Apparatus and method for breakdown measurement with overcurrent protection

Abstract

An apparatus for performing a breakdown measurement of a DUT includes a power amplifier configured to amplify a voltage of an input signal to provide an amplified signal, wherein the power amplifier includes a decoupling capacitance; a current suppression circuit including a current suppression resistance and a bypass switch; a voltage and current sense circuit configured to receive the amplified signal, apply the amplified signal as a DUT signal to a DUT and measure a voltage and / or a current of the DUT signal; and a controller configured to determine a current of the DUT signal based on the measured current and / or voltage of the DUT signal received from the voltage and current sense circuit, and automatically control operation of the bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current does not exceed a predetermined maximum current value.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Application No. 63 / 779,849, filed March 28, 2025, pursuant to 35 USC § 119(e). The entire disclosure of U.S. Provisional Application No. 63 / 779,849 is expressly incorporated herein by reference in its entirety. Background Technology

[0002] In semiconductor research and manufacturing, the breakdown voltage of the dielectric and the breakdown voltage of the PN junction determine the operating range of semiconductor devices. These values, known as "breakdown voltages," are crucial for evaluating semiconductor characteristics.

[0003] A common method for breakdown measurements uses a source measurement unit (SMU). An SMU is an electronic instrument that applies voltage or current to a device under test (DUT) while simultaneously measuring the current or voltage, and is widely used for evaluating semiconductor characteristics. However, while an SMU can apply and measure DC signals, it cannot apply and measure fast-response signals. Therefore, when measuring fast-response phenomena such as breakdown that cause short circuits in the DUT, the SMU's output signal control cannot keep up with the rapid load changes associated with the DUT's breakdown. Consequently, the SMU continues to apply overcurrent or overvoltage for a sufficient period, damaging the DUT, DUT contact pads and / or terminals, and probes. Damage to probes may include, for example, damage to probe clips and contact pads, necessitating probe clip repair or wafer discard.

[0004] To avoid such problems, a conventional method has been proposed to insert a resistor or inductor between the output of the measuring instrument and the DUT to limit the current flowing to the DUT. However, when a resistor is inserted, the resistor causes a voltage drop due to the DUT current, resulting in a significant error between the applied voltage and the set voltage when the DUT current is large.

[0005] When an inductor is inserted, the DC voltage from the SMU can be correctly applied. However, in general semiconductor evaluation, for example, it is sometimes necessary to use measurement instruments other than the SMU, such as a pulse generator, to evaluate AC characteristics. Here, the path between the pulse generator and the DUT partially overlaps with the SMU measurement path. Therefore, if the inductor is placed on the pulse generator measurement path, the AC signal output from the pulse generator cannot be correctly applied to the DUT. Consequently, it is impossible to measure breakdown and other characteristics on the same path. Therefore, it is necessary to prepare paths with and without current-limiting elements and switch between these paths during measurement, which complicates the measurement setup for semiconductor characteristic evaluation (including breakdown measurement) and increases the overall measurement time due to signal path switching. These problems exist not only in semiconductors but also in any material where breakdown occurs.

[0006] More specifically, excessive current can be prevented by inserting a resistor between the SMU output and the DUT. However, while such a current-limiting resistor is necessary for breakdown measurements, it hinders SMU operation when measuring other characteristics. Therefore, in older products, users had to manually attach and remove the resistor, which was time-consuming and labor-intensive. In relatively newer products, a switch has been implemented to bypass this resistor, allowing the resistor bypass to be enabled or disabled during the measurement procedure. However, this adds the task of turning the bypass on or off depending on the measurement item, and there is a risk that the user might forget to enable current limiting during breakdown measurements. Additionally, placing the current-limiting element and its switch within or closer to the DUT in the voltage and current sensing circuitry can degrade the performance of small current measurements due to leakage current. Using a protected reed switch can ensure small current performance, but since the on / off switching time is typically on the order of milliseconds, a protected reed switch can reduce overall measurement throughput. In any case, the voltage drop caused by the current-limiting element cannot be avoided, resulting in errors in the applied voltage.

[0007] Alternatively, a device protection circuit can be implemented between the measuring instrument and the DUT. Because the device protection circuit is added to the output of the measuring instrument for current sensing and measurement, its impedance cannot be ignored when performing measurements other than those involving breakdown. This impedance can interfere with the characteristics of the AC signal and cause errors between the applied voltage and the measured voltage. To avoid this, the user must manually attach and remove the device protection circuit as needed. However, this also introduces the possibility of errors, such as forgetting to attach or remove the device protection circuit.

[0008] Therefore, what is needed is an electronic circuit and method that avoids problems such as probe, contact pad, or terminal damage caused by overcurrent that may occur during breakdown measurement without increasing the complexity of the setup or affecting the characteristics of the measurement path shared with other measurement resources. Attached Figure Description

[0009] When with attachment Figure 1 When reading this document, the exemplary embodiments are best understood from the following detailed description. It should be emphasized that the various features are not necessarily drawn to scale. In fact, dimensions may be arbitrarily increased or decreased for clarity of discussion. Where applicable and practicable, the same reference numerals refer to the same elements.

[0010] Figure 1 This is a simplified circuit diagram of a conventional device for performing breakdown measurements without overcurrent protection.

[0011] Figure 2A This is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection, based on a representative implementation scheme.

[0012] Figure 2B It is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection according to a representative embodiment, including current flow.

[0013] Figure 3A This is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection, based on a representative implementation scheme.

[0014] Figure 3B It is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection according to a representative embodiment, including current flow.

[0015] Figure 4 It is a simplified block diagram of a controller configured to control overcurrent protection according to a representative implementation scheme.

[0016] Figure 5 This is a simplified circuit diagram of the apparatus setup used to determine the damage to contact pads caused by capacitor discharge.

[0017] Figure 6A This is an image of damage to the pads of the DUT caused by excessive current, which can be prevented by the implementation method described in this article.

[0018] Figure 6B It is a trace of the current waveform that indicates a current spike indicating excessive current, which can be prevented by the implementation described herein.

[0019] Figure 7This is a flowchart of a method for performing breakdown measurements with overcurrent protection, based on a representative implementation scheme. Detailed Implementation

[0020] In the following detailed description, representative embodiments with specific details are illustrated for illustrative purposes rather than limiting, in order to provide a thorough understanding of embodiments according to this teaching. Descriptions of known systems, apparatuses, materials, methods of operation, and methods of manufacture may be omitted to avoid obscuring the description of representative embodiments. Nevertheless, systems, apparatuses, materials, and methods within the knowledge of those skilled in the art are also within the scope of this teaching and can be used according to representative embodiments. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The defined terminology is supplementary to the technical and scientific meaning of the defined terminology as commonly understood and accepted in the art field of this teaching.

[0021] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are used only to distinguish one element or component from another. Therefore, without departing from the teachings of this disclosure, the first element or component discussed below may be referred to as the second element or component.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the specification and appended claims, the singular forms of the terms “a,” “an,” and “the” are intended to include both singular and plural forms unless the context clearly specifies otherwise. Additionally, when used herein, the terms “comprises” and / or “comprising” and / or similar terms indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0023] Unless otherwise stated, when an element or component is referred to as being “connected to,” “coupled to,” or “proximity to” another element or component, it will be understood that the element or component may be directly connected to or coupled to the other element or component, or that there may be intermediary elements or components. That is, these and similar terms cover situations where one or more intermediate elements or components may be used to connect two elements or components. However, when an element or component is referred to as being “directly connected” to another element or component, this only covers situations where the two elements or components are connected to each other without any intermediate or intermediary elements or components.

[0024] As illustrated in the accompanying drawings, relational terms such as “above,” “below,” “top,” “bottom,” “upper,” and “lower” can be used to describe the relationship between various elements and each other. In addition to the orientations depicted in the drawings, these relational terms are also intended to cover different orientations of the device and / or elements. For example, if the device is inverted relative to the view in the drawings, an element described as being “above” another element will now be “below” that element. Similarly, if the device is rotated 90° relative to the view in the drawings, an element described as being “above” or “below” another element will now be “adjacent” to that other element; where “adjacent” means adjacent to another element, or that there are one or more layers, materials, structures, etc., between these elements.

[0025] Therefore, this disclosure is intended to demonstrate one or more advantages specifically pointed out below through its various aspects, embodiments, and / or specific features or sub-components. Exemplary embodiments with specific details disclosed are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of embodiments implemented according to this teaching. However, other embodiments consistent with this disclosure but departing from the specific details disclosed herein remain within the scope of the appended claims. Furthermore, descriptions of well-known devices and methods may be omitted so as not to obscure the description of the exemplary embodiments. Such methods and devices are within the scope of this disclosure.

[0026] Typically, the implementation described herein provides continuous performance of breakdown measurements and other characteristic measurements without requiring user intervention to change measurement settings. Switching to accommodate different measurements is automatic, preventing user setup errors. Furthermore, switching does not interfere with the impedance of measurement paths for equipment other than the SMU (Signal Unit), such as pulse generators. In analog circuitry, the applied voltage and the measured voltage are always matched, eliminating the need for voltage drop correction calculations. Moreover, the implementation avoids measurement performance degradation due to leakage current in the switch (a problem with conventional methods) and allows the use of switching elements that are more durable and have faster switching times than, for example, protected reed switches.

[0027] According to a representative embodiment, an apparatus is provided for performing a breakdown measurement of a device under test (DUT). The apparatus includes: a power amplifier configured to amplify a voltage of an input signal to provide an amplified signal, wherein the power amplifier includes a decoupling capacitor; a current suppression circuit coupled to the power amplifier to receive the amplified signal, wherein the current suppression circuit includes a bypass switch; a voltage and current sensing circuit coupled to the current suppression circuit to receive the amplified signal and apply the amplified signal as a DUT signal to the DUT, wherein the voltage and current sensing circuit is configured to measure at least one of a voltage or current of the DUT signal and is positioned after the current suppression circuit; and a controller configured to determine a current of the DUT signal passing through the DUT based on at least one of the measured current or voltage of the DUT signal received from the voltage and current sensing circuit, and to automatically control the operation of the bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current of the DUT signal does not exceed a predetermined maximum current value.

[0028] According to another representative embodiment, a method for performing a breakdown measurement of a device under test (DUT) is provided. The method includes: amplifying the voltage of an input signal using a power amplifier to provide an amplified signal to a voltage and current sensing circuit; applying the amplified signal as a DUT signal to the DUT, and determining the current of the DUT signal using the voltage and current sensing circuit; comparing the determined current of the DUT signal with a predetermined maximum current value; when the current of the DUT signal does not exceed the predetermined maximum current value, automatically and selectively connecting a current suppression resistor to the power amplifier to suppress the current of the amplified signal, and performing a breakdown measurement of the DUT using the suppressed current; and when the current of the DUT signal exceeds the predetermined maximum current value, automatically and selectively disconnecting the current suppression resistor from the power amplifier to avoid suppressing the current of the amplified signal, and performing measurements of the DUT other than the breakdown measurement using the unsuppressed current.

[0029] According to another representative embodiment, an apparatus for performing breakdown measurements of a device under test (DUT) is provided. The apparatus includes: a current suppression circuit coupled between a power amplifier and voltage and current sensing circuits, wherein the current suppression circuit is configured to receive an amplified signal output from the power amplifier as a DUT signal output to the DUT, wherein the current suppression circuit includes a bypass switch and a current suppression resistor connected in parallel with the bypass switch; and a controller configured to determine a current through the DUT signal based on at least one of the current or voltage of the DUT signal measured by the voltage and current sensing circuits, and to automatically control the operation of the bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current of the DUT signal does not exceed a predetermined maximum current value.

[0030] Figure 1 This is a simplified circuit diagram of a conventional device for performing breakdown measurements without overcurrent protection. (Reference) Figure 1 The device 100 may be, for example, an SMU for performing measurements (including breakdown measurements) on the DUT 160. The device 100 includes a power amplifier 110, a ground power supply 105, a floating power supply 120, and voltage and current sensing circuitry 140 for measuring the voltage and current of the DUT 160. The ground power supply 105 is indicated as DC voltage sources 105A and 105B connected to ground. DC voltage sources 105A and 105B provide a positive supply voltage to the positive terminal 116 and a negative supply voltage to the negative terminal 117 of the power amplifier 110, respectively. The power supply 120 is indicated as DC voltage sources 120A and 120B connected to the output of the power amplifier 110, wherein DC voltage sources 120A and 120B provide a positive supply voltage to the positive terminal 116 and a negative supply voltage to the negative terminal 117 of the power amplifier 110, respectively. The power amplifier 110 includes an internal decoupling capacitor 115 indicated by a first decoupling capacitor 111 and a second decoupling capacitor 112.

[0031] As shown in the figure, device 100 does not provide a resistor to suppress the current discharged from the first decoupling capacitor 111 and the second decoupling capacitor 112. That is, considering the current discharge during breakdown, when measuring the breakdown voltage of DUT 160, device 100 gradually increases the output voltage until it reaches the breakdown voltage of DUT 160. When the output voltage of device 100 reaches the breakdown voltage, breakdown occurs, and the impedance of DUT 160 drops sharply. At this time, the charge stored in the first decoupling capacitor 111 and the second decoupling capacitor 112 of power amplifier 110 is rapidly discharged and flows through the output of power amplifier 110, power supply 120, and voltage and current sensing circuit 140, eventually reaching DUT 160. Because there are no components that obstruct this discharge path from the first decoupling capacitor 111 and the second decoupling capacitor 112 to DUT 160, a large amount of charge flows out unimpeded in a short period of time. Therefore, during breakdown, excessive current may be immediately applied to DUT 160, the contact pads of DUT 160, and the probes 165 contacting DUT 160, potentially damaging or destroying them. Unrestricted current flow is indicated by arrows I11, I12, I13, and I14 originating from the first decoupling capacitor 111 and the second decoupling capacitor 112 of power amplifier 110, and terminates unrestricted at DUT 160 after passing through device 100, as indicated by arrow I15.

[0032] As mentioned above, a conventional current-limiting circuit can be implemented in device 100 (e.g., SMU), which will be placed between voltage and current sensing circuit 140 and DUT 160. However, the current-limiting circuit generates leakage current (especially in the switching elements), which directly leads to an error between the current value measured by device 100 and the actual current flowing to DUT 160. To mitigate this, low-leakage switching elements, such as protected reed switches, can be used in the current-limiting circuit, as discussed above. However, such low-leakage switching elements have undesirable trade-offs, such as shorter lifespan, longer switching times (which increase overall test time), and involve increased implementation area and cost.

[0033] Figure 2A This is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection, based on a representative implementation. (Reference) Figure 2AThe device 200 may be, for example, an SMU for performing measurements (including breakdown measurements) on the DUT 260. The device 200 includes a power amplifier 210, a ground power supply 205, a current suppression circuit 230, voltage and current sensing circuitry 240 for measuring the voltage and current of the DUT 260, and a controller 245 for controlling the current suppression circuitry 230, in part based on the measured current. The device 200 may further include a pulse generator 250 and a switch 255, the switch being used to selectively connect the pulse generator 250 to the DUT 260 for performing other types of measurements on the DUT 260 besides breakdown measurements. The pulse generator 250 may be configured to generate pulses supplied to the DUT 260 and measure the DUT 260's response to the pulses when the pulse generator 250 is connected to the DUT 260 via the switch 255. For example, DUT 260 may be a field-effect transistor (FET), in which case voltage and current sensing circuitry 240 and / or pulse generator 250 can be used to measure characteristics such as gate threshold voltage, gate leakage current, ON-drain current, and OFF-drain current. Alternatively, pulse generator 250 and switch 255 may be separate from device 200 but still included in the test. Without departing from the scope of this teaching, other types of test instruments may be selectively connected to DUT 260, in addition to or instead of pulse generator 250, to enable various types of measurements. Non-limiting examples of other types of test instruments that may be connected to DUT 260 include impedance meters and digital multimeters (DMMs).

[0034] Grounding power supply 205 is indicated as DC voltage source 205A and DC voltage source 205B connected to ground, which respectively provide a positive supply voltage to the positive terminal 216 and a negative supply voltage to the negative terminal 217 of power amplifier 210. Power amplifier 210 is configured to take an input signal and amplify the voltage of the input signal to provide an amplified signal to be output to DUT 260. Power amplifier 210 may be a voltage amplifier including an internal decoupling capacitor 215 indicated as a first decoupling capacitor 211 and a second decoupling capacitor 212. Decoupling capacitor 215 supplies current during transient signals and suppresses power supply noise from being transmitted to the output of device 200.

[0035] The current suppression circuit 230 is located between the output of the power amplifier 210 and the input of the voltage and current sensing circuit 240, and is configured to selectively limit the current flowing from the power amplifier 210 to the DUT 260 while performing a breakdown measurement. Therefore, the current suppression circuit 230 does not interfere with the current or voltage measurements of the DUT 260 performed by the voltage and current sensing circuit 240. Similarly, even when used with another instrument (such as the pulse generator 250) sharing a measurement path, the current suppression circuit 230 does not disrupt the characteristics of that measurement path.

[0036] In the depicted embodiment, the current suppression circuit 230 includes a current suppression resistor 235 indicated by resistor 231. The current suppression circuit 230 further includes a bypass switch 234, which is operable under the control of a controller 245 discussed below to selectively connect a shunt 239 in parallel with the current suppression resistor 235 to bypass the current suppression resistor 235. In the depicted embodiment, when the bypass switch 234 is closed, the shunt 239 is connected between the terminals of the resistor 231, thereby bypassing the resistor. When the bypass switch 234 is open, the shunt 239 is removed and the current output by the power amplifier 210 is suppressed by resistor 231. Throughout this disclosure, "suppressed" means a reduction in current (e.g., a reduction to an amount that avoids damage to the DUT 260, one or more DUT contact pads, and / or probes 265) but not a complete halt.

[0037] As will be apparent to those skilled in the art, the voltage and current sensing circuit 240 can be implemented by any compatible circuit capable of measuring the voltage and current provided by the device 200. The voltage and current sensing circuit 240 is configured to receive an amplified signal from the power amplifier 210, apply the amplified signal as a DUT signal to the DUT 260, and measure the voltage and current of the DUT signal passing through the DUT 260. The voltage and / or current measurements are output by the voltage and current sensing circuit 240 to a controller 245, which is configured to monitor the current of the DUT 260 and selectively switch the current suppression resistor 235 into or out of the circuitry of the device 200, at least in part, based on the value of the monitored current. When the current exceeds a predetermined maximum current value (current threshold), the controller 245 closes (activates) the bypass switch 234, causing the current suppression resistor 235 to be bypassed by the shunt 239 connected in parallel with the resistor 231. In this case, the current from the amplified signal of the power amplifier 210 is not suppressed and is output to the DUT 260 as a DUT signal. When the current does not exceed the predetermined maximum current value (current threshold), the controller 245 opens (disables) the bypass switch 234, causing the current suppression resistor 235 to be connected to the output terminal of the power amplifier 210, thereby placing the resistor 231 of the current suppression resistor 235 in the path of the signal output by the power amplifier 210. In this case, the current from the amplified signal of the power amplifier 210 is suppressed and is output to the DUT 260 as a DUT signal.

[0038] Typically, measuring the current supplied to the DUT 260 and performing a switching operation based on the measured current is much slower than the occurrence of a breakdown in the DUT 260 and the subsequent flow of surge current. Therefore, after the breakdown current begins to flow, there is insufficient time to enable the current limiting function by opening the bypass switch 234. Thus, the bypass switch 234 is set to the desired bypass state before breakdown begins. In this scenario, the DUT 260 typically has high resistance before breakdown, resulting in a lower current flowing from the device 200. Therefore, when the current value of the DUT signal determined by the controller 245 is less than (does not exceed) a predetermined maximum current value, there is a possibility that a breakdown measurement is being performed, and the current limiting function should be enabled by opening the bypass switch 234 to anticipate breakdown. Otherwise, when the current value of the DUT signal is greater than (exceeds) a predetermined maximum current value (indicating medium or low resistance), it can be assumed that no breakdown measurement is being performed, and therefore the bypass switch 234 can be closed, thereby bypassing the current suppression resistor.

[0039] Figure 2B It is based on a representative implementation scheme for performing breakdown measurements with overcurrent protection. Figure 2AA simplified circuit diagram of the device, including current flow. (Reference) Figure 2B The above reference shows... Figure 2A The described device 200, in which the bypass switch 234 is in the open position, enables current suppression via the current suppression circuit 230, for example, during the discharge of the first decoupling capacitor 211 and the second decoupling capacitor 212 of the power amplifier 210. Therefore, the suppression resistor 231 is switched into the discharge path by the controller 245 for performing a breakdown measurement. Thus, for example, compared to the conventional device 100, the current flows gradually over a longer period, thereby avoiding rapid discharge. This prevents damage and / or destruction of the DUT 260 and its contact pads in the event of a breakdown. The suppressed current flow is indicated by arrows I21 and I22 originating from the power amplifier 210 (including the first decoupling capacitor 211 and the second decoupling capacitor 212), indicating the suppressed current flow originating from the power amplifier 210 and passing through the resistor 231 of the current suppression circuit 230 to the DUT 260.

[0040] Figure 3A This is a simplified circuit diagram of a device for performing breakdown measurements with overcurrent protection, based on a representative implementation. (Reference) Figure 3A The device 300 may be, for example, an SMU for performing measurements (including breakdown measurements) on the DUT 160. The device 300 includes a power amplifier 210, a ground power supply 205, a floating power supply 320, a current suppression circuit 330, voltage and current sensing circuitry 240 for measuring the voltage and current of the DUT 260, and a controller 245 for controlling the current suppression circuitry 330, in part based on the measured current. The device 300 may further include a pulse generator 250 and a switch 255 for selectively connecting the pulse generator 250 to the DUT 260 for performing other types of measurements on the DUT 260 besides breakdown measurements, as discussed above.

[0041] Ground power supply 205 is indicated as DC voltage source 205A and DC voltage source 205B connected to ground, which respectively provide a positive supply voltage to the positive terminal 216 and a negative supply voltage to the negative terminal 217 of power amplifier 210. Floating power supply 320 is indicated as DC voltage source 320A and DC voltage source 320B, which also respectively provide a positive supply voltage to the positive terminal 216 and a negative supply voltage to the negative terminal 217 of power amplifier 210. As discussed above, power amplifier 210 is configured to take an input signal and amplify the voltage of the input signal to provide an amplified signal to be output to DUT 260. Power amplifier 210 may be a voltage amplifier including an internal decoupling capacitor 215 indicated as a first decoupling capacitor 211 and a second decoupling capacitor 212. As mentioned above, decoupling capacitor 215 supplies current during transient signals and suppresses power supply noise from being transmitted to the output of device 300.

[0042] A current suppression circuit 330 is positioned between the output of the power amplifier 210 and the input of the voltage and current sensing circuit 240, and is configured to selectively limit the current flowing from the power amplifier 210 to the DUT 260. As mentioned above regarding the current suppression circuit 230, due to its placement prior to the voltage and current sensing circuit 240, it does not interfere with current or voltage measurements of the DUT 260 performed by the voltage and current sensing circuit 240, or with measurements performed by other instruments, such as the pulse generator 250. The current suppression circuit 330 includes a current suppression resistor 335 and a capacitor 338, as discussed below. In the depicted embodiment, the current suppression resistor 335 is indicated as a first resistor 331, a second resistor 332, and a third resistor 333, and the capacitor 338 is indicated by a first capacitor 336 and a second capacitor 337. The current suppression circuit 330 further includes a bypass switch 334, which is operable under the control of the controller 245 discussed below to selectively connect the shunt 339 in parallel with the current suppression resistor 335 to bypass the current suppression resistor 335. Specifically, in the depicted embodiment, when the bypass switch 334 is closed, the shunt 339 is connected between the terminals of the resistor 331, thereby bypassing the first resistor 331. When the bypass switch 334 is open, the shunt 339 is removed and the current output by the power amplifier 210 is suppressed by the first resistor 331, the second resistor 332, and the third resistor 333. The ground power supply 205 is indicated as DC voltage sources 205A and 205B connected to ground, which respectively provide a positive supply voltage to the positive terminal 216 and a negative supply voltage to the negative terminal 217 of the power amplifier 210. The floating power supply 320 is designated as DC voltage source 320A and DC voltage source 320B, which also provide positive power supply to the positive terminal 216 of the power amplifier 210 and negative power supply to the negative terminal 217, respectively.

[0043] like Figure 3A As shown, referencing the output voltage of power amplifier 210, DC voltage sources 320A and 320B apply positive and negative power supply voltages to the positive and negative terminals 216 and 217 of power amplifier 210, respectively. The power supply path can also become a path for excessive current flow; therefore, when bypass switch 334 is closed, the second resistor 332 and the third resistor 333 of current suppression resistor 335 are also placed in this path. Specifically, the second resistor 332 is connected between DC voltage source 320A and the positive terminal 216 of power amplifier 210, and the third resistor 333 is connected between DC voltage source 320B and the negative terminal 217 of power amplifier 210.

[0044] When current flows through the second resistor 332 and the third resistor 333, the positive and negative power supply voltages supplied to the power amplifier 210 may change suddenly, potentially adversely affecting the operation of the power amplifier 210 and the device 300. To address this issue, the current suppression circuit 330 further includes a capacitor 338 to form an RC filter together with the first resistor 331, the second resistor 332, the third resistor 333, and the bypass switch 334 to stabilize the power supply voltage and maintain the normal operation of the power amplifier 210. As mentioned above, the capacitor 338 is indicated by the first capacitor 336 and the second capacitor 337, wherein the first capacitor 336 is coupled between the second resistor 332 and the output terminal of the power amplifier 210, and the second capacitor 337 is coupled between the third resistor 333 and the output terminal of the power amplifier 210. In various implementations, for example, the values ​​of the first resistor 331, the second resistor 332, and the third resistor 333 can range from about 10 ohms to about 10 kiloohms, although the resistance values ​​can vary to provide unique benefits for any particular situation or to meet application-specific design requirements of various implementations. Generally, as will be apparent to those skilled in the art, the maximum permissible resistance value can be calculated by determining the maximum current that may flow during normal operation and the maximum permissible voltage drop that will not affect normal operation.

[0045] As discussed above, voltage and / or current measurements are output by voltage and current sensing circuit 240 to controller 245, which is configured to monitor the current of DUT 260 and selectively switch current suppression resistor 335 into or out of the circuitry of device 300, at least in part, based on the value of the monitored current. When the DUT current exceeds a predetermined maximum current value (current threshold), controller 245 closes bypass switch 334, causing current suppression resistor 335 to be bypassed by shunt 339 connected in parallel with first resistor 331. In this case, the current from the amplified signal of power amplifier 210 is not suppressed and is output to DUT 260 as a DUT signal. When the current does not exceed a predetermined maximum current value (current threshold), the controller 245 disconnects the bypass switch 334, causing the current suppression resistor 335 to be connected to the output of the power amplifier 210. This places the first resistor 331, the second resistor 332, and the third resistor 333 of the current suppression resistor 335 in the path of the signal output from the power amplifier 210. In this situation, the current from the amplified signal of the power amplifier 210 is suppressed and output as a DUT signal to the DUT 260, thereby protecting the DUT 260, one or more DUT contact pads, and probes 265.

[0046] Figure 3BIt is based on a representative implementation scheme for performing breakdown measurements with overcurrent protection. Figure 3A A simplified circuit diagram of the device, including current flow. (Reference) Figure 3B The above reference shows... Figure 3A The described device 300, in which the bypass switch 334 is in the open position, enables current suppression via the current suppression circuit 330, for example, during the discharge of the first decoupling capacitor 211 and the second decoupling capacitor 212 of the power amplifier 210. As discussed above, when the output voltage of device 300 reaches the breakdown voltage of DUT 160, the impedance of DUT 260 drops sharply, and the charge in the first decoupling capacitor 211 and the second decoupling capacitor 212 discharges rapidly through DUT 260, potentially damaging it. However, the first resistor 331, the second resistor 332, and the third resistor 333 of the current suppression circuit 330 are switched into the discharge path by the controller 245, which disconnects the bypass switch 334 to perform a breakdown measurement. For example, compared to conventional device 100, disconnecting the bypass switch 334 results in a more gradual current flow over a longer period and avoids rapid discharge. This prevents damage and / or destruction of DUT 160 and its contact pads.

[0047] The suppressed current flow is indicated by arrows originating from power amplifier 210 (including first decoupling capacitor 211 and second decoupling capacitor 212). Specifically, arrows I31 and I32 indicate suppressed current flow originating from first decoupling capacitor 211 and second decoupling capacitor 212 and flowing from the output of power amplifier 210 through first resistor 331 to DUT 260. Arrows I33 and I34 indicate suppressed current flow originating from first decoupling capacitor 211 and second decoupling capacitor 212 and flowing from the positive terminal 216 and negative terminal 217 of power amplifier 210, respectively, through first capacitor 336 and second capacitor 337, through first resistor 331 to DUT 260. Arrows I35 and I36 indicate suppressed current flow originating from the first decoupling capacitor 211 and the second decoupling capacitor 212 and flowing from the positive terminal 216 and the negative terminal 217 of the power amplifier 210 through the second resistor 332 and the third resistor 333 to the DUT 260.

[0048] Notably, the current suppression circuit 330 prevents discharge from the decoupling capacitor 215 inside the power amplifier 210, but does not prevent discharge from the capacitor (not shown) inside the voltage and current sensing circuit 240 or the capacitor (not shown) of the DUT cable connected between the output of the device 300 and the DUT 260. However, the decoupling capacitor 215 in the power amplifier 210 (which is necessary for stable operation) cannot be removed and requires tens of nanofarads. In contrast, the capacitance of the voltage and current sensing circuit 240 and the DUT cable has fewer constraints and can be reduced to a few nanofarads. In the device 300, the energy level of the voltage and current sensing circuit 240 is significantly smaller than that of the power amplifier 210; therefore, even when the voltage and current sensing circuit 240 (and the DUT cable) are ignored, the current suppression performance of the current suppression circuit 330 is not significantly impaired.

[0049] Device 300 thus enables continuous performance of breakdown measurements and other characteristic measurements of the DUT 260 without requiring user intervention in measurement settings. Switching the bypass switch 334 is performed automatically under the control of controller 245, preventing user errors in setting the DUT 260 for breakdown measurements. Furthermore, switching does not interfere with the impedance of measurement paths for equipment other than device 300 (e.g., SMU), such as pulse generator 250. In analog circuitry, the applied voltage and the measured voltage are always matched, eliminating the need for voltage drop correction calculations. Moreover, switching avoids measurement performance degradation due to leakage current in the bypass switch 334 (a problem in conventional systems) and allows the use of switching elements that are more durable and have faster switching times than, for example, protected reed switches.

[0050] Furthermore, because the current suppression circuit 330 is implemented before the voltage and current sensing circuit 240, no current measurement error occurs even if leakage current occurs in the bypass switch 334. Therefore, unlike the low-leakage switching elements in conventional current limiting circuits, the bypass switch 334 can be implemented using switching elements with long lifespan and fast switching times without the risk of measurement error. In summary, the various embodiments described herein enable DUT testing while avoiding the problem of damage to the DUT, one or more DUT contact pads, and / or probes due to overcurrent during breakdown measurements, without introducing setup complexity or affecting the characteristics of measurement paths shared with other measurement resources.

[0051] In alternative implementations, various impedance circuits can be used instead of the current suppression circuit 330. For example, a current suppression inductor can be implemented instead of the current suppression resistor 335, provided that the voltage drop across the inductor does not affect the operation of the internal circuitry of device 300 (or device 200). The current suppression inductor may include a first inductor, a second inductor, and a third inductor, replacing the first resistor 331, the second resistor 332, and the third resistor 333, respectively. For example, the first, second, and third inductors may have values ​​ranging from about 1 μH to about 100 μH, although the inductance values ​​can vary to provide unique benefits for any particular situation or to meet application-specific design requirements of various implementations. Typically, the specific selection of the inductance value will be based on ensuring that the voltage drop caused by the inductor does not interfere with normal operation, as will be clear to those skilled in the art. The voltage drop across each inductor depends on the time derivative of the current. When the current suppression circuit includes a first inductor, a second inductor, and a third inductor, capacitor 338 is used to construct an RLC filter together with the first inductor, the second inductor, and the third inductor (each connected in series with an associated resistor) and bypass switch 334. Similar to an RC filter, the RLC filter stabilizes the power supply voltage and maintains normal operation of the power amplifier 210. In an alternative configuration, only the first resistor 331 is replaced by an inductor (and an associated resistor), while the second resistor 332 and the third resistor 333 remain resistors to form the RLC filter.

[0052] Furthermore, in alternative embodiments, one or more of the resistor paths may include multiple impedance circuits arranged in parallel, which have switching capabilities between the resistor paths, thereby allowing fine selection of impedance based on the output voltage range. For example, each of the first resistor 331, the second resistor 332, and the third resistor 333 may include multiple selectable resistors connected in parallel and having different resistance values, making it possible to select a desired resistance value for each of the first resistor 331, the second resistor 332, and the third resistor 333.

[0053] In various implementations, the controller 245 can be implemented by a processing unit and a memory, as shown in reference 1. Figure 4 The diagram discussed is a simplified block diagram of a controller configured to control overcurrent protection provided by current suppression circuits 230 and 330, according to a representative embodiment. Reference Figure 4The controller 245 includes a processing unit 410, a memory 420, an instrument interface 430, a user interface 440, and a display 450. The processing unit 410, together with the memory 420, implements at least a portion of the functionality of devices 200 and 300, including controlling the operation of corresponding switches 234 and 334 to selectively engage current suppression circuitry. For example, the memory 420 may store instructions executable by the processing unit 410 for performing breakdown measurements with overcurrent protection as described herein.

[0054] Processing unit 410 may be implemented using any combination of hardware, software, firmware, hardwired logic circuitry, or a combination thereof, by one or more of a field-programmable gate array (FPGA), application-specific integrated circuit (ASIC), general-purpose computer, central processing unit (CPU), computer processor, microprocessor, state machine, programmable logic device, or a combination thereof. Processing unit 410 may include multiple processors, parallel processors, or both. Multiple processors may be included in or coupled to a single device or multiple devices. Processing unit 410 may also refer to a collection of processors within a single computer system or distributed across multiple computer systems (such as in cloud-based or other multi-site applications). The program has software instructions that are executed by one or more processors, which may be within the same computing device or distributed across multiple computing devices.

[0055] Memory 420 is configured to store instructions executable by processing unit 410, which, when executed, cause processing unit 410 to perform all or part of the various further processes discussed herein. Memory 420 may include main memory and / or static memory, wherein such memories may communicate with each other and with the processing unit via one or more buses. Memory may be implemented by, for example, any number, type, and combination of random access memory (RAM) and read-only memory (ROM), and may store various types of information, such as software algorithms, artificial intelligence (AI) machine learning models, and computer programs, all executable by the processing unit. Various types of ROM and RAM may include any number, type, and combination of computer-readable storage media, such as disk drives, flash memory, electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, removable disks, magnetic tape, optical disc read-only memory (CD-ROM), digital universal disk (DVD), floppy disks, Blu-ray discs, universal serial bus (USB) drives, or any other form of storage media. Memory 420 is a tangible storage medium for storing data and executable software instructions and is non-transitory during the time the software instructions are stored. As used herein, the term "non-transitory" should not be interpreted as a permanent characteristic of a state, but rather as a characteristic of a state that will last for a period of time. The term "non-transitory" explicitly denies transient characteristics, such as carrier waves or signals, or other forms of characteristics that exist only temporarily at any time and place.

[0056] The controller 245 further includes an instrument interface 430 configured to interface the processing unit 410 and / or the memory 420 with the voltage and current sensing circuit 240, as will be apparent to those skilled in the art. The voltage and current sensing circuit 240 can output analog or digital signals indicating at least the voltage and / or current of the DUT 260. When the signal output by the voltage and current sensing circuit 240 is an analog signal, the instrument interface 430 may include an analog-to-digital converter (ADC) for receiving and digitizing the analog signal. The instrument interface 430 thus provides the digitized electrical test signal to the processing unit 410, which performs additional processing.

[0057] In various implementations, controller 245 may optionally include user interface 440 and display 450. User interface 440 is configured to provide a user with information and data output by processing unit 410 and / or memory 420, and / or receive information and data input by the user. That is, user interface 440 enables the user to input data and control or manipulate aspects of the process described herein, and also enables processing unit 410 to indicate the effect of user input, which may include, for example, inputting a predetermined maximum current value corresponding to DUT 260. For example, display 450 may be a computer monitor, television, liquid crystal display (LCD), organic light-emitting diode (OLED), flat panel display, solid-state display, or cathode ray tube (CRT) display or electronic whiteboard.

[0058] The display 450 and / or user interface 440 may include one or more display interfaces, in which case the display 450 provides a graphical user interface (GUI) for displaying information to and receiving information from the user.

[0059] Experiments have confirmed that capacitance of approximately a few nanofarads does not damage the DUT (such as...). Figure 3A The DUT 260 and the DUT contact pads. Figure 5 This is a simplified circuit diagram of an experimental setup for determining the current level required to damage the contact pads (wafer pads) of DUT 540 due to capacitor discharge, simulating the discharge of the first decoupling capacitor 211 and the corresponding effect on DUT 260.

[0060] refer to Figure 5 The test circuit includes a 100 V voltage source 530, a 100 kΩ resistor 531, and a capacitor 532 charged to 100 V via resistor 531. Capacitor 532 is connected to probes (probes) 535 via cable 534. For example, cable 534 can be a triaxial cable that can be connected to probes 535 via a bayonet-type Neil Conseilman (BNC) connector. DUT 540 includes contact pads 542 and a PN junction diode 543.

[0061] Initially, probe 541 remains suspended above contact pad 542 and then slowly descends. At a certain point of approach, a discharge occurs from capacitor 532. After this discharge, any damage to probe 535 or contact pad 542 is examined. Experimental results show that damage to contact pad 542 was observed when the capacitance of capacitor 532 was 20 nF or greater. However, when the capacitance of capacitor 532 was 10 nF or less, no damage to probe 535 or contact pad 542 was observed even after multiple experiments. Therefore, it can be concluded that for probes and contact pads commonly used in wafer testing, capacitance values ​​of a few nanofarads (e.g., less than or equal to about 10 nF) do not cause damage, even without current-limiting elements.

[0062] Figure 6A This is an image of damage to the pads of the DUT caused by excessive current (e.g., during breakdown), which can be prevented by the implementation described herein. That is, Figure 6A The DUT 540 is shown, which has contact pads 542 damaged due to, for example, a voltage source 530 applying 100 V and a capacitance value of, for example, a capacitor 532 of 20 nF. Figure 6B This is a trace of the current waveform indicating a current spike that signals excessive current, which can be prevented by the implementation described herein. That is, Figure 6B The current waveform 630 is shown, which includes a current spike 635 caused by the overcurrent resulting from the breakdown of the capacitance value of 20 nF in response to the application of 100 V.

[0063] about Figure 3A and Figure 3B The device 300, for example, utilizing a current suppression circuit 330, can simulate breakdown by short-circuiting the output at 100 V and measuring the current at that point. The results show a peak current of approximately 3.5 A, which is consistent with the actual breakdown voltage. Figure 5 The peak current of capacitor 532 in the circuit is approximately the same when it discharges at 4.7 nF. Therefore, applying the disclosed method to a practical SMU confirmed the overcurrent suppression effect that can prevent damage to the DUT, DUT contact pads, and probes.

[0064] In the above experiments, it is assumed that device 300 is an SMU with a maximum output of 100 V. However, the permissible range of capacitance values ​​varies depending on the maximum voltage applied to device 300. The same procedure and the design of the current suppression circuit 330 based on capacitance values ​​can be used to experimentally determine the safe range of capacitance values. Although not explicitly shown, some capacitance exists within the circuitry of voltage and current sensing circuit 240 and within the cable connecting DUT 260. If DUT 260 is short-circuited while outputting 100 V, current from these capacitors will flow into DUT 260 without any resistance limitation, as the embodiment described herein does not prevent such current. Therefore, it is necessary to ensure that the capacitance values ​​and corresponding stored energy within voltage and current sensing circuit 240 and the cable are acceptablely small, and to redesign the circuitry of voltage and current sensing circuit 240 as needed and / or select alternative cables with lower capacitance.

[0065] After confirming the current suppression effect, the impact of the current suppression circuit 330 on the operation of the SMU (including voltage and current sensing circuit 240) was also considered. The current suppression resistor 335 of the current suppression circuit 330 carries the measurement current, resulting in a voltage drop. However, when the DUT 260 is a semiconductor wafer, for example, the measurement current used for breakdown measurements of the test element group (TEG) of the wafer rarely exceeds 1 mA, so the voltage drop across the current suppression resistor 335 is small enough not to interfere with the operation of the internal circuitry of the device 300. Therefore, 1 mA can be used as a predetermined maximum current value. Furthermore, since there is no current limiting element in the path between the voltage and current sensing circuit 340 and the DUT 260, there is no error between the set voltage at the output of the device 300 and the applied voltage to the DUT 260, thus eliminating the need for voltage drop correction calculations. Of course, if the DUT 260 is another type of device, it may be necessary to consider replacing 1 mA with another suitable current value as the predetermined maximum current value, as will be clear to those skilled in the art.

[0066] On the other hand, when measuring the characteristics of the DUT 260 other than breakdown using device 300 (e.g., SMU), a current exceeding 1 mA can be used. In this case, the voltage drop across the current suppression resistor 335 becomes excessive, interfering with the operation of the internal circuitry of device 300. Therefore, when a current setting exceeding 1 mA is applied to device 300, device 300 automatically closes (activates) the bypass switch 334 to connect the shunt 339 in parallel with the current suppression resistor 335 to bypass the current suppression resistor 335, thereby preventing the voltage drop across the current suppression resistor 335 and normalizing the operation of the internal circuitry of device 300. When the bypass switch 334 is closed, the overcurrent suppression function is unavailable. However, since no breakdown measurement is performed at this time, the occurrence of excessive current associated with breakdown phenomena need not be considered.

[0067] In the above discussion, for an SMU with specific product specifications, 1 mA is considered an appropriate predetermined maximum current value for the overcurrent suppression function of the turn-on current suppression circuit 330. However, without departing from the scope of this teaching, for SMUs with different product specifications, the predetermined maximum current value (current threshold) that may damage the DUT 260 can be adjusted based on the internal capacitance, output voltage range, circuit design, and intended application.

[0068] like Figure 3A As shown, when the pulse generator 250 is implemented in (or together with) the device 300, there is no current limiting element in the path from the pulse generator 250 to the DUT 260. Therefore, for the same reason, the current suppression circuit 330 does not interfere with the pulse generator 250 or any other measuring instruments that may be used.

[0069] Figure 7 This is a flowchart illustrating a method for performing breakdown measurements with overcurrent protection, based on a representative implementation scheme. (Reference) Figure 7 In block S711, a power amplifier is used to amplify the voltage of the input signal to provide an amplified signal as the DUT signal output to the DUT. In block S712, voltage and current sensing circuitry is used to determine the current of the DUT signal output to the DUT.

[0070] In block S712, the current through the DUT signal is determined. Voltage and current sensing circuitry can be used to measure the current.

[0071] In block S713, the determined current of the DUT signal is compared with a predetermined maximum current value. The maximum current value can be predetermined based on the operating characteristics of the DUT. For example, the predetermined maximum current value can be set based on the current-voltage characteristics of the DUT before breakdown occurs during a breakdown measurement. However, as discussed above, when the DUT is a semiconductor wafer including a TEG, the predetermined maximum current is typically set (or defaulted to) 1 mA. This current will be lower than the expected current drawn by the DUT during other types of measurements.

[0072] Based on a comparison with a predetermined maximum current value, it is determined in block S714 whether the current exceeds or does not exceed the predetermined maximum current value. When the current does not exceed the predetermined maximum current value (block S714: No), in block S715, a current suppression resistor is automatically and selectively connected to the power amplifier to suppress the current of the amplified signal. Selectively connecting the current suppression resistor to the power amplifier may include disconnecting a bypass switch connected in parallel with the current suppression resistor, causing the current of the amplified signal to flow through the current suppression resistor. In block S716, the amplified signal with the suppressed current is output to the DUT as a DUT signal. In block S717, a breakdown measurement is performed on the DUT using the suppressed current. The current suppression resistor is selectively connected or disconnected from the power amplifier in the circuit before the voltage and current sensing circuits.

[0073] When the current exceeds a predetermined maximum current value (block S714: Yes), the current suppression resistor is automatically and selectively disconnected from the power amplifier in block S718 to avoid suppressing the current of the amplified signal. Selectively disconnecting the current suppression resistor from the power amplifier may include closing a bypass switch to provide a shunt connected in parallel with the current suppression resistor, thereby causing the current of the amplified signal to bypass the current suppression resistor. In block S719, the amplified signal with unsuppressed current is output to the DUT as a DUT signal. In block S720, measurements other than a breakdown measurement are performed on the DUT using the unsuppressed current.

[0074] While this disclosure has been detailed and described in the accompanying drawings and the foregoing description, such descriptions should be considered illustrative or exemplary rather than restrictive; this disclosure is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude the inclusion of other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that certain measures are referenced in mutually different dependent claims does not indicate that combinations of these measures cannot be advantageously used.

[0075] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of various embodiments. The illustrations are not intended as a complete description of all elements and features of the disclosure described herein. Many other embodiments may become clear to those skilled in the art after reading this disclosure. Other embodiments can be utilized and derived from this disclosure, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. Furthermore, the illustrations are merely representative and may not be drawn to scale. Some scales in the illustrations may be exaggerated, while others may be minimized. Therefore, this disclosure and the accompanying drawings are to be considered illustrative rather than restrictive.

[0076] The abstract of the disclosure is provided to comply with 37 CFR §1.72(B), and it is understood at the time of filing that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, various features may be grouped together or described in a single embodiment for the purpose of binding the disclosure together as a whole. This disclosure should not be construed as reflecting that the claimed embodiment requires the use of more features than expressly recited in each claim. Rather, as reflected in the appended claims, the subject matter of the invention may address fewer than all features of any of the disclosed embodiments. Therefore, the appended claims are incorporated into the detailed description, wherein each claim independently defines a separately claimed subject matter.

[0077] The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to practice the concepts described in this disclosure. Thus, the subject matter disclosed above should be considered illustrative rather than restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments falling within the true spirit and scope of this disclosure. Therefore, to the maximum extent permitted by law, the scope of this disclosure will be determined by the broadest permissible interpretation of the appended claims and their equivalents, without being bound by or limited by the foregoing detailed description.

[0078] While representative embodiments have been disclosed herein, those skilled in the art will understand that many variations based on these teachings are possible and still within the scope of the appended claims. Therefore, the invention is limited only by the scope of the appended claims.

[0079] This invention also includes the following: 1. An apparatus for performing a breakdown measurement of a device under test (DUT), the apparatus comprising: A power amplifier configured to amplify the voltage of an input signal to provide an amplified signal, wherein the power amplifier includes a decoupling capacitor; A current suppression circuit, coupled to the power amplifier to receive the amplified signal, wherein the current suppression circuit includes a bypass switch; A voltage and current sensing circuit, coupled to the current suppression circuit to receive the amplified signal and apply the amplified signal as a DUT signal to the DUT, wherein the voltage and current sensing circuit is configured to measure at least one of the voltage or current of the DUT signal and is located after the current suppression circuit; and A controller configured to determine the current of the DUT signal passing through the DUT based on at least one of the measured current or voltage of the DUT signal received from the voltage and current sensing circuit, and to automatically control the operation of the bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current of the DUT signal does not exceed a predetermined maximum current value. 2. The apparatus according to claim 1, wherein the current suppression circuit further includes a current suppression resistor connected in parallel with the bypass switch. 3. The apparatus according to claim 1, wherein the current suppression circuit further includes a current suppression inductor connected in parallel with the bypass switch. 4. The apparatus according to claim 2, wherein the controller is configured to selectively suppress the current of the amplified signal in such a way that: When the current of the DUT signal does not exceed the predetermined maximum current value, the bypass switch is disconnected, so that the current suppression resistor is connected to the power amplifier, wherein the current of the amplified signal is suppressed. 5. The apparatus according to item 4, wherein, during the breakdown measurement of the DUT, the current of the DUT signal does not exceed the predetermined maximum current value. 6. The apparatus according to claim 2, wherein the controller is configured to selectively suppress the current of the amplified signal in such a way that: When the current of the DUT signal exceeds the predetermined maximum current value, the bypass switch is closed, so that the current suppression resistor is bypassed by the shunt connected in parallel with the suppression resistor, wherein the current of the amplified signal is not suppressed. 7. The apparatus according to claim 2, wherein the current suppression resistor of the current suppression circuit comprises: A first resistor is connected between the output of the power amplifier and the input of the voltage and current sensing circuit. The bypass switch is connected in parallel with the first resistor. 8. The apparatus according to claim 2, wherein the current suppression circuit further comprises: An RC filter is configured to stabilize the power supply voltage of the power amplifier, thereby maintaining the normal operation of the power amplifier. 9. The apparatus according to claim 8, wherein the RC filter comprises: A first resistor is connected between the output terminal of the power amplifier and the input terminal of the voltage and current sensing circuit, wherein the bypass switch is connected in parallel with the first resistor. A second resistor is connected between the floating power supply and the positive terminal of the power amplifier; A third resistor is connected between the floating power supply and the negative terminal of the power amplifier; A first capacitor is coupled between the second resistor and the output terminal of the power amplifier; and A second capacitor is coupled between the third resistor and the output terminal of the power amplifier. 10. The apparatus according to claim 3, wherein the controller is configured to selectively suppress the current of the amplified signal in such a way that: When the current of the DUT signal does not exceed the predetermined maximum current value, the bypass switch is disconnected, so that the current suppression inductor is connected to the power amplifier, wherein the current of the amplified signal is suppressed. 11. The apparatus according to claim 10, wherein the controller is configured to selectively suppress the current of the amplified signal in such a way that: When the current of the DUT signal exceeds the predetermined maximum current value, the bypass switch is closed, so that the current suppression inductor is bypassed by the shunt connected in parallel with the suppression inductor, wherein the current of the amplified signal is not suppressed. 12. The apparatus according to claim 1, further comprising: A pulse generator configured to generate pulses to provide to the DUT and to measure the DUT's response to the pulses; and A switch configured to selectively connect the pulse generator to the DUT. 13. A method for performing a breakdown measurement of a device under test (DUT), the method comprising: A power amplifier is used to amplify the voltage of the input signal to provide the amplified signal to the voltage and current sensing circuits; The amplified signal is applied to the DUT as a DUT signal, and the current of the DUT signal is determined using the voltage and current sensing circuit. The determined current of the DUT signal is compared with a predetermined maximum current value; When the current of the DUT signal does not exceed the predetermined maximum current value, a current suppression resistor is automatically and selectively connected to the power amplifier to suppress the current of the amplified signal, and the breakdown measurement of the DUT is performed using the suppressed current; and When the current of the DUT signal exceeds the predetermined maximum current value, the current suppression resistor is automatically and selectively disconnected from the power amplifier to avoid suppressing the current of the amplified signal, and the DUT is measured using the unsuppressed current, except for the breakdown measurement. 14. The method according to item 13, wherein the current suppression resistor is selectively connected or disconnected from the power amplifier before the voltage and current sensing circuit. 15. The method according to claim 13, wherein selectively connecting the current suppression resistor to the power amplifier comprises: disconnecting a bypass switch connected in parallel with the current suppression resistor, thereby causing the current of the amplified signal to pass through the current suppression resistor. 16. The method according to claim 15, wherein selectively disconnecting the current suppression resistor from the power amplifier comprises: closing the bypass switch to provide a shunt connected in parallel with the current suppression resistor, thereby causing the current of the amplified signal to bypass the current suppression resistor. 17. An apparatus for performing a breakdown measurement of a device under test (DUT), the apparatus comprising: A current suppression circuit, coupled between a power amplifier and a voltage and current sensing circuit, wherein the current suppression circuit is configured to receive an amplified signal output from the power amplifier for output to the DUT as a DUT signal, wherein the current suppression circuit includes a bypass switch and a current suppression resistor connected in parallel with the bypass switch; and A controller is configured to determine the current of the DUT signal passing through the DUT based on at least one of the current or voltage of the DUT signal measured by voltage and current sensing circuitry, and to automatically control the operation of a bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current of the DUT signal does not exceed a predetermined maximum current value. 18. The apparatus according to claim 17, wherein the controller is configured to selectively suppress the current of the amplified signal in such a way that: When the current of the DUT signal does not exceed the predetermined maximum current value, the bypass switch is disconnected, causing the current suppression resistor to be connected to the power amplifier, and the current of the amplified signal is suppressed; and When the current of the DUT signal exceeds the predetermined maximum current value, the bypass switch is closed, so that the current suppression resistor is bypassed by the shunt connected in parallel with the suppression resistor, and the current of the amplified signal is not suppressed. 19. The apparatus according to claim 17, wherein the current suppression resistor of the current suppression circuit comprises: A first resistor is connected between the output of the power amplifier and the input of the voltage and current sensing circuit, wherein the bypass switch is connected in parallel with the first resistor. 20. The apparatus according to claim 19, wherein the current suppression circuit further comprises: A second resistor is connected between the floating power supply and the positive terminal of the power amplifier; A third resistor is connected between the floating power supply and the negative terminal of the power amplifier; A first capacitor is coupled between the second resistor and the output terminal of the power amplifier; and A second capacitor is coupled between the third resistor and the output terminal of the power amplifier.

Claims

1. An apparatus for performing a breakdown measurement of a device under test (DUT), the apparatus comprising: A power amplifier configured to amplify the voltage of an input signal to provide an amplified signal, wherein the power amplifier includes a decoupling capacitor; A current suppression circuit, coupled to the power amplifier to receive the amplified signal, wherein the current suppression circuit includes a bypass switch; A voltage and current sensing circuit, coupled to the current suppression circuit to receive the amplified signal and apply the amplified signal as a DUT signal to the DUT, wherein the voltage and current sensing circuit is configured to measure at least one of the voltage or current of the DUT signal and is located after the current suppression circuit; and A controller configured to determine the current of the DUT signal passing through the DUT based on at least one of the measured current or voltage of the DUT signal received from the voltage and current sensing circuit, and to automatically control the operation of the bypass switch based on the determined current of the DUT signal to selectively suppress the current of the amplified signal when the determined current of the DUT signal does not exceed a predetermined maximum current value.

2. The apparatus according to claim 1, wherein, The current suppression circuit further includes a current suppression resistor connected in parallel with the bypass switch.

3. The apparatus according to claim 2, wherein, The controller is configured to selectively suppress the current of the amplified signal in the following manner: When the current of the DUT signal does not exceed the predetermined maximum current value, the bypass switch is disconnected, causing the current suppression resistor to be connected to the power amplifier, wherein the current of the amplified signal is suppressed. During the breakdown measurement of the DUT, the current of the DUT signal does not exceed the predetermined maximum current value.

4. The apparatus according to claim 2, wherein, The controller is configured to selectively suppress the current of the amplified signal in the following manner: When the current of the DUT signal exceeds the predetermined maximum current value, the bypass switch is closed, so that the current suppression resistor is bypassed by the shunt connected in parallel with the suppression resistor, wherein the current of the amplified signal is not suppressed.

5. The apparatus according to claim 2, wherein, The current suppression resistor in the current suppression circuit includes: A first resistor is connected between the output of the power amplifier and the input of the voltage and current sensing circuit. The bypass switch is connected in parallel with the first resistor.

6. The apparatus according to claim 2, wherein, The current suppression circuit further includes: An RC filter is configured to stabilize the power supply voltage of the power amplifier, thereby maintaining the normal operation of the power amplifier.

7. The apparatus according to claim 6, wherein, The RC filter includes: A first resistor is connected between the output terminal of the power amplifier and the input terminal of the voltage and current sensing circuit, wherein the bypass switch is connected in parallel with the first resistor. A second resistor is connected between the floating power supply and the positive terminal of the power amplifier; A third resistor is connected between the floating power supply and the negative terminal of the power amplifier; A first capacitor is coupled between the second resistor and the output terminal of the power amplifier; and A second capacitor is coupled between the third resistor and the output terminal of the power amplifier.

8. The apparatus according to claim 1, wherein, The current suppression circuit further includes a current suppression inductor connected in parallel with the bypass switch, and The controller is configured to selectively suppress the current of the amplified signal in the following manner: When the current of the DUT signal does not exceed the predetermined maximum current value, the bypass switch is disconnected, causing the current suppression inductor to be connected to the power amplifier, wherein the current of the amplified signal is suppressed; and When the current of the DUT signal exceeds the predetermined maximum current value, the bypass switch is closed, so that the current suppression inductor is bypassed by the shunt connected in parallel with the suppression inductor, wherein the current of the amplified signal is not suppressed.

9. The apparatus according to claim 1, further comprising: A pulse generator configured to generate pulses to provide to the DUT and to measure the DUT's response to the pulses; as well as A switch configured to selectively connect the pulse generator to the DUT.

10. A method for performing a breakdown measurement of a device under test (DUT), the method comprising: A power amplifier is used to amplify the voltage of the input signal to provide the amplified signal to the voltage and current sensing circuits; The amplified signal is applied to the DUT as a DUT signal, and the current of the DUT signal is determined using the voltage and current sensing circuit. The determined current of the DUT signal is compared with a predetermined maximum current value; When the current of the DUT signal does not exceed the predetermined maximum current value, a current suppression resistor is automatically and selectively connected to the power amplifier to suppress the current of the amplified signal, and the breakdown measurement of the DUT is performed using the suppressed current. as well as When the current of the DUT signal exceeds the predetermined maximum current value, the current suppression resistor is automatically and selectively disconnected from the power amplifier to avoid suppressing the current of the amplified signal, and the unsuppressed current is used to perform measurements of the DUT other than the breakdown measurement. The current suppression resistor is selectively connected or disconnected from the power amplifier before the voltage and current sensing circuit.

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