阅读说明：本技术 Ligbt、制备方法、智能功率模块、驱动电路及电器 (LIGBT, preparation method, intelligent power module, driving circuit and electric appliance ) 是由 兰昊 严允健 于 2021-07-14 设计创作，主要内容包括：本发明公开了一种横向绝缘栅双极型晶体管、制备方法、智能功率模块、驱动电路及电器,通过对横向绝缘栅双极型晶体管的阳极结构进行设计,在第四掺杂区上方设置有第二栅结构,因此可以通过第二栅结构控制阳极的载流子通路。当横向绝缘栅双极型晶体管导通时,第二栅结构下方的第四掺杂区以及第五掺杂区正常向漂移区注入载流子,阳极不存在短路结构,因此可以避免横向绝缘栅双极型晶体管产生snapback现象；当横向绝缘栅双极型晶体管关断时,第二栅结构可以控制第四掺杂区表面反型,抽取漂移区以及第二掺杂区中的载流子,从而加速横向绝缘栅双极型晶体管的关断,进而降低了横向绝缘栅双极型晶体管的关断损耗。(The invention discloses a transverse insulated gate bipolar transistor, a preparation method, an intelligent power module, a driving circuit and an electric appliance. When the transverse insulated gate bipolar transistor is conducted, the fourth doped region and the fifth doped region below the second gate structure normally inject carriers into the drift region, and the anode does not have a short-circuit structure, so that the phenomenon of snapback of the transverse insulated gate bipolar transistor can be avoided; when the transverse insulated gate bipolar transistor is turned off, the second gate structure can control the surface inversion of the fourth doped region and extract carriers in the drift region and the second doped region, so that the turn-off of the transverse insulated gate bipolar transistor is accelerated, and the turn-off loss of the transverse insulated gate bipolar transistor is reduced.)

1. A transverse insulated gate bipolar transistor is characterized by comprising a substrate, a drift region and an electrode structure which are sequentially arranged from bottom to top, wherein the drift region is provided with a first doped region and a second doped region;

a third doped region is arranged in the first doped region, a fourth doped region and a fifth doped region which is in contact with the fourth doped region are arranged in the second doped region, the fourth doped region is positioned on one side close to the first doped region, and the fifth doped region is positioned on one side far away from the first doped region;

the doping types of the drift region, the second doping region and the third doping region are all first doping types; the doping types of the first doping region, the fourth doping region and the fifth doping region are all second doping types; the first doping type is different from the second doping type;

the electrode structure includes: the emitter electrode is conducted with one side, far away from the second doped region, of the first doped region and the third doped region; the first gate structure is positioned above one side of the first doped region close to the second doped region; the second gate structure is positioned above the fourth doped region; a collector electrode in conduction with the fourth doped region and the fifth doped region.

2. The lateral insulated gate bipolar transistor of claim 1,

the doping concentration of one side of the first doping region, which is far away from the second doping region, is higher than that of one side of the first doping region, which is close to the second doping region;

the doping concentration of the fifth doping area is higher than that of the fourth doping area.

3. The lateral insulated gate bipolar transistor of claim 1, wherein the first doping type is an N-type doping and the second doping type is a P-type doping.

4. The lateral insulated gate bipolar transistor of claim 1, wherein a buried oxide layer is disposed between the substrate and the drift region.

5. The lateral insulated gate bipolar transistor of claim 1, wherein:

when the transverse insulated gate bipolar transistor is conducted, the voltage of the second gate structure is equal to the voltage of the collector electrode;

the voltage of the second gate structure is higher than the voltage of the collector electrode when the lateral insulated gate bipolar transistor is off.

6. A preparation method of a transverse insulated gate bipolar transistor is characterized by comprising the following steps:

preparing an upper drift region on a substrate;

forming a first doping region and a second doping region on two sides of the drift region, forming a third doping region in the first doping region, and forming a fourth doping region and a fifth doping region in the second doping region, wherein the doping types of the drift region, the second doping region and the third doping region are all the first doping type; the doping types of the first doping region, the fourth doping region and the fifth doping region are all second doping types; the first doping type is different from the second doping type;

forming an emitter electrode on one side of the first doped region far away from the second doped region and the third doped region; forming a first gate structure above one side of the first doped region close to the second doped region; forming a second gate structure above the fourth doped region; forming a collector electrode on the fourth doped region and the fifth doped region.

7. An intelligent power module, characterized in that it comprises a lateral insulated gate bipolar transistor according to any of claims 1 to 5.

8. The smart power module of claim 7, further comprising a logic control circuit, the logic control circuit comprising:

the first grid structure voltage detection module is connected with the first grid structure and is used for judging the on and off of the insulated gate bipolar transistor;

the bootstrap circuit module is connected with a voltage source and is used for obtaining a voltage higher than the voltage of the collector electrode;

and the logic judgment module is connected with the first gate structure voltage detection module and the bootstrap circuit module and is used for judging whether the voltage obtained by the bootstrap circuit module is provided for the second gate structure according to the detection result of the first gate structure voltage detection module.

9. A driver circuit comprising a lateral insulated gate bipolar transistor according to any of claims 1 to 5.

10. An electrical appliance comprising a lateral insulated gate bipolar transistor according to any of claims 1 to 5.

Technical Field

The invention relates to the field of power semiconductor devices, in particular to an LIGBT, a preparation method, an intelligent power module, a driving circuit and an electric appliance.

Background

Lateral Insulated Gate Bipolar Transistor (LIGBT) has the advantages of easy integration, high input impedance, reduced on-state voltage, etc., and has been widely used in the fields of communication, traffic, energy, household appliances, etc.

The traditional LIGBT device has obvious charge storage effect in the turn-off process, which causes larger turn-off loss; on the basis of a traditional LIGBT device, an anode short-circuit structure N + electrode is introduced into an anode of an anode short-circuit type transverse Insulated Gate Bipolar Transistor (SA-LIGBT), so that on one hand, the injection efficiency of a P + region is reduced in the conduction process of the LIGBT device, and therefore holes accumulated in a base region in a steady state are reduced, and on the other hand, an extraction channel is provided for a current carrier in the turn-off process, so that the turn-off speed is increased, and the turn-off loss of the LIGBT device is reduced.

However, the off-state loss of the current SA-LIGBT device in specific application is still large, and the introduction of an anode short-circuit structure also enables the device to generate a snapback phenomenon, so that the wide application of the LIGBT device in more fields is limited.

Disclosure of Invention

In view of the above, the present invention has been made to provide a LIGBT, a manufacturing method, a smart power module, a driving circuit and an electrical appliance that overcome or at least partially solve the above problems.

In a first aspect, an insulated gate bipolar transistor is provided, which includes a substrate, a drift region and an electrode structure, which are sequentially arranged from bottom to top, wherein the drift region is provided with a first doped region and a second doped region;

a third doped region is arranged in the first doped region, a fourth doped region and a fifth doped region which is in contact with the fourth doped region are arranged in the second doped region, the fourth doped region is positioned on one side close to the first doped region, and the fifth doped region is positioned on one side far away from the first doped region;

the doping types of the drift region, the second doping region and the third doping region are all first doping types; the doping types of the first doping region, the fourth doping region and the fifth doping region are all second doping types; the first doping type is different from the second doping type;

the electrode structure includes: the emitter electrode is conducted with one side, far away from the second doped region, of the first doped region and the third doped region; the first gate structure is positioned above one side of the first doped region close to the second doped region; the second gate structure is positioned above the fourth doped region; a collector electrode in conduction with the fourth doped region and the fifth doped region.

Optionally, the doping concentration of the first doping region on the side far away from the second doping region is higher than the doping concentration of the first doping region on the side near the second doping region;

the doping concentration of the fifth doping area is higher than that of the fourth doping area.

Optionally, the first doping type is N-type doping, and the second doping type is P-type doping.

Optionally, a buried oxide layer is disposed between the substrate and the drift region.

Optionally, when the LIGBT is turned on, the voltage of the second gate structure is equal to the voltage of the collector electrode, so as to avoid a voltage rebound phenomenon;

when the LIGBT is turned off, the voltage of the second gate structure is higher than that of the collector electrode, so that the surface of the fourth doped region is inverted to form a minority carrier extraction channel.

In a second aspect, a method for fabricating an LIGBT device is provided, including:

preparing an upper drift region on a substrate;

forming a first doping region and a second doping region on two sides of the drift region by adopting an ion implantation method, forming a third doping region in the first doping region, and forming a fourth doping region and a fifth doping region in the second doping region, wherein the doping types of the drift region, the second doping region and the third doping region are all first doping types; the doping types of the first doping region, the fourth doping region and the fifth doping region are all second doping types; the first doping type is different from the second doping type;

forming an emitter electrode on one side of the first doped region far away from the second doped region and the third doped region; forming a first gate structure above one side of the first doped region close to the second doped region; forming a second gate structure above the fourth doped region; forming a collector electrode on the fourth doped region and the fifth doped region.

In a third aspect, a smart power module is provided, which includes the LIGBT of any of the first aspects.

Optionally, the smart power module further comprises a logic control circuit, the logic control circuit comprising:

the first grid structure voltage detection module is connected with the first grid structure and is used for judging the on and off of the insulated gate bipolar transistor;

the bootstrap circuit module is connected with a voltage source and is used for obtaining a voltage higher than the voltage of the collector electrode;

and the logic judgment module is connected with the first gate structure voltage detection module and the bootstrap circuit module and is used for judging whether the voltage obtained by the bootstrap circuit module is provided for the second gate structure according to the detection result of the first gate structure voltage detection module.

In a fourth aspect, a driving circuit is provided, which includes the LIGBT of any of the first aspects.

In a fifth aspect, an electrical appliance is provided, which includes the LIGBT of any of the first aspects.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

the anode structure of the LIGBT is designed, and the second grid structure is arranged above the fourth doping area, so that a current carrier passage of the anode can be controlled through the second grid structure. When the LIGBT is conducted, the fourth doped region and the fifth doped region below the second gate structure normally inject carriers into the drift region, and at the moment, the anode of the LIGBT does not have a short-circuit structure, so that a snapback phenomenon can be avoided, and the reliability of the device is improved; when the LIGBT is turned off, an inversion layer is formed on the surface of the fourth doping region below the second gate structure, and minority carriers are accumulated, so that the drift region and the second doping region can be communicated with the fifth doping region and the collector electrode through the inversion layer to form a carrier extraction channel, the turn-off of the LIGBT is accelerated, and the off-state loss of the LIGBT is reduced.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a schematic view of an LIGBT structure provided in an embodiment of the present invention;

fig. 2 is a schematic diagram of an N-type LIGBT structure based on fig. 1 provided in an embodiment of the present application;

fig. 3 is a flow chart of a LIGBT preparation method provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of a smart power module provided in an embodiment of the present application;

FIG. 5 is a schematic diagram of a logic control circuit provided in an embodiment of the present application;

FIG. 6 is a schematic diagram of a driving circuit provided in an embodiment of the present application;

fig. 7 is a schematic diagram of an electrical appliance provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

For convenience of description, spatially relative terms, such as "bottom," "front," "upper," "lower," "top," "inner," "horizontal," "outer," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. This spatially relative relationship is intended to encompass different orientations of the mechanism in use or operation in addition to the orientation depicted in the figures. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention is described below with reference to specific embodiments in conjunction with the accompanying drawings.

First, a LIGBT1000 provided by an embodiment of the present invention is described with reference to fig. 1, which includes:

the drift region 1200 is formed by a substrate 1100, a drift region 1300 and an electrode structure 1300, wherein the electrode structure 1300 is arranged on the drift region 1200, and the drift region 1200 is arranged on the substrate 1100;

the first doped region 1400 and the second doped region 1500 are disposed on the drift region 1200;

the third doped region 1600 is disposed in the first doped region 1400, the fourth doped region 1700 and the fifth doped region 1800 are disposed in the second doped region 1500, the fourth doped region 1700 is located in a region close to the first doped region 1400, the fifth doped region 1800 is located in a region far from the first doped region 1400, and the fourth doped region 1700 contacts the fifth doped region 1800;

the drift region 1200, the second doped region 1500 and the third doped region 1600 have the same doping type, which are all the first doping type; the doping types of the first doping region 1400, the fourth doping region 1700 and the fifth doping region 1800 are the same and are all the second doping type; the first doping type is different from the second doping type;

the electrode structure 1300 includes four electrodes, which are an emitter electrode 1310, a first gate structure 1320, a second gate structure 1330 and a collector electrode 1340, respectively, wherein the emitter electrode 1310 is conducted with the third doped region 1600 and a side of the first doped region 1400 away from the second doped region 1500; the first gate structure 1320 is disposed above the first doped region 1400 and near the second doped region 1500; the second gate structure 1330 is disposed above the fourth doped region 1700; the collector electrode 1340 is in conduction with the fourth doped region 1700 and the fifth doped region 1800.

It should be noted that, an N + collector is disposed at a lower end of an anode of a typical anode short-circuit structure LIGBT, and when the LIGBT is turned off, the short-circuit structure can extract minority carriers in the N-type drift region to accelerate the turn-off of the LIGBT.

When the insulated gate bipolar transistor is conducted in the forward direction, electrons enter the N-type drift region through the MOS channel between the N + emitter and the N-type drift region, so that the P + collector can be attracted to inject a large number of holes into the N-type drift region, and at the moment, a large number of electron-hole pairs exist in the N-type drift region to generate a conductance modulation effect, so that the conduction resistance is greatly reduced, and the forward conduction voltage of the LIGBT is further reduced. However, in the forward conduction process of the device, electrons also pass through the surface channel of the N + emitter and the P body region, the N-type drift region and the N + collector to form a parasitic MOS structure, so that an electron current path is generated, and a voltage rebound phenomenon (i.e., snapback effect) occurs, so that the reliability of the device is affected, the application of the device is limited, and in the structure, the off-state loss of the LIGBT is still high.

In the LIGBT device provided by the present invention, the second gate structure 1330 is introduced into the anode, and the fourth doped region 1700 and the fifth doped region 1800 are correspondingly arranged to have the same doping type, so that the carrier path of the LIGBT anode can be controlled by the second gate structure 1330, thereby avoiding snapback phenomenon and accelerating the turn-off of the LIGBT.

Specifically, when the LIGBT is turned on, the voltage applied to the second gate structure 1330 is controlled to be equal to the voltage applied to the collector electrode, so that the fourth doped region 1700 under the second gate structure 1330 injects carriers into the drift region 1200 together with the fifth doped region 1800. At this time, since the anode of the LIGBT does not have a short-circuit structure, the LIGBT does not generate a snapback phenomenon, and since the fourth doping region 1700 also injects carriers into the drift region 1200, the on-resistance of the LIGBT can be further reduced.

When the LIGBT is turned off, the voltage applied to the second gate structure 1330 is controlled to be larger than the voltage applied to the collector electrode 1340, so that the surface of the fourth doped region 1700 in contact with the second gate structure 1330 is inverted, and minority carriers in the drift region 1200 and the second doped region 1500 are accumulated, so that the inversion layer can enable the drift region 1200 and the second doped region 1500 to be communicated with the fifth doped region 1800 and the collector electrode 1340, thereby accelerating the turn-off process of the LIGBT and reducing the off-state loss of the LIGBT.

In some embodiments, different regions in the first doped region 1400 have different doping concentrations, so that when the LIGBT device is turned on in the forward direction, a larger number of carriers are generated, thereby reducing the forward turn-on voltage of the LIGBT.

Specifically, the doping concentration of both sides of the first doping region 1400 is different, wherein the carrier doping concentration of the side of the doping region relatively far away from the second doping region 1500 is higher than the carrier doping concentration of the side of the doping region relatively close to the second doping region 1500. Furthermore, the side close to the second doped region 1500 is lightly doped, and the side far from the second doped region 1500 is heavily doped, so that when the LIGBT is turned on in the forward direction, the carriers in the fourth doped region 1700 and the fifth doped region 1800 can enter the drift region 1200 faster, and the remaining minority carriers in the drift region 1200 from the fourth doped region 1700 and the fifth doped region 1800 can be attracted to flow out of the emitter electrode 1310 through the lightly doped region.

The second doped region 1500 is lightly doped with a doping type different from that of the fourth doped region 1700 and the fifth doped region 1800, and mainly reduces the flow velocity of carriers in the fourth doped region 1700 and the fifth doped region 1800, so that the carriers from the fourth doped region 1700 and the fifth doped region 1800 can be combined with the carriers from the third doped region 1600 as much as possible to generate a better conductivity modulation effect. The third doped region 1600 is heavily doped to inject a large number of carriers into the drift region 1200 when the LIGBT is turned on.

The doping type of the fourth doped region 1700 is the same as that of the fifth doped region 1800, and the doping concentration of the fourth doped region 1700 is less than that of the fifth doped region 1800, specifically, the fourth doped region 1700 is lightly doped to provide an extraction channel for carriers in the drift region when the LIGBT is turned off; the fifth doped region 1800 is heavily doped so that a large number of carriers can be injected into the drift region 1200 when the LIGBT is turned on.

It should be noted that heavily doped means that the ratio of the concentration of dopant atoms to the concentration of semiconductor atoms is about one thousandth, while for lightly doped, the ratio of the concentration of dopant atoms to the concentration of semiconductor atoms may be as low as one part per billion.

In some embodiments, the third doped region 1600 may be specifically located at a position offset to one side of the second doped region 1500 in the middle of the first doped region 1400, so as to allow more carriers to enter the drift region 1200; the fourth doped region 1700 may be specifically located in the middle of the second doped region 1500 biased to one side of the first doped region 1400 to extract more carriers during the LIGBT turn-off process, thereby accelerating the LIGBT turn-off, and the fifth doped region 1800 may be located in the second doped region 1500 away from the first doped region 1400, so that a greater distance is provided between the fifth doped region 1800 and the third doped region 1600, thereby sufficiently combining the carriers from the third doped region 1600 and the carriers from the fifth doped region 1800, and further reducing the on-resistance of the LIGBT. Of course, the third doped region 1600, the fourth doped region 1700 and the fifth doped region 1800 may be disposed at other positions according to the actual requirement, which is not limited in this respect.

In some embodiments, the sizes of the third doped region 1600, the fourth doped region 170 and the fifth doped region 1800 may be designed according to actual requirements, for example, if the on-resistance of the LIGBT is required to be small, the size of the third doped region 1600 may be made larger or the size of the fifth doped region 1800 may be made smaller than that of the fourth doped region 1700, and if the off-state loss of the LIGBT is required to be small, the size of the fourth doped region 1700 may be made larger than that of the fifth doped region 1800. The sizes of the third doped region 1600, the fourth doped region 1700, and the fifth doped region 1800 are also not particularly limited.

An electrode structure 1300 including an emitter electrode 1310, a first gate structure 1320, a second gate structure 1330, and a collector electrode 1340 is disposed on the drift region 1200.

The emitter electrode 1310 is disposed above the third doped region 1600 and the lightly doped region in the first doped region 1400, and the emitter electrode 1310 is disposed above the third doped region 1600, so that some minority carriers generated from the anode during the turn-on process of the LIGBT can flow out from the emitter electrode 1310, thereby ensuring that the LIGBT generates a good conductance modulation effect.

The first gate structure 1320 is disposed above the lightly doped region in the first doped region 1400, and forms a MOS structure together with the third doped region 1600 and the drift region 1200, so as to provide a channel for the carriers in the third doped region 1600 to enter the drift region 1200, or alternatively, the first gate structure 1320 may also be disposed above the lightly doped region in the third doped region and the first doped region 1400, so as to more precisely control the channel length of the MOS structure.

The second gate structure 1330 is disposed above the fourth doped region 1700 to control the flow of carriers in the fourth doped region 1700, or the second gate structure 1330 may also be disposed above the second doped region 1500 and the fourth doped region 1700 to more precisely control the flow of carriers in the fourth doped region 1700.

The collector electrode 1340 is disposed above the fifth doped region 1800, or above the fourth doped region 1700 and the fifth doped region 1800, and can drain minority carriers extracted from the drift region 1200 in addition to providing a voltage to the LIGBT.

In some embodiments, the first gate structure 1320 and the second gate structure 1330 are further located on a gate oxide layer on the drift region 1200, and the gate oxide layer may specifically use silicon dioxide, polysilicon, etc., without limitation. More specifically, the first gate structure 1320 and the second gate structure 1330 may be located on the same gate oxide layer, so as to simplify the LIGBT manufacturing process and save the process time. The emitter electrode 1310, the first gate structure 1320, the second gate structure 1330, and the collector electrode 1340 may be made of magnesium, aluminum, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium, molybdenum, lead, silver, tungsten, platinum, gold, or other conductive metals, or alloys of these conductive metals.

In some embodiments, a buried oxide layer 1800 is disposed above the substrate 1100 and below the drift region 1200, i.e., in between, to completely isolate the drift region 1200 from the substrate 1100, prevent substrate current leakage and withstand the vertical voltage of the LIGBT device. The material of the buried oxide layer 1800 may be, but is not limited to, silicon dioxide, polysilicon, etc. implanted with oxygen.

In some embodiments, the first doping type may be a doping such that the doped region is an N-type semiconductor, e.g., the dopant ions are phosphorous, arsenic, antimony, bismuth, etc., and the second doping type may be a doping such that the doped region is a P-type semiconductor, e.g., the dopant ions are boron, indium, etc.

The LIGBT can be divided into N-type channel LIGBT and P-type channel LIGBT according to channel type, the N-type channel IGBT has electron flow in the conducting process, the P-type channel LIGBT uses hole in the conducting process, because the mobility of electron is generally three times of that of hole, the working efficiency of the N-type channel LIGBT is higher than that of the P-type channel LIGBT, and the application is wider than that of the P-type channel LIGBT. In a specific implementation process, the type of LIGBT can be selected according to actual needs, and in the embodiment of the present invention, an N-type channel LIGBT is taken as an example for description.

As shown in fig. 2, the substrate 1100 is a P-type substrate, the drift region 1200 is an N-drift region, and the buried oxide layer 1800 is disposed on the substrate 1100 to isolate the substrate 1100 from the drift region 1200 disposed on the buried oxide layer 1800, thereby avoiding the substrate current leakage.

A first doped region 1400 is disposed on the N-drift region 1200, and the doping type thereof is P-type. Specifically, two regions with different doping concentrations are arranged inside the first doping region 1400, wherein a region 1420 far away from the second doping region 1500 is P-type heavily doped and is called a P + body region, and a remaining region 1410 in the first doping region 1400 is P-type lightly doped and is called a P body region; the third doped region 1600 is located between the P + body regions 1420 and the P body regions 1410, and is heavily doped N-type, referred to as an N + emitter.

The second doped region 1500 is disposed on the N-drift region 1200 opposite to the first doped region 1400, and the doping type of the second doped region is N-type lightly doped, which is called an N-type buffer region; a P-doped layer 1700 and a P + collector 1800 are disposed within the N-type buffer region 1500, wherein the P-doped layer 1700 and the P + collector 1800 contact each other.

An electrode structure 1300 is also disposed over the N-drift region 1200. Wherein an emitter electrode 1310 is disposed on the P + body region 1420 and the N + emitter 1600, and a collector electrode 1340 is disposed on the P + collector 1800 and the P-doped layer 1700; a first gate structure 1320 is disposed on the N + emitter 1600 and the P body region 1410, and a second gate structure 1330 is disposed above the P-doped layer 1700 and the N-type buffer region 1500, and more specifically, the first gate structure 1320 and the second gate structure 1330 are disposed on the gate oxide layer 1350.

The working principle of the LIGBT device is described in detail below with reference to fig. 2:

in fig. 2, the P + collector 1800, N-drift region 1200 and P body region 1410 form a horizontal PNP bipolar transistor; the N + emitter 1600, the P body region 1410, and the N-drift region 1200 form a vertical NPN bipolar transistor; the N + emitter 1600, the first gate structure 1320, and the N-drift region 1200 form an NMOS structure, which may be referred to as a cathode NMOS structure; the P-doped layer 1700, the second gate structure 1330, and the N-type buffer 1500 form a field effect transistor.

When a sufficient forward bias is applied to the first gate structure 1320 and a certain forward bias is applied to the collector electrode 1340 and the second gate structure 1330 (at this time, the voltages of the second gate structure 1330 and the collector electrode 1340 are set to be equal), the electron current from the N + emitter 1600 passes through the cathode NMOS structure and enters the drift region 1200, and accumulates at the PN junction boundary of the horizontal PNP bipolar transistor, which lowers the potential at the N region side of the PN junction, and when the voltage across the PN junction is greater than the turn-on voltage, the P + collector 1800 injects holes into the drift region 1200, and the horizontal PNP bipolar transistor is in a conducting state, that is, the LIGBT starts to conduct.

In this process, since the voltage at the second gate structure 1330 is equal to the voltage of the collector electrode 1340 and has the same direction, the second gate structure 1330 controls the P-doped layer 1700 to normally inject holes into the drift region 1200, and since the anode of the LIGBT has no short-circuit structure in this process, a parasitic capacitance structure from the cathode to the anode is not generated, thereby avoiding the snapback phenomenon in the LIGBT and ensuring the stability and reliability of the LIGBT.

When the LIGBT is turned off, the voltage applied on the second gate structure 1330 is controlled to be higher than the voltage applied on the collector electrode 1340, and at this time, the surface of the P-doped layer 1700 below the second gate structure 1330 is inverted to attract electrons in the N-drift region 1200 and the N-type buffer region 1500, and the electrons flow out from the P + collector electrode 1800 and the collector electrode 1340 which are in contact with the P-doped layer 1700, so that the turn-off process of the LIGBT is accelerated, and the turn-off loss of the LIGBT is reduced.

Next, a method for preparing LIGBT according to an embodiment of the present invention is described with reference to fig. 1 and fig. 3, including:

step S301, an epitaxial layer with a certain thickness is fabricated on the substrate 1100, and ion implantation is performed on the epitaxial layer to fabricate the drift region 1200;

step S302, respectively preparing a first doped region 1400 and a second doped region 1500 on two sides of the drift region 1200 by using an ion implantation method, then preparing a third doped region 1600 in the first doped region 1400, and preparing a fourth doped region 1700 and a fifth doped region 1800 in the second doped region 1500, wherein the drift region 1200, the second doped region 1500, and the third doped region 1600 are of a first doping type; the first doped region 1400, the fourth doped region 1700, and the fifth doped region 1800 are of a second doping type; the first doping type is different from the second doping type;

in step S303, an electrode structure is further formed on the device formed in step S302, including forming an emitter electrode 1310, a first gate structure 1320, a second gate structure 1330, and a collector electrode 1340.

Wherein, the emitter electrode 1310 is formed above the third doped region 1600 and the region of the first doped region 1400 far from the second doped region 1500; the first gate structure 1320 is formed over the first doped region 1400 adjacent to the second doped region 1500; a second gate structure 1330 is formed over the fourth doped region 1700; a collector electrode 1340 is formed on the fifth doped region 1800 and the fourth doped region 1700.

In some embodiments, the first doping type is N-type doping, and the second doping type is P-type doping, wherein the N-type doping and the P-type doping can be achieved by phosphorus ion implantation and boron ion implantation processes, respectively.

In some embodiments, when the first doped region 1400 is formed, the doping concentration of the side close to the second doped region 1500 is lower than that of the side far from the second doped region 1500; and the doping concentration of the fourth doping region 1700 is lower than that of the fifth doping region 1800.

The LIGBT preparation method provided by this embodiment does not introduce additional process steps, and is completely compatible with the conventional preparation method.

Next, an Intelligent Power Module (IPM) provided by an embodiment of the present invention, including the LIGBT1000 provided by an embodiment of the present invention, is described with reference to fig. 4.

IPM is an advanced power switch device, which is essentially a power driving type product integrating a power device and a power device driving circuit. The IPM is widely applied to the fields of variable frequency speed regulation of alternating current motors, chopper speed regulation of direct current motors, various high-performance power supplies, industrial electrical automation, new energy and the like, and has a wide market.

In some embodiments, the smart power module 4000 further includes a logic control circuit 4001, and the logic control circuit 4001 is mainly configured to provide a voltage to the second gate structure 1330 of the LIGBT according to the on/off state of the LIGBT.

With reference to fig. 5, the logic control circuit 4001 includes a bootstrap circuit block 5002, a first gate structure voltage detection block 5001 and a logic determination block 5003.

The bootstrap circuit block 5002 is connected to a voltage source, and can obtain a voltage higher than the voltage at the collector electrode; specifically, the first gate structure voltage detection module 5001 mainly comprises threshold voltage comparison logic and first gate structure voltage variation trend logic, so as to accurately determine the on-off state of the LIGBT in real time; the first gate structure voltage detection module 5001 and the bootstrap circuit module 5002 are respectively connected to the logic determination module 5003, so that the logic determination module 5003 can determine whether to provide the voltage generated by the bootstrap circuit module 5002 to the second gate structure 1330 according to the detection result of the first gate structure voltage detection module 5001.

That is, when the first gate structure voltage detection module 5001 detects that the LIGBT is turned on, the signal is transmitted to the logic determination module 5003, and the logic determination module 5003 controls the voltage obtained by the bootstrap circuit module 5002 not to be provided to the second gate structure 1330, at this time, the voltage at the second gate structure 1330 is equal to the voltage at the collector electrode 1340, and the fourth doped region 1700 and the fifth doped region 1800 together inject carriers into the drift region 1200 normally, that is, there is no anode short-circuit structure in the LIGBT at this time, so that the snapback phenomenon can be avoided, thereby ensuring the reliability of the LIGBT and further ensuring the reliability of the IPM.

When the first gate structure voltage detection module 5001 detects that the LIGBT is turned off, the logic determination module 5003 receives the LIGBT turn-off signal sent from the first gate structure voltage detection module 5001, and controls the bootstrap circuit module 5002 to obtain a voltage higher than the collector electrode 1340 and provide the voltage to the second gate structure 1330, so that the second gate structure 1330 can control the surface inversion of the fourth doped region 1700 and continuously extract minority carriers in the drift region 1200 and the second doped region 1500, thereby reducing the turn-off time of the LIGBT and further reducing the turn-off loss of the IPM.

Next, a driving circuit 6000 provided by an embodiment of the present invention is described with reference to fig. 6, including: such as LIGBT1000 according to any of the above embodiments of the present invention.

Since the LIGBT provided by the present embodiment has no snapback effect and low off-state loss, the power loss of the drive circuit equipped with the LIGBT is also reduced synchronously.

Next, an electrical apparatus 7000 provided in an embodiment of the present invention is described with reference to fig. 7, including: such as LIGBT1000 according to any of the above embodiments of the present invention. The electrical apparatus 7000 may be an air conditioner, an ac motor, a dc motor, and various high performance Power supplies such as a UPS (Uninterruptible Power System), an electric welding machine, an induction heater, etc., and as long as the LIGBT includes the embodiments of the present invention, all of which fall within the intended scope of the present invention.

By assembling the LIGBT provided by the embodiment in the electric appliance, the power loss of the electric appliance is reduced, the heat dissipation effect of the electric appliance is improved, and the reliability of the electric appliance is improved

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.