US5218222A
Expired / Lapsed
US
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Output ESD protection circuit
Assignee: Micron Technology Inc
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Filing: 1992-09-16
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Granted: 1993-06-08
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Expires: 2012-09-16
Abstract
Abstract The basic component of the output ESD protection circuit of the present invention comprises a low resistance connected in series between an output pad and conventional active output pad pullup and pulldown drivers. In a preferred embodiment, a polysilicon resistor is connected in series between an output pad and a metal bus. On the metal bus, a lateral bipolar device is connected in parallel to an n-channel pulldown at an output node and a common potential (conventionally labeled as V SS ). The pullup device is also an active n-channel pullup device connected between an operating potential (conventionally labeled as V CC ) and the output node. Both drains of the two n-channel devices have n-well underneath the n+ diffusion in the area where metal contacts are formed to thereby prevent metal spiking to the substrate during an ESD event. This circuitry combination provides ESD protection equal to or greater than the voltage range of +8000/-2000 V for the HBM response (the Mil. Std. human body model [HBM] test model) as well as protection equal to or greater than the voltage range of +900/-700 V for the MM EIAJ response (the EIAJ machine model [MM] test model). The concept of using a low resistance between a pad and associated active devices (i.e., ESD protection circuitry) will work in combination with other ESD protection circuitry layouts and work equally well for input pad ESD protection.
Inventors
- 👤 Gregory N. Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:08
CPC Classifications
H; H10; H10D; H10D89/00; H10D89/60; H10D89/601
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
70 words
An electrostatic discharge (ESD) protection structure for a semiconductor device constructed on a substrate comprising: a series resistance connecting between a conductive pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and an ESD output protection structure comprising active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 2
Dependent Claim
70 words
An electrostatic discharge (ESD) protection structure for a semiconductor device constructed on a substrate comprising: a series resistance connecting between a conductive pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and an ESD output protection structure comprising active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 3
Dependent Claim
16 words
The electrostatic discharge (ESD) protection structure of claim 1 wherein said substrate comprises a silicon substrate.
Claim 4
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 1 wherein said series resistance has a value of approximately 5Ω.
Claim 5
Dependent Claim
17 words
The electrostatic discharge (ESD) protection structure of claim 1 wherein said series resistance comprises a polysilicon resistor.
Claim 6
Dependent Claim
18 words
The electrostatic discharge (ESD) protection structure of claim 1 wherein said series resistance comprises a silicided polysilicon resistor.
Claim 7
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 1 wherein said conductive pad and said conductive bus comprise metal.
Claim 8
Dependent Claim
73 words
An electrostatic discharge (ESD) output protection circuit for a dynamic random access memory semiconductor device constructed on a silicon substrate comprising: a series silicided polysilicon resistance connecting between a conductive output pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 9
Dependent Claim
73 words
An electrostatic discharge (ESD) output protection circuit for a dynamic random access memory semiconductor device constructed on a silicon substrate comprising: a series silicided polysilicon resistance connecting between a conductive output pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 10
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 7 wherein said series resistance has a value of approximately 5Ω.
Claim 11
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 7 wherein said conductive pad and said conductive bus comprise metal.
Claim 12
Dependent Claim
66 words
An electrostatic discharge (ESD) protection structure constructed on a substrate comprising: a series resistance connecting between a conductive pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and an ESD output protection structure comprising active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 13
Dependent Claim
66 words
An electrostatic discharge (ESD) protection structure constructed on a substrate comprising: a series resistance connecting between a conductive pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conductive bus; and an ESD output protection structure comprising active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 14
Dependent Claim
16 words
The electrostatic discharge (ESD) protection structure of claim 10 wherein said substrate comprises a silicon substrate.
Claim 15
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 10 wherein said series resistance has a value of approximately 5Ω.
Claim 16
Dependent Claim
17 words
The electrostatic discharge (ESD) protection structure of claim 10 wherein said series resistance comprises a polysilicon resistor.
Claim 17
Dependent Claim
18 words
The electrostatic discharge (ESD) protection structure of claim 10 wherein said series resistance comprises a silicided polysilicon resistor.
Claim 18
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 10 wherein said conductive pad and said conductive bus comprise metal.
Claim 19
Dependent Claim
65 words
An electrostatic discharge (ESD) output protection circuit constructed on a silicon substrate comprising: a series silicided polysilicon resistance connecting between a conductive output pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conducive bus; and active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 20
Dependent Claim
65 words
An electrostatic discharge (ESD) output protection circuit constructed on a silicon substrate comprising: a series silicided polysilicon resistance connecting between a conductive output pad and a conductive bus; a lateral n-p-n transistor ESD protection circuit electrically connected to said conducive bus; and active n-channel pullup and pulldown output devices connected between a first and second potential, respectively, with their outputs connected to said conductive bus.
Claim 21
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 16 wherein said series resistance has a value of approximately 5Ω.
Claim 22
Dependent Claim
19 words
The electrostatic discharge (ESD) protection structure of claim 16 wherein said conductive pad and said conductive bus comprise metal.
References Cited (Backward Citations)
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