Electrostatic Discharge Voltage Resistive Current Modeling Method of Electrostatic Discharge Protection Device

• US 20090171635A1
• Filed: 12/18/2008
• Published: 07/02/2009
• Est. Priority Date: 12/26/2007
• Status: Active Grant

• Current Assignee: DB HiTek Co., Ltd.
• Original Assignee: Dongbu HiTek Co., Ltd. (DB HiTek Co., Ltd.)
• Inventors: JANG, Chang Soo
• Granted Patent: US 8,108,185 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods

Abstract

Provided is a method for modeling an ESD breakdown current. According to one variation, a first proportional constant is based on a circumference of the ESD protection device and a second proportional constant based on an area of the ESD protection device. A dual first order equation is derived by sampling circumferences and areas of two ESD protection devices. According to another variation, an equation is defined in which a third value (an ESD breakdown current) is a sum of a first value and a second value, the first value being obtained by multiplying a circumference of an ESD protection device by a first proportional constant, the second value being obtained by multiplying an area of the ESD protection device by a second proportional constant. Then, circumferences and areas of first and second ESD protection samples are calculated. Next, first and second equations are derived by reflecting the first and second circumferences and areas to the equation.

Claims

1. A method for modeling an electrostatic discharge (ESD) breakdown current in an ESD protection device, the method comprising:

defining a first proportional constant based on a circumference of the ESD protection device and a second proportional constant based on an area of the ESD protection device; and

deriving a dual first order equation by sampling circumferences and areas of two ESD protection devices.

2. The method according to claim 1, further comprising calculating the dual first order equation using the first and second proportional constants as variables.

3. The method according to claim 1, wherein the two ESD protection devices comprise anodes having different respective sizes.

4. The method according to claim 3, wherein the anodes of the two ESD protection devices have different respective lengths and/or widths.

5. The method according to claim 1, wherein the ESD protection device further comprises an N-type diffusion layer operating as an anode, a P-type diffusion layer operating as a cathode, and a junction layer between the N-type diffusion layer and the P-type diffusion layer.

6. The method according to claim 1, wherein the ESD protection device has a circumference and an area defined by a circumference and an area of an anode of the ESD protection device, respectively.

7. The method according to claim 2, further comprising calculating the first and second proportional constants for the dual first order equation to generate a model equation for the ESD breakdown current using the circumference and area of the ESD protection devices as variables.

8. The method according to claim 2, comprising:

calculating numerical values of the first and second proportional constants as constants in the dual first order equation; and

deriving a normalized model equation for the ESD breakdown current by including the circumference and area of a third ESD protection device in the dual first order equation as variables.

9. A method for modeling an ESD breakdown current in an ESD protection device, the method comprising:

defining an equation in which the ESD breakdown current is a sum of a first value and a second value, the first value being obtained by multiplying a circumference of an ESD protection device by a first proportional constant, the second value being obtained by multiplying an area of the ESD protection device by a second proportional constant;

calculating a first circumference and a first area of a first sample ESD protection device and calculating a second circumference and a second area of a second sample ESD protection; and

deriving a first equation by including the first circumference and the first area in the equation and deriving a second equation by including the second circumference and the second area in the equation.

10. The method according to claim 9, further comprising calculating a dual first order equation using the first proportional constant and the second proportional constant as variables.

11. The method according to claim 9, wherein the ESD protection device comprises an N-type diffusion layer operating as an anode, a P-type diffusion layer operating as a cathode, and a junction layer between the N-type diffusion layer and the P-type diffusion layer.

12. The method according to claim 11, wherein the ESD protection device has a circumference defined by a circumference of the anode and an area defined by an area of the anode.

13. The method according to claim 9, wherein the first and second sample ESD protection devices comprise anodes having different respective sizes.

14. The method according to claim 13, wherein the anodes of the first and second sample ESD protection devices have different respective lengths and/or widths.

15. The method according to claim 10, further comprising designing a third ESD protective device with a circumference and area providing a predetermined ESD breakdown current in accordance with the dual first order equation.

16. The method according to claim 15, further comprising fabricating an integrated circuit having the third ESD protective device designed therefor.