CN2247873Y - Solid discharge diode - Google Patents

Abstract

The utility model relates to a solid discharge diode, which is a protector for preventing lightning and waves from damaging electronic devices. The utility model is formed by both surfaces of the bottom of an n-shaped silicon lining provided with boron diffusion regions and phosphorus diffusion regions. Two phosphorus diffusion regions are positioned at both sides of the two boron diffusion regions, and are uniformly distributed with circular short dots. The utility model forms an axially symmetric structure which can rotate with 180 DGE. The short dots are distributed in a regular triangle (or can be a square). The edges of both sides of the phosphorus diffusion regions are in semicircular structures. The utility model has the advantages of simple technology and structure, low cost, high finished product rate, etc.

Description

The solid discharge diode

The utility model is a kind of current mode silicon device of surge protector, belongs to semiconductor die brake tube technical field.

Solid discharging tube is a kind of protector as communication equipment, data conveyer and semiconductor integrated circuit etc.Existing solid discharging tube adopts mesa structure usually or adopts pressure limiting ring, equipotential ring structure, and the device technology complexity of mesa structure needs to adopt technology for passivating glass, adopts the pressure limiting ring, and the device of equipotential ring structure is unfavorable for improving rate of finished products because of complex structure.

The purpose of this utility model is at the deficiencies in the prior art, and a kind of simple in structure, solid discharge diode that manufacture craft is easy is provided, and it is low to have a production cost, and characteristics such as rate of finished products height are convenient to apply at home.

The utility model adopts two-way two end silicon Darlistor structures, can by at the bottom of the n type silicon, boron diffusion district and phosphorous diffusion district form, be characterized in that two boron diffusion districts are positioned at the substrate tow sides, two phosphorous diffusion districts are positioned at the both sides in two boron diffusion districts, equally distributed circular short dot is arranged in two phosphorous diffusion districts, and entire device constitutes the axially symmetric structure of Rotate 180 °.The home position of circular short dot can be equilateral triangle and distribute, and also can be square profile.In order to solve the homogeneity question of start trigger electric current, both sides of the edge, phosphorous diffusion district are semicircular structure with respect to short dot.

The utility model compared with prior art has that structure and technology are simple, cost is low and the rate of finished products advantages of higher, does not need to use potential dividing ring, by ring and technology for passivating glass.Compare with gas discharge tube; have that response is fast, electric leakage is little, insulation resistance big, stable performance, advantage such as current capacity is big and the life-span is long; can be used for thunderbolt, eletric power induction and power line are touched and the protection of possible damage equipment; the lightning protection surge protection of for example various communication equipments (electron exchanger, stored-program control exchange, facsimile machine, wireless machine etc.), data conveyer; the AC line of telecommunication circuit is mixed and is touched protection, and the protection of various integrated circuit (IC) and very lagre scale integrated circuit (VLSIC) semiconductor device such as (LSI).

Fig. 1 is a structural representation of the present utility model; Fig. 2 is the planar structure schematic diagram of embodiment; Fig. 3 is current-voltage (I-V) performance diagram of device.

The utility model can adopt scheme shown in the drawings to realize.As shown in Figure 1, according to V _BRRequirement can select for use certain resistivity, crystal orientation to be (111) and n type twin polishing silicon chip n ₃Through once oxidation, adopt the dual surface lithography technology to carve two-sided boron diffusion district, adopt the crystallite boron diffusion source to diffuse to form two-sided boron diffusion district P ₂And P ₄, adopt the dual surface lithography technology again, diffuse to form phosphorous diffusion district n with phosphorus oxychloride (POCl3) liquid source ₁And n ₅, dual surface lithography carves fairlead for the third time, and double-sided metalization wherein simultaneously can be aluminium (Al) layer again; Another side can be multiple layer metal, as chromium nickel gold (CrNiAu), forms metal inner electrode by dual surface lithography again; Adopt the encapsulation of freezing of double-faced packaging technology at last.Encapsulate the available dual mode of adopting and realize, the firstth, adopt plastic packaging, the multi-layered electrode one side is freezed on base with terne metal, another side Si-Al wire ultrasonic bonding makes the aluminium electrode link to each other with pin, then plastic packaging.The secondth, adopt metal electrode to freeze, freeze with terne metal, the burned one side of elder generation, the another side that reburns forms electrode T ₁And T ₂A-A ' among Fig. 2 is a profile position, and Y-Y ' is a Rotate 180 ° symmetry axis, the short dot that (1) distributes for equilateral triangle, and (2) are semicircular phosphorous diffusion area edge, and (3) are the boron diffusion district, and (4) are the n silicon substrate, and (5) among Fig. 1 are interior electrode, (6) are SiO ₂Substrate also can adopt P type silicon, and this moment, two boron-doping districts were positioned at two both sides of mixing the phosphorus district.T1 end in Fig. 1 adds positive voltage, T ₂When end added negative voltage, its I-V characteristic was shown in the first quartile among Fig. 3.When applied voltage V does not reach its puncture voltage V _BRThe time, the solid discharge diode presents high resistant (10 ⁹～10 ¹⁰Ω), leakage current minimum (during 50V less than 1 μ A); As V 〉=V _BRThe time, electric current increases suddenly; When V reaches breakover voltage V _BoThe time, entering negative differential conductance district (dI/dV＜0), this moment, electric current was very big, and conducting resistance is minimum.Along with surge voltage reduces, the electric current by device refluxes gradually, keeps electric current I when electric current I drops to _HThe time, device is converted to high-impedance state rapidly from low resistance state, and this has just finished the single step of releasing electric process.Work as T ₁Add negative voltage, T ₂When adding malleation, its I-V characteristic is shown in the third quadrant among Fig. 3.

Claims (3)

1. one kind is used to prevent that lightning surge from damaging the solid discharge diode of electronic equipment and device, constitute by n type silicon substrate, boron diffusion district and phosphorous diffusion district, it is characterized in that two boron diffusion districts are positioned at the substrate tow sides, two phosphorous diffusion districts are positioned at the both sides in two boron diffusion districts, equally distributed circular short dot is all arranged in two phosphorous diffusion districts, and entire device constitutes the axially symmetric structure of Rotate 180 °.

2. solid discharge diode according to claim 1 is characterized in that the home position of circular short dot is the equilateral triangle distribution.

3. solid discharge diode according to claim 1 and 2 is characterized in that both sides of the edge, phosphorous diffusion district are semicircular structure with respect to short dot.