CN87209110U

CN87209110U - Mos grid-controlled transverse thyristor

Info

Publication number: CN87209110U
Application number: CN 87209110
Authority: CN
Inventors: 谢世健; 张会珍; 朱静远
Original assignee: NANJING POLYTECHNICAL COLLEGE
Current assignee: NANJING POLYTECHNICAL COLLEGE
Priority date: 1987-06-10
Filing date: 1987-06-10
Publication date: 1988-06-08

Abstract

The utility model discloses an MOS grid controlled transverse thyristor with a novel structure. A PNPN layer which forms the thyristor has a transverse structure, the utility model is compounded by an MOS transistor and a bipolar transistor, and a leakage region of the MOS transistor and a base region of the bipolar transistor are common regions. Because the utility model adopts a grid of the MOS transistor to control the switching of a thyristor, the utility model can be directly controlled by a low voltage digital circuit. Because three electrodes of the thyristor are elicited from the surface, the utility model can realize the integration with a normal CMOS low voltage logic control circuit through dielectric isolation. The utility model is suitable for manufacturing various high voltage power integrated circuits, and can be widely used in occasions such as the motor drive, the industrial control, etc.

Description

Mos grid-controlled transverse thyristor

The utility model belongs to field of semiconductor devices, is a kind of thyristor of new structure.

Existing thyristor adopts longitudinal P NPN four-layer structure, is a kind of current control device.It can not directly control its conducting with the digital circuit of low pressure, because three electrodes of vertical structure thyristor are not to draw from a plane, therefore is unfavorable for realizing circuit integration.

The purpose of this utility model is to develop a kind ofly can use the conducting of low pressure Digital Circuit Control, and is convenient to realize the new structure thyristor of circuit integration.

The utility model is made up of the PNPN four-layer structure, the PNPN layer that its characteristics are to form thyristor is a transversary, adopt metal-oxide-semiconductor and the compound formation of bipolar transistor, the emitter region of the source of metal-oxide-semiconductor, drain region and bipolar transistor and collecting region are formed the four-layer structure of lateral thyristor, and wherein the base of the drain region of metal-oxide-semiconductor and bipolar transistor is a public domain.Mos gate control thyristor can be divided into pmos type and nmos type two classes, and they adopt PMOS pipe and the compound formation of NPN bipolar transistor respectively, perhaps adopts NMOS pipe and the compound formation of PNP bipolar transistor.

The utility model compared with prior art, it is simple to have a control circuit, advantage such as easily manufactured.Because three electrodes of thyristor are all drawn from the surface, its input impedance height, adopt voltage control, as long as being arranged, the cut-in voltage of metal-oxide-semiconductor just can control its conducting, so can realize with conventional cmos low voltage logic control circuit integrated by dielectric isolation, help making various high-voltage power integrated circuits, be used for occasions such as motor driven and Industry Control.

Fig. 1 is the equivalent circuit diagram of PMOS grid-controlled transistor.

Fig. 2 is the generalized section of PMOS grid-controlled transistor.

The utility model can take following mode to implement: a kind of high voltage PMOS gated lateral thyristor, and it is composited by PMOS pipe and ambipolar NPN transistor, and its equivalent electric circuit and generalized section are as depicted in figs. 1 and 2.Between the anode A of PMOS grid-controlled transistor and negative electrode K, add forward voltage, i.e. A ground connection, when K connects negative potential, since anode A and substrate short circuit, J ₁Knot (the P between anode and substrate ⁺The N knot) be in zero partially, and J ₃Knot (emitter junction of NPN transistor) is in positively biased, J ₂Knot (the collection knot of NPN transistor) then is in partially anti-, and applied voltage drops to J basically ₂Tie.At J ₂Before the junction breakdown, the electric current by thyristor is J ₂The reverse saturation current of knot, thyristor presents the forward blocking state.In order to improve the forward blocking ability, will improve J ₂The reverse breakdown voltage of knot, (generally selecting resistivity is 5～30 Ω-cm), also must eliminate the influence to puncture voltage of skin effect and PN junction radius of curvature as far as possible except adopting the high resistant backing material.The utility model is taked drift region and field plate structure, i.e. PMOS grid-control tube drain region and bipolar transistor N ⁺PN ^-The public domain of base adopts ion to inject and forms lightly doped P ^-The drift region, and on the drift region, be provided with the source field plate of extension.In order further to improve the forward blocking ability of thyristor, can also form the grid field plate by the gate electrode that extends metal-oxide-semiconductor.Except above measure, in graphic designs with bigger semicircle of radius of curvature or be similar to the public domain of the arcuate structure of sports ground as metal-oxide-semiconductor drain region and bipolar transistor base.The channel length L of PMOS pipe gets (10～20) micron, and channel width-over-length ratio W/L gets (200～1000); The drift region length L _RGet (50～70) micron, elongated source field pole plate length L _Sf=L _s' f+L _s" f gets (30～40) micron, extends polysilicon gate field plate length L _s' f gets (12～18) micron, L _s" f is the length of source field plate greater than the grid field plate.The grid of metal-oxide-semiconductor adopt polysilicon to mix phosphorus entirely; The drift region secondary ion injects, and (dosage is 2 * 10 in the injection of whole drift region for the first time ¹²/ cm ²), (dosage is 3 * 10 for the drift region beyond the grid field plate is injected for the second time ¹²/ cm ²), junction depth is (4～5) micron; Ambipolar N ⁺PN ^-Transistorized base diffusion junction depth is (10～15) micron, and emitter region diffusion junction depth is (4～8) micron.Select (100) the N type silicon materials of resistance substrate rate for (10～15) Ω-cm for use, adopt Si-gate PMOS and bipolar transistor common process can prepare thyristor, its reverse blocking voltage is more than 350 volts.

The anode A ground connection of PMOS gated lateral thyristor, when negative electrode K connects negative potential, J ₁Knot is in zero inclined to one side, J ₂Knot is in anti-inclined to one side, J ₃Knot is in positively biased, if add negative potential this moment on the grid G of PMOS pipe, makes the PMOS pipe open its source-drain current I _DSBecome ambipolar N ⁺PN ^-Transistorized base current makes this transistor be in magnifying state, owing to pass through J ₂The electronic current that knot flows to substrate produces voltage drop on resistance substrate, make J ₁Knot becomes positively biased partially by zero, thereby makes by PMOS pipe source region P ⁺, substrate N ^-The parasitic bipolar transistor that constitutes with PMOS pipe drain region P satisfies the bias condition of magnifying state, from P ⁺The district is through J ₁Knot is to substrate N ^-District's injected hole, and by J ₂The reversed electric field of knot sweeps the P district and forms hole current.Because N ⁺PN ^-Transistorized electronic current and P ⁺N ^-The hole current of P parasitic transistor is at J ₂The accumulation of knot both sides progressively makes J ₂The reverse biased of knot reduces, and becomes forward bias, the J of thyristor ₁Knot, J ₂Knot and J ₃Knot all is in forward bias, thereby makes thyristor be in conducting state.

Add reverse voltage between the anode of PMOS gated lateral thyristor and negative electrode, i.e. anode A ground connection is when negative electrode K connects positive potential, because the source and the substrate of PMOS pipe link, so J ₁Knot is in zero partially, and J ₂Knot is in positively biased, J ₃Knot then is in partially anti-.Because applied voltage all drops to J basically ₃Knot is so the reverse blocking voltage of thyristor is decided by J ₃The puncture voltage of knot.Because the J of PMOS gated lateral thyristor ₃Junction breakdown voltage is lower, therefore, increases the high-voltage great-current backward diode at the negative electrode K of thyristor end usually, so that improve the reverse blocking voltage of thyristor.

Claims

1, a kind of thyristor of new structure, form by the PNPN four-layer structure, the PNPN layer that it is characterized in that forming thyristor is a transversary, adopt metal-oxide-semiconductor and the compound formation of bipolar transistor, the emitter region of the source of metal-oxide-semiconductor, drain region and bipolar transistor and collecting region are formed the four-layer structure of lateral thyristor, and wherein the base of the drain region of metal-oxide-semiconductor and bipolar transistor is a public domain.

2, thyristor according to claim 1 is characterized in that thyristor is by PMOS pipe with the NPN bipolar transistor is compound constitutes.

3, thyristor according to claim 1 is characterized in that thyristor is by NMOS pipe with the PNP bipolar transistor is compound constitutes.

4, thyristor according to claim 1 and 2 is characterized in that thyristor takes drift region and field plate structure, i.e. PMOS grid-control tube drain region and bipolar transistor N ⁺PN ^-The public domain P of base ^-Adopt ion to inject and form lightly doped drift region, and on the drift region, be provided with the source field plate of extension and extend to form the grid field plate by the metal-oxide-semiconductor gate electrode.

5, thyristor according to claim 4 is characterized in that channel length L=(10～20 of PMOS pipe) micron, channel width-over-length ratio (W/L)=(200～1000), drift region length L _R=(50～70) micron, source field plate length L _Sf=(30～40) micron, grid field plate length L _s' f=(12～18) micron.