TWI650845B - Diode with high static protection capability - Google Patents

Abstract

A diode with high electrostatic protection capability includes a first diffusion region of a first conductivity type, a second diffusion region of a second conductivity type, and an insulation region. The first diffusion region has a plurality of recessed portions. The insulating region surrounds the first diffusion region and is conformal with the first diffusion region. The second diffusion region surrounds the insulation region. The insulation region is used to isolate the first diffusion region from the second diffusion region.

Description

Diode with high electrostatic protection ability

The embodiment of the present disclosure relates to a diode, and more particularly to a diode with high electrostatic protection capability.

The damage of static electricity to electronic products has always been a difficult problem to solve, especially in the application of high-frequency circuits. In order not to affect the normal working performance of the product, the input and output interfaces of the circuit usually require electrostatic protection components to have a strong current discharge capability. At present, the more common high-frequency circuits, the electrostatic protection components of the input and output interfaces are mostly diodes. When an electrostatic discharge occurs, the N-type diode is used to discharge the forward current from the ground terminal to the input and output interface, and the P-type diode is used to discharge the forward current from the input and output interface to the power terminal. In order to improve the diode's own current withstand ability and thus improve the electrostatic protection ability, it is usually necessary to increase the area of the diode. However, this method is not conducive to miniaturization of the product.

The purpose of this disclosure is to propose a diode with high electrostatic protection ability, which can increase the P / N by changing the shape of the diffusion region inside the diode. The perimeter of the interface improves the current withstand capability of the diode itself, and the diode does not need to increase its area to enable the diode to have high electrostatic protection capabilities.

According to the above object of the present disclosure, a diode with high electrostatic protection capability is proposed, which includes a first diffusion region of a first conductivity type, a second diffusion region of a second conductivity type, and an insulation region. The first diffusion region has a plurality of recessed portions. The insulating region surrounds the first diffusion region and is conformal with the first diffusion region. The second diffusion region surrounds the insulation region. The insulation region is used to isolate the first diffusion region from the second diffusion region.

In some embodiments, each of the depressions has a U-shape.

In some embodiments, each of the above-mentioned depressions has a circular arc shape.

In some embodiments, the recesses are symmetrical to the corresponding center points of the first diffusion region.

In some embodiments, each of the first diffusion regions with respect to each side of the second diffusion region has at least one recessed portion of the same number.

In some embodiments, the first diffusion region opposite to the at least one set of opposite sides of the second diffusion region has the same number of at least one recessed portion opposite to the side.

In some embodiments, the first diffusion region of the first conductivity type is an N + type diffusion region, and the second diffusion region of the second conductivity type is a P + type diffusion region.

In some embodiments, the first diffusion region of the first conductivity type is a P + type diffusion region, and the second diffusion region of the second conductivity type is an N + type diffusion region.

In some embodiments, the method of forming the insulating region is a local oxidation method (Local Oxidation of Silicon, LOCOS) or a shallow trench isolation (Shallow Trench Isolation, STI).

In some embodiments, the first diffusion region has a smooth outer shape.

In order to make the above-mentioned features and advantages of the present disclosure more comprehensible, embodiments are described below in detail with reference to the accompanying drawings.

100, 200, 300, 400, 500‧‧‧ diodes

110, 210, 310, 410, 510‧‧‧ first diffusion zone

212, 312, 412, 512‧‧‧ recess

120, 220, 320, 420, 520‧‧‧ second diffusion zone

130, 230, 330, 430, 430‧‧‧ insulated areas

A better understanding of the aspects of the present disclosure can be obtained from the following detailed description in conjunction with the accompanying drawings. It should be noted that, according to industry standard practice, features are not drawn to scale. In fact, to make the discussion clearer, the dimensions of each feature can be arbitrarily increased or decreased.

[Fig. 1] A schematic structural diagram of one of the conventional diodes.

[FIG. 2] A schematic structural diagram of a diode according to a first embodiment of the present disclosure.

3 is a schematic structural diagram of a diode according to a second embodiment of the present disclosure.

4 is a schematic structural diagram of a diode according to a third embodiment of the present disclosure.

5 is a schematic structural diagram of a diode according to a fourth embodiment of the present disclosure.

Embodiments of the invention are discussed in detail below. It is understood, however, that the embodiments provide many applicable concepts that can be embodied in a wide variety of specific content. The embodiments discussed and disclosed are for illustration only and are not intended to limit the scope of the invention. In addition, the terms "first", "second", ... and the like used herein do not specifically refer to the order or the order, but merely to distinguish the elements or operations described in the same technical terms.

FIG. 1 is a schematic structural diagram of a conventional diode 100. The conventional diode 100 includes a first diffusion region 110 of a first conductivity type, a second diffusion region 120 of a second conductivity type, and an insulation region 130. The insulation region 130 surrounds the first diffusion region 110, and the second diffusion region 120 surrounds the insulation region 130. The insulating region 130 is used to isolate the first diffusion region 110 from the second diffusion region 120.

FIG. 2 is a schematic structural diagram of a diode 200 according to the first embodiment of the present disclosure. The diode 200 includes a first diffusion region 210 of a first conductivity type, a second diffusion region 220 of a second conductivity type, and an insulation region 230. The first diffusion region 210 has a plurality of recessed portions 212. The insulating region 230 surrounds the first diffusion region 210 and is conformal with the first diffusion region 210. The second diffusion region 220 surrounds the insulation region 230. The insulating region 230 is used to isolate the first diffusion region 210 from the second diffusion region 220.

In the disclosed embodiment, the first diffusion region of the first conductivity type is an N + type diffusion region, and the second diffusion region of the second conductivity type is a P + type diffusion region. In this case, the diode is an N type. A diode; or, the first diffusion region of the first conductivity type is a P + -type diffusion region, and the second diffusion region of the second conductivity type is an N + -type diffusion region. In this case, the diode is a P-type diffusion region. Polar body. In the embodiment of the present disclosure, a method of forming the insulating region 130 is a local oxidation method (LOCOS) or a shallow trench isolation (STI).

For some embodiments of the present disclosure, each side of the first diffusion region with respect to each side of the second diffusion region has the same number of at least one recessed portion. Taking the first embodiment of the present disclosure as an example, as shown in FIG. 2, with respect to each side of the first diffusion region 210 on each side of the second diffusion region 220 (ie, upper side / lower side / left side / right side) ( That is, each of the upper side, the lower side, the left side and the right side has one recessed portion 212, but the embodiment of the present disclosure is not limited thereto.

In the first embodiment of the present disclosure, as shown in FIG. 2, each of the recessed portions 212 has a U-shape, but the embodiment of the present disclosure is not limited thereto, and each of the recessed portions may have a circular arc. Shape. For the embodiment of the present disclosure, the concave portions are symmetrical to the corresponding center points of the first diffusion region. Taking the first embodiment of the present disclosure as an example, as shown in FIG. 2, the concave portions 212 are symmetrical to the first diffusion. The corresponding center point of the area 210.

It should be noted that this disclosure does not limit the dimensional relationship of the recessed portion with respect to the first diffusion region, as long as its design can conform to the manufacturing process of the diode, and the first diffusion region does not have an overly protruded or recessed shape, resulting in It is not conducive to improving the electrostatic protection ability of the diode.

For the embodiment of the present disclosure, the first diffusion region having a plurality of recessed portions has a smooth shape, so that the P / N interface used to discharge current will not cause sharp discharge or current concentration due to sharp turns. At the tip, it is not conducive to improving the electrostatic protection of the diode.

Please refer to FIG. 1 and FIG. 2 together. Compared with the conventional diode 100, the diode 200 of the first embodiment of the present disclosure keeps the diode area unchanged. In the case of changing the shape of the first diffusion region 210 to increase the perimeter of the P / N interface (that is, under the same unit area, the path through which the current flows increases) so as to improve the current resistance of the diode 200 itself. Subject to capacity.

FIG. 3 is a schematic structural diagram of a diode 300 according to a second embodiment of the present disclosure. The diode 300 includes a first diffusion region 310 of a first conductivity type, a second diffusion region 320 of a second conductivity type, and an insulation region 330. The first diffusion region 310 has a plurality of recessed portions 312. The insulating region 330 surrounds the first diffusion region 310 and is conformal with the first diffusion region 310. The second diffusion region 320 surrounds the insulation region 330. The insulating region 330 is used to isolate the first diffusion region 310 from the second diffusion region 320.

For some embodiments of the present disclosure, the first diffusion region with respect to at least one set of opposite sides of the second diffusion region has at least one recessed portion opposite to the side. Taking the second embodiment of the present disclosure as an example, as shown in FIG. 3, the first diffusion region 310 opposite to the set of opposite sides (ie, left / right) of the second diffusion region 320 is opposite to that side (ie, left / right). ) Each has two recessed portions 312, but the embodiment of the present disclosure is not limited thereto.

In the second embodiment of the present disclosure, as shown in FIG. 3, each of the recessed portions 312 has a U-shape, but the embodiment of the present disclosure is not limited thereto, and each of the recessed portions may have a circular arc. Shape. For the embodiment of the present disclosure, the concave portions are symmetrical to the corresponding center points of the first diffusion region. Taking the second embodiment of the present disclosure as an example, as shown in FIG. 3, the concave portions 312 are symmetrical to the first diffusion. The corresponding center point of zone 310.

Please refer to FIG. 1 and FIG. 3 together. Compared with the conventional diode 100, the diode 300 of the second embodiment of the present disclosure keeps the area of the diode unchanged. In the case of changing the shape of the first diffusion region 310, the perimeter of the P / N interface is increased to improve the current tolerance of the diode 300 itself.

FIG. 4 is a schematic structural diagram of a diode 400 according to a third embodiment of the present disclosure. The diode 400 includes a first diffusion region 410 of a first conductivity type, a second diffusion region 420 of a second conductivity type, and an insulation region 430. The first diffusion region 410 has a plurality of recessed portions 412. The insulating region 430 surrounds the first diffusion region 410 and is conformal with the first diffusion region 410. The second diffusion region 420 surrounds the insulation region 430. The insulating region 430 is used to isolate the first diffusion region 410 and the second diffusion region 420.

For some embodiments of the present disclosure, each side of the first diffusion region with respect to each side of the second diffusion region has the same number of at least one recessed portion. Taking the third embodiment of the present disclosure as an example, as shown in FIG. 4, with respect to each side of the first diffusion region 410 on each side of the second diffusion region 420 (ie, upper side / lower side / left side / right side) ( That is, each of the upper side / lower side / left side / right side) has two recessed portions 412, but the embodiment of the present disclosure is not limited thereto.

In the third embodiment of the present disclosure, as shown in FIG. 4, each of the recessed portions 412 has an arc-shaped outer shape, but the embodiment of the present disclosure is not limited thereto. Word shape. For the embodiment of the present disclosure, the concave portions are symmetrical to the corresponding center points of the first diffusion region. Taking the third embodiment of the present disclosure as an example, as shown in FIG. 4, the concave portions 412 are symmetrical to the first diffusion. The corresponding center point of zone 410.

Please refer to FIG. 1 and FIG. 4 together. Compared with the conventional diode 100, the diode 400 of the third embodiment of the present disclosure can change the first diffusion region by keeping the area of the diode unchanged. 410 form factor to increase the P / N boundary The perimeter of the surface thus improves the current tolerance of the diode 400 itself.

FIG. 5 is a schematic structural diagram of a diode 500 according to a fourth embodiment of the present disclosure. The diode 500 includes a first diffusion region 510 of a first conductivity type, a second diffusion region 520 of a second conductivity type, and an insulation region 530. The first diffusion region 510 has a plurality of recessed portions 512. The insulating region 530 surrounds the first diffusion region 510 and is conformal with the first diffusion region 510. The second diffusion region 520 surrounds the insulation region 530. The insulating region 530 is used to isolate the first diffusion region 510 and the second diffusion region 520.

For some embodiments of the present disclosure, the first diffusion region with respect to at least one set of opposite sides of the second diffusion region has at least one recessed portion opposite to the side. Taking the fourth embodiment of the present disclosure as an example, as shown in FIG. 5, with respect to the three opposite sides of the second diffusion region 520 (ie, upper side / lower side; left upper left / right lower right; right upper right / left lower left) The opposite sides of the first diffusion region 510 (ie, upper side / lower side; upper left side / lower right side; upper right side / lower left side) each have a recessed portion 512, but the embodiment disclosed herein is not limited thereto.

In the fourth embodiment of the present disclosure, as shown in FIG. 5, each of the recessed portions 512 has a circular arc shape, but the embodiment of the present disclosure is not limited thereto, and each of the recessed portions may have a U-shape. Word shape. For the embodiment of the present disclosure, the concave portions are symmetrical to the corresponding center points of the first diffusion region. Taking the fourth embodiment of the present disclosure as an example, as shown in FIG. 5, the concave portions 512 are symmetrical to the first diffusion. The corresponding center point of zone 510.

Please refer to FIG. 1 and FIG. 5 together. Compared with the conventional diode 100, the diode 500 of the fourth embodiment of the present disclosure is configured to change the first diffusion region. The shape of 510 increases the perimeter of the P / N interface to improve the current tolerance of the diode 500 itself.

To sum up, this disclosure proposes a diode with high electrostatic protection ability. By changing the shape of the diffusion region inside the diode, the perimeter of the P / N interface is increased to improve the current tolerance of the diode itself. It is necessary to increase the area of the diode so that the diode has a high electrostatic protection ability.

The features of several embodiments are summarized above, so those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art should understand that they can easily use this disclosure as a basis to design or modify other processes and structures, thereby achieving the same goals and / or achieving the same advantages as the embodiments described herein. . Those skilled in the art should also understand that these equivalent constructions do not depart from the spirit and scope of this disclosure, and that they can make various changes, substitutions and alterations without departing from the spirit and scope of this disclosure.

Claims (10)

A diode with high electrostatic protection capability includes: a first diffusion region of a first conductivity type having a plurality of depressions; an insulating region surrounding the first diffusion region and sharing the same with the first diffusion region And a second diffusion region of a second conductivity type surrounding the insulation region, wherein the insulation region is used to isolate the first diffusion region from the second diffusion region. As described in item 1 of the scope of the patent application, the diodes with high electrostatic protection capabilities, wherein each of the recesses has a U-shape. As described in item 1 of the scope of the patent application, the diodes with high electrostatic protection capability, wherein each of the recessed portions has an arc-like shape. As described in item 1 of the scope of the patent application, a diode having high electrostatic protection capability, wherein the recessed portions are symmetrical to the corresponding center point of the first diffusion region. The diode having high electrostatic protection capability as described in item 1 of the scope of patent application, wherein each side of the first diffusion region with respect to each side of the second diffusion region has at least one recessed portion of the same number . As described in item 1 of the scope of the patent application, a diode with high electrostatic protection capability, wherein the first diffusion region has at least one Depression. As described in item 1 of the scope of the patent application, a diode with high electrostatic protection capability, wherein the first diffusion region of the first conductivity type is an N + type diffusion region, and the second diffusion region of the second conductivity type is P + type diffusion region. As described in item 1 of the scope of patent application, a diode with high electrostatic protection capability, wherein the first diffusion region of the first conductivity type is a P + type diffusion region, and the second diffusion region of the second conductivity type is N + type diffusion region. The diode having high electrostatic protection capability as described in item 1 of the scope of the patent application, wherein the method for forming the insulating region is a local oxidation method (Local Oxidation of Silicon (LOCOS)) or a shallow trench isolation (Shallow Trench Isolation, STI) ). The diode having high electrostatic protection capability as described in item 1 of the patent application scope, wherein the first diffusion region has a smooth shape.