Test structure for high-side switching device

Abstract

According to the test structure for the high-side switching device, the high-side switching device comprises a substrate, a shield gate trench device and a bipolar complementary metal oxide device, the shield gate trench device and the bipolar complementary metal oxide device are located on the substrate and arranged at an interval, and a gate of the shield gate trench device and a gate of the bipolar complementary metal oxide device are electrically connected with each other through a gate interconnection line; the test structure includes a first test pad on the substrate and a diode string structure in which at least two diodes are connected in series, in which cathodes of the at least two diodes are connected to each other, an anode of one of the diodes is connected to the gate interconnection line, and the first test pad is also connected to the gate interconnection line. According to the invention, under the condition that the bipolar complementary metal oxide device is not affected, the voltage endurance capability parameter of the shield gate trench device can be tested and monitored, the test failure ratio is reduced, and the product quality of a high-side switching device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, in particular to a test structure for a high-side switch device. BACKGROUND

[0002] The integrated high-side switch device (hereinafter referred to as IPS device) is generally an SGT (Shielded-Gate Trench) device integrated with several BCD (Bipolar-CMOS-DMOS) devices.

[0003] Because the integrated conventional BCD device has a low-voltage application (much lower than the withstand voltage of the integrated SGT device), it cannot be recovered under high-power test conditions, and at the same time, the Gate / Drain of the SGT is connected in series with the BCD device, which causes the conventional SGT withstand voltage parameters to be unable to be monitored before packaging is completed, and there is a quality risk. SUMMARY

[0004] A series of simplified concepts are introduced in the summary part, which will be further described in detail in the specific embodiment part. The summary part of the present application does not mean to try to limit the key features and necessary technical features of the claimed technical solution, nor does it mean to try to determine the protection scope of the claimed technical solution.

[0005] In view of the existing problems, the present application provides a test structure for a high-side switch device, the high-side switch device comprising a substrate and a shielded gate trench device and a bipolar complementary metal oxide device arranged on the substrate and spaced apart, wherein the gate of the shielded gate trench device and the gate of the bipolar complementary metal oxide device are electrically connected to each other through a gate interconnection line; the test structure comprises a first test pad on the substrate and a diode string structure of at least two diodes connected in series, wherein the cathodes of the at least two diodes are connected to each other, the anode of one of the diodes is connected to the gate interconnection line, and the first test pad is also connected to the gate interconnection line.

[0006] In some embodiments of the present application, the diode string structure further comprises at least one diode connected to the anode of another diode of the at least two diodes, the cathode of the at least one diode is connected to the anode of the another diode of the at least two diodes, and when the number of the at least one diode is greater than one, the anodes of the at least one diode and the cathodes of the adjacent diodes are connected to each other.

[0007] In some embodiments of the present application, the side of the diode string structure not connected to the gate interconnection line is grounded.

[0008] In some embodiments of the present application, the diode string structure is arranged along the outer peripheral edge of the first test pad.

[0009] In some embodiments of the present application, the bipolar complementary metal oxide device is provided with one or more second test pads.

[0010] In some embodiments of the present application, the clamping voltage of the diode string structure is less than the threshold voltage of the shielded gate trench device, and the clamping voltage of the diode string structure is less than the threshold voltage of the bipolar complementary metal oxide device.

[0011] In some embodiments of the present application, the test voltage of the shielded gate trench device is less than or equal to the clamping voltage of the diode string structure.

[0012] In some embodiments of the present application, the first test pad is used as the gate of the high-side switch device to test the threshold voltage or on-resistance of the shielded gate trench device.

[0013] In some embodiments of the present application, the test structure is used as the source of the high-side switch device to test the drain-source breakdown voltage of the shielded gate trench device.

[0014] The test structure for high-side switch device according to the embodiments of the present application, by integrating the test structure including the first test pad and the diode string structure on the high-side switch device, when the voltage withstanding capability of the shielded gate trench device integrated on the high-side switch device is tested before packaging is completed, it can be ensured that the bipolar complementary metal oxide device integrated on the high-side switch device will not be damaged due to DS breakdown during the test process, so that the test and monitoring of the voltage withstanding capability parameters of the shielded gate trench device can be completed without affecting the bipolar complementary metal oxide device, thereby reducing the test failure rate and improving the product quality of the high-side switch device. BRIEF DESCRIPTION OF DRAWINGS

[0015] The following drawings of the present application are hereby incorporated into the present application as part of the present application for the purpose of understanding the present application. The drawings of the present application and its description show the embodiments of the present application, which are used to explain the principles of the present application.

[0016] Figure 1 A structure schematic diagram of a high-side switch device in the related art is shown.

[0017] Figure 2 A structure schematic diagram of a high-side switch device and a test structure of one embodiment of the present application is shown.

[0018] Figures 3A to 3D The layout of the test structure obtained by sequentially implementing the manufacturing method of the test structure of one embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] In the following description, numerous specific details are given to provide a thorough understanding of the application. However, it will be apparent that the application can be practiced without one or more of the specific details. In other instances, well-known

[0020] It should be understood that the application can be practiced with the elements in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and fully convey the scope of the application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions can be exaggerated for clarity. Like reference numerals can represent like elements throughout.

[0021] It should be understood that when an element or layer is referred to as being "on" or "connected to" another element or layer, it can be directly on or connected to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

[0022] Spatially relative terms, such as "beneath", "below", "lower", "under", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, 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.

[0024] In the related art, as shown in FIG. 1, a high-side switch device includes a substrate and a shielded gate trench device 120 and a bipolar complementary metal-oxide device 130 located on the substrate and spaced apart, wherein a gate of the shielded gate trench device 120 and a gate of the bipolar complementary metal-oxide device 130 are electrically connected to each other through a gate interconnection line 110. Figure 1

[0025] Since the voltage that can be withstood by the bipolar complementary metal-oxide device 130 integrated on the high-side switch device is low (much lower than the voltage resistance of the shielded gate trench device 120 integrated on the high-side switch device), the high-side switch device cannot be recovered under a large power test condition, and at the same time, the Gate / Drain end of the shielded gate trench device 120 is in series with the bipolar complementary metal-oxide device 130, which causes the various voltage resistance parameters of the shielded gate trench device 120 to be unable to be monitored before packaging is completed, and there is a quality risk.

[0026] To solve at least one of the above technical problems, the application provides a test structure for a high-side switch device, the high-side switch device including a substrate and a shielded gate trench device and a bipolar complementary metal-oxide device located on the substrate and spaced apart, wherein a gate of the shielded gate trench device and a gate of the bipolar complementary metal-oxide device are electrically connected to each other through a gate interconnection line; the test structure includes a first test pad on the substrate and a diode string structure of at least two diodes connected in series, wherein the cathodes of the at least two diodes are connected to each other, the anode of one of the diodes is connected to the gate interconnection line, and the first test pad is also connected to the gate interconnection line.

[0027] ​According to the test structure for high-side switching device provided by the present application, by integrating the test structure including the first test pad and the diode string structure on the high-side switching device, when the withstand voltage capability of the shielded gate trench device integrated on the high-side switching device is tested before the packaging is completed, it can be ensured that the bipolar complementary metal oxide device integrated on the high-side switching device will not be damaged due to the breakdown of the DS end during the test, so that the test and monitoring of the withstand voltage capability parameters of the shielded gate trench device can be completed without affecting the bipolar complementary metal oxide device, the test failure rate is reduced, and the product quality of the high-side switching device is improved.

[0028] In order to thoroughly understand the present application, detailed steps and structures will be presented in the following description in order to explain the technical solutions provided by the present application. The preferred embodiments of the present application are described in detail as follows, however, in addition to these detailed descriptions, the present application can also have other implementation manners.

[0029] The test structure for high-side switching device according to an embodiment of the present application will be described below with reference to Figure 2 、 Figures 3A to 3D The test structure 240 for high-side switching device according to an embodiment of the present application will be described below with reference to

[0030] By integrating the test structure 240 on the high-side switching device, when the withstand voltage capability of the shielded gate trench device 220 integrated on the high-side switching device is tested before the packaging is completed, the test voltage can be controlled to be not higher than the clamping voltage of the test structure 240, so that it can be ensured that the bipolar complementary metal oxide device 230 integrated on the high-side switching device will not be damaged due to the breakdown of the DS end (wherein D represents the drain and S represents the source) during the test, the test and monitoring of the withstand voltage capability parameters of the shielded gate trench device 220 can be completed without affecting the bipolar complementary metal oxide device 230, the test failure rate is reduced, and the product quality of the high-side switching device is improved.

[0031] Specifically, the high-side switching device in the related art cannot generally CP (chip probing) monitor the threshold voltage, on-resistance, drain-source breakdown voltage and other key parameters of the shielded gate trench device 220, and the shielded gate trench device 220 can only be monitored by Inline WAT (Inline Wafer Acceptance Test), and the FT yield (Final Test yield) of the high-side switching device after packaging is lower than that of the BCD / Power MOS device of a similar process level, thereby causing waste of packaging cost.

[0032] In some embodiments, the first test pad 242 is used as a gate of the high-side switching device to test the threshold voltage (VTH) or on-resistance (Rdson) of the shielded gate trench device 220.

[0033] In this embodiment, by using the first test pad 242 as the gate of the high-side switching device, the first test pad 242 can be directly electrically connected to the corresponding test instrument, thereby CP monitoring the threshold voltage or on-resistance and other non-destructive parameters of the shielded gate trench device 220, and making up for the shortcomings in the related art.

[0034] In some embodiments, the test structure 240 is used as a source of the high-side switching device to test the breakdown voltage drain-source (BVDS) of the shielded gate trench device 220.

[0035] In this embodiment, by using the test structure 240 as the source of the high-side switching device, the test structure 240 can be directly electrically connected to the corresponding test instrument, and by controlling the clamping voltage of the test structure 240 to be slightly lower than the withstand voltage design value of the shielded gate trench device 220 / bipolar complementary metal oxide device 230, the test voltage of the shielded gate trench device 220 can be controlled to be not higher than the clamping voltage during the test process, and it is ensured that the bipolar complementary metal oxide device 230 will not be damaged due to DS (wherein D represents drain and S represents source) breakdown during the test process.

[0036] Specifically, during the test process, the clamping voltage of the diode string structure 241 can be controlled to be less than the threshold voltage of the shielded gate trench device 220, and the clamping voltage of the diode string structure 241 can be controlled to be less than the threshold voltage of the bipolar complementary metal oxide device 230; at the same time, the test voltage of the shielded gate trench device 220 can also be controlled to be less than or equal to the clamping voltage of the diode string structure 241.

[0037] In some embodiments, such as Figure 2 As shown, the diode string structure 241 may include multiple PN junctions connected in series. Two adjacent P-type doped regions share one N-type doped region, and two adjacent N-type doped regions share one P-type doped region. The clamping voltage of the diode string structure 241 can be controlled by adjusting the number of PN junctions, ensuring that the clamping voltage of the diode string structure 241 is less than the threshold voltage of the shielded gate trench device 220 / bipolar complementary metal-oxide device 230, and that the test voltage of the shielded gate trench device 220 is less than or equal to the clamping voltage of the diode string structure 241.

[0038] In some embodiments, since the diode string structure 241 is obtained by connecting at least two diodes in series, the clamping voltage of the diode string structure 241 can be made less than the threshold voltage of the shielded gate trench device 220 / bipolar complementary metal oxide device 230, and the test voltage of the shielded gate trench device 220 can be made less than or equal to the clamping voltage of the diode string structure 241 by adjusting the number of diodes connected in series.

[0039] In some embodiments, when performing a withstand voltage test on the shielded gate trench device 220 integrated on the high-side switching device, the side of the diode string structure 241 that is not connected to the gate interconnect 210 is grounded.

[0040] In some embodiments, the diode string structure 241 further includes at least one diode connected to the anode of another of the at least two diodes, and the cathode of the at least one diode connected to the anode of the other of the at least two diodes. When the number of at least one diode is greater than one, the anode of the at least one diode is connected to the cathode of the adjacent diode. Specifically, when the diode string structure 241 includes multiple diodes connected in series, the cathode of the preceding diode is connected to the anode of the following diode, and so on, so that multiple diodes are connected in series to form the diode string structure 241.

[0041] In some embodiments, the diode string structure 241 extends along the outer peripheral edge of the first test pad 242.

[0042] Specifically, the manufacturing method of test structure 240 can be as follows: Figures 3A to 3D As shown. First, as Figure 3A As shown, a gate is formed on the substrate, and then as... Figure 3B As shown, an N-type doped region is formed at the inner peripheral edge of the gate region, and then as follows... Figure 3C As shown, a contact (CT) structure is formed in the gate region between the N-type doped regions, and then as... Figure 3DAs shown, the metal interconnection line is formed. Thus, the test structure 240 can be obtained by the above preparation method, and in the obtained test structure 240, the diode string structure 241 is arranged along the outer peripheral edge of the first test pad 242.

[0043] In some embodiments, as shown in FIG. 2, the bipolar complementary metal oxide device 230 is arranged with one or more second test pads 231. Figure 2

[0044] In summary, according to the test structure for the high-side switch device in the embodiments of the present application, by integrating the test structure including the first test pad and the diode string structure on the high-side switch device, when the withstand voltage capability of the shield gate trench device integrated on the high-side switch device is tested before packaging is completed, it can be ensured that the bipolar complementary metal oxide device integrated on the high-side switch device will not be damaged due to breakdown of the DS end in the testing process, so that the test and monitoring of the withstand voltage capability parameters of the shield gate trench device can be completed without affecting the bipolar complementary metal oxide device, the test failure rate is reduced, and the product quality of the high-side switch device is improved.

[0045] Although example embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the example embodiments are only exemplary and are not intended to limit the scope of the present application. Those of ordinary skill in the art can make various changes and modifications without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0046] Similarly, it is to be understood that, in order to simplify the present application and help understand one or more of the various application aspects, in the description of the example embodiments of the present application, various features of the present application are sometimes grouped together in a single embodiment, figure, or description thereof. However, this should not be interpreted as reflecting an intention that the claimed present application requires more features than those explicitly recited in each claim. Rather, as reflected by the corresponding claims, the application point is that the corresponding technical problem can be solved with fewer features than all the features of a certain disclosed single embodiment. Therefore, the claims following the specific embodiments are hereby expressly incorporated into the specific embodiments, where each claim itself is a separate embodiment of the present application.

[0047] In addition, those skilled in the art can understand that although some embodiments described herein include certain features and not others included in other embodiments, the combination of features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination. ​

[0048] It should be noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present application. While the application has been described with reference to preferred embodiments and illustrations, the person of ordinary skill in the art will be able to design many alternative embodiments without departing from the scope of the application. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The use of the words "first", "second", and "third", etc. does not imply any order. These words are to be interpreted as names.

Claims

1. A test structure for a high-side switching device, characterized by, The high-side switching device comprises a substrate and a shielded gate trench device and a bipolar complementary metal oxide device arranged on the substrate and spaced apart, wherein the gate of the shielded gate trench device and the gate of the bipolar complementary metal oxide device are electrically connected to each other through a gate interconnection line; The test structure comprises a first test pad and a diode string structure of at least two diodes connected in series on the substrate, wherein the cathodes of the at least two diodes are connected to each other, and the anode of one of the diodes is connected to the gate interconnection line, and the first test pad is also connected to the gate interconnection line.

2. The test structure of claim 1, wherein, The diode string structure further comprises at least one diode connected to the anode of another diode of the at least two diodes, and the cathode of the at least one diode is connected to the anode of another diode of the at least two diodes, and when the number of the at least one diode is greater than one, the anodes of the at least one diode and the cathodes of the adjacent diodes are connected to each other.

3. A test structure as claimed in claim 1 or 2, characterized in that The side of the diode string structure not connected to the gate interconnection line is grounded.

4. The test structure of claim 1, wherein, The diode string structure is arranged along the outer peripheral edge of the first test pad.

5. The test structure of claim 1, wherein, The bipolar complementary metal oxide device is provided with one or more second test pads.

6. The test structure of claim 1, wherein, The clamping voltage of the diode string structure is less than the threshold voltage of the shielded gate trench device, and the clamping voltage of the diode string structure is less than the threshold voltage of the bipolar complementary metal oxide device.

7. The test structure of claim 1, wherein, The test voltage of the shielded gate trench device is less than or equal to the clamping voltage of the diode string structure.

8. The test structure of claim 1, wherein, The first test pad is used as the gate of the high-side switching device to test the threshold voltage or on-resistance of the shielded gate trench device.

9. The test structure of claim 1, wherein, The test structure is used as the source of the high-side switching device to test the drain-source breakdown voltage of the shielded gate trench device. The test structure is used as the source of the high-side switching device to test the drain-source breakdown voltage of the shielded gate trench device.

Images