阅读说明：本技术 一种高压瞬态电压抑制二极管 (A kind of high-voltage transient voltage suppressor diode ) 是由 刘聪 孔谋夫 陈罕之 于 2019-08-12 设计创作，主要内容包括：一种高压瞬态电压抑制二极管,属于半导体器件技术领域。包括第一导电类型掺杂区,位于第一导电类型掺杂区下方的第二导电类型掺杂区,位于第二导电类型掺杂区下方的第二导电类型轻掺杂外延层,位于第二导电类型轻掺杂外延层之中、远离第二导电类型掺杂区一侧的梳状结构的第一金属阴极,完全覆盖第一金属阴极表面的第一导电类型注入区,与第二导电类型轻掺杂外延层肖特基接触的第二金属阴极,位于第一导电类型掺杂区上方的金属阳极。本发明结构可有效提高二极管的击穿电流,改善器件的性能。(A kind of high-voltage transient voltage suppressor diode, belongs to technical field of semiconductor device.Including the first conduction type doped region, the second conduction type doped region below the first conduction type doped region, the second conduction type lightly doped epitaxial layer below the second conduction type doped region, among the second conduction type lightly doped epitaxial layer, the first metallic cathode of the pectinate texture far from the second conduction type doped region side, the first conductivity type implanted region of the first metal cathode surface is completely covered, with the second metallic cathode of the second conduction type lightly doped epitaxial layer Schottky contacts, metal anode above the first conduction type doped region.Structure of the invention can effectively improve the breakdown current of diode, improve the performance of device.)

1. a kind of high-voltage transient voltage suppressor diode, including the first conduction type doped region (1), mix positioned at the first conduction type The second conduction type doped region (2) below miscellaneous area (1) is located at the second conduction type doped region (2) far from the first conduction type First conductivity type implanted region (5) of doped region (1) side is located at the second conduction type doped region (2) and the first conduction type First metallic cathode (4) of injection region (5) lower surface, the metal anode (3) being located above the first conduction type doped region (1).

2. a kind of high-voltage transient voltage suppressor diode, including the first conduction type doped region (1), mix positioned at the first conduction type The second conduction type doped region (2) below miscellaneous area (1) is located at below the second conduction type doped region (2), is conductive far from first The first metallic cathode (4) of the pectination of type doped region (1) side, is completely covered the first conductive-type of the first metal cathode surface Type injection region (5), the metal anode (3) being located above the first conduction type doped region (1).

3. a kind of high-voltage transient voltage suppressor diode, including the first conduction type doped region (1), mix positioned at the first conduction type The second conduction type doped region (2) below miscellaneous area (1) is located at below the second conduction type doped region (2), is conductive far from first The first metallic cathode (4) of the pectinate texture of type doped region (1) side, first that the first metal cathode surface is completely covered are led Electric type implanted region (5), the second metallic cathode (6) with second conduction type doped region (2) Schottky contacts, leads positioned at first Metal anode (3) above electric type doped region (1).

4. a kind of high-voltage transient voltage suppressor diode, including the first conduction type doped region (1), mix positioned at the first conduction type The second conduction type doped region (2) below miscellaneous area (1), the second conductive-type being located at below the second conduction type doped region (2) Type lightly doped epitaxial layer (7) is located among the second conduction type lightly doped epitaxial layer (7), far from the second conduction type doped region (2) the first conduction type injection of the first metal cathode surface is completely covered in the first metallic cathode (4) of the pectinate texture of side Area (5), the second metallic cathode (6) with second conduction type lightly doped epitaxial layer (7) Schottky contacts are located at the first conductive-type Metal anode (3) above type doped region (1).

5. high-voltage transient voltage suppressor diode according to any one of claims 1 to 4, which is characterized in that the high pressure In transient voltage suppressor diode, when the first conduction type is p-type, the second conduction type is N-type；When the first conduction type is When N-type, the second conduction type is p-type.

6. high-voltage transient voltage suppressor diode according to any one of claims 1 to 4, which is characterized in that described first Graded transition junction is used at the junction of conduction type doped region (1).

Technical field

The invention belongs to technical field of semiconductor device, and in particular to a kind of transient voltage suppressor diode.

Background technique

From natural phenomenas such as thunders and lightnings to the various electromagnetic interferences being artificially formed, all electronic circuit system can be caused seriously to endanger Evil.Therefore, transient voltage suppressor diode (Transient Voltage Suppressors, abbreviation TVS) is as protection device It is widely used.Traditional TVS is chiefly used in the protection of static discharge, and breakdown voltage is smaller.And high-breakdown-voltage TVS diode There is important protective effect in the circuit systems such as power circuit, LED illumination circuit, at present for the research of high-voltage TVS diode It is less, how to improve the breakdown current density of high-voltage TVS diode and is more a lack of with the research for reducing chip area.

Summary of the invention

It is an object of the present invention to propose a kind of high voltage transient voltage inhibition two for defect existing for background technique Pole pipe, the structure can effectively improve the breakdown current density of diode, improve the performance of device.

To achieve the above object, The technical solution adopted by the invention is as follows:

A kind of high-voltage transient voltage suppressor diode is located at first as shown in Figure 1, including the first conduction type doped region 1 Second conduction type doped region 2 of 1 lower section of conduction type doped region is located at the second conduction type doped region 2 far from the first conduction First conductivity type implanted region 5 of 1 side of type doped region, is located at the second conduction type doped region 2 and the first conduction type is infused The first metallic cathode 4 for entering 5 lower surface of area, the metal anode 3 above the first conduction type doped region 1.

A kind of high-voltage transient voltage suppressor diode is located at first as shown in Fig. 2, including the first conduction type doped region 1 Second conduction type doped region 2 of 1 lower section of conduction type doped region is located at 2 lower section of the second conduction type doped region, far from first The of the first metallic cathode pectinate texture surface is completely covered in first metallic cathode 4 of the pectination of 1 side of conduction type doped region One conductivity type implanted region 5, the metal anode 3 above the first conduction type doped region 1.

A kind of high-voltage transient voltage suppressor diode is located at first as shown in figure 3, including the first conduction type doped region 1 Second conduction type doped region 2 of 1 lower section of conduction type doped region is located at 2 lower section of the second conduction type doped region, far from first First metallic cathode 4 of the pectinate texture of 1 side of conduction type doped region, first that the first metal cathode surface is completely covered are led Electric type implanted region 5, the second metallic cathode 6 with 2 Schottky contacts of the second conduction type doped region are located at the first conduction type The metal anode 3 of 1 top of doped region.

A kind of high-voltage transient voltage suppressor diode is located at first as shown in figure 4, including the first conduction type doped region 1 Second conduction type doped region 2 of 1 lower section of conduction type doped region, second positioned at 2 lower section of the second conduction type doped region leads Electric type lightly doped epitaxial layer 7 is located at 7 lower section of the second conduction type lightly doped epitaxial layer, far from the second conduction type doped region 2 The first conductivity type implanted region 5 of the first metal cathode surface is completely covered in first metallic cathode 4 of the pectinate texture of side, With the second metallic cathode 6 of 7 Schottky contacts of the second conduction type lightly doped epitaxial layer, it is located at the first conduction type doped region 1 The metal anode 3 of top.

Further, in the high-voltage transient voltage suppressor diode, when the first conduction type is p-type, second is conductive Type is N-type；When the first conduction type is N-type, the second conduction type is p-type.

Further, graded transition junction is used at the junction of the first conduction type doped region 1.

Compared with prior art, the invention has the benefit that

High voltage transient provided by the invention inhibits diode, and the Transient Suppression Diode of specific high-breakdown-voltage may be implemented (Transient Suppression Diode that such as breakdown voltage is about 120V), and breakdown current density is effectively increased, reach raising surge Absorbability and the purpose for reducing chip area.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of high-voltage transient voltage suppressor diode provided by the invention；

Fig. 2 is a kind of structural schematic diagram of the high-voltage transient voltage suppressor diode of embodiment provided by the invention；

Fig. 3 is a kind of structural schematic diagram of the high-voltage transient voltage suppressor diode of embodiment provided by the invention；

Fig. 4 is a kind of structural schematic diagram of the high-voltage transient voltage suppressor diode of embodiment provided by the invention；

Fig. 5 is the thickness schematic diagram of p-type injection region in the diode that embodiment provides；

Fig. 6 is the simulation result correlation curve of the diode of different structure；Wherein curve con-TVSD is traditional only by P The breakdown characteristics for the diode that type doped region and N-doped zone are formed, curve PG-TVSD, TG-TVSD, STG-TVSD are respectively The breakdown characteristics of the diode of structure shown in Fig. 1, Fig. 2, Fig. 3, curve LSTG-TVSD are the breakdown for the diode that embodiment provides Characteristic.

Wherein, 1 is P-doped zone, and 2 be N-doped zone, and 3 be metal anode, and 4 be the first metallic cathode, and 5 inject for p-type Area, 6 be the second metallic cathode, and 7 be N-type lightly doped epitaxial layer；

Specific embodiment

It is clear in order to be more clear the purpose of the present invention, technical scheme and beneficial effects, below in conjunction with of the invention real The attached drawing in mode is applied, the technical solution in embodiment of the present invention is clearly and completely described, it is clear that described Embodiment is only some embodiments of the invention, rather than whole embodiments.Based on the embodiment party in the present invention Formula, every other embodiment obtained by those of ordinary skill in the art without making creative efforts, all belongs to In the scope of protection of the invention.

As shown in Figure 1, being a kind of structural schematic diagram of high-voltage transient voltage suppressor diode provided by the invention.The wink State voltage suppression diode includes the PN junction that P-doped zone 1 is formed with N-doped zone 2 below, and wherein P-doped zone 1 is adopted With graded transition junction, N-doped zone 2 uses abrupt junction；In formation p-type injection region 5 of the N-doped zone 2 far from 1 side of P-doped zone； The first metallic cathode 4 is made below N-doped zone 2, makes metal anode 3 above P-doped zone 1.The present invention is in P-doped zone Graded transition junction is used at 1 junction, can effectively improve the avalanche multiplication factor and reverse saturation current density, and then increase breakdown potential Stream, improves the absorption rate of surge.The present invention increases p-type injection region 5 below N-doped zone 2, and p-type injection region 5 and N-type are light Doped epitaxial layer forms another PN junction.When applied voltage, which reaches certain value, makes the PN junction forward conduction, p-type injection region 5 is flowed A large amount of hole forms high density hole current out, effectively increases the breakdown current density of device.

As shown in Fig. 2, being that a kind of structure of the high-voltage transient voltage suppressor diode of embodiment provided by the invention is shown It is intended to.The transient voltage suppressor diode includes the PN junction that P-doped zone 1 is formed with N-doped zone 2 below, wherein P Type doped region 1 uses graded transition junction, and N-doped zone 2 uses abrupt junction；N-doped zone 2 is performed etching formed in its bottom it is recessed Slot makes one layer of p-type injection region 5 along groove inner wall and surface, in inside grooves and 2 lower surface of N-doped zone filling gold Belong to and be used as the first metallic cathode 4, top device makes metal anode 3.The present invention forms groove in the bottom of device, along groove Wall and surface form one layer of p-type injection region 5, and filling metal is as the first metallic cathode 4 in groove.Bottom device PN junction in this way Junction area greatly increases, and especially the high depth of slot provides the wide region being injected laterally to hole, effectively enhances Hole injection, further improves device entirety breakdown current.

As shown in figure 3, being that a kind of structure of the high-voltage transient voltage suppressor diode of embodiment provided by the invention is shown It is intended to.The transient voltage suppressor diode includes the PN junction that P-doped zone 1 is formed with N-doped zone 2 below, wherein P Type doped region 1 uses graded transition junction, and N-doped zone 2 uses abrupt junction；N-doped zone 2 is performed etching formed in its bottom it is recessed Slot makes one layer of p-type injection region 5 along groove inner wall and surface, in inside grooves filling metal as the first metallic cathode 4, The part that bottom device is contacted with N-doped zone 2 makes the second metallic cathode 6, and the second metallic cathode 6 uses Schottky contacts, Top device makes metal anode 3.Second metallic cathode 6 of the invention uses Schottky contacts.Firstly, Schottky contacts is relatively first It is connected and provides a large amount of carrier to N-doped zone 2 to reduce the conducting resistance of N-doped zone 2, make p-type injection region 5 and N The PN junction that type doped region 2 is constituted can be connected under smaller applied voltage, therefore its conducting electric current is higher under identical applied voltage.Its Secondary, Schottky diode provides a large amount of electronic current as how sub- device, is equivalent to and increases additionally for reverse breakdown current A part.

As shown in figure 4, the structural schematic diagram of the high-voltage transient voltage suppressor diode for one embodiment of the present invention, institute Stating transient voltage suppressor diode includes the PN junction that P-doped zone 1 is formed with N-doped zone 2 below, and wherein p-type is adulterated Area 1 uses graded transition junction, and N-doped zone 2 uses abrupt junction.N-doped zone 2 lower section extension, one layer of N-type lightly doped epitaxial layer 7, to N Type lightly doped epitaxial layer 7, which is performed etching, forms groove in its bottom, makes one layer of p-type injection region 5 along groove inner wall and surface, In inside grooves filling metal as the first metallic cathode 4, part that bottom device is contacted with N-type lightly doped epitaxial layer makes the Two metallic cathodes 6, the second metallic cathode 6 use Schottky contacts, and top device makes metal anode 3.Its substrate is by two parts Composition, wherein being N-type lightly doped epitaxial layer 7 close to one end of metallic cathode.The electronics that lightly doped epitaxial layer reduces the area N is dense Degree reduces the hole of the outflow of p-type injection region 5 in the compound of the area N, and then reduces loss, improves hole injection efficiency.The high pressure Transient Suppression Diode, production method specifically:

Step 1, above N-type substrate by diffusing, doping acceptor impurity formed P-doped zone 1, it is remaining undoped with by The substrate of main impurity is N-doped zone 2；

Step 2 carries out lightly doped n type extension in the lower surface of N-doped zone 2, forms N-type lightly doped epitaxial layer 7；

Step 3 is performed etching in the lower section of N-type lightly doped epitaxial layer 7, forms groove；

Step 4 forms p-type injection region 5 by doping in groove inner wall and surface；

Step 5 fills metal by the methods of vapor deposition in groove, as the first metallic cathode 4；

Step 6, the suitable metal of selection can be obtained by the methods of deposit production metal anode 3, the second metallic cathode 6 Inhibit diode to the high voltage transient.

Specifically, boron ion is adulterated on N-type silicon chip and form P-doped zone 1, with remaining undoped with region n-type doping Area forms PN junction.Wherein, the doping concentration and area of P-doped zone 1 and N-doped zone 2 can according to structure need and it is specific Breakdown voltage value be adjusted, the parameter of 1 graded transition junction of P-doped zone, which also can according to need, to be adjusted, and is considerably increased The flexibility of device design.Adjusting to area ratio shared by N-type lightly doped epitaxial layer and doping concentration can effectively change The raising degree for becoming breakdown voltage, influencing breakdown current.

Specifically, the depth-to-width ratio of groove can be changed by adjusting etching anisotropy and etch period, for different structure Device design different number groove.

Specifically, one layer of p-type injection region 5, the thickness of p-type injection region 5 are made by doping boron along groove inner wall and surface Degree can be adjusted according to the requirement of the device of different structure.

Specifically, the metal for selecting the work functions ratio Si such as Ni big makes metal anode, the first metallic cathode and the second metal Cathode.