Insulated gate bipolar transistor
By introducing a groove structure and optimizing the doping type in the insulated gate bipolar transistor, the problems of reduced cell size and high on-resistance were solved, resulting in higher cell density and reverse breakdown voltage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAMEN SILAN ADVANCED COMPOUND SEMICON CO LTD
- Filing Date
- 2025-05-06
- Publication Date
- 2026-06-16
Smart Images
Figure CN224368219U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of integrated circuits, specifically to an insulated gate bipolar transistor. Background Technology
[0002] Insulated-gate bipolar transistors (MOSFETs) can withstand high current and high voltage, and are widely used in electric vehicles, photovoltaic inverters, and charging piles. MOSFETs are further divided into planar gate and trench gate structures. For planar gate MOSFETs, reducing the cell pitch is the main method to improve the device's conduction capability. The design of the emitter conductor width is limited by the ohmic contact resistivity of the emitter region and the body contact region. There is a need in the art to provide a design that reduces the cell pitch without increasing the on-resistance. Utility Model Content
[0003] This application provides an insulated gate bipolar transistor that reduces cell size, thereby increasing cell density, reducing on-resistance, and enhancing reverse breakdown voltage.
[0004] An insulated-gate bipolar transistor (IGBT) includes a plurality of cells, the cells comprising:
[0005] The substrate includes opposing first and second surfaces, and the substrate is of a first doping type.
[0006] An epitaxial layer is formed on the first surface of the substrate, and the epitaxial layer is of the first doping type;
[0007] The drift region extends from the first surface of the epitaxial layer into the epitaxial layer. The drift region is of the first doping type, and the doping concentration of the drift region is higher than that of the epitaxial layer.
[0008] The body region extends from the surface of the drift region into the drift region, and the body region is of the second doping type;
[0009] A groove extends downward from the upper surface of the middle of the body region, and the depth of the groove is a first distance, which is less than the depth of the body region.
[0010] The emitter region extends downward from the lower surface of the groove into part of the body region, and the emitter region is of the first doping type;
[0011] The body contact region extends from the lower surface of the groove to the bottom of the body region. The body contact region is in contact with the emitter region. The body contact region is located in the middle area of the body region, and the emitter region is located on both sides of the body contact region. The body contact region is a second doping type, and the doping concentration of the body contact region is higher than that of the drift region.
[0012] A collector implantation region is formed on the second surface of the substrate, and the collector implantation region has a second doping type;
[0013] A first insulating dielectric layer covers a portion of the body region, the sidewall of the groove, and the surface of a portion of the emission region.
[0014] Gate polycrystalline, where the gate polycrystalline layer covers part or all of the first insulating dielectric layer;
[0015] The second insulating dielectric layer covers: the gate polycrystalline structure, the emitter region not covered by the first insulating dielectric layer, the first insulating dielectric layer not covered by the gate polycrystalline structure, and the drift region not covered by the first insulating dielectric layer.
[0016] Preferably, the cell further includes:
[0017] The emitter leads out a first metal from the second opening of the second insulating dielectric layer, and the first metal is connected to a portion of the emitter region and the body contact region.
[0018] The gate electrode is led out from the first opening in the first insulating dielectric layer, and the second metal is polycrystalline connected to the gate electrode.
[0019] The collector electrode is located on the second surface of the substrate.
[0020] Preferably, the opening of the groove on the first surface of the epitaxial layer is a first opening, and the opening of the groove in the drift region is a second opening, wherein the width of the first opening is greater than or equal to that of the second opening.
[0021] Preferably, the epitaxial layer is one of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), carbon (C), and gallium arsenide (GaAs).
[0022] Preferably, the substrate is one of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), carbon (C), aluminum nitride (AlN), gallium arsenide (GaAs), and sapphire.
[0023] Preferably, the body area of the bottom surface of the groove, the sidewall of the groove, and the top of the body area adjacent to the groove form a channel, and the channel is stepped.
[0024] Preferably, the groove length of the body area portion at the bottom of the groove is the first groove distance, the groove length of the sidewall portion of the groove is the second groove distance, and the groove length of the top portion of the body area adjacent to the groove is the third groove distance.
[0025] Preferably, the distance from the body contact center to the edge of the body region is the fourth distance, and the sum of the first groove distance and the third groove distance is 20%-40% of the fourth distance.
[0026] Preferably, along the direction perpendicular to the substrate, the depth of the body region is the fifth distance, and the distance of the third channel is 5%-60% of the fifth distance.
[0027] Preferably, along the direction perpendicular to the substrate, the depth of the body region is the fifth distance, and the distance of the third channel is 20%-40% of the fifth distance.
[0028] Preferably, the body contact area extends from the surface of the emission area to the bottom of the body area and extends through the bottom of the body area into the drift area.
[0029] Preferably, the first distance is 5%-60% of the depth of the body region.
[0030] Preferably, the doping concentration of the collector implantation region is greater than the doping concentration of the substrate, and the doping depth of the collector implantation region is less than or equal to 50% of the doping depth of the substrate.
[0031] The insulated gate bipolar transistor provided in this application reduces the horizontal length of the channel and the cell size by setting a groove structure, thereby increasing the cell density, reducing the on-resistance, and enhancing the reverse withstand voltage. Attached Figure Description
[0032] The above and other objects, features, and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:
[0033] Figure 1 A cross-sectional view of an insulated gate bipolar transistor according to the first embodiment of this application is shown;
[0034] Figure 2 A partial cross-sectional view of an insulated gate bipolar transistor according to the first embodiment of this application is shown;
[0035] Figures 3-10 A cross-sectional view showing the manufacturing process of the insulated gate bipolar transistor according to the first embodiment of this application is shown;
[0036] Figure 11 A cross-sectional view of an insulated gate bipolar transistor according to a second embodiment of this application is shown; Detailed Implementation
[0037] The present application is described below based on embodiments, but it is not limited to these embodiments. In the detailed description of the present application below, certain specific details are described in detail. Those skilled in the art can fully understand the present application without these details. To avoid obscuring the substance of the present application, well-known methods, processes, flows, elements, and circuits are not described in detail.
[0038] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.
[0039] Unless the context explicitly requires it, words such as "including" or "contains" throughout the application should be interpreted as including rather than exclusive or exhaustive; that is, meaning "including but not limited to".
[0040] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0041] Figure 1 , Figure 11 This is a cross-sectional view of the insulated gate bipolar transistor of this utility model.
[0042] like Figure 1 and Figure 2 As shown, the insulated gate bipolar transistor of the first embodiment of this application includes a plurality of cells, the cells including:
[0043] Substrate 101, which includes opposing first and second surfaces, is of a first doping type;
[0044] Epitaxial layer 103 is formed on the first surface of substrate 101, and epitaxial layer 103 is of the first doping type;
[0045] Drift region 105, the doping concentration of drift region 105 is higher than the doping concentration of epitaxial layer 103, drift region 105 extends from the first surface of epitaxial layer 103 into epitaxial layer 103, drift region 105 is of the first doping type;
[0046] Body region 107 extends from the surface of drift region 105 into drift region 105. Body region 107 is located on both sides of the cell and is a second doping type.
[0047] The groove extends downward from the upper surface in the middle of the body region 107, and the depth of the groove is a first distance, which is less than the depth of the body region 107.
[0048] The emitter region 109 extends from the lower surface of the groove into the body region 107, and the emitter region 109 is of the first doping type.
[0049] Body contact region 121 extends from the lower surface of the groove to the bottom of body region 107. Body contact region 121 is in contact with emitter region 109. Body contact region 121 is located in the middle region of body region 107. Emitter region 109 is located on both sides of body contact region 121. Body contact region 121 is of the second doping type. The doping concentration of body contact region 121 is higher than that of drift region 105.
[0050] Collector implantation region 102 is formed on the second surface of substrate 101, and collector implantation region 102 has a second doping type.
[0051] In some embodiments, the doping concentration of the collector injection region 102 is greater than the doping concentration of the substrate 101, and the doping depth of the collector injection region 102 is less than or equal to 50% of the doping depth of the substrate 101.
[0052] The insulated gate bipolar transistor further includes: a first insulating dielectric layer 113, which covers the surface of a portion of the drift region 105, a portion of the body region 107, the groove sidewall, and a portion of the emitter region 109; the first insulating gate dielectric layer 113 is a gate oxide dielectric layer or a gate nitride dielectric layer.
[0053] Gate polycrystalline 115, gate polycrystalline 115 covers part or all of the first insulating dielectric layer 113;
[0054] The second insulating dielectric layer 117 covers the gate polycrystalline 115, the emitter region 109 not covered by the first insulating dielectric layer 113, the first insulating dielectric layer 113 not covered by the gate polycrystalline 115, and the drift region not covered by the first insulating dielectric layer.
[0055] Insulated gate bipolar transistors also include:
[0056] The emitter 119 is led out from the second opening of the second insulating dielectric layer 117 and connected to the emitter 109 at the junction of the first metal contact area 121 and part of the contact area 121.
[0057] The gate (not shown in the figure) is led out from the first opening of the first insulating dielectric layer 113 and connected to the gate polycrystalline 115 through the second metal;
[0058] Collector 111 is located in collector injection region 102.
[0059] like Figure 11 The opening of the groove on the first surface of the epitaxial layer 103 is a first opening, and the opening of the groove in the drift region 105 is a second opening, as described above. Figure 11 The width of the first opening shown is greater than that of the second opening.
[0060] The epitaxial layer 103 is one of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), carbon (C), and gallium arsenide (GaAs).
[0061] The substrate 101 is one of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga2O3), carbon (C), aluminum nitride (AlN), gallium arsenide (GaAs), and sapphire.
[0062] The body area 107 at the bottom of the groove, the sidewall of the groove, and the top of the body area 107 form a channel.
[0063] The length of the groove in the body area 107 at the bottom of the groove is the first groove distance, the length of the groove on the side wall of the groove is the second groove distance, and the length of the groove at the top of the body area 107 is the third groove distance.
[0064] The distance from the body contact center to the edge of body region 107 is the fourth distance, and the sum of the distances of the first and third channels is 20%-40% of the fourth distance.
[0065] Along the direction perpendicular to the substrate 101, the depth of the body region 107 is the fifth distance, and the distance of the third channel is 5%-60% of the fifth distance.
[0066] Along the direction perpendicular to the substrate 101, the depth of the body region 107 is the fifth distance, and the third channel distance is 20%-40% of the fifth distance.
[0067] The body contact area 121 extends from the surface of the emission area 109 to the bottom of the body area 107 and extends through the bottom of the body area 107 into the drift area 105.
[0068] The groove extends downward from the middle surface of the body region 107 by a first distance, which is 5%-60% of the depth of the body region 107.
[0069] like Figure 1 As shown, the pitch between the emitter conductors of two adjacent cells is the cell pitch of this insulated-gate bipolar transistor. The drift region between the body regions of the two cells is the JFET region. The smaller the width of the JFET region and the width of the emitter conductor, the smaller the cell pitch and the higher the cell density. As mentioned before, the width of the JFET region is limited by the design requirements of the JFET region resistance and the total on-resistance, and the width of the emitter conductor is limited by the ohmic contact resistivity of the emitter region and the body contact region. Therefore, the reduction of the cell pitch is limited.
[0070] This application discloses an insulated gate bipolar transistor (IGBT) having a groove, wherein a body region 107 portion at the bottom of the groove, the sidewalls of the groove, and the top of the body region 107 form a channel. The body region 107 portion at the bottom of the groove is the first channel distance D1, the sidewalls of the groove are the second channel distance D2, and the top of the body region 107 is the third channel distance D3. The distance from the center of the body contact to the edge of the body region 107 is a fourth distance D4, and the sum of the first channel distance D1 and the third channel distance D3 is 20%-40% of the fourth distance D4. Along a direction perpendicular to the substrate 101, the depth of the body region 107 is a fifth distance D5, and the third channel distance is 5%-60% of the fifth distance D5. Preferably, along a direction perpendicular to the substrate 101, the depth of the body region 107 is the fifth distance D5, and the third channel distance D3 is 20%-40% of the fifth distance D5.
[0071] The groove extends downward from the middle surface of the body region 107, and the groove depth is the first distance D11. The first distance D11 is 5%-60% of the fifth distance D5 of the depth of the body region 107.
[0072] This application reduces the horizontal length of the channel, decreases the cell size, thereby increasing the cell density, reducing the on-resistance, and enhancing the reverse withstand voltage.
[0073] In this application, the first doping type is one of N-type doping and P-type doping, and the second doping type is the other of N-type doping and P-type doping. N-type doping can be selected from the following substances: nitrogen, phosphorus, arsenic, antimony, bismuth, and combinations thereof, while P-type doping can be selected from the following substances: boron, aluminum, gallium, indium, thallium, and combinations thereof.
[0074] In some embodiments, the doping concentration of the SiC substrate 101 is greater than the doping concentration of the SiC epitaxial layer 103.
[0075] The materials of the first insulating dielectric layer and the second insulating dielectric layer are, for example, silicon oxide, silicon nitride, etc.
[0076] Figure 1 , Figure 2 and Figure 11 The red line in the image shows a portion of the channel of an insulated-gate bipolar transistor (IGBT). The channel of an IGBT is stepped.
[0077] like Figures 3 to 10 The following is a method for manufacturing the insulated gate bipolar transistor of this invention:
[0078] like Figure 3 As shown, a substrate 101 is provided, the substrate 101 includes a first surface and a second surface opposite to each other, and the substrate 101 is of a first doping type.
[0079] An epitaxial layer 103 is formed on the first surface of the substrate 101, and the epitaxial layer 103 is of the first doping type.
[0080] like Figure 4 As shown, a drift region 105 is formed. The doping concentration of the drift region 105 is higher than that of the epitaxial layer 103. The drift region 105 extends from the first surface of the epitaxial layer 103 into the epitaxial layer 103. The drift region 105 is of the first doping type.
[0081] like Figure 5 As shown, a body region 107 is formed, which extends from the surface of the drift region 105 into the drift region 105. The body region 107 is located on both sides of the cell and is a second doping type.
[0082] like Figures 6-7 As shown, a groove is formed, which extends downward from the upper surface in the middle of the body region 107. The depth of the groove is a first distance D1, and the depth of the first distance D1 is less than the depth of the body region 107.
[0083] The emitter region 109 extends from the lower surface of the groove into the body region 107, and the emitter region 109 is of the first doping type.
[0084] Body contact region 121 extends from the lower surface of the groove to the bottom of body region 107. Body contact region 121 is in contact with emitter region 109. Body contact region 121 is located in the middle region of body region 107. Emitter region 109 is located on both sides of body contact region 121. Body contact region 121 is of the second doping type. The doping concentration of body contact region 121 is higher than that of drift region 105.
[0085] like Figures 8-10 As shown, a first insulating dielectric layer 113 is formed, which covers the surface of a portion of the drift region 105, a portion of the body region 107, the groove sidewall, and a portion of the emitter region 109; the first insulating gate dielectric layer 113 is a gate oxide dielectric layer or a gate nitride dielectric layer.
[0086] A gate polycrystalline 115 is formed, which covers part or all of the first insulating dielectric layer 113.
[0087] A second insulating dielectric layer 117 is formed, which covers the gate polycrystalline 115, the emitter region 109 not covered by the first insulating dielectric layer 113, the first insulating dielectric layer 113 not covered by the gate polycrystalline 115, and the drift region not covered by the first insulating dielectric layer.
[0088] A doped layer 102 is formed on the second surface of the substrate 101. A collector electrode 111 is formed on the doped layer 102.
[0089] like Figure 11 As shown, the opening of the groove on the first surface of the epitaxial layer 103 is the first opening, and the opening of the groove in the drift region 105 is the second opening, as... Figure 7 The width of the first opening shown is greater than that of the second opening.
[0090] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. An insulated-gate bipolar transistor, the insulated-gate bipolar transistor comprising a plurality of cells, characterized in that, The cells include: A substrate, the substrate comprising opposing first and second surfaces, the substrate being of a first doping type; An epitaxial layer is formed on a first surface of the substrate, and the epitaxial layer is of a first doping type; A drift region extends from the first surface of the epitaxial layer into the epitaxial layer, the drift region being of a first doping type, and the doping concentration of the drift region being higher than the doping concentration of the epitaxial layer; A body region extending from the surface of the drift region into the drift region, wherein the body region is of the second doping type; A groove extends downward from the upper surface of the middle of the body region, and the depth of the groove is a first distance, which is less than the depth of the body region; The emission region extends downward from the lower surface of the groove into a portion of the body region, and the emission region is of a first doping type; The body contact region extends from the lower surface of the groove to the bottom of the body region, the body contact region contacts the emitter region, the body contact region is located in the middle region of the body region, the body contact region is of the second doping type, and the doping concentration of the body contact region is higher than that of the drift region; A first insulating dielectric layer covers a portion of the body region, the sidewall of the groove, and the surface of a portion of the emission region; Gate polycrystalline, wherein the gate polycrystalline material covers part or all of the first insulating dielectric layer; The second insulating dielectric layer covers: the gate polycrystalline structure, the emission region not covered by the first insulating dielectric layer, the first insulating dielectric layer not covered by the gate polycrystalline structure, and the drift region not covered by the first insulating dielectric layer. A collector implantation region is formed on the second surface of the substrate, and the collector implantation region has a second doping type.
2. The insulated gate bipolar transistor according to claim 1, characterized in that, Also includes: An emitter, wherein a first metal is led out from a second opening in the second insulating dielectric layer, and the first metal is connected to a portion of the emitter region and the body contact region; A gate electrode, wherein a second metal is led out from a first opening in the first insulating dielectric layer, and the second metal is polycrystalline connected to the gate electrode. Collector, the collector being located in the collector injection region.
3. The insulated gate bipolar transistor according to claim 1, characterized in that, The opening of the groove on the first surface of the epitaxial layer is a first opening, and the opening of the groove in the drift region is a second opening, wherein the width of the first opening is greater than or equal to the width of the second opening.
4. The insulated gate bipolar transistor according to claim 1, characterized in that, The epitaxial layer is one of silicon, silicon carbide, gallium nitride, gallium oxide, carbon, and gallium arsenide.
5. The insulated gate bipolar transistor according to claim 1, characterized in that, The substrate is one of silicon, silicon carbide, gallium nitride, gallium oxide, carbon, aluminum nitride, gallium arsenide, and sapphire.
6. The insulated gate bipolar transistor according to claim 1, characterized in that, The body area of the bottom surface of the groove, the sidewall of the groove, and the top of the body area adjacent to the groove form a channel, which is stepped.
7. The insulated gate bipolar transistor according to claim 6, characterized in that, The groove length of the body area portion at the bottom of the groove is the first groove distance, the groove length of the sidewall portion of the groove is the second groove distance, and the groove length of the top portion of the body area portion adjacent to the groove is the third groove distance.
8. The insulated gate bipolar transistor according to claim 7, characterized in that, The distance from the center of the body contact area to the edge of the body area is the fourth distance, and the sum of the first channel distance and the third channel distance is 20%-40% of the fourth distance.
9. The insulated gate bipolar transistor according to claim 7, characterized in that, Along a direction perpendicular to the substrate, the depth of the body region is a fifth distance, and the third channel distance is 5%-60% of the fifth distance.
10. The insulated gate bipolar transistor according to claim 7, characterized in that, Along a direction perpendicular to the substrate, the depth of the body region is a fifth distance, and the third channel distance is 20%-40% of the fifth distance.
11. The insulated gate bipolar transistor according to claim 1, characterized in that, The body contact area extends from the surface of the emission area to the bottom of the body area and through the bottom of the body area into the drift area.
12. The insulated gate bipolar transistor according to claim 1, characterized in that, The first distance is 5%-60% of the depth of the body region.
13. The insulated gate bipolar transistor according to claim 1, characterized in that, The doping concentration of the collector implantation region is greater than that of the substrate, and the doping depth of the collector implantation region is less than or equal to 50% of the doping depth of the substrate.