Electrostatic protection devices and semiconductor devices

Abstract

The present invention provides an electrostatic protection device and a semiconductor device. The electrostatic protection device includes an active area, the active area is rectangular and is provided with at least one column of contact holes, a plurality of the contact holes in each column are spaced apart along a first direction, the first direction is parallel to a side of the active area, and the contact holes in each column are spaced apart along a second direction perpendicular to the first direction; wherein, among the plurality of the contact holes in each column, the areas of the two contact holes at the two ends are smaller than the areas of the remaining contact holes. The electrostatic protection device in the present invention compensates for the difference in temperature distribution caused by uneven thermal conductivity, effectively improves the electrostatic protection capability of the electrostatic protection device, and avoids failure of the device at the corners of shallow trenches.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to an electrostatic protection device and a semiconductor device. Background Art

[0002] As the feature size of integrated circuit components continues to shrink, the electrostatic protection design of chips has become more challenging. Simply increasing the area of ​​electrostatic protection devices can no longer meet the requirements of high-performance chips for the parasitic capacitance of pins and chip area. Most existing technologies increase the electrostatic protection capabilities of chips by increasing the area of ​​a single electrostatic protection device. However, the above measures increase chip costs.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] One object of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide an electrostatic protection device, by designing the arrangement and size of the contact holes, that is, the area of ​​the contact holes close to the corners of the active area is designed to be smaller than the area of ​​the contact holes at other positions, thereby compensating for the difference in temperature distribution caused by uneven thermal conductivity, effectively improving the chip's ability to discharge current, and avoiding failure of the device at the corners of shallow trenches.

[0005] Another object of the present invention is to provide a semiconductor device, comprising the above-mentioned electrostatic protection device.

[0006] According to one aspect of the present invention, an electrostatic protection device is provided, comprising an active area, the active area is rectangular and is provided with at least one column of contact holes, a plurality of the contact holes in each column are spaced apart along a first direction, the first direction is parallel to a side of the active area, and the contact holes in each column are spaced apart along a second direction perpendicular to the first direction. Among the plurality of the contact holes in each column, the areas of the two contact holes at the two ends are smaller than the areas of the remaining contact holes.

[0007] According to an exemplary embodiment of the present invention, each of the contact holes has a first size in the first direction, and the first size of the contact holes located at two ends of each column is smaller than the first size of the remaining contact holes.

[0008] According to an exemplary embodiment of the present invention, the first size of the plurality of contact holes in each column decreases from the middle to both ends of the column.

[0009] According to an exemplary embodiment of the present invention, each of the contact holes has a second size in the second direction, and the second size of the contact holes in each column is the same.

[0010] According to an exemplary embodiment of the present invention, the plurality of contact holes are arranged in a matrix to form a plurality of columns and a plurality of rows, the plurality of columns are parallel to the first direction, and the plurality of rows are parallel to the second direction.

[0011] According to an exemplary embodiment of the present invention, the second size of the contact holes in each row is the same.

[0012] According to an exemplary embodiment of the present invention, the second size of the contact holes in each row decreases from the middle to both sides of the row.

[0013] According to an exemplary embodiment of the present invention, the first size of the contact holes in each row is the same.

[0014] According to an exemplary embodiment of the present invention, the contact hole has a rectangular shape.

[0015] According to an exemplary embodiment of the present invention, in each column, a plurality of the contact holes are arranged at equal intervals along the first direction.

[0016] According to an exemplary embodiment of the present invention, the contact holes in each row are arranged at equal intervals along the second direction.

[0017] According to an exemplary embodiment of the present invention, a shallow trench is further included, which is arranged around the active area.

[0018] According to another aspect of the present disclosure, a semiconductor device is provided, comprising the electrostatic protection device according to the above embodiment.

[0019] It can be seen from the above technical solution that the present invention has at least one of the following advantages and positive effects:

[0020] By designing the arrangement and size of the contact holes, in each column of multiple contact holes, the areas of the two contact holes located at the two ends are smaller than the areas of the remaining contact holes, that is, the areas of the contact holes close to the corners of the active area are designed to be smaller than the areas of the contact holes at other positions, so that the current density in the area where heat is not easy to dissipate is smaller, and the current density in the area where heat is easy to dissipate is larger, which compensates for the difference in temperature distribution caused by uneven thermal conductivity, effectively improves the chip's ability to discharge current, enhances electrostatic protection capabilities, and avoids device failure at shallow trench corners. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0022] Figure 1 A cross-sectional view of the active area of ​​the electrostatic protection device of the present invention;

[0023] Figure 2A schematic diagram of a contact hole structure in an electrostatic protection device in an exemplary embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of a contact hole structure of any active area of ​​an electrostatic protection device in another exemplary embodiment of the present invention;

[0025] Figure 4 is a schematic diagram of a contact hole structure of any active area of ​​an electrostatic protection device in another exemplary embodiment of the present invention;

[0026] Figure 5 is a schematic diagram of a contact hole structure of any active area of ​​an electrostatic protection device in another exemplary embodiment of the present invention;

[0027] Figure 6 is a schematic diagram of a contact hole structure of an electrostatic protection device in another exemplary embodiment of the present invention;

[0028] Figure 7 is a schematic diagram of a contact hole structure of an electrostatic protection device in another exemplary embodiment of the present invention;

[0029] Figure 8 is a schematic diagram of a contact hole structure of an electrostatic protection device in another exemplary embodiment of the present invention;

[0030] Fig. 9 FIG. 4 is a schematic diagram of a contact hole structure of an electrostatic protection device in another exemplary embodiment of the present invention.

[0031] Description of reference numerals:

[0032] Nn type active region;

[0033] Pp type active region;

[0034] S- shallow groove;

[0035] 10-base;

[0036] A-heat concentration area;

[0037] B- easy heat dissipation area;

[0038] 1-Contact hole;

[0039] d1 - first dimension;

[0040] d2 - second dimension;

[0041] F1-first direction;

[0042] F2-second direction;

[0043] R1 - first region;

[0044] R2 - Second region. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0046] Although relative terms such as "top", "bottom", "upper", "lower", "inside" and "outside" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification for convenience only. If the device of the illustration is turned over so that it is upside down, the component described as being "on" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure. The terms "a", "the" and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to indicate an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0047] like Figures 2 to 5 , which representatively shows the contact hole structure of the electrostatic protection device in the embodiment of the present invention. Figure 1 The cross-sectional view of the active area of ​​a representative ESD protection device can more clearly show the positional relationship between the active area of ​​the ESD protection device and the shallow trench S.

[0048] The electrostatic protection device in the present invention takes an electrostatic protection diode as an example. The diode is provided with an n-type active region N and a p-type active region P on a substrate 10, and the n-type active region N and the p-type active region P are isolated by shallow trench isolation (STI), such as Figure 1As shown. A contact hole 1 is provided in the active area. In the related art, the size and arrangement of the contact hole 1 are fixed and uniform, so that the current distribution of the device is relatively uniform during the current discharge process. However, since the active area is isolated by a shallow trench, that is, the shallow trench S is arranged around each active area to isolate each active area. At the corners (corners, i.e., heat concentration area A) where the shallow trench S contacts the active area, heat concentration is easily generated, which makes the heat distribution of the entire electrostatic protection device uneven, thereby affecting the protection ability of the electrostatic protection device. For example, heat is generated in the process of current being transferred from the contact hole of the n-type active area N to the contact hole of the p-type active area P. Although the current flowing through each contact hole is approximately the same, the heat dissipation capacity of different contact holes is different. The shallow trench S can be divided into an easy heat dissipation area B (a part away from the corners) and a heat concentration area A (corner parts). It can be understood that the active area in this application is a rectangle, and the parts of the shallow trench S surrounding the active area that contact the four corners of the active area are all heat concentration areas A, and the areas that contact the side parts between the corners of the active area are all easy heat dissipation areas B. Due to the uneven distribution of heat, the heat concentration area A may be burned first, which in turn causes the electrostatic protection device to fail.

[0049] like Figure 2 As shown, the present invention provides an electrostatic protection device, which includes an active area (such as the above-mentioned n-type active area N and p-type active area P), the active area is rectangular and is provided with at least one column of contact holes 1, and the multiple contact holes 1 in each column are distributed along a first direction F1, the first direction F1 is parallel to a side of the active area, and the contact holes 1 in each column are distributed along a second direction F2 perpendicular to the first direction F1. Among the multiple contact holes 1 in each column, the areas of the two contact holes 1 located at the two ends are smaller than the areas of the remaining contact holes 1.

[0050] It should be noted that, for the sake of clarity, all contact holes 1 in the active area are referred to as contact hole structures. Figure 2 The contact hole structure in each active area has two columns of contact holes 1, or one column. The number of columns of contact holes 1 can be selected according to the size of the active area, which is not limited here. In addition, the shape of the contact hole 1 shown in the figure is rectangular. In addition, the shape of the contact hole 1 can also be circular, elliptical, etc., which is not limited here. In addition, the area of ​​the two contact holes 1 at the two ends mentioned above refers to the area of ​​a single contact hole 1 at the two ends of each column, and does not refer to the sum of the areas of these two contact holes 1. The area of ​​the remaining contact holes 1 mentioned above also refers to the area of ​​a single contact hole 1 among the remaining contact holes 1, and does not refer to the sum of the areas of the remaining contact holes 1.

[0051] Furthermore, if Figure 2As shown, in order to explain more clearly, the figure shows the first direction F1 and the second direction F2, and the first direction F1 and the second direction F2 are perpendicular. In this embodiment, each contact hole 1 has a first size d1 in the first direction F1, and the first size d1 of the contact holes 1 located at both ends of each column is smaller than the first size d1 of other contact holes 1 in the column. The purpose of such a setting is to place the large size close to the easy heat dissipation area B as much as possible, so as to increase the current density of the contact holes 1 close to the easy heat dissipation area B.

[0052] It should be noted that the first size d1 of the two contact holes 1 at the two ends mentioned above refers to the first size d1 of a single contact hole 1 at the two ends of each column, and does not refer to the sum of the first sizes d1 of the two contact holes 1. The first size d1 of the remaining contact holes 1 mentioned above also refers to the first size d1 of a single contact hole 1 among the remaining contact holes 1, and does not refer to the sum of the first sizes d1 of the remaining contact holes 1.

[0053] Furthermore, if Figure 2 As shown, on the basis of the above-mentioned embodiment, the first size d1 of the multiple contact holes 1 in each column decreases from the middle of the column where the multiple contact holes 1 are located to the two ends. That is, the first size d1 of the contact hole 1 corresponding to the easy heat dissipation area B will be larger, and gradually decrease as it approaches the two ends of the active area (along the first direction F1) (that is, the size of the contact hole 1 is the smallest at the contact part of the heat concentration area A close to the shallow trench S), ensuring that the current density in the easy heat dissipation area B is larger and the current density close to the heat concentration area A gradually decreases, thereby compensating for the difference in thermal conductivity and making the temperature distribution more uniform, thereby improving the electrostatic protection capability and avoiding the electrostatic protection device from failing at the corner of the shallow trench S (such as the heat concentration area A).

[0054] Furthermore, if Figure 2 As shown, on the basis of the above embodiment, each contact hole 1 has a second size d2 in the second direction F2, and the second size d2 of each column of contact holes 1 is the same.

[0055] Furthermore, if Figure 3 As shown, an active region is used as an example (the active region can be an n-type active region N or a p-type active region P, which is not limiting and is only an example). Figures 4 to 8The situation is the same), based on the above embodiment, the multiple contact holes 1 can be multiple columns and rows, the contact holes 1 in each column extend along the first direction F1, and the contact holes 1 in each row extend along the second direction F2, that is, the multiple columns are parallel to the first direction F1, and the multiple rows are parallel to the second direction F2, and can be arranged in a matrix. The centers of the multiple contact holes 1 in each column are aligned in the first direction F1, and the centers of the multiple contact holes 1 in each row are aligned in the second direction F2. In addition, on this basis, the second dimension d2 of the contact holes 1 in each row is the same, that is, the width of the contact holes 1 in each row is the same. The first dimension d1 of the contact holes 1 in each column decreases from the middle of the active area to both sides.

[0056] Furthermore, in order to facilitate the preparation of the contact holes 1, based on the above embodiment, the first size d1 of the contact holes 1 in each row remains the same, that is, the size distribution of the contact holes 1 between columns is the same, which effectively improves the electrostatic protection capability of the device while ensuring the convenience of processing.

[0057] like Figure 4 As shown, in another embodiment, the plurality of contact holes 1 may be arranged in multiple rows and columns in a matrix, and the first dimension d1 of the contact holes 1 in each row is the same. Different from the above embodiment, the contact holes 1 in each column are the same size (the first dimension d1 is the same, the second dimension d2 is also the same, or it can be understood that the area is the same), and the second dimension d2 of the contact holes 1 in each row decreases from the middle of the row along the second direction F2 to both sides. It can also be understood that, Figure 3 The arrangement of the contact hole 1 structure after rotating 90° is shown. This design of the contact hole 1 structure can also ensure that the size of the contact hole 1 near the contact portion between the active area and the corner of the shallow trench S is reduced, and can also achieve the difference in thermal conductivity caused by uneven heat dissipation at different positions of the shallow trench S, which can effectively improve the discharge capacity of the device and avoid device failure at the corner of the shallow trench S.

[0058] like Figure 5 As shown, in another embodiment, the plurality of contact holes 1 may be arranged in multiple rows and columns and in a matrix, and the first dimension d1 of the contact holes 1 in each row is the same, and the second dimension d2 of each column is the same. Different from the above-mentioned embodiment, the second dimension d2 (width) of the contact holes 1 in each row decreases from the middle of the row to both sides, and at the same time, the first dimension d1 of the contact holes 1 in each column decreases from the middle of the column to both sides. The contact hole structure in this embodiment realizes the decrease of the first dimension d1 of the contact hole 1 near the corner A of the active area in the first direction F1, and at the same time realizes the decrease of the second dimension d2 of the contact hole 1 near the corner A of the active area in the second direction F2. This method can achieve a balance between the current density and the thermal conductivity difference to a greater extent, making the temperature distribution more uniform, effectively improving the electrostatic protection capability of the device, and avoiding the failure of the device at the corner of the shallow trench S.

[0059] Furthermore, if Figures 2 to 5 As shown, in each column, a plurality of contact holes 1 are arranged at equal intervals along the first direction F1, and the contact holes 1 in each row are arranged at equal intervals along the second direction F2. Such an arrangement ensures the ease of processing of the contact hole structure. In addition, the orderliness of the contact distribution is ensured, which is more conducive to the uniformity of the temperature distribution.

[0060] like Figure 6 As shown, in another embodiment, the plurality of contact holes 1 may be arranged in multiple rows and columns in a matrix, and the first size d1 of the contact holes 1 in each row is the same, and the second size d2 of the contact holes 1 in each column is the same. Different from the above embodiment, in the second direction F2, the second size d2 of each contact hole 1 in each of the two columns located at the edges of both sides of the active area is smaller than the second size d2 of the contact holes 1 in the remaining columns. For example, in Figure 6 There are five columns in total, and the second dimensions d2 of the contact holes 1 in the three middle columns in the second direction F2 are larger than the second dimensions d2 of the contact holes 1 in the two edge columns. Of course, the second dimensions d2 of the contact holes 1 in the middle column may also be larger than the second dimensions d2 of the contact holes 1 in the four symmetrical columns located at the edge.

[0061] like Figure 7 As shown, in another embodiment, the plurality of contact holes 1 may be arranged in multiple rows and columns in a matrix, and the second size d2 of the contact holes 1 in each row is the same, and the second size d2 of the contact holes 1 in each column is also the same. Different from the above embodiment, in the second direction F2, the first size d1 of the contact holes 1 in each column of the two columns located at the two side edges of the active area decreases from the middle of the column to both ends, while the first size d1 and the second size d2 of the contact holes 1 in the remaining columns are the same, and are the same as the first size d1 of the contact holes 1 in the middle of the two side edge columns (i.e., the first size d1 is the largest). For example, Figure 7 The contact hole structure in the embodiment includes seven columns, and the first size d1 and the second size d2 of the contact holes 1 in the middle five columns are the same. Of course, the first size d1 and the second size d2 of the contact holes 1 in the middle three columns may also be the same, such as Figure 8 As shown, the first dimensions d1 of the four symmetrical rows of contact holes 1 located at the two side edges of the active area decrease from the middle of the row along the first direction F1 to both ends, which is not particularly limited here.

[0062] refer to Figure 2 , which is a structure in which the n-type active region N and the p-type active region P are arranged in parallel. In addition, refer to Fig. 9 , the p-type active region P can be arranged inside the n-type active region N, that is, the n-type active region N and the p-type active region P form a Fig. 9The two active regions are also isolated by a shallow trench S. The arrangement of the contact hole structure in the middle p-type active region P can be the same as in the above embodiment. Figures 3 to 5 The contact hole structure shown is the same as that in the p-type active region P. The n-type active region N is divided into a first region R1 and a second region R2. The first region R1 is a portion extending along the first direction F1, and the second region R2 is a portion extending along the second direction F2. The contact hole structure of the first region R1 can be the same as that of the p-type active region P, such as Fig. 9 When the contact hole structure of the second region R2 has multiple rows and columns of contact holes 1, the arrangement of the multiple contact holes 1 can be as shown in the above embodiment. Figures 3 to 8 The contact hole structure of the second region R2 may also have a row, and its second size d2 may decrease from the middle of the row to both sides. The arrangement of the contact hole structure of the n-type active region N may be selected according to the arrangement method in the above embodiment, and is not particularly limited here.

[0063] It should be noted that Figures 2 to 9 The number and position of the heat concentration area A and the heat dissipation area B indicated in the figure are only exemplary. Figure 3 In the figure, the symmetrical parts on the opposite side of the easy heat dissipation area B marked therein are also easy heat dissipation areas, such as the heat concentration area A, which are also the other two corner parts. For the sake of simplicity, they are not fully marked. Those skilled in the art can determine the easy heat dissipation area B and the heat concentration area A based on the above description, so there is no limitation.

[0064] In summary, the contact hole structure of the electrostatic protection device in the present invention is designed by arranging and designing the size of the contact holes 1. The area of ​​the contact holes 1 near the corner A of the active area is designed to be smaller than the area of ​​the contact holes 1 at other positions, so that the current density in the area where heat is not easy to dissipate is smaller, and the current density in the area B where heat is easy to dissipate is larger, which compensates for the difference in temperature distribution caused by uneven thermal conductivity, makes the temperature distribution more uniform, and effectively improves the electrostatic protection capability of the electrostatic protection device, avoiding the failure of the device due to heat accumulation at the corner of the shallow groove S.

[0065] The present invention further provides an electrostatic protection device, which is a protection diode, and the protection diode has the contact hole structure in the above embodiment. The contact hole structure is the same as the above embodiment, and will not be described in detail here.

[0066] It should be understood that the present invention is not limited in its application to the detailed structure and arrangement of the components proposed in this specification. The present invention can have other embodiments and can be implemented and executed in a variety of ways. The aforementioned variations and modifications fall within the scope of the present invention. It should be understood that the present invention disclosed and defined in this specification extends to all alternative combinations of two or more individual features mentioned or evident in the text and / or the drawings. All these different combinations constitute multiple alternative aspects of the present invention. The embodiments described in this specification illustrate the best mode known for implementing the present invention and will enable those skilled in the art to utilize the present invention.

Claims

1. An electrostatic protection device, comprising an active area, characterized in that: The active area is rectangular and is provided with at least one row of contact holes, a plurality of the contact holes in each row are spaced apart along a first direction, the first direction is parallel to a side of the active area, and the contact holes in each row are spaced apart along a second direction perpendicular to the first direction; Among the multiple contact holes in each column, the areas of the two contact holes at the two ends are smaller than those of the other contact holes, and the two contact holes at the two ends are close to the heat concentration area, while the other contact holes are close to the easy heat dissipation area.

2. The electrostatic protection device according to claim 1, characterized in that: Each of the contact holes has a first size in the first direction, and the first size of the contact holes located at two ends of each column is smaller than the first size of the remaining contact holes.

3. The electrostatic protection device according to claim 2, characterized in that: The first size of the contact holes in each column decreases from the middle to both ends of the column.

4. The electrostatic protection device according to claim 3, characterized in that: Each of the contact holes has a second size in the second direction, and the second size of the contact holes in each column is the same.

5. The electrostatic protection device according to claim 4, characterized in that: The plurality of contact holes are arranged in a matrix to form a plurality of columns and a plurality of rows, wherein the plurality of columns are parallel to the first direction, and the plurality of rows are parallel to the second direction.

6. The electrostatic protection device according to claim 5, characterized in that: The second size of the contact holes in each row is the same.

7. The electrostatic protection device according to claim 5, characterized in that: The second size of the contact holes in each row decreases from the middle to both sides of the row.

8. The electrostatic protection device according to claim 6 or 7, characterized in that: The first size of the contact holes in each row is the same.

9. The electrostatic protection device according to claim 8, characterized in that: The contact hole is in a rectangular shape.

10. The electrostatic protection device according to any one of claims 2 to 7, characterized in that: In each column, a plurality of the contact holes are arranged at equal intervals along the first direction.

11. The electrostatic protection device according to claim 2, characterized in that: The contact holes in each row are arranged at equal intervals along the second direction.

12. The electrostatic protection device according to claim 1, characterized in that: It also includes a shallow trench which is arranged around the active area.

13. A semiconductor device, characterized in that: The invention comprises the electrostatic protection device according to any one of claims 1 to 12.

Images