CN109065537B - High-maintenance-current SCR device for ESD protection - Google Patents
High-maintenance-current SCR device for ESD protection Download PDFInfo
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- CN109065537B CN109065537B CN201810973512.4A CN201810973512A CN109065537B CN 109065537 B CN109065537 B CN 109065537B CN 201810973512 A CN201810973512 A CN 201810973512A CN 109065537 B CN109065537 B CN 109065537B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/0203—Particular design considerations for integrated circuits
- H01L27/0248—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
- H01L27/0251—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices
- H01L27/0259—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices using bipolar transistors as protective elements
- H01L27/0262—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices using bipolar transistors as protective elements including a PNP transistor and a NPN transistor, wherein each of said transistors has its base coupled to the collector of the other transistor, e.g. silicon controlled rectifier [SCR] devices
Abstract
The invention provides a high-maintenance current SCR device for ESD protection, which comprises: the semiconductor device comprises a P-type substrate, a first N-type epitaxial layer, a first PWELL area, a first P + contact area, a first N + contact area, a second PWELL area, a second P + contact area and a third N + contact area; a second N + contact region located above the first N-type epitaxial layer and not intersecting the first PWELL region and the second PWELL region; the first N + contact area and the first P + contact area are in short circuit through metal to form a metal cathode; and the second P + contact region, the second N + contact region and the third N + contact region are shorted by metal to form an anode. The invention can adjust the holding current by adjusting the concentration and the length of the second PWELL area, thereby avoiding the latch-up of the device, enabling the IV curve of the device to present the characteristic of multiple snapback and improving the robustness of the device under the ESD pulse current.
Description
Technical Field
The invention belongs to the field of electronic science and technology, mainly relates to an ElectroStatic Discharge (ESD) protection technology on an integrated circuit chip, and particularly relates to an ESD protection device which has low power consumption and strong latch-up resistance and is used for a high-voltage integrated circuit.
Background
ESD, i.e., electrostatic discharge, is a phenomenon that is ubiquitous in nature. ESD exists in every corner of people's daily life. Such conventional electrical phenomena are a fatal threat to sophisticated integrated circuits. However, for a chip that has completed packaging, each power/input/output pin becomes a path for entering of a pulse current such as a Human Body Model (HBM), a Machine Model (MM), a human body metal model (HMM), and the like. The strong ESD pulse not only causes hard failure of the chip, but also induces various effects (such as latch-up, soft failure, etc.) due to improper design of the ESD protection device. In addition, very few ESD failures can be detected directly during the chip manufacturing process. Most of the ESD damage does not have obvious influence on the performance of the chip, so that the ESD damage passes the standard test and finally enters the hands of customers. Such chips "work with trouble" in various applications, continuously threatening the reliability of the system in which they are located.
For high voltage integrated circuits, LDMOS structures (as shown in fig. 1 (a)) cannot generally be used directly for ESD protection due to latch-up like effects. For example, the sustaining voltage of the LDMOS is raised above the VDD voltage in some way to meet the conventional design window of the ESD protection device. Although the latch-up phenomenon can be eliminated by the high-maintenance voltage design, the voltage borne by the device in the on state can be improved so as to improve the power, and the robustness of the LDMOS is greatly reduced due to the influence of the Kerr effect under large current.
In order to enable the LDMOS to have high robustness, the multi-finger layout design can improve the ESD robustness linearly theoretically, but the influence of process errors and the like is added due to the strong snapback. Each finger may not be turned on at the same time. More related technologies (such as ESD gate coupling technologies proposed in IEDM) are therefore well suited to solve this problem. However, in a high voltage application chip with strong ESD requirements, the area of the ESD device may be large, thereby increasing the manufacturing cost. Therefore, the layout area of the ESD device, the avoidance of latch-up and the strong ESD robustness form a contradiction which is difficult to compromise. Namely: latch-up less robust operation is required and increased area is required to improve ESD robustness of latch-up less devices.
To solve this problem, research results show that increasing the holding current can solve the latch-up-like problem of the device to some extent. If the maximum current provided by the power supply cannot guarantee the minimum holding current requirement of the ESD device, latch-up will not occur. This provides a new idea for the design of low holding voltage latch-up free ESD protection device. The ESD protection device breaks through a conventional high-maintenance voltage design window, and the device design is carried out by the high-maintenance current design window. Therefore, the maintaining voltage of the device is lower than that of the traditional ESD protective device with high maintaining voltage, the power consumption is reduced when ESD pulse is discharged, and the ESD robustness of the device is improved. Specifically, on the basis of the traditional SCR, the invention adjusts the holding current of the device through a trap resistor, and realizes the characteristics of adjustable trigger voltage and holding current, low discharge power, high robustness and the like under the condition of not changing the process.
Disclosure of Invention
The invention aims to solve the problems that: under the condition of a certain process, the characteristics of accurate and quick triggering (proper triggering voltage), high maintaining current, low ESD power consumption, high robustness and the like of the ESD device are realized.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a high maintenance current SCR device for ESD protection comprising: the P-type substrate 00, a first N-type epitaxial layer 01 located above the P-type substrate 00, a first PWELL area 201 located on the left side above the inside of the first N-type epitaxial layer 01, a first P + contact area 21 located above the inside of the first PWELL area 201, and a first N + contact area 11 located above the inside of the first PWELL area 201; wherein the first P + contact region 21 is located at the left side of the first N + contact region 11; a second PWELL region 202 located right above the inside of the first N-type epitaxial layer 01, a second P + contact region 22 located above the inside of the second PWELL region 202, and a third N + contact region 13 located above the inside of the second PWELL region 202; wherein the third N + contact region 13 is located at the left side of the second P + contact region 22; a second N + contact region 12 located over the first N-type epitaxial layer and not in contact with the first PWELL region and not in contact with the second PWELL region; the first N + contact region 11 and the first P + contact region 21 form a metal cathode 31 through metal short circuit; the second P + contact region 22, the second N + contact region 12, and the third N + contact region 13 are shorted by metal to form an anode 32.
Preferably, the NWELL region 10 is disposed between the first PWELL region 201 and the second PWELL region 202, and the second N + contact region 12 is disposed above and within the NWELL region 10.
Preferably, a TOP region 23 is disposed above and inside the second PWELL region 202, wherein the TOP region 23 is located to the left of the third N + contact region 13.
Preferably, the TOP region 23 is doped P-type, or N-type.
Preferably, the trigger area 14 is provided on the right side of the first PWELL area 201, which is tangent to the left side of the NWELL area 10, and a part of the trigger area 14 is located in the first PWELL area 201 and a part is located in the NWELL area 10.
Preferably, the trigger region 14 is doped P-type, or N-type.
Preferably, an oxide layer 03 is disposed on the upper surface between the first N + contact region 11 and the second N + contact region 12, and the left side of the oxide layer 03 is tangent to the first N + contact region 11 and the right side of the oxide layer 03 is tangent to the second N + contact region 12; a polysilicon or metal gate 04 is disposed on the upper surface of the oxide layer 03.
Preferably, each doping type in the device is correspondingly changed into opposite doping, namely, the P-type doping is changed into the N-type doping, and meanwhile, the N-type doping is changed into the P-type doping.
The beneficial effects of the invention are that 1: the high-maintenance-current SCR device for ESD protection can adjust the maintenance current by adjusting the concentration and the length of the second PWELL area, so that the device is prevented from latching; 2: the existence of the second PWELL area enables the IV curve of the device to present the characteristics of snapback for a plurality of times, and improves the robustness of the device under the ESD pulse current.
Drawings
FIG. 1(a) is a conventional high-holding-voltage ESD design window;
FIG. 1(b) is a high holding current ESD design window;
FIG. 2 is a block diagram of a conventional bi-directional SCR device;
FIG. 3 is a structural view of embodiment 1;
FIG. 4 is a structural view of embodiment 2;
FIG. 5 is a structural view of embodiment 3;
FIG. 6 is a structural view of embodiment 4;
FIG. 7 is a structural view of embodiment 5;
FIG. 8 is a graph comparing I-V characteristics of example 1 and a conventional bidirectional SCR device;
FIG. 9 is a HBM hybrid emulation circuit diagram;
FIG. 10 is the time domain simulation result of example 1;
00 is a P-type substrate, 01 is a first N-type epitaxial layer, 201 is a first PWELL area, 21 is a first P + contact area, 11 is a first N + contact area, 202 is a second PWELL area, 22 is a second P + contact area, 12 is a second N + contact area, 13 is a third N + contact area, 14 is a trigger area, 10 is an NWELL area, 23 is a TOP area, 03 is an oxide layer, 04 is polysilicon or a metal gate, 31 is a metal cathode, and 32 is a metal anode.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Example 1
As shown in fig. 3, the device structure of the present embodiment includes: the P-type substrate 00, a first N-type epitaxial layer 01 located above the P-type substrate 00, a first PWELL area 201 located on the left side above the inside of the first N-type epitaxial layer 01, a first P + contact area 21 located above the inside of the first PWELL area 201, and a first N + contact area 11 located above the inside of the first PWELL area 201; wherein the first P + contact region 21 is located at the left side of the first N + contact region 11; a second PWELL region 202 located right above the inside of the first N-type epitaxial layer 01, a second P + contact region 22 located above the inside of the second PWELL region 202, and a third N + contact region 13 located above the inside of the second PWELL region 202; wherein the third N + contact region 13 is located at the left side of the second P + contact region 22; a second N + contact region 12 located over the first N-type epitaxial layer and not in contact with the first PWELL region 201 and not in contact with the second PWELL region 202; the first N + contact region 11 and the first P + contact region 21 form a metal cathode 31 through metal short circuit; the second P + contact region 22, the second N + contact region 12, and the third N + contact region 13 are shorted by metal to form an anode 32.
The working principle of the embodiment is as follows:
when the anode ESD voltage rises, the device firstly breaks down at the PN junction formed by the first N-type epitaxial layer 01/the first PWELL area 201 on the surface. The hole current after breakdown flows through the first PWELL region 201, the first P + contact region 21 and is pumped away by the metal cathode 31. Most of the electron current in breakdown will flow through the first N-type epitaxial layer 01 and the second N + contact region 12 and be pumped away by the metal anode.
Although the PN junction is turned on when the current flowing through the first N-type epitaxial layer 01 increases to a certain value, so that the voltage drop between the second PWELL region 202 and the first N-type epitaxial layer 01 reaches 0.7V, the positive feedback of PNPN in the corresponding SCR structure is also turned on. However, since the second PWELL region 202 has a larger well resistance, which is equivalent to a well resistance connected in series with a conventional SCR structure, the device has a higher holding voltage than a conventional bidirectional SCR device at the same current. However, as the current increases, the electrons injected from the first N-type epitaxial layer 01 into the second PWELL region 202 also increase and effectively modulate the conductance of the second PWELL region 202, so that the well resistance of the second PWELL region 202 also decreases. That is, the well resistor connected in series on the SCR structure becomes very small under a large current condition, so the well resistor cannot effectively increase the sustain voltage of the structure, and the sustain voltage of the device is correspondingly reduced.
In order to prove that the device can work under the condition that the VDD is higher than the maintaining voltage of the VDD and the latch-up phenomenon does not occur, the circuit hybrid simulation verification is carried out.
Fig. 8 is an I-V characteristic simulation of example 1, and conv. As can be seen from the simulation results, the trigger voltage of the embodiment 1 is similar to that of the traditional bidirectional SCR device, and the traditional bidirectional SCR device cannot realize high holding current; the IV curve of example 1 is in agreement with the above analysis of the operating principle.
Fig. 9 is a circuit diagram of a Human Body Model (HBM) simulation. The HBM circuit part in the dashed frame on the left side of the circuit is used for simulating an ESD pulse waveform when a human body discharges static electricity; right side of theThe circuit is a power supply circuit of the device, wherein HV source is power supply voltage, RLFor load resistance, the DUT is the test module and isolates the HBM circuit from the HV source loop through a diode to ensure that ESD pulses generated by the HBM circuit do not affect the HV source.
Fig. 10 is a graph showing the results of the latch-up immune hybrid simulation of example 1, which is obtained by the simulation of the HBM circuit shown in fig. 9. As can be seen from the figure, after the analog waveform of the HBM is input, the conventional bidirectional SCR device latches, so that the device cannot be normally turned off after the HBM waveform is passed, and the power supply voltage VDD is clamped below 15V. The high holding current SCR device for ESD protection proposed in this patent is clamped to a potential lower than the power supply voltage VDD for ESD discharge at 130ns, but due to the holding current I of the devicehVery high, when the ESD pulse is removed, the current of the whole loop cannot be maintained at I only by the power supply voltagehThus, the aim of latch-up immunity is achieved.
Example 2
As shown in fig. 4, the device structure of the present embodiment differs from that of embodiment 1 in that: an NWELL area 10 is provided intermediate the first PWELL area 201 and the second PWELL area 202. A second N + contact region 12 is located over the interior of NWELL region 10.
Example 3
As shown in fig. 5, the main differences between this embodiment and embodiment 2 are: inside and above the second PWELL region 202 is a TOP region 23, wherein the TOP region 23 is located to the left of the third N + contact region 13.
Example 4
As shown in fig. 6, the present embodiment is different from embodiment 3 in that: the trigger area 14 is provided on the right side of the first PWELL area 201, which is tangent to the left side of the NWELL area 10, and a part of the trigger area 14 is located in the first PWELL area 201 and a part is located in the NWELL area 10. The trigger region 14 is doped P-type or N-type.
Example 5
As shown in fig. 7, the present embodiment is different from embodiment 3 in that: an oxide layer 03 is disposed on the upper surface between the first N + contact region 11 and the second N + contact region 12, and the left side of the oxide layer 03 is tangent to the first N + contact region 11 and the right side of the oxide layer 03 is tangent to the second N + contact region 12. A polysilicon or metal gate 04 is disposed on the upper surface of the oxide layer 03.
Claims (8)
1. A high maintenance current SCR device for ESD protection, comprising: the P-type epitaxial substrate (00), a first N-type epitaxial layer (01) positioned above the P-type substrate (00), a first PWELL area (201) positioned on the left side above the inner part of the first N-type epitaxial layer (01), a first P + contact area (21) positioned above the inner part of the first PWELL area (201), and a first N + contact area (11) positioned above the inner part of the first PWELL area (201); wherein the first P + contact zone (21) is located on the left side of the first N + contact zone (11); a second PWELL area (202) positioned on the right side above the inner part of the first N-type epitaxial layer (01), a second P + contact area (22) positioned above the inner part of the second PWELL area (202), and a third N + contact area (13) positioned above the inner part of the second PWELL area (202); wherein the third N + contact region (13) is located on the left side of the second P + contact region (22); a second N + contact region (12) over the first N-type epitaxial layer and not in contact with the first PWELL region and not in contact with the second PWELL region; the first N + contact area (11) and the first P + contact area (21) are shorted by metal to form a metal cathode (31); the second P + contact region (22), the second N + contact region (12) and the third N + contact region (13) are shorted by metal to form an anode (32).
2. The high maintenance current SCR device for ESD protection of claim 1, wherein: an NWELL region (10) is disposed between the first PWELL region (201) and the second PWELL region (202), and a second N + contact region (12) is disposed above the inside of the NWELL region (10).
3. The high maintenance current SCR device for ESD protection of claim 2, wherein: a TOP region (23) is arranged above the inside of the second PWELL region (202), wherein the TOP region (23) is positioned at the left side of the third N + contact region (13).
4. The high maintenance current SCR device for ESD protection of claim 3, wherein: the TOP region (23) is doped P-type or N-type.
5. The high maintenance current SCR device for ESD protection of claim 3, wherein: a trigger area (14) is arranged at the position where the right side of the first PWELL area (201) is tangent to the left side of the NWELL area (10), and a part of the trigger area (14) is positioned in the first PWELL area (201) and a part of the trigger area is positioned in the NWELL area (10).
6. The high maintenance current SCR device of claim 5, wherein: the trigger region (14) is doped P-type or N-type.
7. The high maintenance current SCR device for ESD protection of claim 3, wherein: an oxide layer (03) is arranged on the upper surface between the first N + contact area (11) and the second N + contact area (12), the left side of the oxide layer (03) is tangent to the first N + contact area (11), and the right side of the oxide layer (03) is tangent to the second N + contact area (12); and a polysilicon or metal grid (04) is arranged on the upper surface of the oxide layer (03).
8. A high maintenance current SCR device for ESD protection according to any of claims 1 to 7, characterized in that: the doping types in the device are correspondingly changed into opposite doping, namely P-type doping is changed into N-type doping, and simultaneously N-type doping is changed into P-type doping.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1404159A (en) * | 2001-08-30 | 2003-03-19 | 联华电子股份有限公司 | SCR with base triggering effect |
| US20080309394A1 (en) * | 2005-07-08 | 2008-12-18 | Texas Instruments Incorporated | Guardringed scr esd protection |
| CN104269401A (en) * | 2014-08-30 | 2015-01-07 | 电子科技大学 | Novel ESD protection device based on SCR structure |
| CN104576639A (en) * | 2014-12-11 | 2015-04-29 | 江南大学 | High-voltage ESD protection device with small hysteresis window |
| CN105552074A (en) * | 2015-12-23 | 2016-05-04 | 电子科技大学 | Germanium-silicon heterojunction process-based SCR device |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1404159A (en) * | 2001-08-30 | 2003-03-19 | 联华电子股份有限公司 | SCR with base triggering effect |
| US20080309394A1 (en) * | 2005-07-08 | 2008-12-18 | Texas Instruments Incorporated | Guardringed scr esd protection |
| CN104269401A (en) * | 2014-08-30 | 2015-01-07 | 电子科技大学 | Novel ESD protection device based on SCR structure |
| CN104576639A (en) * | 2014-12-11 | 2015-04-29 | 江南大学 | High-voltage ESD protection device with small hysteresis window |
| CN105552074A (en) * | 2015-12-23 | 2016-05-04 | 电子科技大学 | Germanium-silicon heterojunction process-based SCR device |
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