RESISTOR STRUCTURE OF SERIES RESISTOR OF ESD DEVICE

Abstract

Provided is a resistor structure of a series resistor of an Electro-Static Discharge (ESD) device. A poly resistor is divided into N small parts, and each small part is connected to an upper-part metal layer through a respectively corresponding Contact and Via. The Contact and Via corresponding to each small part and the connected upper-part metal layer form an independent unit. A metal aluminum material is adopted for the Via and the upper-part metal layer. The metal aluminum material or an aluminum alloy material is adopted for the Contact. A heat capacity characteristic of metal aluminum is utilized, and an existing structure is ingeniously utilized, so that the resistor may be prevented from being damaged by heating caused by the same ESD current, and meanwhile, an overall size of a circuit where the ESD device is located is greatly reduced.

Claims

1-6. (canceled)

7. A resistor structure of a series resistor of an Electro-Static Discharge (ESD) device, characterized in that a poly resistor is divided into N small parts, and each small part is connected to an upper-part metal layer through a respectively corresponding Contact and Via; the Contact and Via corresponding to each small part and the connected upper-part metal layer form an independent unit; a metal aluminum material is adopted for the Via and the upper-part metal layer; the metal aluminum material or an aluminum alloy material is adopted for the Contact; the poly resistor is circular, and for the same upper-part metal layer, metals on the same equipotential line are connected together and on the equipotential lines of the resistor at intervals; and N is a natural number greater than or equal to 2.

8. The resistor structure of the series resistor of the ESD device according to claim 7, characterized in that the upper-part metal layer comprises a first metal layer and a top metal layer, the Contact is connected to the Via through the first metal layer, and the Via is connected to the top metal layer.

9. The resistor structure of the series resistor of the ESD device according to claim 7, characterized in that a distance between edges of the Contacts of adjacent independent units is 4 m-8 m.

10. The resistor structure of the series resistor of the ESD device according to claim 9, characterized in that the distance between the edges of the Contacts is 6 m.

11. The resistor structure of the series resistor of the ESD device according to claim 7, characterized in that a planar shape of the upper-part metal layer is a square or a rectangle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a sectional view of a process structure according to an embodiment of the present invention.

[0013] FIG. 2 is a plan view of a top-layer metal according to the embodiment shown in FIG. 1.

[0014] FIG. 3 is a circular poly resistor structure according to an embodiment of the present invention.

[0015] FIG. 4 is a comparison structure diagram of a top metal layer based on a poly resistor on the basis of the embodiment shown in FIG. 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will further be described below in combination with the accompanying drawings and embodiments in detail. It should be understood that the specific embodiments described here are only adopted to explain the present invention and not intended to limit the present invention.

[0017] Any characteristic disclosed in the description (including the abstract and the accompanying drawings) may be replaced with another equivalent or alternative characteristic with a similar purpose, unless otherwise stated. That is, each characteristic is merely an example in a series of equivalent or similar characteristics, unless otherwise stated.

Specific Embodiment 1

[0018] FIG. 1 illustrates a resistor structure of a series resistor of an ESD device. A poly resistor 1 is divided into N small parts, and each small part is connected to an upper-part metal layer through a respectively corresponding Contact 2 and Via 3. The Contact and Via corresponding to each small part and the connected upper-part metal layer form an independent unit. A metal aluminum material is adopted for the Via and the upper-part metal layer. The metal aluminum material or an aluminum alloy material is adopted for the Contact. N is a natural number greater than or equal to 2.

[0019] A heat capacity 880 J (kg.Math. C.) of metal aluminum is equivalent to 700 J (kg.Math. C.) of poly. Moreover, in a common process, a thickness of a metal may reach 3 m, and a thickness of the poly is only 1/10 of that of the metal. Therefore, under the same area, the heat capacity of the metal is higher than that of the poly by one order of magnitude. By use of this fact, the poly and the metal may be combined to obtain a proper resistance and a proper heat capacity under a relatively small area.

[0020] In the present specific embodiment, the poly resistor is divided into many small parts by use of existing metal layers, and each small part carries a relatively thick metal, i.e., an existing aluminum metal layer, through the Contact and the Via. A heat capacity characteristic of the metal aluminum is utilized and an existing structure is ingeniously utilized, so that the resistor may be prevented from being damaged by heating under the same ESD current, and meanwhile, an overall size of a circuit where the ESD device may be greatly reduced.

Specific Embodiment 2

[0021] On the basis of specific embodiment 1, as shown in FIG. 3 and FIG. 4, the poly resistor is circular, and for the same upper-part metal layer, metals on the same equipotential line are connected together and located on the equipotential lines of the resistor at intervals. In the present specific embodiment, as shown in FIG. 3, the poly resistor is circular. For maximally enlarging an available metal area, as shown in FIG. 4, the metals on the equipotential lines are connected together and the metals on different equipotential lines are located on the equipotential lines of the resistor at intervals, to form two or more circular upper-part metals.

Specific Embodiment 3

[0022] On the basis of specific embodiment 1 or 2, as shown in FIG. 1, in the present specific embodiment, the upper-part metal layer includes a first metal layer 4 and a top metal layer 5, the Contact is connected to the Via through the first metal layer, and the Via is connected to the top metal layer. Specifically, arrangement may be implemented according to a practical process condition, and is also applied when there are two or more layers of Vias or three or more metal layers.

Specific Embodiment 4

[0023] On the basis of one of specific embodiments 1 to 3, a distance between edges of the Contacts of adjacent independent units is 4 m-8 m.

[0024] By principle, metal arrangement density is as high as possible. However, the Contacts may occupy a certain area, and thus high metal density may bring a higher area requirement; low metal density may make it impossible to dissipate heat when poly between metals is heated. By calculation, in the present specific embodiment, the distance between the edges of the Contacts is 4 m-8 m.

Specific Embodiment 5

[0025] On the basis of specific embodiment 4, in the present specific embodiment, the distance between the edges of the Contacts is 6 m.

Specific Embodiment 6

[0026] On the basis of specific embodiment 1 or one of specific embodiments 3 to 5, a planar shape of the upper-part metal layer is a square or a rectangle. In the embodiment shown in FIG. 2, the top-layer metal is a positive direction, and may also be arranged to be a square or a long strip.