Composite semiconductor device and its driving method
The composite semiconductor device addresses the challenge of simultaneous reduction in forward voltage drop and reverse recovery losses by employing diodes with different impurity concentrations and crystal defect densities, operated at different timings, resulting in improved efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SANKEN ELECTRIC CO LTD
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-09
AI Technical Summary
Existing semiconductor diodes face challenges in simultaneously reducing forward voltage drop and losses during reverse recovery switching.
A composite semiconductor device with diodes of varying impurity concentrations and crystal defect densities, operated at different timings, and a driving method that turns one diode off before the other to minimize forward voltage drop and reverse recovery losses.
The composite semiconductor device achieves low forward voltage drop and reduced losses during reverse recovery switching, enhancing overall performance.
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Abstract
Description
Technical Field
[0001] Regarding the losses of a diode, the forward voltage drop when the diode is on and the loss during reverse recovery switching are attracting attention. The forward voltage drop is realized by thinning the drift layer, etc., and the loss during reverse recovery switching is realized by providing a low lifetime region such as a crystal defect region.
[0002] A diode structure in which crystal defect regions are formed at two locations, near the anode region and at an intermediate position deeper than that, is disclosed in, for example, Patent Document 1 below.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, it has been difficult to reduce both the forward voltage drop when the diode is on and the loss during reverse recovery switching.
[0005] Therefore, the problem of the present invention has been made in view of such problems, and an object thereof is to provide a compound semiconductor device that solves the above problems and a driving method thereof.
Means for Solving the Problems
[0006] The composite semiconductor device of the present invention comprises a first diode having a first semiconductor region, a second semiconductor region of a second conductivity type provided on the first semiconductor region, a third semiconductor region of a first conductivity type provided on the first semiconductor region opposite to the second semiconductor region and having a higher impurity concentration than the first semiconductor region, a first electrode electrically connected to the second semiconductor region, a second electrode electrically connected to the third semiconductor region, and a first crystal defect region provided within the region of the first semiconductor region, a fourth semiconductor region, and a fifth semiconductor region of a second conductivity type provided on the fourth semiconductor region and having a higher impurity concentration than the second semiconductor region. The present invention includes a region, a sixth semiconductor region of a first conductivity type provided on the fourth semiconductor region opposite to the fifth semiconductor region and having a higher impurity concentration than the fourth semiconductor region, a third electrode electrically connected to the fifth semiconductor region, a fourth electrode electrically connected to the sixth semiconductor region, and a second crystal defect region provided within the fourth semiconductor region and having a lower crystal defect density than the first crystal defect region, and a switch in which one of the combinations of the first electrode and the second electrode, or one of the combinations of the first electrode and the second electrode, is electrically connected to the other, and the first diode and the second diode are operated at different timings.
[0007] This makes it possible to provide a composite semiconductor device with low forward voltage drop and reduced losses during reverse recovery switching.
[0008] Furthermore, the thickness of the fifth semiconductor region may be formed to be greater than the thickness of the second semiconductor region. This makes it possible to provide a composite semiconductor device with even lower forward voltage drop and reduced losses during reverse recovery switching.
[0009] Furthermore, as a driving method for the composite semiconductor device of the present invention, the second diode may be turned off before the first diode. This makes it possible to provide a driving method for a composite semiconductor device that exhibits low forward voltage drop and reduced losses during reverse recovery switching.
[0010] Furthermore, as a driving method for the composite semiconductor device of the present invention, the second diode may be turned on before the first diode. This makes it possible to provide a driving method for a composite semiconductor device that exhibits low forward voltage drop and reduced losses during reverse recovery switching. [Effects of the Invention]
[0011] According to the present invention, it is possible to provide a composite semiconductor device and a method for driving it that exhibits low forward voltage drop and reduces losses during reverse recovery switching. [Brief explanation of the drawing]
[0012] [Figure 1] This is a schematic cross-sectional view showing a composite semiconductor device according to an embodiment of the present invention. [Figure 2] This figure shows an operation chart of the driving method for a composite semiconductor device according to an embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing a modified example of a composite semiconductor device according to an embodiment of the present invention. [Modes for carrying out the invention]
[0013] The aforementioned and other features of the Application will become clear from the following description with reference to the drawings. While the specification and drawings specifically disclose some embodiments demonstrating the applicability of the principles of the Application, it should be understood that the Application is not limited to the embodiments described, but rather includes all modifications, variations and equivalents included in the attached claims. Various embodiments of the Application are described below with reference to the drawings. These embodiments are illustrative and not limitations to the Application.
[0014] In the embodiments of this application, terms such as "first," "second," "above," and "below" are used to distinguish different elements, but do not indicate the spatial arrangement or temporal order of these elements, and these elements should not be limited to these terms. "Above" and "below" are not limited to things that are in contact, but also include things that are "above" and "below." Also, "connected" is not limited to things that are in direct contact, but also includes things that are electrically connected with a resistor or the like in between. The term "and / or" includes any one or more of the terms listed together and all combinations thereof. Terms such as "includes," "contains," and "has" mean the presence of the described features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.
[0015] The composite semiconductor device 300 of the embodiment of the present invention shown in Figure 1 has a configuration that includes a first diode 100 and a second diode 200.
[0016] The first diode 100 consists of a first semiconductor region 12 of the first conductivity type, N-type, a second semiconductor region 11 of the second conductivity type, P-type, provided on the first semiconductor region 12, and a third semiconductor region 14 of the first conductivity type, N-type, provided on the N-type first semiconductor region 12 opposite to the P-type second semiconductor region 11. The impurity concentration of the third semiconductor region 14 is higher than that of the first semiconductor region 12. It also consists of a first electrode 10 electrically connected to the P-type second semiconductor region 11 and a second electrode 15 electrically connected to the N-type third semiconductor region 14. A first crystal defect region 13 is provided within the first semiconductor region 12.
[0017] Further, the second diode 200 includes an N-type fourth semiconductor region 18 of a first conductivity type, a P-type fifth semiconductor region 17 provided on the fourth semiconductor region 18, and an N-type sixth semiconductor region 20 of the first conductivity type provided on the N-type fourth semiconductor region 18 on the opposite side of the P-type fifth semiconductor region 17. The impurity concentration of the sixth semiconductor region 20 is higher than that of the fourth semiconductor region 18. And, a third electrode 16 electrically connected to the P-type fifth semiconductor region 17 and a fourth electrode 21 electrically connected to the N-type sixth semiconductor region 20 are formed. A second crystal defect region 19 is provided in the fourth semiconductor region 18. Although the first diode 100 and the second diode 200 are described separately, they may be formed on one drift region. For example, the first semiconductor region 12 and the fourth semiconductor region 18 may be one semiconductor region.
[0018] In the present application, the impurity concentration of the P-type fifth semiconductor region 17 of the second diode 200 is higher than that of the P-type second semiconductor region 11 of the first diode 100.
[0019] Also, in the present application, the defect density of the first crystal defect region 13 in the N-type first semiconductor region 12 of the first diode 100 is higher than the defect density of the second crystal defect region 19 in the N-type fourth semiconductor region 18 of the second diode 200.
[0020] The first switch S1 is provided in the first diode 100. In FIG. 1, the first switch S1 is described as an external switch connected to the first electrode 10 of the first diode 100, but the first switch S1 may be a MOS gate provided to penetrate the second semiconductor region 11 so as to generate a depletion layer in the P-type second semiconductor region 11, or a switch that controls the on / off of the first diode 100 by applying a bias voltage to the P-type second semiconductor region 11.
[0021] The second switch S2 is provided in the second diode 200. Similar to the first switch S1, in FIG. 1, the second switch S2 is described as an external switch connected to the third electrode 16 of the second diode 200. However, the second switch S2 may also be a MOS gate provided to penetrate the fifth semiconductor region 17 so as to generate a depletion layer in the P-type fifth semiconductor region 17, or a switch that controls the on / off of the second diode 200 by applying a bias voltage to the P-type fifth semiconductor region 17. Also, the first switch S1 and the second switch S2 are for operating the first diode and the second diode at different timings, and a switch for detecting the operation of one of the diodes and switching the operation may be provided only in the other diode. Further, in FIG. 1, the second electrode 15 and the fourth electrode 21 are electrically connected to each other, the first electrode 10 is connected to the first switch S1, and the third electrode 16 is connected to the second switch S2. However, the first electrode 10 and the third electrode 16 may be electrically connected to each other, the first switch S1 may be provided on the second electrode 15 side, and the second switch S2 may be provided on the fourth electrode 21 side.
[0022] The operation of the compound semiconductor device 300 will be described with reference to the operation chart of FIG. 2. The turn-on operation of the compound semiconductor device 300 is to first turn on the switch S2 to turn on the second diode 200, and then turn on the switch S1 to turn on the first diode 100. Since the second diode 200 is turned on before the first diode 100, the compound semiconductor device 300 can be turned on relatively quickly. Then, both the first diode 100 and the second diode 200 are in the on state. Eventually, the turn-off operation of the compound semiconductor device 300 is to first turn off the switch S2 to turn off the second diode 200, and then turn off the switch S1 to turn off the first diode 100. Since the second diode 200 is turned off before the first diode 100, the compound semiconductor device 300 can be turned off relatively quickly.
[0023] Figure 3 shows a modified composite semiconductor device 300a of the embodiment of the present invention. The modified composite semiconductor device 300a of the embodiment of the present invention includes a first diode 100a and a second diode 200a. The impurity concentration in the P-type fifth semiconductor region 17a of the second diode 200a is higher than that in the P-type second semiconductor region 11a of the first diode 100a. Furthermore, the thickness of the P-type fifth semiconductor region 17a of the second diode 200a is greater than that of the P-type second semiconductor region 11a of the first diode 100a.
[0024] Furthermore, one of the combinations of the second electrode 15 of the first diode 100a and the fourth electrode 21 of the second diode 200a, or the combination of the first electrode 10 of the first diode 100a and the third electrode 16 of the second diode 200a, is connected to the other, and a switch is provided on the other side to operate the first diode 100a and the second diode 200a at different timings. For example, the second electrode 15 of the first diode 100a and the fourth electrode 21 of the second diode 200a are electrically connected to each other, and at least one of the first electrode 10 of the first diode 100a and the third electrode 16 of the second diode 200a is connected to a switch, and the switch can be used to drive the operation timings of the first diode 100a and the second diode 200a to be different.
[0025] In such a composite semiconductor device 300a, the second diode 200a is turned on before the first diode 100a, and the second diode 200a is turned off before the first diode 100a. This makes it possible to provide a composite semiconductor device 300a that has a lower forward voltage drop and reduces losses during reverse recovery switching.
[0026] Although the present invention is described in a language specific to structural features and / or methodological actions, it should be understood that the invention, as defined in the claims, is not limited to the specific features or actions described above. Conversely, the specific features and actions described above are disclosed as exemplary forms for carrying out these claims.
[0027] While the present application has been described above in relation to specific embodiments, those skilled in the art should recognize that these descriptions are illustrative and do not limit the scope of protection of the present application. Those skilled in the art can make various modifications and alterations to the present application based on its spirit and principles, and these modifications and alterations also fall within the scope of the present application. [Explanation of Symbols]
[0028] 10 1st electrode 11. Semiconductor Area 2 12. Semiconductor Area 1 13. First crystal defect region 14. Third Semiconductor Area 15 2nd electrode 16 Third electrode 17. Fifth Semiconductor Area 18. Fourth Semiconductor Area 19. Second crystal defect region 20. Semiconductor Area 6 21 4th electrode 100 First diode 200 Second diode 300 Composite Semiconductor Devices S1 First switch S2 Second Switch
Claims
1. The first semiconductor region, A second semiconductor region of a second conductivity type provided on the first semiconductor region, A third semiconductor region of a first conductivity type is provided on the first semiconductor region opposite to the second semiconductor region, and has a higher impurity concentration than the first semiconductor region. A first electrode electrically connected to the second semiconductor region, A second electrode electrically connected to the third semiconductor region, A first crystal defect region provided within the region of the first semiconductor region, A first diode having, The fourth semiconductor area, A fifth semiconductor region of a second conductivity type is provided on the fourth semiconductor region and has an impurity concentration higher than that of the second semiconductor region, A sixth semiconductor region of a first conductivity type is provided on the fourth semiconductor region opposite to the fifth semiconductor region, and has a higher impurity concentration than the fourth semiconductor region. A third electrode electrically connected to the fifth semiconductor region, A fourth electrode electrically connected to the sixth semiconductor region, A second crystal defect region is provided within the fourth semiconductor region and has a lower crystal defect density than the first crystal defect region, A second diode having, Includes, The combination of the first electrode and the second electrode, or one of the combinations of the first electrode and the second electrode, is electrically connected to each other. A composite semiconductor device including a switch that causes the first diode and the second diode to operate at different timings.
2. The composite semiconductor device according to claim 1, characterized in that the thickness of the fifth semiconductor region is greater than the thickness of the second semiconductor region.
3. In the composite semiconductor device according to claim 1 or 2, A method for driving a composite semiconductor device, characterized in that the second diode is turned off before the first diode.
3. In the composite semiconductor device according to claim 1 or 2, A method for driving a composite semiconductor device, characterized in that the second diode is turned on before the first diode.