Summary of the invention
The objective of the invention is to; overcome the defective that existing electrostatic discharge protective equipment exists; and provide a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage of new structure; no matter technical problem to be solved is that to make the signal of its protected circuit be high voltage or negative voltage (or the two all has); the electrostatic discharge (ESD) protection of Vdd pattern and Vss pattern all can be provided simultaneously; thereby be suitable for practicality more, and have the value on the industry.
Another object of the present invention is to, a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage is provided, technical problem to be solved is to make it more can derive electrostatic pulse fast, thereby is suitable for practicality more.
The object of the invention to solve the technical problems realizes by the following technical solutions.According to the electrostatic discharge protective equipment a kind of capable of bearing high-voltage and negative voltage that the present invention proposes, be connected to the weld pad in the integrated circuit, this electrostatic discharge protective equipment comprises: one first type substrate; One first type wellblock is arranged in this first type substrate, and this first type wellblock is a suspension joint; One second type wellblock is arranged in this first type substrate, and separates this first type wellblock and this first type substrate, and this second type wellblock is coupled to one first pressure-wire; One second type, first doped region is arranged in this first type wellblock, and is coupled to one second pressure-wire; One second type, second doped region is arranged in this first type wellblock, and is coupled to this weld pad; And an isolation structure, be arranged between this second type, first doped region and this second type, second doped region.
The object of the invention to solve the technical problems also can be applied to the following technical measures to achieve further.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said first type is the P type, then second type is the N type.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, the wherein said second type wellblock is constituted with the dark second type well.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, the wherein said second type wellblock is made of the second type embedding layer and the high pressure second type well.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said isolation structure are field oxide region.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said isolation structure are shallow trench isolation region.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, the voltage of wherein said first pressure-wire are a system voltage, and the voltage of this second pressure-wire is an earthed voltage.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, the voltage of wherein said first pressure-wire and this second pressure-wire is all a system voltage.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, the voltage of wherein said first pressure-wire and this second pressure-wire is all an earthed voltage.
The object of the invention to solve the technical problems also adopts following technical scheme to realize.Electrostatic discharge protective equipment a kind of capable of bearing high-voltage and negative voltage according to the present invention's proposition, in order to protect the internal circuit in the integrated circuit, this internal circuit has that end is exported/gone into at least one high pressure and at least one negative pressure is exported/goes into end, and this electrostatic discharge protective equipment comprises: one first type substrate; One first type, first wellblock is arranged in this first type substrate, and this first type, first wellblock is a suspension joint; One second type, first wellblock is arranged in this first type substrate, and separates this first type, first wellblock and this first type substrate, and this second type, first wellblock is coupled to a system voltage line; One second type, first doped region is arranged in this first type, first wellblock, and is coupled to this system voltage line; One second type, second doped region is arranged in this first type, first wellblock, and is coupled to this high pressure and exports/go into end; One first isolation structure is arranged between this second type, first doped region and this second type, second doped region; One first type, second wellblock is arranged in this first type substrate, and this first type, second wellblock is a suspension joint; One second type, second wellblock is arranged in this first type substrate, and separates this first type, second wellblock and this first type substrate, and this second type, second wellblock is coupled to a ground voltage line; One second type the 3rd doped region is arranged in this first type, second wellblock, and is coupled to this ground voltage line; One second type the 4th doped region is arranged in this first type, second wellblock, and is coupled to this negative pressure and exports/go into end; And one second isolation structure, be arranged between this second type the 3rd doped region and this second type the 4th doped region.
The object of the invention to solve the technical problems also can be applied to the following technical measures to achieve further.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said first type is the P type, then second type is the N type.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said second type, first wellblock and this second type, second wellblock are all constituted with the dark second type well.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said second type, first wellblock and this second type, second wellblock are all constituted with the second type embedding layer and the high pressure second type well.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said first isolation structure and this second isolation structure are all field oxide region.
Aforesaid electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, wherein said first isolation structure and this second isolation structure are all shallow trench isolation region.
The present invention compared with prior art has tangible advantage and beneficial effect.By above technical scheme as can be known, in order to reach aforementioned goal of the invention, major technique of the present invention thes contents are as follows:
The present invention proposes a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, and this electrostatic discharge protective equipment is connected to the weld pad in the integrated circuit.Electrostatic discharge protective equipment comprises the first type substrate, the first type wellblock, the second type wellblock, second type, first doped region, second type, second doped region and isolation structure.The first type wellblock is arranged in the first type substrate, and this first type wellblock is suspension joint (float).The second type wellblock is arranged in the first type substrate, and separates the first type wellblock and the first type substrate.This second type wellblock is coupled to first pressure-wire.Second type, first doped region is arranged in the first type wellblock, and is coupled to second pressure-wire.Second type, second doped region also is arranged in the first type wellblock, and is coupled to weld pad.Isolation structure is arranged between second type, first doped region and second type, second doped region.
According to the described electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage of preferred embodiment of the present invention, wherein so-called first type for example is the P type, and then second type is the N type.The second above-mentioned type wellblock for example can constitute by deep N-well (deep N well), or constitutes with N type embedding layer (NBL, Nburied layer) and high-pressure N-shaped well (high voltage N well).Isolation structure for example is field oxide region (field oxide) or shallow trench isolation region (STI, shallow trenchisolator).In addition, the voltage of first pressure-wire is system voltage for example, and the voltage of second pressure-wire for example is earthed voltage.
The present invention proposes a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage in addition, in order to the internal circuit of protection integrated circuit.This internal circuit has that end is exported/gone into at least one high pressure and end is exported/gone into at least one negative pressure.This electrostatic discharge protective equipment comprises the first type substrate, first type, first wellblock, first type second and district, second type, first wellblock, second type, second wellblock, second type, first doped region, second type, second doped region, second type the 3rd doped region, second type the 4th doped region, first isolation structure and second isolation structure.First type, first wellblock is arranged in the first type substrate and keeps suspension joint (float).Second type, first wellblock is arranged in the first type substrate, and separates first type, first wellblock and the first type substrate.Second type, first wellblock is coupled to the system voltage line.Second type, first doped region is arranged in first type, first wellblock, and is coupled to the system voltage line.Second type, second doped region is arranged in first type, first wellblock, and end is exported/gone into to the high pressure that is coupled to aforementioned internal circuit.First isolation structure then is arranged between second type, first doped region and second type, second doped region.
In addition, first type, second wellblock also is arranged in the first type substrate and keeps suspension joint.Second type, second wellblock is arranged in the first type substrate, and separates first type, second wellblock and the first type substrate.Second type, second wellblock is coupled to ground voltage line.Second type the 3rd doped region is arranged in first type, second wellblock, and is coupled to ground voltage line.Second type the 4th doped region is arranged in first type, second wellblock, and end is exported/gone into to the negative pressure that is coupled to aforementioned internal circuit.Second isolation structure is arranged between second type the 3rd doped region and second type the 4th doped region.
Via as can be known above-mentioned, the invention relates to a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, it comprises the first type substrate, the first type wellblock, the second type wellblock, second type, first doped region, second type, second doped region and isolation structure.The first type wellblock is arranged in the first type substrate, and this first type wellblock is suspension joint (float).The second type wellblock is arranged in the first type substrate, and separates the first type wellblock and the first type substrate.The second type wellblock is coupled to first pressure-wire.Second type, first doped region is arranged in the first type wellblock, and is coupled to second pressure-wire.Second type, second doped region also is arranged in the first type wellblock, and is coupled to weld pad.Isolation structure is arranged between second type, first doped region and second type, second doped region.
By technique scheme, the present invention's electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage has following advantage at least:
Therefore the present invention is provided electrostatic discharge (ESD) protection because of transistor (being NPN transistor among the embodiment) structure of the first type wellblock (for example being the p type wells district) that utilizes suspension joint, isolation structure (for example being field oxide region) and conducting when the static discharge.Because the first type wellblock keeps suspension joint, when electrostatic pulse causes PN interface collapse reverse in the device and produces extracurrent temporarily, this extracurrent causes the transistor (comprising lateral transistor and vertical transistor) in the device to enter conducting state at once, so electrostatic pulse is able to be directed to system voltage line or ground voltage line via this device in good time, avoids inner and burnt.
In sum; the electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage of special construction of the present invention; overcome the defective that existing electrostatic discharge protective equipment exists; a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage of new structure is provided; no matter making the signal of its protected circuit is high voltage or negative voltage (or the two all has); the electrostatic discharge (ESD) protection of Vdd pattern and Vss pattern all can be provided simultaneously; thereby more can derive electrostatic pulse fast; it has above-mentioned many advantages and practical value; and in like product, do not see have similar structural design to publish or use and really genus innovation; no matter it all has bigger improvement on the structure of product or function; have large improvement technically; and produced handy and practical effect; and more existing electrostatic discharge protective equipment has the multinomial effect of enhancement; thereby being suitable for practicality more, and having the extensive value of industry, really is a novelty; progressive; practical new design.
Above-mentioned explanation only is the general introduction of technical solution of the present invention, for can clearer understanding technological means of the present invention, and can be implemented according to the content of specification, below with preferred embodiment of the present invention and conjunction with figs. describe in detail as after.
The specific embodiment of the present invention is provided in detail by following examples and accompanying drawing thereof.
Embodiment
Below in conjunction with accompanying drawing and preferred embodiment, to its concrete structure of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage, feature and the effect thereof that foundation the present invention proposes, describe in detail as after.
Many integrated circuits can be exported (or input) high voltage and negative voltage signal in same link, for example the source electrode driven integrated circuit of display panels is promptly at the link output HIGH voltage or the negative voltage of same driving liquid crystal panel channel.Therefore, according to the invention provides an embodiment, not only can bear high voltage at this, and also can bear the electrostatic discharge (ESD) protection of negative voltage to reach in single electrostatic discharge protective equipment.
Seeing also shown in Figure 1ly, is the electrostatic discharge protective equipment circuit structure diagram a kind of capable of bearing high-voltage and negative voltage that illustrates according to a preferred embodiment of the present invention.See also shown in Figure 1ly, be illustrated in desire protective circuit in the integrated circuit encapsulation, the pad that the pin that weld pad (pad) 120 then encapsulates for internal circuit 110 and integrated circuit is connected at this internal circuit 110.At this, internal circuit 110 sees through same weld pad 120 output high pressure signal and negative pressure signals.In other words, the operating voltage range of the output signal 111 that is transmitted through weld pad 120 be between high pressure and the negative pressure (for example+6V~-3V between).Therefore, must guarantee under the operating voltage range of high pressure and negative pressure, all can not start electrostatic discharge protective equipment.
According to viewpoint of the present invention; at this present embodiment a kind of electrostatic discharge protective equipment capable of bearing high-voltage and negative voltage 130 is proposed; see also shown in Figure 1; comprise P type substrate (P substrate) 141, by high-pressure N-shaped well (HVNW; high voltage N well) 142 with N type embedding layer (NBL, N buried layer) 143 N type wellblock (N well), p type wells district (Pwell) 144, N type doped region 145, N type doped regions 146 that constituted and utilize field oxide region (field oxide) 147 isolation structures that constituted.
P type wells district 144 is arranged in the P type substrate 141 and keeps suspension joint (float).Then be arranged in the P type substrate 141 by high-pressure N-shaped well 142 and the N type wellblock that N type embedding layer 143 is constituted, and separate p type wells district 144 and P type substrate 141.This N type wellblock is drawn to connect and is discharge end 133.N type doped region 145 is arranged in the p type wells district 144, and draws to connect and be electrostatic discharge (ESD) protection end 131.N type doped region 146 also is arranged in the p type wells district 144, and draws to connect and be discharge end 132.147 of field oxide regions are arranged between N type doped region 145 and the N type doped region 146.
Above-mentioned isolation structure still can utilize shallow trench isolation region (STI, shallow trench isolator) or alternate manner to finish except implementing with field oxide region 147.And above-mentioned N type wellblock is except constituting with high-pressure N-shaped well 142 and N type embedding layer 143 as present embodiment, also can deep N-well (deep N well) or alternate manner finish.Above-mentioned change all belongs to category of the present invention.
Please continue to consult shown in Figure 1, in the present embodiment, the electrostatic discharge (ESD) protection end 131 of electrostatic discharge protective equipment 130 is coupled to weld pad 120, and discharge end 132 is coupled to ground voltage line VSS, and discharge end 133 is coupled to system voltage line VDD.When internal circuit 110 output high pressure signals (for example being 6V), N type doped region 145 can be considered contrary inclined to one side diode with the face that connects in p type wells district 144.The p type wells district 144 of this suspension joint is because no current (or the reverse saturation current of trace, reversesaturation current) and make its voltage V
PWLevel off to earthed voltage VSS.At this moment, the base-emitter voltage V of horizontal NPN transistor (lateral NPN) (for example being constituted with N type doped region 146) and vertical NPN transistor (vertical NPN) (for example being constituted with N type embedding layer 143) by N type doped region 145, p type wells district 144 by N type doped region 145, p type wells district 144
BE=V
PW-VSS is less than starting (turn on) transistorized critical voltage (for example 0.7V).Therefore, electrostatic discharge protective equipment 130 remains in cut-off state.
When internal circuit 110 output negative pressure signals (for example be-3V) time, N type doped region 146 can be considered contrary inclined to one side diode (face that connects in N type wellblock and p type wells district 144 is also same) with the face that connects in p type wells district 144.The p type wells district 144 of this suspension joint makes its voltage V because of no current (or reverse saturation current of trace)
PWLevel off to the voltage V of weld pad 120
PADAt this moment, the base-emitter voltage V of horizontal NPN transistor and vertical NPN transistor
BE=V
PW-V
PADSmaller or equal to starting transistorized critical voltage (for example 0.7V).Therefore, electrostatic discharge protective equipment 130 remains in cut-off state.
Connect when entering from weld pad 120 as positive electrostatic pulse (its voltage is much larger than system voltage VDD usually), what will cause N type doped region 145 and p type wells district 144 contraryly connects face collapse (breakdown) partially.At this moment, produce a large amount of electric currents from N type doped region 145 by p type wells district 144, these a large amount of electric currents cause the voltage V in the p type wells district 144 of suspension joint because of its internal resistance
PWMoment rises.Therefore make the base-emitter voltage V of transistor (horizontal and vertical)
BE(be V
PW-VSS or V
PW-VDD) greater than starting transistorized critical voltage.Therefore, electrostatic discharge protective equipment 130 can start moment.When 130 moments of electrostatic discharge protective equipment start, can will be directed to system voltage line VDD via N type doped region 145, p type wells district 144 and N type wellblock (for example constituting with N type embedding layer 143) because of positive pulse electric current that static discharge caused by high-pressure N-shaped well 142.This kind is called PD pattern (positive pulse VDD mode) with the pattern of system voltage line VDD guiding positive pulse electrostatic current.In addition, when 130 moments of electrostatic discharge protective equipment start, also can will be directed to ground voltage line VSS via N type doped region 145, p type wells district 144 and N type doped region 146 because of positive pulse electric current that static discharge caused.This kind is called PS pattern (positive pulse VSS mode) with the pattern of ground voltage line VSS guiding positive pulse electrostatic current.Therefore, the present invention can be fast and effectively positive electrostatic pulse is directed to ground voltage line VSS and system voltage line VDD and avoids damaging internal circuit 110.
Connect when entering from weld pad 120 as negative electrostatic pulse (its voltage is much smaller than earthed voltage VSS usually), what will cause N type doped region 146 and p type wells district 144 contraryly connects face collapse (break down) partially and makes the voltage V in p type wells district 144 of suspension joint
PWMoment descends.At this moment, produce a large amount of electric currents from N type doped region 146 by p type wells district 144, these a large amount of electric currents cause the p type wells district 144 voltage V of suspension joint because of its internal resistance
PWWith weld pad 120 voltage V
PADBetween voltage difference (be the base-emitter voltage V of lateral transistor and vertical transistor
BE) greater than starting transistorized critical voltage.Therefore, electrostatic discharge protective equipment 130 can start moment.When 130 moments of electrostatic discharge protective equipment start, can will be directed to system voltage line VDD via N type doped region 145, p type wells district 144 and N type wellblock (for example constituting with N type embedding layer 143) because of negative pulse electric current that static discharge caused by high-pressure N-shaped well 142.This kind is called ND pattern (negative pulse VDD mode) with the pattern of system voltage line VDD guiding negative pulse electrostatic current.In addition, when 130 moments of electrostatic discharge protective equipment start, also can will be directed to ground voltage line VSS via N type doped region 145, p type wells district 144 and N type doped region 146 because of negative pulse electric current that static discharge caused.This kind is called NS pattern (negative pulse VSS mode) with the pattern of ground voltage line VSS guiding negative pulse electrostatic current.Therefore, the present invention can be fast and will be born electrostatic pulse effectively and be directed to ground voltage line VSS and system voltage line VDD and avoid damaging internal circuit 110.
At this in addition for an embodiment, more to clearly demonstrate application of the present invention.Seeing also shown in Figure 2ly, is the electrostatic discharge protective equipment circuit diagram a kind of capable of bearing high-voltage and negative voltage that illustrates according to another preferred embodiment of the present invention.See also shown in Figure 2ly, generally speaking, the high pressure signal of internal circuit desire output is exported by high-voltage output end 112 and negative pressure output 113 respectively with negative pressure signal system, exports the integrated circuit outside to via same weld pad 120 then.Therefore, can utilize even respectively high-voltage output end 112 and negative pressure output 113, its result spirit also according to the invention of being connected to of electrostatic discharge protective equipment 210 and 220 (identical) with the electrostatic discharge protective equipment 130 of Fig. 1.
In the present embodiment, the electrostatic discharge (ESD) protection end 211 of electrostatic discharge protective equipment 210 is coupled to high-voltage output end 112, and discharge end 212 all is coupled to system voltage line VDD with discharge end 213.The electrostatic discharge (ESD) protection end 221 of electrostatic discharge protective equipment 220 is coupled to negative pressure output 113, and discharge end 222 all is coupled to ground voltage line VSS with discharge end 223.When the voltage of high-voltage output end 112 and negative pressure output 113 during all in the normal working voltage scope, electrostatic discharge protective equipment 210 and 220 is cut-off state.Connect when entering from weld pad 120 as positive electrostatic pulse or negative electrostatic pulse; electrostatic discharge protective equipment 210 and 220 starts immediately automatically; therefore positive electrostatic pulse or negative electrostatic pulse can be directed to ground voltage line VSS and system voltage line VDD rapidly, and avoid damaging internal circuit 110.Electrostatic discharge protective equipment 210 and 220 class of operation are described like last embodiment, so do not give unnecessary details at this.
The above, it only is preferred embodiment of the present invention, be not that the present invention is done any pro forma restriction, though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention, any those skilled in the art, in not breaking away from the technical solution of the present invention scope, when the technology contents that can utilize above-mentioned announcement is made a little change or is modified to the equivalent embodiment of equivalent variations, in every case be the content that does not break away from technical solution of the present invention, according to technical spirit of the present invention to any simple modification that above embodiment did, equivalent variations and modification all still belong in the scope of technical solution of the present invention.