TW201322409A - Electrostatic discharge protection device - Google Patents

Abstract

An ESD protection device including second P-type wells, first P+-type doped regions, first N+-type doped regions and a P-type substrate having a first P-type well, an N-type well and an N-type deep well is provided. The second P-type wells are disposed in the N-type deep well. The first P+-type doped regions and the first N+-type doped regions are respectively disposed in the first P-type well, the N-type well and the second P-type wells in alternation. The first P+-type doped region in the N-type well and the N-type deep well are electrically connected to the first connection terminal. The doped regions in the first P-type well and the P-type substrate are electrically connected to the second connection terminal. The second P-type wells and the first N+-type doped regions therein form a diode string connected in series between the first N+-type doped region of the N-type well and the second connection terminal.

Description

Electrostatic discharge protection component

This invention relates to a protective element and, more particularly, to an electrostatic discharge protection element.

Electrostatic discharge (ESD) is often the main cause of electrostatic overstress or permanent damage in integrated circuits. Therefore, common methods are in core circuits and pads. An electrostatic discharge protection element is added between them to prevent damage from electrostatic discharge. Among many electrostatic discharge protection components, diode-triggered silicon controlled rectifier (DTSCR) is widely used in various types of integrated circuits because of its low trigger voltage and fast turn-on characteristics. .

1 is a cross-sectional view of a conventional diode triggered chirp rectifier. Referring to FIG. 1, the diode-triggered pilot rectifier 100 includes a P-type substrate 110 and a P-type well region 120 and N-type well regions 131-134 disposed in the P-type substrate 110. Further, the P+ doping regions 141 to 145 and the N+ doping regions 151 to 155 are alternately disposed in the P-type well region 120 and the N-type well region 131 to 134. In the electrical connection, a plurality of diodes composed of the P+ doping regions 142 to 145 and the N-type well regions 131 to 134 are connected in series between the pad 101 and the ground wiring GND1. Furthermore, the P+ doping region 141 and the N+ doping region 151 in the P-type well region 120 and the P+ doping region 146 in the P-type substrate 110 are electrically connected to the ground wiring GND1.

Thereby, the layout structure of the controlled rectifier 100 can be equivalent to the circuit diagram shown in FIG. 2. As shown in FIG. 2, the diode-triggered rectifier rectifier 100 includes a voltage-controlled rectifier circuit composed of a PNP transistor MP21 and an NPN transistor MN2, and a PNP transistor MP22 connected to a Darlington configuration. ~MP24 and resistor R2. In operation, ESD events can be classified into multiple modes, such as PS mode and NS mode. The PS mode is that a positive pulse signal is input to the pad 101 and the ground wiring GND1 is grounded, and in the NS mode, a negative pulse signal is input to the pad 101 and the ground wiring GND1 is grounded. When the electrostatic signal from the pad 101 is a positive pulse signal, that is, the ESD event of the PS mode occurs, the PNP transistors MP22~MP24 will contribute a small current to trigger the combination of the PNP transistor MP21 and the NPN transistor MN2. A controlled rectifier circuit. Thereby, the positive pulse signal from the pad 101 can be guided to the ground wiring GND1 through the step-controlled rectifier circuit.

However, when the electrostatic signal from the pad 101 is a negative pulse signal, that is, an ESD event of the NS mode occurs, the diode-triggered rectifier rectifier 100 will not be able to provide a discharge path. In other words, the diode-triggered rectifier rectifier 100 does not have the electrostatic discharge protection function of the NS mode, so the integrated circuit must additionally provide the reverse diode D2. In addition, when the core circuit 102 is operating normally, the diode strings formed by the N-type well regions 131-134 and the P+-type doping regions 142-145 will be biased under forward bias. At this time, the equivalent PNP transistors MP22~MP24 in the diode-triggered rectifier rectifier 100 will generate a longitudinal leakage path, which in turn causes the diode to trigger the gated rectifier 100 to generate a large leakage current.

In other words, the diode-triggered rectifier rectifier 100 will not be able to meet the low leakage current conditions required for high-speed transmission components, and thus cannot be applied to high-speed transmission components. In addition, the diode-triggered rectifier rectifier 100 does not have an electrostatic discharge protection function of the NS mode.

The present invention provides an electrostatic discharge protection element that utilizes a P-type well region and an N+-type doped region in an N-type deep well region to form a diode string to block the generation of a longitudinal leakage path. Thereby, the electrostatic discharge protection element of the present invention can be applied to a high speed transmission element.

The present invention provides an electrostatic discharge protection element that utilizes an N-type deep well region and a P-type substrate to form a reversed diode. Thereby, the electrostatic discharge protection element of the present invention will have an electrostatic discharge protection function of the PS mode and the NS mode.

The present invention provides an electrostatic discharge protection component having a first connection end and a second connection end, and includes a P-type substrate, M second P-type well regions, a plurality of first P+-type doped regions, and a plurality of first N+ Type doped region, M is an integer greater than one. The P-type substrate has a first P-type well region, an N-type well region, and an N-type deep well region. Wherein, the N-type deep well region is electrically connected to the first connection end, and the P-type substrate is electrically connected to the second connection end. The M second P-type well zones are disposed in the N-type deep well zone. The first P+ type doping regions are respectively disposed in the first P-type well region, the N-type well region, and the second P-type well regions. The first N+ doped regions are respectively disposed in the first P-type well region, the N-type well region, and the second P-type well regions, and the first N+-type doped regions and the first P+-type doped regions Alternate configuration.

In an embodiment of the invention, the first P+ doping region and the first N+ doping region in the first P-type well region are electrically connected to the second connection terminal. The first P+ doped region and the first N+ doped region located in the N-type well region are electrically connected to the first P+ type doping in the first connection end and the first second P-type well region, respectively. Area. The first N+ type doped region in the i-th second P-type well region is electrically connected to the first P+-type doped region in the i+1th second P-type well region, and the Mth second P The first N+ type doped region in the well region is electrically connected to the second connection end, i is an integer and 1≦i≦(M-1).

In an embodiment of the invention, the N-type well location is between the first P-type well area and the N-type deep well area, and the N-type well area is in contact with the first P-type well area, and the N-type well area is N-type deep well areas do not touch each other.

In an embodiment of the invention, the M second P-type well regions are not in contact with each other.

In an embodiment of the invention, the electrostatic discharge protection device further includes a second N+ type doping region. Wherein, the second N+ doping region is disposed in the N-type deep well region and adjacent to the Mth second P-type well region, and the N-type deep well region is electrically connected to the first connection through the second N+-type doping region end.

In an embodiment of the invention, the electrostatic discharge protection device further includes a second P+ doped region. The second P+ type doped region is disposed in the P-type substrate and adjacent to the N-type deep well region, and the P-type substrate is electrically connected to the second connection end through the second P+-type doped region.

The present invention provides an electrostatic discharge protection element having a first connection end and a second connection end, and includes a P-type substrate, a second P-type well region, a plurality of first P+-type doped regions, and a plurality of first N+-type doping Miscellaneous area. The P-type substrate has a first P-type well region, an N-type well region and an N-type deep well region, wherein the N-type deep well region is electrically connected to the first connection end, and the P-type substrate is electrically connected to the second connection end. The second P-type well region is disposed in the N-type deep well region. The first P+ doped regions are respectively disposed in the first P-type well region, the N-type well region, and the second P-type well region. The first N+ doped regions are respectively disposed in the first P-type well region, the N-type well region, and the second P-type well region, and the first N+-type doped regions are alternated with the first P+-type doped regions. Configuration.

In an embodiment of the invention, the first P+ doping region and the first N+ doping region in the first P-type well region are electrically connected to the second connection terminal. The first P+ doped region and the first N+ doped region located in the N-type well region are electrically connected to the first P+-type doped region in the first connection end and the second P-type well region, respectively. The first N+-type doped region located in the second P-type well region is electrically connected to the second connection terminal.

Based on the above, the present invention provides an N-type deep well region in a P-type substrate, and a diode string composed of a P-type well region and an N+-type doped region in the N-type deep well region. In addition, the N-type deep well region is electrically connected to the first connection end, and the P-type substrate is electrically connected to the second connection end. Thereby, when an electrostatic discharge event occurs, the electrostatic discharge protection component can use the diode string in the N-type deep well region to trigger the internal controlled rectifier circuit or turn on the internal reverse diode. In addition, when the core circuit is operating normally, the N-type deep well region will be connected to the pad by the first connection of the component, thereby biasing at the reverse voltage. Thereby, the electrostatic discharge protection element of the present invention will have both an electrostatic discharge protection function of the PS mode and the NS mode, and can be applied to a high speed transmission element.

The above described features and advantages of the present invention will be more apparent from the following description.

3 is a cross-sectional view of an electrostatic discharge protection element according to an embodiment of the present invention, wherein the electrostatic discharge protection element 300 has a first connection end TM31 and a second connection end TM32, and the same second connection end is provided for convenience of description. TM32 is marked in different places. Referring to FIG. 3, the electrostatic discharge protection component 300 includes a P-type substrate 310, a P-type well region 320, an N-type well region 330, an N-type deep well region 340, a plurality of P-type well regions 351-353, and a plurality of P+-type doped regions. 361~366 and a plurality of N+ doped regions 371~376.

In configuration, the P-type well region 320, the N-type well region 330, and the N-type deep well region 340 are disposed within the P-type substrate 310. In addition, the N-type well region 330 is located between the P-type well region 320 and the N-type deep well region 340. The N-type well region 330 is in contact with the P-type well region 320, and the N-type well region 330 and the N-type deep well region 340 are not in contact with each other. Furthermore, the P-type well regions 351-353 are disposed in the N-type deep well region 340, and the P-type well regions 351-353 are not in contact with each other.

In another aspect, the P-type well region 320, the N-type well region 330, and the P-type well regions 351-353 disposed in the N-type deep well region 340 each include a P+ doped region and an N+ doped region, for example: A P+ doping region 361 and an N+ doping region 371 are disposed in the P-type well region 320, and a P+ doping region 362 and an N+ doping region 372 are disposed in the N-type well region 330. In addition, the P+ doping regions 361 to 365 and the N+ doping regions 371 to 375 located in the P-type well region 320, the N-type well region 330, and the P-type well region 351-353 are alternately arranged.

In the electrical connection, the P+ doping region 361 and the N+ doping region 371 in the P-type well region 320 are electrically connected to the second connection terminal TM32. The P+ doping region 362 and the N+ doping region 372 in the N-type well region 330 are electrically connected to the P+-type doping region 363 in the first connection terminal TM31 and the P-type well region 351, respectively. For the doped regions in the P-type well regions 351-353, the N+-type doping region 373 is electrically connected to the P+-type doping region 364, and the N+-type doping region 374 is electrically connected to the P+-type doping region 365. The N+ doping region 375 is electrically connected to the second connection terminal TM32.

In addition, the N+ doped region 376 is disposed within the N-type deep well region 340 and adjacent to the P-type well region 353. Furthermore, the N+ doping region 376 is electrically connected to the first connection terminal TM31. In other words, the N-type deep well region 340 is electrically connectable to the first connection terminal TM31 through the N+ type doping region 376. In another aspect, the P+ doped region 366 is disposed within the P-type substrate 310 and adjacent to the N-type deep well region 340. In addition, the P+ doping region 366 is electrically connected to the second connection terminal TM32. In other words, the P-type substrate 310 can be electrically connected to the second connection end TM32 through the P+ type doping region 366.

4 is an equivalent circuit diagram for explaining the electrostatic discharge protection element of FIG. 3. Referring to FIG. 3 and FIG. 4 simultaneously, in practical applications, both ends TM31 and TM32 of the electrostatic discharge protection component 300 can be respectively connected to the pad 301 and the grounding GND3 in the integrated circuit, and the electrostatic discharge protection component 300 is used. The damage caused by the electrostatic discharge event to the core circuit 302 is avoided. As far as the layout structure is concerned, the N+ doping region 371, the P-type well region 320, and the N-type well region 330 will form a lateral NPN transistor MN4, and the P+ doping region 362, the N-type well region 330, and the P-type substrate. 310 will form a longitudinal PNP transistor MP41. Thereby, the NPN transistor MN4 and the PNP transistor MP41 will form a voltage controlled rectifier circuit. In addition, resistor R4 is the equivalent resistance contributed by P-well region 320.

Furthermore, the P-type well region 351, the N-type deep well region 340, and the P-type substrate 310 will form a longitudinal PNP transistor MP42. Similarly, the P-type well region 352, the N-type deep well region 340, and the P-type substrate 310 will form a longitudinal PNP transistor MP43, and the P-type well region 353, the N-type deep well region 340, and the P-type substrate 310 will form a longitudinal PNP. Transistor MP44. On the other hand, the P-type well region 351 and the N+-type doped region 373 will form a diode D41, and the P-type well region 352 and the N+-type doped region 374 will form a diode D42, and the P-type well region 353 and N+ The doped region 375 will form a diode D43. That is, the P-type well regions 351-353 and the N+-type doping regions 373-375 in the N-type deep well region 340 form a diode string, that is, a diode formed by connecting the diodes D41 to D43 in series. Body string. In addition, the N-type deep well region 340 and the P-type substrate 310 will form a reversed diode D44.

In other words, the P-type well region 320, the N-type well region 330, and the doped regions 361-362 and 371-372 are mainly used to form a controlled rectifier circuit, and the diode strings in the N-type deep well region 340 are used. To trigger the controlled rectifier circuit. Therefore, the electrostatic discharge protection component 300 is a diode-triggered SCR.

In practical applications, when the electrostatic signal from the pad 301 is a positive pulse signal, that is, an ESD event in the PS mode occurs, then the diode string will provide a small current, which is triggered by the NPN transistor MN4 and PNP. A voltage controlled rectifier circuit formed by the transistor MP41. Thereby, the positive pulse signal from the pad 301 can be guided to the ground wiring GND3 through the large current path provided by the step-controlled rectifier circuit. In addition, when the electrostatic signal from the pad 301 is a negative pulse signal, that is, the ESD event of the NS mode occurs, the diode D44 at this time will be turned on, thereby providing a path to the ground wiring GND3 to the negative pulse signal. . In other words, in practical applications, the electrostatic discharge protection component 300 does not need to additionally provide a reverse diode, and has both an electrostatic discharge protection function of the PS mode and the NS mode.

Furthermore, in terms of the layout structure of the electrostatic discharge protection component 300, the equivalent PNP transistors MP42~MP44 do not form a Darlington configuration. In addition, the diode strings formed by the P-type well region and the N+-type doped region are disposed in the N-type deep well region 340, and the N-type deep well region 340 is electrically connected to the bonding pad 301. Thus, when the core circuit 302 is operating normally, the N-type deep well region 340 will be biased at a reverse voltage, thereby blocking the generation of a longitudinal leakage path. That is, when the core circuit 302 operates normally, the equivalent PNP transistors MP42 to MP44 in the electrostatic discharge protection element 300 will not generate a leakage path. In other words, when the core circuit 302 operates normally, the electrostatic discharge protection element 300 does not generate a large leakage current. Thereby, the electrostatic discharge protection element 300 can satisfy the condition of low leakage current required for the high-speed transmission element, and can be applied to the high-speed transmission element.

It should be noted that the diode strings exemplified in the embodiment of FIG. 3 are formed by connecting three diodes D41 to D43 in series, but it is not intended to limit the present invention, and those skilled in the art may also rely on The design needs to change the number of components of the diode string. For example, the diode strings in the N-type deep well region 340 may be formed by connecting M diodes in series, and M is an integer greater than 1. At this time, M P-type well regions will be disposed in the N-type deep well area 340. In addition, in the electrical connection, the P+ type doped region in the first P-type well region is electrically connected to the N+-type doped region 372 in the N-type well region 330. The N+ type doped region in the i-th P-type well region is electrically connected to the P+-type doped region in the i+1th P-type well region, and the N+-type doped region in the Mth P-type well region Electrically connected to the second connection terminal TM32, i is an integer and 1≦i≦(M-1).

In addition, if applied under low voltage operation, the diode string in the N-type deep well region 340 can also be composed of a single diode. At this time, a single P-type well zone will be disposed in the N-type deep well zone 340. In addition, for a single P-type well region in the N-type deep well region 340, the internal P+-type doped region is electrically connected to the N+-type doped region 372 in the N-type well region 330, and its internal N+ The doped region is electrically connected to the second connection terminal TM32.

In summary, the present invention provides an N-type deep well region in a P-type substrate, and a diode string composed of a P-type well region and an N+-type doped region in the N-type deep well region. Thereby, when an electrostatic discharge event occurs, the electrostatic discharge protection component can use the diode string in the N-type deep well region to trigger the internal controlled rectifier circuit or turn on the internal reverse diode. In addition, when the core circuit is operating normally, the N-type deep well region will be connected to the pad by the first connection of the component, thereby biasing at the reverse voltage. In this way, the generation of the longitudinal leakage path can be blocked, thereby suppressing the generation of leakage current of the electrostatic discharge protection element. In other words, the electrostatic discharge protection element of the present invention has both an electrostatic discharge protection function of the PS mode and the NS mode, and can be applied to a high speed transmission element.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100. . . Diode triggered voltage controlled rectifier

110, 310. . . P-type substrate

120, 320, 351~353. . . P type well area

131~134, 330. . . N type well area

141~146, 361~366. . . P+ doped region

151~155, 371~376. . . N+ doped region

GND1, GND3. . . Ground wiring

101, 301. . . Solder pad

102, 302. . . Core circuit

MP21~MP24, MP41~MP44. . . PNP transistor

MN2, MN4. . . NPN transistor

R2, R4. . . resistance

D2, D41~D44. . . Dipole

300. . . Electrostatic discharge protection component

TM31. . . First connection

TM32. . . Second connection

340. . . N type deep well area

1 is a cross-sectional view of a conventional diode triggered chirp rectifier.

2 is an equivalent circuit diagram for explaining a conventional diode-triggered voltage-controlled rectifier.

Figure 3 is a cross-sectional view of an electrostatic discharge protection device in accordance with an embodiment of the present invention.

4 is an equivalent circuit diagram for explaining the electrostatic discharge protection element of FIG. 3.

300. . . Electrostatic discharge protection component

310. . . P-type substrate

320, 351~353. . . P type well area

330. . . N type well area

340. . . N type deep well area

361~366. . . P+ doped region

371~376. . . N+ doped region

301. . . Solder pad

TM31. . . First connection

TM32. . . Second connection

GND3. . . Ground wiring

Claims (11)

An ESD protection component has a first connection end and a second connection end, and includes:
a P-type substrate having a first P-type well region, an N-type well region, and an N-type deep well region, wherein the N-type deep well region is electrically connected to the first connection end, and the P-type substrate is electrically connected to the first Two connection ends;
M second P-type well regions, disposed in the N-type deep well region, wherein M is an integer greater than 1;
a plurality of first P+ doping regions respectively disposed in the first P-type well region, the N-type well region, and the second P-type well regions; and a plurality of first N+-type doping regions respectively configured In the first P-type well region, the N-type well region, and the second P-type well regions, and the first N+-type doped regions are alternately arranged with the first P+-type doped regions. The electrostatic discharge protection device of claim 1, wherein the first P+ doped region and the first N+ doped region in the first P-type well region are electrically connected to the first a second connection end, the first P+ type doped region and the first N+ type doped region located in the N-type well region are electrically connected to the first connection end and the first second P-type well region, respectively The first P+ doping region in the first P+ well region is electrically connected to the first region in the i+1th second P-type well region a P+-type doped region, and the first N+-type doped region in the Mth second P-type well region is electrically connected to the second connection terminal, where i is an integer and 1≦i≦(M-1). The electrostatic discharge protection device of claim 1, wherein the N-type well location is between the first P-type well region and the N-type deep well region, and the N-type well region and the first P-type When the well area is in contact, the N-type well area and the N-type deep well area do not contact each other. The electrostatic discharge protection component of claim 1, wherein the second P-type well regions are not connected to each other. The electrostatic discharge protection component of claim 1, further comprising:
a second N+ type doping region is disposed in the N-type deep well region adjacent to the Mth second P-type well region, wherein the N-type deep well region is electrically connected through the second N+-type doping region The first connection end. The electrostatic discharge protection component of claim 1, further comprising:
A second P+-type doped region is disposed in the P-type substrate adjacent to the N-type deep well region, wherein the P-type substrate is electrically connected to the second connection terminal through the second P+-type doped region. An ESD protection component has a first connection end and a second connection end, and includes:
a P-type substrate having a first P-type well region, an N-type well region, and an N-type deep well region, wherein the N-type deep well region is electrically connected to the first connection end, and the P-type substrate is electrically connected to the first Two connection ends;
a second P-type well region disposed in the N-type deep well region;
a plurality of first P+ doped regions respectively disposed in the first P-type well region, the N-type well region and the second P-type well region; and a plurality of first N+-type doped regions respectively disposed at The first P-type well region, the N-type well region and the second P-type well region, and the first N+-type doped regions are alternately arranged with the first P+-type doped regions. The electrostatic discharge protection device of claim 7, wherein the first P+ doping region and the first N+ doping region in the first P-type well region are electrically connected to the first The first P+ type doped region and the first N+ doped region located in the N-type well region are electrically connected to the first connection end and the second P-type well region respectively The first P+-type doped region, and the first N+-type doped region located in the second P-type well region is electrically connected to the second connection terminal. The electrostatic discharge protection device of claim 7, wherein the N-type well location is between the first P-type well region and the N-type deep well region, and the N-type well region and the first P-type When the well area is in contact, the N-type well area and the N-type deep well area do not contact each other. The electrostatic discharge protection component of claim 7, further comprising:
a second N+-type doping region disposed in the N-type deep well region adjacent to the second P-type well region, wherein the N-type deep well region is electrically connected to the second N+-type doped region A connection. The electrostatic discharge protection component of claim 7, further comprising:
A second P+-type doped region is disposed in the P-type substrate adjacent to the N-type deep well region, wherein the P-type substrate is electrically connected to the second connection terminal through the second P+-type doped region.