CN201430142Y

CN201430142Y - Asymmetric fast switching thyristor

Info

Publication number: CN201430142Y
Application number: CN2009200868432U
Authority: CN
Inventors: 颜家圣; 吴拥军; 张桥; 杨成标; 刘小俐; 刘鹏; 肖彦
Original assignee: HUBEI TECH SEMICONDUCTORS Co Ltd
Current assignee: HUBEI TECH SEMICONDUCTORS Co Ltd
Priority date: 2009-06-24
Filing date: 2009-06-24
Publication date: 2010-03-24
Anticipated expiration: 2019-06-24

Abstract

The utility model provides an asymmetric fast switching thyristor, belongs to the technical field of power semiconductor devices, and mainly aims to solve the problems that when the conventional fastswitching thyristor is applied in series inversion, the pressure drop is large, and the dynamic characteristic is poor. The utility model is mainly characterized in that the fast switching thyristor comprises a tube shell and a PNPN semi-conductor chip which is provided with a four-layered three-ended structure and is encapsulated in the tube shell; the junction depth of the P1 anodic area (1) ofthe semi-conductor chip is 20 to 70 percent that of the P2 cathodic area (3) of the semi-conductor chip; and a P+ high concentration area (8) is arranged in the P1 anodic area (1). When the fast switching thyristor is applied in series inversion, on-state voltage drop can be reduced remarkably, thereby improving on-state capability and operational reliability; meanwhile, the utility model has thecharacteristics that the internal structure is optimized at the same time, the storage electric charges with large infusion are reduced, and the restoration softness is improved, thereby being used mainly in high-power series inverter power supply devices.

Description

A kind of asymmetric high speed thyristor

Technical field

The utility model belongs to the power semiconductor technical field.Be specifically related to a kind of semiconductor variable flow device, be mainly used in high-power series resonant inverter supply unit.

Background technology

At present, the most parallel inverter technology that adopt of induction heating power, used semiconductor device is a high speed thyristor, typical circuit is as shown in Figure 1.After reactor is output as direct current, the inverter bridge of being made up of 4 high speed thyristors receives the triggering signal that control unit sends to the three-phase alternating current of input, and direct current is carried out conversion, exports high-frequency single-phase alternating current through over commutation.And a kind of more efficient, stable and bigger scheme of fan-out capability is the series resonant inverter technology, and typical circuit as shown in Figure 2.Different with the parallel inverter technology is that inverter bridge is high-frequency ac voltage output with the dc voltage conversion of rectifier bridge output.

High speed thyristor is the semiconductor device of four layer of three end structure of a kind of PNPN, through improving structural design and minority carrier control technology, makes it have higher switching speed than triode thyristor, thereby is applicable to the power converter of 200Hz～10kHz.No matter series resonant inverter or parallel inverter, the domestic high speed thyristor that all uses forward and reverse voltage identical (symmetry), promptly the P1 anode region is identical with the junction depth in cathode terminal P2 district, and N1 growing base area layer thickness is bigger.When being applied to series resonant inverter, because of its through-current capability of pressure drop ambassador is restricted.And because dynamic characteristic is relatively poor, stability and reliability that single unit system is moved easily produce harmful effect.

Summary of the invention

The purpose of this utility model provides a kind of when being applied to series resonant inverter at above-mentioned weak point exactly, can obviously reduce on-state voltage drop, thereby improve the on-state ability and improve functional reliability, simultaneously can more optimize internal structure, reduce the big store charge that injects, improve the asymmetric high speed thyristor that recovers softness.

Technical solution of the present utility model is: a kind of asymmetric high speed thyristor, comprise shell and the semiconductor chip that is encapsulated in four layer of three end structure of PNPN in this shell, it is characterized in that: the junction depth of the P1 anode region of described semiconductor chip is 20～70% of a cathode terminal P2 district junction depth, and P1 is provided with P in the anode region ⁺High concentration region.

The junction depth of the P1 anode region described in the utility model technical solution is 15～80 μ m; The junction depth in cathode terminal P2 district is 45～130 μ m, and surface concentration is 1.5～8 * 10 ¹⁷Cm ^-3The thickness of N1 growing base area is 110～350 μ m; P in the P1 anode region ⁺The surface concentration of high concentration region is 2 * 10 ¹⁹～9.5 * 10 ²⁰Cm ^-3

P in the P1 anode region described in the utility model technical solution ⁺High concentration region is that single window diffuses to form P ⁺The high concentration region junction depth is less than P1 anode region junction depth.

P in the P1 anode region described in the utility model technical solution ⁺High concentration region is that multiwindow diffuses to form, P ⁺The high concentration region junction depth is less than P1 anode region junction depth.

P in the P1 anode region described in the utility model technical solution ⁺High concentration region is that multiwindow diffuses to form, P ⁺The high concentration region junction depth is greater than P1 anode region junction depth.

The utility model is because more shallow than the junction depth in cathode terminal P2 district with the junction depth design of the P1 anode region of the semiconductor chip of PNPN four floor three end structure, and the thickness of N1 growing base area is than general thyristor thin 20%～30%; P1 anode region surface concentration also is higher than cathode terminal P2 district, thereby makes the asymmetric design in two P districts of thyristor, has obviously reduced the on-state voltage drop of device, thereby improves the reliability of on-state ability and work.The utility model has overcome the deficiencies in the prior art, has when being applied to series resonant inverter, can obviously reduce on-state voltage drop, thereby improve the on-state ability and improve functional reliability, simultaneously can more optimize internal structure, reduce the big store charge that injects, improve the characteristics of recovering softness.The utility model is mainly used in high-power series resonant inverter supply unit.

Description of drawings

Fig. 1 is the parallel inverter circuit theory diagrams;

Fig. 2 is the series resonant inverter circuit theory diagrams;

Fig. 3 is high speed thyristor chip structure figure;

Fig. 4 is the chip structure figure of the utility model embodiment 1;

Fig. 5 is the chip structure figure of the utility model embodiment 2;

Fig. 6 is the chip structure figure of the utility model embodiment 3.

Embodiment

Embodiment 1 as shown in Figure 4.Asymmetric thyristor comprises shell and is encapsulated in the semiconductor chip of four layer of three end structure of PNPN in this shell.The junction depth of P1 anode region 1 is 15～80 μ m; The junction depth in cathode terminal P2 district 3 is 45～130 μ m, and surface concentration is 1.5～8 * 10 ¹⁷Cm ^-3The thickness of N1 growing base area 2 is 110～350 μ m; P in the P1 anode region 1 ⁺The surface concentration of high concentration region 8 is 2 * 10 ¹⁹～9.5 * 10 ²⁰Cm ^-3The junction depth of the P1 anode region 1 of semiconductor chip is 20～70% of cathode terminal P2 district 3 junction depths, and the thickness of N1 growing base area 2 is thinner 20%～30% than general thyristor, the P in the P1 anode region 1 ⁺ High concentration region 8 is that single window diffuses to form P ⁺ High concentration region 8 junction depths are less than P1 anode region 1 junction depth.

According to different application requirements:

Silicon single crystal is selected the NTD material for use, and resistivity is 30～140 Ω .cm, thickness 380～600 μ m.Choosing of gross thickness both requires to guarantee the withstand voltage requirement of N1 growing base area 2 realization device forwards, is unlikely to increase pressure drop again.

P1 anode region 1 and cathode terminal P2 district 3 are carried out the p type impurity diffusion first time simultaneously and are obtained by two-sided, can be Ga or Al.Junction depth 45～130 μ m, surface concentration 1.5～8 * 10 ¹⁷Cm ^-3

With the surface protection in cathode terminal P2 district 3 good after, by methods such as grinding, sandblast and chemical corrosions, silicon chip is carried out skiving from the P1 end handles.Remove 30～150 μ m.

Behind the wafer thinning, P1 anode region 1 and cathode terminal P2 district 3 are done surface oxidation treatment simultaneously.Target end P2 district 3 surface oxide layers carry out selective etching then, and N type diffusion of impurities is done on 3 surfaces, target end P2 district again, form N2 cathodic region 4, junction depth 12～28 μ m, surface concentration 2 * 10 ¹⁹～9.5 * 10 ²⁰

1 surface, P1 anode region is diffuseed to form P through too high surface concentration P type ⁺ High concentration region 8, junction depth 25～70 μ m.P in case of necessity ⁺Diffusion is selected on high concentration region 8 surfaces.

For improving asymmetric thyristor switch speed, to spreading good silicon chip gold doping or mixing the platinum diffusion, to reduce minority carrier lifetime.Diffusion temperature is 830～880 ℃, 20～45 minutes time.Also adopt electron irradiation, be characterized in that leakage current is little, hot properties is better.

On molybdenum sheet, selective etch is again carried out after the metal evaporation on target

end P2 district

3 and 4 surfaces, N2 cathodic region with ready-made asymmetric thyristor silicon chip sintering, clear needed figure and gate pole 5, the negative electrode 6 isolated, and molybdenum sheet is as the anode 7 of chip.At last chip is installed in the standard shell of customization, finishes the final packaging and testing of the asymmetric high speed thyristor of the utility model.

Table one is the 76mm high speed thyristor and the main static index test contrast of asymmetric thyristor of same specification:

Table one

Data show, when identical forward off state voltage design, and the average V of asymmetric thyristor on-state voltage drop _TMThan the low 0.72V of conventional high speed thyristor, reach 25%.This shows its lower on-state loss that is in operation.

Table two

Table two is dynamic parameter sample testing contrasts.Therefrom see: asymmetric thyristor is faster than the service time summary of conventional high speed thyristor, and it is less to recover electric charge, and expansion voltage is lower.By Computer Simulation, its switching loss is little by 27%.

Above result of the test shows that asymmetric high speed thyristor, has than remarkable advantages with respect to the thyristor of conventional symmetric design on dynamic and static characteristic.

Embodiment 2 as shown in Figure 5.P+ high concentration region 9 in the P1 anode region 1 is that multiwindow diffuses to form as different from Example 1, P ⁺High concentration region 9 junction depths are less than P1 anode region 1 junction depth.

Embodiment 3 as shown in Figure 6.P+ high concentration region 10 in the P1 anode region is that multiwindow diffuses to form as different from Example 1, P ⁺High concentration region 10 junction depths are greater than P1 anode region junction depth.

Claims

1, a kind of asymmetric high speed thyristor, comprise shell and the semiconductor chip that is encapsulated in four layer of three end structure of PNPN in this shell, it is characterized in that: the junction depth of the P1 anode region (1) of described semiconductor chip is 20～70% of cathode terminal P2 district (a 3) junction depth, and the P1 anode region is provided with P in (1) ⁺High concentration region (8).

2, a kind of asymmetric high speed thyristor according to claim 1 is characterized in that: the junction depth of described P1 anode region (1) is 15～80 μ m; The junction depth in cathode terminal P2 district (3) is 45～130 μ m, and surface concentration is 1.5～8x10 ¹⁷Cm ^-3The thickness of N1 growing base area (2) is 110～350 μ m; P in the P1 anode region (1) ⁺The surface concentration of high concentration region (8) is 2x10 ¹⁹～9.5x10 ²⁰Cm ^-3

3, a kind of asymmetric high speed thyristor according to claim 1 and 2 is characterized in that: the P in the described P1 anode region (1) ⁺The single window of high concentration region (8) diffuses to form P ⁺High concentration region (8) junction depth is less than P1 anode region (1) junction depth.

4, a kind of asymmetric high speed thyristor according to claim 1 and 2 is characterized in that: the P in the described P1 anode region ⁺High concentration region (8) is that multiwindow diffuses to form, P ⁺High concentration region (8) junction depth is less than P1 anode region junction depth.

5, a kind of asymmetric high speed thyristor according to claim 1 and 2 is characterized in that: the P in the described P1 anode region ⁺High concentration region (8) is that multiwindow diffuses to form, P ⁺High concentration region (8) junction depth is greater than P1 anode region junction depth.