CN118248732A - Semiconductor device with a semiconductor layer having a plurality of semiconductor layers - Google Patents

Abstract

The application provides a semiconductor device, which comprises a substrate, a semiconductor epitaxial layer and a terminal doping structure. The terminal doping structure is arranged in an edge terminal area of the semiconductor epitaxial layer, and comprises a main junction structure surrounding the outside of the active area and a plurality of fork-shaped structures arranged on a first side and a second side opposite to the main junction structure; wherein, two adjacent fork structures are arranged at intervals. Specifically, through the arrangement, when the device receives reverse voltage, the fork-shaped structure that the main junction structure is connected with the main junction forms a reverse-biased PN junction with the semiconductor epitaxial layer, compared with a floating field limiting ring, the formed PN junction is stronger in built-in electric field and can bear stronger reverse electric field, so that the effect of protecting the device from early reverse breakdown can be realized by smaller terminal area.

Description

Semiconductor device with a semiconductor layer having a plurality of semiconductor layers

Technical Field

The application relates to the technical field of semiconductors, in particular to a semiconductor device.

Background

A MOSFET (metal oxide semiconductor field effect transistor) is a commonly used semiconductor device, has characteristics of high voltage, high electric field, high current, and has advantages of high speed, low power consumption, reliability, and the like, and is widely used in electronic devices and integrated circuits.

In some specific high power applications, termination protection techniques are required to protect the MOSFET from over-voltage or over-current; in the traditional field limiting ring terminal protection technology, a plurality of field limiting rings encircle an active region to form protection, and the high electric field of the active region is gradually released through the ring spacing by controlling the ring width and the ring spacing to form a plurality of lower electric field peaks, so that the device is protected from being directly broken down by the high electric field.

However, as the number of field limiting rings increases, the bearing pressure of the peripheral rings is lower and lower, the voltage-resistant lifting effect on the device is poorer and poorer, and the waste of the chip area can be caused.

Disclosure of Invention

The application provides a semiconductor device capable of realizing an effect of protecting the device from early reverse breakdown with a smaller termination area.

In order to solve the technical problems, the application adopts a technical scheme that: provided is a semiconductor device including: a substrate; a semiconductor epitaxial layer disposed on the substrate, the substrate and the semiconductor epitaxial layer each having a first conductivity type, the semiconductor epitaxial layer comprising: an active region surrounding an edge termination region outside the active region; a termination doping structure disposed within the edge termination region and extending from the edge termination region surface in a first direction of the substrate, the termination doping structure having a second conductivity type, the termination doping structure comprising: a main junction structure surrounding the outside of the active region, and a plurality of fork-shaped structures disposed on opposite first and second sides of the main junction structure; the two adjacent fork-shaped structures are arranged at intervals, each fork-shaped structure comprises a main body part and at least two first fork-shaped parts, the first ends of the main body parts are connected with the main junction structure, and the second ends of the main body parts extend towards a second direction deviating from the active area; the first bifurcation part is arranged at the second end of the main part and extends towards the second direction.

Compared with the prior art, the semiconductor device provided by the application has the beneficial effects that the semiconductor device comprises the terminal doping structure arranged in the edge terminal region, wherein the terminal doping structure comprises a main junction structure surrounding the outside of the active region, and a plurality of fork-shaped structures arranged on the first side and the second side opposite to the main junction structure; the active area is arranged in a first direction, and the active area is arranged in a second direction opposite to the first direction; the first bifurcation part is arranged at the second end of the main part and extends towards the second direction. Specifically, through the arrangement, when the device receives reverse voltage, the fork-shaped structure that the main junction structure is connected with the main junction forms a reverse-biased PN junction with the semiconductor epitaxial layer, compared with a floating field limiting ring, the formed PN junction is stronger in built-in electric field and can bear stronger reverse electric field, so that the effect of protecting the device from early reverse breakdown can be realized by smaller terminal area.

Drawings

For a clearer description of the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:

fig. 1 is a schematic structural diagram of a semiconductor device according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of an embodiment of a semiconductor epitaxial layer of a semiconductor device according to the present application at a first viewing angle;

FIG. 3 is a cross-sectional view of one embodiment of a semiconductor device according to the present application taken along line A-A in FIG. 2;

FIG. 4 is a schematic diagram of a terminal doping structure according to an embodiment of the present application;

FIG. 5 is an enlarged view of the structure of area B of FIG. 4;

FIG. 6 is a schematic diagram of another embodiment of a terminal doping structure according to the present application;

FIG. 7 is a schematic diagram of a structure of a terminal doping structure according to another embodiment of the present application;

FIG. 8 is a schematic diagram of a structure of a terminal doping structure according to another embodiment of the present application;

Fig. 9 is an enlarged view of the structure of the region C in fig. 8.

Description of the reference numerals:

A semiconductor device-100; a substrate-10; a semiconductor epitaxial layer-20; terminal doping structure-30; a main junction structure-31; fork-shaped structure-32; a main part-321; a first bifurcation portion-322; a second split-323; bar-shaped doping structures-33; fork tooth structure-34; a main body part-341; a first split-342; a first metal layer-40; dielectric layer-50; a second metal layer-60; gate structure-70, gate-61; a gate insulating layer-62; p contact region-80; p-type base region-90.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms "first," "second," "third," and the like in this disclosure are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. All directional indications (such as up, down, left, right, front, back … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement, etc. between the components in a particular gesture (as shown in the drawings), and if the particular gesture changes, the directional indication changes accordingly. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Referring to fig. 1-4, fig. 1 is a schematic structural diagram of a semiconductor device according to an embodiment of the present application; fig. 2 is a schematic structural diagram of an embodiment of a semiconductor epitaxial layer of a semiconductor device according to the present application at a first viewing angle; FIG. 3 is a cross-sectional view of one embodiment of a semiconductor device according to the present application taken along line A-A in FIG. 2; fig. 4 is a schematic structural diagram of an embodiment of a terminal doping structure according to the present application.

The present application provides a semiconductor device 100, wherein the semiconductor device 100 comprises a substrate 10, a semiconductor epitaxial layer 20 and a termination doping structure 30.

Wherein the semiconductor epitaxial layer 20 is disposed on the substrate 10, and the substrate 10 and the semiconductor epitaxial layer 20 each have a first conductivity type.

In some embodiments, the material of the substrate 10 includes one of silicon, silicon carbide, gallium nitride, and the like, without limitation.

The semiconductor epitaxial layer 20 includes an active region and an edge termination region, wherein the edge termination region is understood to be a termination structure region of the semiconductor device 100, and the edge termination region surrounds the active region.

The active region shown in fig. 1 is only an example, and specifically, the structure and function of the active region of the present application are identical to those of the active region of the semiconductor device in the prior art, which is not described herein.

Wherein the termination doping structure 30 is disposed within the edge termination region and extends from the edge termination region surface toward the first direction of the substrate 10, the termination doping structure 30 having the second conductivity type.

One of the first conductivity type and the second conductivity type is a P-type doped semiconductor, and the other is an N-type doped semiconductor. The application takes the first conductive type as N-type doped semiconductor and the second conductive type as P-type doped semiconductor as an example.

In one embodiment, the termination doping structure 30 includes: surrounding the main junction structure 31 outside the active region, and a number of fork structures 32 arranged on opposite first and second sides of the main junction structure 31.

The first side and the second side opposite to each other of the main junction structure 31 may be any opposite sides of the main junction structure 31, which is not limited herein. Preferably, the fork structures 32 are disposed on two opposite long sides of the main knot structure 31, so that the number of the fork structures 32 can be increased.

With reference to fig. 4, two adjacent fork structures 32 are disposed at intervals, and each fork structure 32 includes a main portion 321 and at least two first branch portions 322, a first end of the main portion 321 is connected with the main junction structure 31, and a second end of the main portion 321 extends toward a second direction away from the active area; the first bifurcation portion 322 is disposed at the second end of the trunk portion 321 and extends toward the second direction.

Specifically, the embodiment of the present application has the following advantages by providing the terminal doping structure 30 in the edge termination region, and the terminal doping structure 30 includes a main junction structure 31 surrounding the outside of the active region, and a plurality of fork structures 32 disposed on the opposite first and second sides of the main junction structure 31:

1. When the device receives reverse voltage, the fork-shaped structure 32, which is connected with the main junction structure 31, and the main junction structure 31 forms a reverse-biased PN junction with the semiconductor epitaxial layer 20, and compared with a floating field limiting ring, the formed PN junction has stronger built-in electric field and can bear stronger reverse electric field; 2. the plurality of fork structures 32 are spaced apart, meaning that the electric field can extend outwardly along the spacing of the fork structures 32, the electric field being continuously reduced by the resistance of the semiconductor epitaxial layer 20 as it approaches the outer edge of the edge termination region, down to a safe electric field. Specifically, the electric field is directed outward in the second direction until the forked structures 32 diverge, where the electric field is "intercepted" to form an electric field spike, a portion of the electric field extends outward from the middle of the forked structures 32 beyond the built-in electric field formed by the forked structures 32 and the semiconductor epitaxial layer 20, and a portion of the electric field is "dredged" outward from the spaces between the forked structures 32 until it is as low as a safe electric field. Thus, the application can realize the effect of protecting the device from early reverse breakdown with smaller terminal area by arranging the terminal doping structure 30 in the edge terminal area.

Referring to fig. 3, in an embodiment, semiconductor device 100 further includes a first metal layer 40 and a dielectric layer 50. Wherein the first metal layer 40 is at least partially disposed on the surface of the main junction structure 31 and extends to the surface of the active region; the dielectric layer 50 is disposed on at least a portion of the surface of the edge termination region, and the dielectric layer 50 is connected to the first metal layer 40.

In some embodiments, the main junction structure 31 may be located entirely under the first metal layer 40; or the main junction structure 31 is at least below the junction of the dielectric layer 50 and the first metal layer 40.

Wherein the first metal layer 40 may be the source of the device.

Wherein, in the present application, reference numeral 70 denotes a gate structure of an active region, which includes a gate electrode 61 and a gate insulating layer 62; reference numeral 80 denotes a P contact region of the active region; reference numeral 90 denotes the P-type base region of the active region. The P-type base region 90 may be connected to or spaced from the main junction structure 31, which is not limited herein, and the P-type base region 90 is spaced from the main junction structure 31.

Specifically, the main junction structure 31 is connected with the first metal layer 40, and the fork-shaped structure 32 is connected with the main junction structure 31, when the device is subjected to reverse voltage, the fork-shaped structure 32 and the semiconductor epitaxial layer 20 form a reverse-biased PN junction, and the formed PN junction has stronger built-in electric field and can bear stronger reverse electric field; in addition, the plurality of fork structures 32 are spaced apart, which means that the electric field of the source region can extend outwards along the spacing of the fork structures 32, and the electric field is continuously reduced by the resistance of the semiconductor epitaxial layer 20 as it approaches the outer edge of the edge termination region until the electric field is as low as a safe electric field, so that the effect of protecting the device from early reverse breakdown can be achieved with a smaller termination area.

With continued reference to fig. 3, in one embodiment, the semiconductor device 100 further includes a second metal layer 60, the second metal layer 60 being located on a side of the substrate 10 facing away from the semiconductor epitaxial layer 20. Wherein the second metal layer 60 may be the device drain.

Referring to fig. 5, fig. 5 is an enlarged view of the structure of the region B in fig. 4. In one embodiment, the fork structures 32 are identical in structure and size; the spacing L1 between two adjacent fork structures 32 is the same.

Specifically, by setting the structures and the dimensions of the plurality of fork-shaped structures 32 to be the same, and the distances between two adjacent fork-shaped structures 32 to be the same, the consistency of blocking and dredging of the reverse electric field in different regions of the terminal doping structure 30 can be improved, and the effect that the protection device does not generate advanced reverse breakdown is achieved.

With continued reference to fig. 5, in one embodiment, a distance L1 between two adjacent fork structures 32 is less than or equal to a distance L2 between the second ends of two adjacent first fork portions 322 in each fork structure 32. For example, the distance L1 between two adjacent fork structures 32 is less than the distance L2 between the second ends of two adjacent first prongs 322 in each fork structure 32. For another example, the distance L1 between two adjacent fork structures 32 is equal to the distance L2 between the second ends of two adjacent first prongs 322 in each fork structure 32.

With continued reference to fig. 5, in some embodiments, the distance L3 between two adjacent stems 321 is greater than the distance L1 between two adjacent fork structures 32. And/or, the distance L3 between two adjacent trunk portions 321 is greater than the distance L2 between the second ends of two adjacent first bifurcation portions 322 in each fork-like structure 32.

Specifically, by providing the distance L3 between two adjacent trunk portions 321, it is greater than the distance L1 between two adjacent fork-like structures 32; and/or, the distance L3 between two adjacent trunk portions 321 is greater than the distance L2 between the second ends of two adjacent first bifurcation portions 322 in each fork structure 32, so that the interval between the adjacent fork structures 32 near the end of the main junction structure 31 is wider, the depletion electric field between the fork structures 32 is lower, the electric field is outwards along the second direction until the bifurcation of the fork structures 32, the electric field can be "intercepted" at the bifurcation to form an electric field peak, a part of the electric field crosses the built-in electric field formed by the fork structures 32 and the semiconductor epitaxial layer 20, extends outwards from the middle of the fork structures 32, and a part of the electric field is outwards "dredged" from the interval between the fork structures 32 until the electric field is as low as a safe electric field. Thus, the application can realize the effect of protecting the device from early reverse breakdown with smaller terminal area by arranging the terminal doping structure 30 in the edge terminal area.

Referring to fig. 5-7, fig. 6 is a schematic structural diagram of another embodiment of a terminal doping structure provided by the present application, and fig. 7 is a schematic structural diagram of another embodiment of a terminal doping structure provided by the present application.

In some embodiments, each prong 32 is an axisymmetric pattern, and the axis of symmetry of each prong 32 coincides with the direction of extension of the stem 321 in that prong 32.

Specifically, by setting each fork-shaped structure 32 to be an axisymmetric pattern, the design of the fork-shaped structure 32 can be optimized, the space waste of the edge terminal region can be reduced, and the consistency of the different regions of the terminal doping structure 30 on the interception and the dispersion of the reverse electric field can be improved.

With continued reference to fig. 5, in some embodiments, two first prongs 322 are included in each prong 32, and a first included angle α1 is formed between the two first prongs 322 in each prong 32, and the angle of the first included angle α1 ranges from 120 ° to 150 °.

In one embodiment, the doping concentration of the fork structure 32 is reduced in the second direction. For example, in the second direction, the doping concentration of the fork structure 32 may gradually decrease, or may decrease stepwise.

Referring to fig. 6, in some embodiments, each fork structure 32 may further include three first prongs 322, or more first prongs 322, where first ends of the first prongs 322 in each fork structure 32 are connected to second ends of the trunk 321, and second ends of the first prongs 322 in each fork structure 32 extend toward the second direction and are spaced apart.

Referring to fig. 7, in some embodiments, each fork structure 32 further includes a number of second prongs 323; the first end of the first bifurcation portion 322 is connected to the second end of the trunk portion 321, the second end of the first bifurcation portion 322 extends toward the second direction, and at least two second bifurcation portions 323 are disposed at the second end of the first bifurcation portion 322 and extend toward the second direction.

Specifically, at least two second bifurcation portions 323 are disposed at the second end of each first bifurcation portion 322, and the plurality of second bifurcation portions 323 on the second end of each first bifurcation portion 322 further extend toward the second direction and are disposed at intervals.

As shown in fig. 7, in an embodiment, each fork structure 32 includes two first bifurcation portions 322, and a first included angle α1 is formed between the two first bifurcation portions 322 in each fork structure 32; and the second end of each first bifurcation portion 322 is provided with two second bifurcation portions 323, and a second included angle α2 is formed between the two second bifurcation portions 323, where the angle of the second included angle α2 is the same as the angle of the first included angle α1 between the two first bifurcation portions 321 on the same bifurcation structure 32. And the angular range is 120-150 deg..

Of course, in other embodiments, each main junction structure 31 may further include a plurality of x-th bifurcation portions, the x-th bifurcation portions are disposed at a second end of the (x-1) -th bifurcation portion, and the second end of the (x-1) -th bifurcation portion is at least provided with two x-th bifurcation portions, and the plurality of x-th bifurcation portions extend towards the second direction and are disposed at intervals. And are not limited herein.

Specifically, by changing the doping concentration gradient of the fork structure 32, the branching manner of the fork structure 32, and/or the branching number of the fork structure 32, the terminal doping structure 30 can bear a stronger reverse electric field, and the electric field is continuously reduced by the resistance of the semiconductor epitaxial layer 20 along with approaching to the outer edge of the edge terminal region until reaching a safe electric field, so that the effect of protecting the device from early reverse breakdown can be achieved with a smaller terminal area.

Referring to fig. 2, in an embodiment, the terminal doping structure 30 further includes a plurality of stripe-shaped doping structures 33, the plurality of stripe-shaped doping structures 33 are symmetrically disposed on a third side and a fourth side opposite to the main junction structure 31, and two adjacent stripe-shaped doping structures 33 are spaced apart.

Specifically, the stripe-shaped doping structures 33 are similar to the principle of field limiting ring termination, by providing a plurality of stripe-shaped doping structures 33 spaced apart in the semiconductor epitaxial layer 20 to gradually release the electric field when the device is voltage-resistant, down to a safe electric field.

In addition, it can be appreciated that, because the electric field gradually decreases to the safe electric field along the third side or the fourth side of the main junction structure 31 as it approaches the outer edge of the edge termination region, the reverse electric field of the edge termination region in the second direction gradually decreases, and the pressure bearing of the stripe-shaped doped structure 33 closer to the outer edge of the edge termination region is smaller.

In this way, in order to reduce the manufacturing process and to save costs, in some embodiments, referring to fig. 2, the lengths of the plurality of strip-shaped doping structures 33 disposed on the same side of the main junction structure 31 in the second direction tend to decrease. For example, in the second direction, the lengths of the plurality of stripe-shaped doping structures 33 located at the same side of the main junction structure 31 gradually decrease, or stepwise decrease.

And/or, referring to fig. 5, in the second direction, the distance L4 between two adjacent stripe-shaped doping structures 33 tends to increase. For example, in the second direction, the distance L4 between two adjacent stripe-shaped doping structures 33 has a gradually increasing trend, or has a stepwise increasing trend.

And/or, referring to fig. 3, in the second direction, the depths H1 of the plurality of stripe-shaped doping structures 33 extending toward the first direction have a decreasing tendency. For example, in the second direction, the depths H1 of the plurality of stripe-shaped doping structures 33 extending toward the first direction have a gradually decreasing trend, or have a stepwise decreasing trend.

And/or, in the second direction, the doping concentration of the plurality of stripe-shaped doping structures 33 is in a decreasing trend. For example, in the second direction, the doping concentration of the plurality of stripe-shaped doping structures 33 gradually decreases, or decreases stepwise.

Specifically, as long as the plurality of strip-shaped doped structures 33 can realize the effect of gradually releasing the electric field when the device is voltage-resistant until the effect of the safety electric field is low, the doping concentration gradient of the plurality of strip-shaped doped structures 33, the intervals among the plurality of strip-shaped doped structures 33, the lengths and the depths of the plurality of strip-shaped doped structures 33 can be reasonably set so as to achieve the purposes of reducing the preparation process and saving the cost.

In one embodiment, referring to fig. 5, the distance L5 between the stripe-shaped doped structure 33 near the main junction structure 31 and the fork-shaped structure 32 near the edge of the main junction structure 31 is equal to the distance L1 between two adjacent fork-shaped structures 32; wherein the spacing L1 between two adjacent fork structures 32 is the same.

In an embodiment, please continue to refer to fig. 5, the widths W2 of the first branch portions 322 on the main junction structures 31 are the same, the widths W1 of the strip-shaped doped structures 33 are the same, and the width W2 of each strip-shaped doped structure 33 is the same as the width W1 of the first branch portion 322.

Referring to fig. 8 and 9, fig. 8 is a schematic structural diagram of a further embodiment of a terminal doping structure provided in the present application, and fig. 9 is an enlarged structural view of a region C in fig. 8.

In an embodiment, unlike the embodiment shown in fig. 2, the terminal doping structure 30 further comprises a number of tine structures 34 arranged on opposite third and fourth sides of the main junction structure 31.

In this embodiment, a plurality of fork-shaped structures 32 are disposed on two opposite long sides of the main structure 31, and a plurality of fork-shaped structures 34 are disposed on two opposite short sides of the main structure 31.

With continued reference to fig. 8, two adjacent tine structures 34 are disposed at intervals, and each tine structure 34 includes a main body portion 341 and at least two first separation portions 342, a first end of the main body portion 341 is connected to the main junction structure 31, and a second end of the main body portion 341 extends toward a second direction away from the active region; the first separating portion 342 is disposed at the second end of the main body portion 341 and extends toward the second direction.

Specifically, the embodiment of the present application has the following advantages by providing the terminal doping structure 30 in the edge termination region, and the terminal doping structure 30 includes the main junction structure 31 surrounding the active region, the fork structures 32 disposed on the opposite first and second sides of the main junction structure 31, and the fork structures 34 disposed on the opposite third and fourth sides of the main junction structure 31:

1. When the device is subjected to reverse voltage, the fork-shaped structure 32 and the fork-shaped structure 34, which are connected with the main junction structure 31, form a reverse-biased PN junction with the semiconductor epitaxial layer 20, and compared with a floating field limiting ring, the formed PN junction has stronger built-in electric field and can bear stronger reverse electric field; 2. the plurality of fork structures 32 and the plurality of fork structures 34 are each spaced apart, meaning that the electric field may extend outwardly along the plurality of fork structures 32 and the plurality of fork structures 34, the electric field being continuously reduced by the resistance of the semiconductor epitaxial layer 20 as it approaches the outer edge of the edge termination region until it is as low as a safe electric field. Specifically, the electric field is directed outward in the second direction until the fork structure 32 or the fork structure 34 is branched, and the electric field is "intercepted" at the branching to form an electric field peak, a portion of the electric field crosses the fork structure 32 or the fork structure 34, a built-in electric field formed with the semiconductor epitaxial layer 20 extends outward from the middle of the fork structure 32 or the fork structure 34, and a portion of the electric field is "dredged" outward from the spaces between the fork structures 32 or the fork structures 34 until the electric field is as low as a safe electric field. Thus, the application can realize the effect of protecting the device from early reverse breakdown with smaller terminal area by arranging the terminal doping structure 30 in the edge terminal area.

In one embodiment, the plurality of tine structures 34 are identical in structure and size; the spacing L6 between adjacent two tine formations 34 is the same.

In one embodiment, the structure and dimensions of the prong structure 34 are the same as the structure and dimensions of the prong structure 32.

Specifically, by arranging the plurality of fork-shaped structures 34 with the same structure and size as the fork-shaped structures 32, and the same spacing between two adjacent fork-shaped structures 34, the consistency of the different regions of the terminal doping structure 30 on blocking and dredging of the reverse electric field can be improved, and the effect that the protection device does not generate advanced reverse breakdown is realized.

Referring to fig. 9, in one embodiment, a distance L6 between two adjacent tine structures 34 is less than or equal to a distance L7 between second ends of two adjacent first separated portions 342 in each tine structure 34. For example, the distance L6 between two adjacent tine structures 34 is less than the distance L7 between the second ends of two adjacent first splits 342 in each tine structure 34. As another example, the distance L6 between two adjacent tine structures 34 is equal to the distance L7 between the second ends of two adjacent first splits 342 in each tine structure 34.

With continued reference to fig. 9, in some embodiments, the distance L8 between two adjacent body portions 341 is greater than the distance L6 between two adjacent tine structures 34. And/or, the distance L8 between two adjacent body portions 341 is greater than the distance L7 between the second ends of two adjacent first separation portions 342 in each tine formation 34.

Specifically, by providing the distance L8 between the adjacent two main body portions 341, it is larger than the distance L6 between the adjacent two tine structures 34; and/or, the distance L8 between two adjacent main body portions 341 is greater than the distance L7 between the second ends of two adjacent first separation portions 342 in each of the fork tooth structures 34, so that the space between the adjacent fork tooth structures 34 near the end of the main junction structure 31 is wider, the depletion electric field between the fork tooth structures 34 is lower, the electric field is outwards along the second direction until the fork tooth structures 34 are branched, the electric field can be intercepted at the branched position to form electric field peaks, a part of the electric field passes over the fork tooth structures 34 and forms a built-in electric field with the semiconductor epitaxial layer 20, extends outwards from the middle of the fork tooth structures 34, and a part of the electric field is outwards 'dredged' from the space between the fork tooth structures 34 until the electric field is as low as a safe electric field. Thus, the application can realize the effect of protecting the device from early reverse breakdown with smaller terminal area by arranging the terminal doping structure 30 in the edge terminal area.

In addition, it can be appreciated that, since the structure and the size of the fork-shaped structure 32 are the same as those of the fork-shaped structure 34 in the present application, the fork-shaped structure 34 in the present application can be further expanded to form the fork-shaped structure 34 similar to the fork-shaped structure 32 in fig. 6 or fig. 7, and the description thereof will be omitted.

Specifically, in the semiconductor device 100 provided by the application, the plurality of fork-shaped structures 32 are connected with the source region, when the device is voltage-resistant, a stronger built-in electric field can be formed by reverse bias to bear higher reverse voltage, the reverse electric field is reduced in a mode of interception and dredging through the structural design of the fork-shaped structures 32, and the effect of protecting the device from early reverse breakdown is realized by combining a plurality of strip-shaped doped structures 33 similar to a floating field limiting ring or combining a plurality of fork-shaped structures 34 with the structure and the same size of the fork-shaped structures 32 with smaller terminal area.

The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application or directly or indirectly applied to other related technical fields are included in the scope of the present application.

Claims (20)

1. A semiconductor device, comprising:

A substrate;

a semiconductor epitaxial layer disposed on the substrate, the substrate and the semiconductor epitaxial layer each having a first conductivity type, the semiconductor epitaxial layer comprising: an active region surrounding an edge termination region outside the active region;

A termination doping structure disposed within the edge termination region and extending from the edge termination region surface in a first direction of the substrate, the termination doping structure having a second conductivity type, the termination doping structure comprising: a main junction structure surrounding the outside of the active region, and a plurality of fork-shaped structures disposed on opposite first and second sides of the main junction structure;

The two adjacent fork-shaped structures are arranged at intervals, each fork-shaped structure comprises a main body part and at least two first fork-shaped parts, the first ends of the main body parts are connected with the main junction structure, and the second ends of the main body parts extend towards a second direction deviating from the active area; the first bifurcation part is arranged at the second end of the main part and extends towards the second direction.

2. The semiconductor device according to claim 1, further comprising:

The first metal layer is at least partially arranged on the surface of the main junction structure and extends to the surface of the active region;

And the dielectric layer is arranged on at least part of the surface of the edge terminal region and is connected with the first metal layer.

3. The semiconductor device of claim 2, wherein the structure and dimensions of the plurality of fork-like structures are the same; the spacing between two adjacent fork-shaped structures is the same.

4. The semiconductor device of claim 2, wherein a distance between two adjacent fork-like structures is less than or equal to a distance between second ends of two adjacent first fork-like portions in each of the fork-like structures.

5. The semiconductor device of claim 2, wherein a distance between two adjacent ones of the stem portions is greater than a distance between two adjacent ones of the fork-like structures;

and/or the distance between two adjacent trunk parts is larger than the distance between the second ends of two adjacent first bifurcation parts in each fork-shaped structure.

6. The semiconductor device of claim 2, wherein each of the fork-like structures is an axisymmetric pattern, and wherein an axis of symmetry of each of the fork-like structures coincides with an extension direction of the stem in the fork-like structure.

7. The semiconductor device of claim 6, wherein each of the fork-shaped structures includes two of the first fork-shaped portions, and wherein the two of the first fork-shaped portions of each of the fork-shaped structures have a first included angle therebetween, and wherein the first included angle ranges from 120 ° to 150 °.

8. The semiconductor device of claim 6, wherein each of the fork-shaped structures includes three first prongs, the first ends of the three first prongs are each connected to the second end of the stem, and the second ends of the three first prongs extend toward the second direction and are spaced apart.

9. The semiconductor device of claim 1, wherein the termination doping structure further comprises:

The strip-shaped doping structures are symmetrically arranged on a third side and a fourth side which are opposite to each other and adjacent to each other.

10. The semiconductor device of claim 9, wherein lengths of the plurality of stripe-shaped doping structures located on the same side of the main junction structure in the second direction are in a decreasing trend.

11. The semiconductor device of claim 9, wherein a distance between two adjacent stripe-shaped doping structures in the second direction tends to increase.

12. The semiconductor device of claim 9, wherein in the second direction, a depth of the plurality of stripe-shaped doping structures extending toward the first direction is in a decreasing trend.

13. The semiconductor device of claim 9, wherein a distance between the stripe-shaped doped structure adjacent to the main junction structure and the fork-shaped structure adjacent to an edge of the main junction structure is equal to a distance between two adjacent fork-shaped structures;

wherein, the interval between two adjacent fork-shaped structures is the same.

14. The semiconductor device of claim 9, wherein a doping concentration of the fork-like structure in the second direction is in a decreasing trend; and the doping concentration of the plurality of strip-shaped doping structures is in a decreasing trend.

15. The semiconductor device of claim 9, wherein a width of a first bifurcation on a plurality of the main junction structures is the same, a width of a plurality of the stripe-shaped doped structures is the same, and a width of each of the stripe-shaped doped structures is the same as a width of the first bifurcation.

16. The semiconductor device of claim 6, wherein each of the fork-like structures further comprises a plurality of second branches;

the first end of the first bifurcation part is connected with the second end of the main part, the second end of the first bifurcation part extends towards the second direction, and at least two second bifurcation parts are arranged at the second end of the first bifurcation part and extend towards the second direction.

The second end of each first bifurcation is further provided with at least two second bifurcation portions, and the at least two second bifurcation portions on the second end of each first bifurcation portion further extend toward the second direction.

17. The semiconductor device of claim 16, wherein each of the fork-shaped structures comprises two of the first prongs, and wherein the two of the first prongs in each of the fork-shaped structures have a first included angle therebetween;

the second end of each first bifurcation part is provided with two second bifurcation parts, and a second included angle is formed between the two second bifurcation parts of the second end of each first bifurcation part, and the second included angle is the same as the first included angle.

18. The semiconductor device of claim 1, wherein the termination doping structure further comprises:

a plurality of tine structures disposed on opposite third and fourth sides of the primary junction structure;

the two adjacent fork tooth structures are arranged at intervals, each fork tooth structure comprises a main body part and at least two first separation parts, the first ends of the main body parts are connected with the main junction structure, and the second ends of the main body parts extend towards a second direction deviating from the active area; the first separation portion is disposed at the second end of the main body portion and extends toward the second direction.

19. The semiconductor device of claim 18, wherein the plurality of tine structures are the same structure and size; the spacing between two adjacent fork tooth structures is the same.

20. The semiconductor device of claim 18, wherein a distance between two adjacent ones of the body portions is greater than a distance between two adjacent ones of the tine structures;

and/or the distance between two adjacent main body parts is larger than the distance between the second ends of two adjacent first separated parts in each fork tooth structure.