CN209658183U - A kind of single-chip TVS of five layers of composite construction - Google Patents

Abstract

The utility model provides a kind of single-chip TVS of five layers of composite construction, including N-type substrate, the two sides of N-type substrate are successively arranged the diffusion region P+, the diffusion region N+ and metal layer from inside to outside, and the digging groove of N-type substrate and the diffusion region P+ junction forms cyclic annular passivation groove.The utility model carries out p type impurity diffusion in N-type substrate, then further progress N-type impurity is spread on p-type inversion layer, form N-type inversion layer, ultimately form NPNPN composite construction, to achieve the effect that single-chip replaces dual chip lamination, greatly reduces cost, improves production tube reliability and encapsulation yield.

Description

A kind of single-chip TVS of five layers of composite construction

Technical field

The utility model relates to technical field of semiconductors, more particularly to a kind of single-chip TVS of five layers of composite construction.

Background technique

TVS pipe is a kind of new product to grow up on voltage-stabiliser tube Process ba- sis, when TVS pipe both ends are subjected to the height of moment When energy impact, it can be such that its impedance reduces suddenly with high speed, while absorb a high current, by the electricity between its both ends Pressure clamp one it is scheduled numerically, so that it is guaranteed that subsequent circuit element from transient state high-energy impact and damage. The response time is fast, transient power is big, capacitor is low, leakage current is low, breakdown voltage deviation is small, clamping voltag since it has for TVS pipe Be relatively easy to control, without damage limit, it is small in size, be easily installed the advantages that, be widely used at present computer system, communication set The every field such as standby, consumer electronics, power supply, household electrical appliance.

Present TVS production tube is as shown in Figure 1, generally use the packaged type of dual chip lamination in production process to improve function Rate grade, but its production cost also obviously increases, and double-layer chip lamination production tube reliability it is poor and there are laminations not In place, the low risk of encapsulation yield.

Utility model content

The purpose of the utility model is to overcome the above-mentioned deficiency of the prior art, a kind of single-chip TVS and its production are provided Method solves the problems, such as that existing TVS production tube high production cost in technical field of semiconductors, poor reliability, encapsulation yield are low.

To achieve the above object, the utility model provides a kind of single-chip TVS of five layers of composite construction, including N-type lining Bottom, the two sides of the N-type substrate are successively arranged the diffusion region P+, the diffusion region N+ and metal layer from inside to outside, the N-type substrate and The digging groove of the diffusion region P+ junction forms cyclic annular passivation groove.

Further, the depth of the passivation groove is 65-85 μm, and width is at 300-500 μm.

Further, the single-chip TVS is with a thickness of 450-550 μm.

The utility model has the beneficial effects that p type impurity diffusion is carried out in N-type substrate, then in p-type inversion layer enterprising one Step carries out N-type impurity diffusion, forms N-type inversion layer, ultimately forms NPNPN composite construction, replaces dual chip lamination to reach Effect greatly reduces cost, improves production tube reliability and encapsulation yield.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of existing TVS production tube.

Fig. 2 is the structural schematic diagram of the single-chip TVS of the utility model.

Wherein: 1, N-type substrate, 2, the diffusion region P+, 3, the diffusion region N+, 4, metal layer, 5, passivation groove.

Specific embodiment

Specific embodiment of the present utility model is described with reference to the accompanying drawing.

As shown in Fig. 2, a kind of single-chip TVS of five layers of composite construction, including N-type substrate 1, the two of the N-type substrate 1 Side is successively arranged the diffusion region P+ 2, the diffusion region N+ 3 and metal layer 4,2 junction of the N-type substrate 1 and the diffusion region P+ from inside to outside Digging groove form cyclic annular passivation groove 5.Wherein, the depth for being passivated groove 5 is 65-85 μm, and width is at 300-500 μm.Single Piece TVS is with a thickness of 450-550 μm.

A kind of production method of the single-chip TVS of five layers of composite construction includes following processing step:

(1) boron is spread: being coated boron source on the two sides of 1 material of N-type substrate, is then carried out boron diffusion, form the diffusion region P+ 2；

(2) phosphorus diffusion: using the rotten net surface oxide layer of BOE corrosive liquid, then using phosphorus oxychloride as doped source, in N-type 1 material two sides pre-deposited phosphorus of substrate steeps and carries out phosphorus after the phosphorosilicate glass on net surface again and spread knot again, forms the diffusion region N+ 3；

(3) photoetching slot: face cutting is adulterated in the diffusion region N+ 3 of chip, slot photoetching is carried out using slot version；

(4) mesa etch: ring is formed to mesa etch is carried out at the digging groove of 2 junction of N-type substrate 1 and the diffusion region P+ Shape is passivated groove 5, and the groove depth that passivation groove 5 corrodes is 65-85 μm, and groove width is at 300-500 μm；

(5) it glassivation: is passivated using the material that glass passivation process obtains step (4)；

(6) lead version lithography fair lead, extraction electrode photoetching lead: are used；

(7) surface metalation: chip is put into evaporator evaporation, is put into alloying furnace and heats after evaporation is qualified, form table Face metal layer 4；

(8) test: automatic test machine tests chip electrical parameter；

(9) scribing: sand-wheel slice cutting machine cuts chip；

(10) it arranges: chip being arranged, is packed.

In step (1), diffusion temperature are as follows: 1280 DEG C of 1250-, time 30-40h, Bxj=30-45 μm.

In step (2), the specific gravity of HF and NH4F in BOE corrosive liquid are 1:5.

In step (2), diffusion is divided into prediffusion and spreads again；Wherein, 1000-1050 DEG C of prediffusion temperature, time 80- 100min, Rs=0.9-1.0 Ω/；1220-1250 DEG C of diffusion temperature again, time 3-5h, Xj=15-20 μm.

The utility model carries out p type impurity diffusion in N-type substrate, and then further progress N-type is miscellaneous on p-type inversion layer Matter diffusion, forms N-type inversion layer, ultimately forms NPNPN composite construction, to achieve the effect that replace dual chip lamination, greatly It reduces costs, improve production tube reliability and encapsulation yield.

Claims (3)

1. a kind of single-chip TVS of five layers of composite construction, it is characterised in that: including N-type substrate, the two sides of the N-type substrate It is successively arranged the diffusion region P+, the diffusion region N+ and metal layer, the ditching of the N-type substrate and the diffusion region P+ junction from inside to outside Flute profile is circlewise passivated groove.

2. the single-chip TVS of five layers of composite construction according to claim 1, it is characterised in that: the depth of the passivation groove Degree is 65-85 μm, and width is at 300-500 μm.

3. the single-chip TVS of five layers of composite construction according to claim 1, it is characterised in that: the single-chip TVS thickness It is 450-550 μm.