g., 2,400MHz), and the Sn value is greater than a reference Si i value (e.g., greater than 5). In an embodiment, if one or more of impedance, resonant frequency, or S 11 value fall outside of specification, then the thermal break is considered out of specification and will not be integrated into a tool.

[0067] Referring now to Figure 8, a block diagram of an exemplary computer system 800 of a processing tool is illustrated in accordance with an embodiment. In an embodiment, computer system 800 is coupled to and controls processing in the processing tool. Computer system 800 may be connected (e.g., networked) to other machines in a Local Area Network (LAN), an intranet, an extranet, or the Internet. Computer system 800 may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer- to-peer (or distributed) network environment. Computer system 800 may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated for computer system 800, the term “machine” shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies described herein.

[0068] Computer system 800 may include a computer program product, or software 822, having a non- transitory machine-readable medium having stored thereon instructions, which may be used to program computer system 800 (or other electronic devices) to perform a process according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine- readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0069] In an embodiment, computer system 800 includes a system processor 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory 818 (e.g., a data storage device), which communicate with each other via a bus 830.

[0070] System processor 802 represents one or more general-purpose processing devices such as a microsystem processor, central processing unit, or the like. More particularly, the system processor may be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. System processor 802 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal system processor (DSP), network system processor, or the like. System processor 802 is configured to execute the processing logic 826 for performing the operations described herein.

[0071] The computer system 800 may further include a system network interface device 808 for communicating with other devices or machines. The computer system 800 may also include a video display unit 810 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 816 (e.g., a speaker).

[0072] The secondary memory 818 may include a machine-accessible storage medium 831 (or more specifically a computer-readable storage medium) on which is stored one or more sets of instructions (e.g., software 822) embodying any one or more of the methodologies or functions described herein. The software 822 may also reside, completely or at least partially, within the main memory 804 and / or within the system processor 802 during execution thereof by the computer system 800, the main memory 804 and the system processor 802 also constituting machine-readable storage media. The software 822 may further be transmitted or received over a network 861 via the system network interface device 808. In an embodiment, the network interface device 808 may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.

[0073] While the machine- accessible storage medium 831 is shown in an exemplary embodiment to be a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store the one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media.

[0074] In the foregoing specification, specific exemplary embodiments have been described. It will be evident that various modifications may be made thereto without departing from the scope of the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Claims

CLAIMSWhat is claimed is:

1. A method for testing a thermal break, comprising: sweeping a frequency between a start frequency and a stop frequency with a vector network analyzer (VNA) on a test bench that comprises a dielectric resonator antenna (DRA) and the thermal break electrically coupled to the VNA; detecting a resonant frequency of the DRA and an impedance at an input of the thermal break; and comparing the resonant frequency and the impedance to a reference resonant frequency and a reference impedance of a known good thermal break.

2. The method of claim 1, wherein the start frequency is 2,000MHz and the stop frequency is 3,000MHz.

3. The method of claim 1, wherein the VNA is communicatively coupled to a computer.

4. The method of claim 1, wherein the DRA comprises: a dielectric puck with a hole into a top surface of the dielectric puck; and a pin inserted into the hole, wherein the pin is electrically conductive.

5. The method of claim 4, wherein the pin is electrically coupled to the thermal break.

6. The method of claim 1, wherein the thermal break is a quarter- wavelength impedance transformer.

7. The method of claim 1, wherein the thermal break fails the testing when the impedance is at least ±10% different than the reference impedance.

8. The method of claim 1, wherein the thermal break fails the testing when the resonant frequency is within at least ±10MHz compared to the reference resonant frequency.

9. The method of claim 1 , wherein the testing is done after the thermal break is manufactured and before being integrated into a tool.

10. The method of claim 1, wherein the testing is done after the thermal break was integrated into a tool.

11. An apparatus, comprising: a dielectric resonator antenna (DRA); a thermal break electrically coupled to the DRA; a vector network analyzer (VNA) electrically coupled to the thermal break; and a computer electrically coupled to the VNA.

12. The apparatus of claim 11, wherein the DRA, the thermal break, and the VNA are arranged in a vertical stack.

13. The apparatus of claim 11, wherein the computer is a laptop, and wherein the laptop is coupled to the VNA by a USB cable.

14. The apparatus of claim 11, wherein the DRA is surrounded by an electrically conductive housing.

15. The apparatus of claim 14, wherein the DRA comprises: a dielectric puck with a hole into a top surface of the dielectric puck; and a pin inserted into the hole, wherein the pin is electrically conductive.

16. The apparatus of claim 15, wherein the pin is electrically coupled to the thermal break.

17. A method for testing a thermal break, comprising: sweeping a frequency between a start frequency and a stop frequency with a vector network analyzer (VNA) on a test bench that comprises a dielectric resonator antenna (DRA) and the thermal break electrically coupled to the VNA; detecting a resonant frequency of the DRA, an impedance at an input of the thermal break, and an Sn value; and comparing the resonant frequency, the impedance, and the S 11 value to a reference resonant frequency, a reference impedance, and a reference Sn value of a known good thermal break.

18. The method of claim 17, wherein the thermal break fails the testing if one or more of the resonant frequency is more than ±10MHz different than the reference resonant frequency, the impedance is ±10% or more different than the reference impedance, or the Sn value is below 5.

19. The method of claim 17, wherein the start frequency is 2,000MHz and the stop frequency is 3,000MHz.

20. The method of claim 17, wherein the thermal break is a quarter-wavelength impedance transformer.

Images