Manufacturing method and structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor

Abstract

This invention provides a method for manufacturing an optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: providing a semiconductor structure for the optocoupled three-terminal bidirectional AC switching device; and providing a resistive layer within the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device. This method can be applied to current-limiting protection of the optocoupled three-terminal bidirectional AC switching device.

Description

Technical Field

[0001] This invention provides a method for manufacturing an optically coupled three-terminal bidirectional AC switching device and its structure, particularly a method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor and its structure. Prior Technology

[0002] A photo-triode for alternating current (AAC) is a switching device that combines the features of an optocoupler and a TRIAC. An optocoupler is an electronic component that uses light to electrically isolate two circuits. A TRIAC, typically a three-terminal semiconductor device, is used to control the flow of alternating current.

[0003] The working principle of a photo TRIAC is generally as follows: it receives a small current signal from the input terminal through an optocoupler and converts it into an optical signal. The optical signal is then transmitted to the photosensitive gate of the TRIAC, thereby turning on the TRIAC and allowing alternating current to flow through the output terminal.

[0004] One of the main advantages of Photo TRIAC is its ability to provide electrical isolation. This isolation avoids direct electrical connections between the input and output terminals, preventing damage caused by noise and excessive electrical signals. Photo TRIAC also boasts advantages such as small size, low power consumption, and high reliability.

[0005] To ensure proper operation of the Photo Triac, a current-limiting resistor is typically placed in the basic trigger circuit of the Photo Triac to prevent potential damage caused by excessive current. Summary of the Invention

[0006] However, existing conventional photo trigger circuits, in order to prevent damage from excessive current, place the current-limiting resistor in the trigger circuit connected to the photo trigger pins, outside of the photo trigger itself. This design, with its external current-limiting resistor, leads to space constraints, complex support structure design, and increased costs due to the increasing demands for miniaturization and integration in overall systems, thus limiting the application of photo triggers. One solution is to omit the current-limiting resistor, but this would again lead to the aforementioned potential damage to the photo trigger.

[0007] Therefore, the purpose of this invention is to provide a structure and method for manufacturing a Photo TRIAC that eliminates the need for an additional current-limiting resistor in the trigger circuit outside the Photo TRIAC to protect it, while retaining the characteristics and function of the current-limiting resistor. This allows the overall system to achieve numerous advantages such as increased integration, space saving, cost reduction, and improved applicability.

[0008] In view of this, the present invention provides a method and structure for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor. The characteristics and functions of the current-limiting resistor are directly integrated into the Photo TRIAC itself through a semiconductor process, thereby greatly increasing the flexibility of the Photo TRIAC with the current-limiting resistor, reducing the electronic components required for the external trigger circuit, and simultaneously protecting the Photo TRIAC.

[0009] One aspect of the present invention provides a method for manufacturing an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor, comprising: providing a semiconductor structure of an optically coupled three-terminal bidirectional AC switch device; and providing a resistive layer in the semiconductor structure of the optically coupled three-terminal bidirectional AC switch device.

[0010] As described above, in the method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, a resistive layer is formed on a gate layer of the semiconductor structure of the optically coupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

[0011] The manufacturing method of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: providing a substrate; forming an oxide layer on the substrate; forming a P-type semiconductor layer on the substrate; forming an N-type semiconductor layer in the P-type semiconductor layer; forming a gate layer on the N-type semiconductor layer; forming a resistive layer on the gate layer; forming an isolation layer between adjacent N-type semiconductor layers and gate layers; and forming a metal interconnect layer to electrically connect the same electrical regions.

[0012] The manufacturing method of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above, wherein: the P-type semiconductor layer includes a well region, a body region and a contact region; the N-type semiconductor layer includes a first N-type semiconductor region, a second N-type semiconductor region, a third N-type semiconductor region and a fourth N-type semiconductor region; the first N-type semiconductor region, the second N-type semiconductor region and the third N-type semiconductor region are formed in the well region, and the fourth N-type semiconductor region is formed in the body region; a gate layer is formed between the first N-type semiconductor region and the second N-type semiconductor region, and partially covers the first N-type semiconductor region and the second N-type semiconductor region; an isolation layer is formed covering the first N-type semiconductor region and the second N-type semiconductor region at the adjacent locations of the gate layer and the gate layer, and also forms a portion covering the first N-type semiconductor region, the second N-type semiconductor region, the third N-type semiconductor region and the fourth N-type semiconductor region.

[0013] As described above, in the method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, a resistive layer is formed on an isolation layer of the semiconductor structure of the optically coupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

[0014] The manufacturing method of the optically coupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: providing a substrate; forming an oxide layer on the substrate; forming a P-type semiconductor layer on the substrate; forming an N-type semiconductor layer in the P-type semiconductor layer; forming a gate layer on the N-type semiconductor layer; forming an isolation layer, wherein at least a portion of the isolation layer is formed in a first terminal region and a second terminal region; forming a resistive layer on the isolation layer formed in the first terminal region and the second terminal region; and forming a metal interconnect layer to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

[0015] The method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor as described above further includes: providing a substrate; forming an oxide layer on the substrate; forming a P-type semiconductor layer on the substrate; forming an N-type semiconductor layer in the P-type semiconductor layer; forming an isolation layer, wherein at least a portion of the isolation layer is formed in a first terminal region and a second terminal region; forming a resistive layer on the isolation layer formed in the first terminal region and the second terminal region; and forming a metal interconnect layer to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

[0016] As described above, in the method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, the resistive layer is formed in the semiconductor structure of the optically coupled three-terminal bidirectional AC switching device by implantation.

[0017] The method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor as described above further includes: providing a substrate; forming an oxide layer on the substrate; forming a P-type semiconductor layer on the substrate; forming an N-type semiconductor layer in the P-type semiconductor layer; forming an isolation layer, wherein at least a portion of the isolation layer is formed in a first terminal region and a second terminal region; forming a resistive layer in the first terminal region and the second terminal region; and forming a metal interconnect layer to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

[0018] The manufacturing method of the optically coupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: forming a well region of a P-type semiconductor layer; and forming a low-concentration N-type semiconductor region in the well region of the P-type semiconductor layer.

[0019] Another aspect of the present invention provides a structure for an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: an optically coupled three-terminal bidirectional AC switching device semiconductor structure; and a resistive layer formed in the optically coupled three-terminal bidirectional AC switching device semiconductor structure.

[0020] As described above, the structure of the optocoupled three-terminal bidirectional AC switch device with current-limiting resistor is such that the resistive layer is formed on a gate layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device, and the resistive layer is a low-doped polycrystalline silicon material.

[0021] The structure of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: a substrate; an oxide layer formed on the substrate; a P-type semiconductor layer formed on the substrate; an N-type semiconductor layer formed in the P-type semiconductor layer; an isolation layer formed between adjacent N-type semiconductor layers and a gate layer; and a metal interconnect layer formed on the isolation layer to electrically connect the same electrical regions; wherein the gate layer is formed on the N-type semiconductor layer; and wherein the resistive layer is formed on the gate layer.

[0022] The structure of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above includes: a P-type semiconductor layer comprising a well region, a body region, and a contact region; an N-type semiconductor layer comprising a first N-type semiconductor region, a second N-type semiconductor region, a third N-type semiconductor region, and a fourth N-type semiconductor region; the first N-type semiconductor region, the second N-type semiconductor region, and the third N-type semiconductor region are formed in the well region, and the fourth N-type semiconductor region is formed in the body region; a gate layer is formed between the first N-type semiconductor region and the second N-type semiconductor region, and partially covers the first N-type semiconductor region and the second N-type semiconductor region; an isolation layer is formed covering the first N-type semiconductor region, the second N-type semiconductor region, and the gate layer at their adjacent locations, and also forms covering portions of the first N-type semiconductor region, the second N-type semiconductor region, the third N-type semiconductor region, and the fourth N-type semiconductor region.

[0023] As described above, the structure of the optocoupled three-terminal bidirectional AC switch device with current-limiting resistor is such that the resistive layer is formed on an isolation layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device, and the resistive layer is a low-doped polycrystalline silicon material.

[0024] The structure of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: a substrate; an oxide layer formed on the substrate; a P-type semiconductor layer formed on the substrate; an N-type semiconductor layer formed in the P-type semiconductor layer; a gate layer formed on the N-type semiconductor layer; and a metal interconnect layer, at least a portion of which is formed on the resistive layer and electrically connects the same electrical regions; wherein at least a portion of the isolation layer is formed in a first terminal region and a second terminal region; and wherein the resistive layer is formed on the isolation layer formed in the first terminal region and the second terminal region.

[0025] The structure of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: a substrate; an oxide layer formed on the substrate; a P-type semiconductor layer formed on the substrate; an N-type semiconductor layer formed in the P-type semiconductor layer; a metal interconnect layer, at least a portion of which is formed on the resistive layer and electrically connects the same electrical regions; wherein at least a portion of the isolation layer is formed in a first terminal region and a second terminal region; wherein the resistive layer is formed on the isolation layer formed in the first terminal region and the second terminal region.

[0026] As described above, the structure of the optocoupled three-terminal bidirectional AC switch device with current-limiting resistor is wherein the resistor layer is formed in the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device by implantation.

[0027] The structure of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: a substrate; an oxide layer formed on the substrate; a P-type semiconductor layer formed on the substrate; an N-type semiconductor layer formed in the P-type semiconductor layer; an isolation layer, at least a portion of which is formed in a first terminal region and a second terminal region, wherein the resistive layer is formed in the first terminal region and the second terminal region; and a metal interconnect layer, at least a portion of which is formed on the resistive layer, and electrically connects the same electrical regions.

[0028] The structure of the optically coupled three-terminal bidirectional AC switching device with current-limiting resistor as described above further includes: a well region of a P-type semiconductor layer; and a low-concentration N-type semiconductor region formed in the well region of the P-type semiconductor layer.

[0029] By employing the manufacturing method and specific structure of this invention, which involves providing a resistive layer within the semiconductor structure of an optocoupled three-terminal bidirectional AC switch, the optocoupled three-terminal bidirectional AC switch can directly incorporate a current-limiting resistor. This provides protection against damage caused by excessive current, eliminating the need for an additional current-limiting resistor in the trigger circuit of the optocoupled three-terminal bidirectional AC switch. Simultaneously, the characteristics and function of the current-limiting resistor are preserved, resulting in numerous beneficial effects such as improved overall system integration, space saving, cost reduction, and enhanced applicability. Furthermore, through semiconductor manufacturing processes, without the need for additional external configuration, the optocoupled three-terminal bidirectional AC switch with a current-limiting resistor can be manufactured simultaneously with the optocoupled three-terminal bidirectional AC switch. Simple Explanation of the Diagram

[0030] Figure 1 shows a schematic diagram of the basic trigger circuit configuration of a conventional optically coupled three-terminal bidirectional AC switching device; Figure 2 shows a schematic diagram of the trigger circuit configuration of the optically coupled three-terminal bidirectional AC switching device with an equivalent current-limiting resistor in one embodiment of the present invention; Figure 3 shows a flowchart of the steps of a method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor according to an embodiment of the present invention; Figure 4 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device according to an embodiment of the present invention; Figure 5 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in one embodiment of the present invention; Figure 6 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor in one embodiment of the present invention; Figure 7 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in one embodiment of the present invention; Figure 8 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device according to an embodiment of the present invention; Figure 9 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor in one embodiment of the present invention; Figure 10 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor according to an embodiment of the present invention; Figure 11 shows an equivalent circuit diagram of the semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in one embodiment of the present invention. Implementation

[0031] To illustrate the technical content of this invention in detail, the following description, in conjunction with embodiments and accompanying drawings, provides further explanation. It should be noted that, throughout this document, terms such as "first," "second," and "third" are used to distinguish between elements, rather than to limit the elements themselves or indicate a specific order of elements. Furthermore, throughout this document, unless a specific quantity is specifically indicated, the article "a" refers to one element or more than one element.

[0032] To fully understand the purpose, features and effects of the present invention, the present invention will be described in detail below with reference to the following specific embodiments and accompanying drawings.

[0033] Figure 1 shows a schematic diagram of the basic trigger circuit configuration of a conventional optically coupled three-terminal bidirectional AC switching device.

[0034] Referring to Figure 1, in the prior art, the basic trigger circuit of the conventional photocoupled three-terminal bidirectional AC switching device (Photo TRIAC) 80 uses the configuration shown in Figure 1. To prevent damage to the Photo TRIAC 80 due to excessive current, a current-limiting resistor 90 is conventionally placed in the trigger circuit connected outside the Photo TRIAC 80's pin (as shown by pin 6 of the Photo TRIAC 80 in Figure 1). This design of the current-limiting resistor 90 outside the Photo TRIAC 80 achieves the function of protecting the Photo TRIAC 80. However, as mentioned earlier, with the increasing demands for miniaturization and integration of overall systems, placing the current-limiting resistor 90 outside the Photo TRIAC 80 may result in problems such as large space occupation, complex surrounding support design, and increased manufacturing costs in different applications, thus limiting the application of the Photo TRIAC 80. However, without using the current-limiting resistor 90, there is a potential risk of damage to the Photo TRIAC 80. In Figure 1, the Zero Crossing Circuit refers to the zero-point triggering circuit. T1 and T2 are the endpoints in the Photo TRIAC circuit. The remaining components are the familiar basic triggering circuits of Photo TRIAC. Their basic configuration and operating conditions will not be described in detail in this article.

[0035] Figure 2 shows a schematic diagram of the trigger circuit configuration of an optically coupled three-terminal bidirectional AC switching device with an equivalent current-limiting resistor in one embodiment of the present invention.

[0036] Referring to Figure 2, to address the aforementioned problem arising from placing the current-limiting resistor 90 outside the photocoupled three-terminal bidirectional AC switch (Photo TRIAC) 80, the present invention provides a manufacturing method and structure for a photocoupled three-terminal bidirectional AC switch 10 with a current-limiting resistor 20. This method integrates the current-limiting resistor 20 directly into the original photocoupled three-terminal bidirectional AC switch 10 using a semiconductor process, effectively integrating a semiconductor structure with equivalent resistance. Its position in the basic trigger circuit of the overall photocoupled three-terminal bidirectional AC switch 10 is equivalent to that of the current-limiting resistor 20 shown in Figure 2. By placing the current-limiting resistor 20 within the photocoupled three-terminal bidirectional AC switch 10 using a semiconductor process and structure, the flexibility of use of the photocoupled three-terminal bidirectional AC switch 10 with the integrated current-limiting resistor 20 can be increased, while simultaneously protecting the photocoupled three-terminal bidirectional AC switch 10. The method and specific structure for effectively integrating the current-limiting resistor 20 into the photocoupled three-terminal bidirectional AC switch 10 will be described later in the embodiments of the present invention. Among them, the remaining external triggering circuits and operating conditions of the optically coupled three-terminal bidirectional AC switching device 10 with current-limiting resistor 20 disclosed in this invention are no substantially different from the basic triggering circuit of the conventional Figure 1, except for the different positions of current-limiting resistor 20 and current-limiting resistor 90, and will not be described in detail here.

[0037] Figure 3 shows a flowchart of the steps of a method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in one embodiment of the present invention; Figure 4 shows a flowchart of the steps of a method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in one embodiment of the present invention.

[0038] Referring to Figure 3, one embodiment of the present invention provides a method for manufacturing an optocoupled three-terminal bidirectional AC switch device with a current-limiting resistor, comprising: step (S100) providing a semiconductor structure for the optocoupled three-terminal bidirectional AC switch device; and step (S200) providing a resistive layer in the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device. The semiconductor structure of the optocoupled three-terminal bidirectional AC switch device includes a gate layer, and the resistive layer is formed on and in contact with the gate layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device. The optocoupled three-terminal bidirectional AC switch device may, for example, have an NPN transistor, and the resistive layer is formed on and over the gate layer of this NPN transistor. In one embodiment, the resistive layer may directly contact the gate layer. The resistive layer may be a material with electrically resistive properties, such as polysilicon or other materials with resistive properties, to form an appropriate resistance above the gate layer.

[0039] Therefore, by directly providing a resistive layer with resistive properties into the semiconductor structure of the optocoupled three-terminal bidirectional AC switch, it can be used for current limiting protection of the optocoupled three-terminal bidirectional AC switch without having to connect a current limiting resistor outside the optocoupled three-terminal bidirectional AC switch.

[0040] In one embodiment, the step of (S100) providing the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device further includes: providing a substrate, such as an n-substrate; forming an oxide layer on the substrate; forming a P-type semiconductor layer on the substrate; forming an N-type semiconductor layer in the P-type semiconductor layer to constitute the main component region; forming a gate layer on the N-type semiconductor layer, wherein the gate layer may be an oxide material; forming an isolation layer between adjacent N-type semiconductor layers and gate layers; and forming a metal interconnect layer to electrically connect regions of the same electrical properties. Furthermore, the step of (S200) providing a resistive layer on the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device further includes: forming a resistive layer on the gate layer to provide a resistor of appropriate resistance value for current limiting protection. In one embodiment of the present invention, the manufacturing method of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor can follow the above sequence, but is not limited thereto. Any manufacturing method that can produce a similar structure and provide resistive characteristics is a variation of the present invention. In one embodiment, the resistive layer is a low-doped polycrystalline silicon material with a resistive value, and the gate layer is, for example, a high-doped polycrystalline silicon material. In one embodiment, the insulating layer is a borosilicate glass material.

[0041] In one embodiment, the aforementioned P-type semiconductor layer includes a well region, a body region, and a contact region; the N-type semiconductor layer includes a first N-type semiconductor region, a second N-type semiconductor region, a third N-type semiconductor region, and a fourth N-type semiconductor region; wherein the first N-type semiconductor region, the second N-type semiconductor region, and the third N-type semiconductor region are formed in the well region, and the fourth N-type semiconductor region is formed in the body region; a gate layer is formed between the first N-type semiconductor region and the second N-type semiconductor region, and partially covers the first N-type semiconductor region and the second N-type semiconductor region; the isolation layer is formed covering the first N-type semiconductor region, the second N-type semiconductor region, and the gate layer at their adjacent locations, and also forms covering portions of the first N-type semiconductor region, the second N-type semiconductor region, the third N-type semiconductor region, and the fourth N-type semiconductor region. The following description will be supplemented by the structure of another embodiment of the present invention: an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor.

[0042] Figure 4 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device according to an embodiment of the present invention, using a Metal-gate zero-point triggered (ZC) Photo TRIAC as an example; Figure 5 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor according to an embodiment of the present invention, using a Poly-gate Photo TRIAC (ZC) as an example; Figure 6 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor according to an embodiment of the present invention, using a Poly resistor Photo TRIAC (ZC) as an example; Figure 7 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor according to an embodiment of the present invention, using an Implant resistor Photo TRIAC (ZC) as an example; Figure 8 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device according to an embodiment of the present invention, using a Random Phase Triggered (RP) Photo TRIAC as an example; Figure 9 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switch device with a current-limiting resistor according to an embodiment of the present invention, using a Poly resistor Photo TRIAC as an example. TRIAC(RP) is used as an example; Figure 10 shows a schematic diagram of the semiconductor structure configuration of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in an embodiment of the present invention, with Photo TRIAC(RP) of an Implant resistor as an example; Figure 11 shows an equivalent circuit schematic diagram of the semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor in an embodiment of the present invention.

[0043] Please refer to Figure 4, which shows the semiconductor structure 100 of an optically coupled three-terminal bidirectional AC switching device without a specific current-limiting resistor. It includes a substrate 110, for example, an n-substrate (denoted as n-Sub in the figure), and an oxide layer formed on the substrate. A P-type semiconductor layer 120 is formed on the substrate 110. The P-type semiconductor layer 120 may include a well region PW, a body region PB, and a contact region PR, as shown in Figure 4. An N-type semiconductor layer 130 (denoted as N+ in the figure, where N+ indicates high concentration) is formed in the P-type semiconductor layer 120 to constitute the main component region. The N-type semiconductor layer 130 can be divided into a first N-type semiconductor region 131, a second N-type semiconductor region 132, a third N-type semiconductor region 133, and a fourth N-type semiconductor region 134. The first N-type semiconductor region 131, the second N-type semiconductor region 132, and the third N-type semiconductor region 133 are formed in the well region PW, and the fourth N-type semiconductor region 134 is formed in the body region PB. A gate layer 140 is formed on the N-type semiconductor layer 130, between the first N-type semiconductor region 131 and the second N-type semiconductor region 132, and partially covers both regions. The gate layer 140 is an oxide layer; however, it should be noted that this designation is for illustrative purposes, but the oxide material also covers areas shown in Figure 4, such as regions PB, the third N-type semiconductor region 133 and the fourth N-type semiconductor region 134, and the thick oxide Fox formed between the two central NPN transistors. A metal interconnect layer 160 is formed on the gate layer 140 and partially covers it to electrically connect regions with the same electrical properties. The material of the metal interconnect layer 160 is, for example, aluminum (as shown in Figures 4 and 5, AL). T1 and T2 are terminals that can be connected to external terminals. The semiconductor structure 100 of the optically coupled three-terminal bidirectional AC switching device can be achieved by means of the semiconductor structure shown in Figure 4.

[0044] Please refer to Figure 5, which shows the semiconductor structure 200 of an optocoupled three-terminal bidirectional AC switch device with a current-limiting resistor in one embodiment of the present invention. Taking a zero-point triggered optocoupled three-terminal bidirectional AC switch device as an example, the resistor is formed in a polygate manner and can be manufactured by the aforementioned manufacturing method of the optocoupled three-terminal bidirectional AC switch device with a current-limiting resistor. The semiconductor structure 200 of the optocoupled three-terminal bidirectional AC switch device also includes a substrate 110, for example, an n-substrate (represented as n-Sub in the figure), and an oxide layer formed on the substrate. A P-type semiconductor layer 120 is formed on the substrate 110. In one embodiment, the P-type semiconductor layer 120 may include a well region PW, a body region PB, and a contact region PR, as shown in Figure 5. An N-type semiconductor layer 130 (denoted as N+ in the figure, where N+ represents high concentration) is formed within a P-type semiconductor layer 120 to constitute the main component region. In one embodiment, the N-type semiconductor layer 130 can be divided into a first N-type semiconductor region 131, a second N-type semiconductor region 132, a third N-type semiconductor region 133, and a fourth N-type semiconductor region 134, which are different regions. The first N-type semiconductor region 131, the second N-type semiconductor region 132, and the third N-type semiconductor region 133 are formed in the well region PW, and the fourth N-type semiconductor region 134 is formed in the bulk region PB. A gate layer 140 is formed on the N-type semiconductor layer 130. In one embodiment, the gate layer 140 is formed between the first N-type semiconductor region 131 and the second N-type semiconductor region 132, and covers portions of the first N-type semiconductor region 131 and the second N-type semiconductor region 132, respectively. The gate layer 140 is an oxide material. A resistive layer 150 is formed over the gate layer 140. In one embodiment, the resistive layer 150 is formed by forming a material with an appropriate resistance value on the gate layer 140. The resistive layer is a low-doped polycrystalline silicon material with a resistive value, providing resistive characteristics above the gate and serving as current-limiting protection. An isolation layer 145 is formed between adjacent N-type semiconductor layers 130 and the gate layer 140. Specifically, it is formed covering the first N-type semiconductor region 131 and the second N-type semiconductor region 132 adjacent to the gate layer 140 and the resistive layer 150 thereon to provide isolation between the electrode regions. It also forms covering portions of the first N-type semiconductor region 131, the second N-type semiconductor region 132, the third N-type semiconductor region 133, and the fourth N-type semiconductor region 134, as shown in FIG5. In one embodiment, the isolation layer 145 is a borosilicate glass material. In addition, the oxide material of the isolation layer 145 also covers other regions formed as shown in Figure 5, such as the PB region of each body and the thick oxide Fox formed between the two central NPN transistors.A metal interconnect layer 160 is formed above the gate layer 140 and the resistive layer 150 thereon, and covers and connects to each electrical region so that regions with the same electrical properties can be electrically connected to each other. Specifically, the metal interconnect layer 160 above the gate layer 140 and the resistive layer 150 is connected to the metal interconnect layer 160 on the third N-type semiconductor region 133, and the metal interconnect layer 160 of the second N-type semiconductor region 132 is connected to the metal interconnect layer 160 of the fourth N-type semiconductor region 134 and connected to the T1 terminal.

[0045] In other embodiments, such as those shown in Figures 6 and 7, Figure 6 shows a schematic diagram of the semiconductor structure 300 of a zero-crossing (ZC) optocoupled three-terminal bidirectional AC switching device using a Poly resistor as the current-limiting resistor in one embodiment of the present invention; while Figure 7 shows a schematic diagram of the semiconductor structure of a zero-crossing (ZC) optocoupled three-terminal bidirectional AC switching device using an Implant resistor as the current-limiting resistor in one embodiment of the present invention. In Figures 6 and 7, the component symbols or abbreviations that are the same as those in Figures 4 and 5 refer to the same components, materials, etc., and will not be repeated hereafter.

[0046] In one embodiment, the resistive layer 150 of FIG. 6 is formed on the isolation layer 145 or oxide layer in the form of poly resistance, and is connected to other doped electrical regions and externally connected endpoints (as shown in T1 and T2) by a metal interconnect layer 160. By utilizing different doping levels, for example, poly material at low doping concentrations can act as a resistor. For example, between the electrical regions of the first and second endpoint regions in the left and right areas of FIG. 6 and the externally connected endpoints T1 and T2, the resistive layer 150 is disposed between the conductive metal interconnect layer 160 to serve as the resistance of the semiconductor structure itself. It should be noted that the poly resistance can be disposed anywhere on the layout, as long as a similar electrical function is achieved, and is not limited to being formed between the electrical regions of the first and second endpoint regions as shown in FIG. 6.

[0047] In one embodiment, the resistive layer in FIG7 is formed on the substrate 110 or oxide layer by means of implant resistance. Specifically, the resistive layer 150 is formed by embedding a well region PW of a P-type semiconductor layer therein, and a low-concentration N-type semiconductor region (as shown by N-) is formed in the well region PW of the P-type semiconductor layer by means of implantation, and thus serves as a resistor. In this way, between the electrical regions of the first and second endpoint regions on the left and right sides of FIG7, and the externally connected endpoints T1 and T2, the resistive layer 150 is disposed between the conductive metal interconnect layer 160, thereby serving as the resistance of the semiconductor structure itself. It should be noted that the poly resistance can be placed anywhere on the layout, as long as a similar function can be achieved electrically, and is not limited to being formed and disposed between the electrical regions of the first and second endpoint regions as shown in FIG7.

[0048] In other embodiments, such as those shown in Figures 9 and 10, Figure 9 shows a schematic diagram of the semiconductor structure 600 of a random phase-triggered (RP) optically coupled three-terminal bidirectional AC switch device using a poly resistor as a current-limiting resistor in one embodiment of the present invention; while Figure 10 shows a schematic diagram of the semiconductor structure of a random phase-triggered (RP) optically coupled three-terminal bidirectional AC switch device 700 using an implant resistor as a current-limiting resistor in one embodiment of the present invention; and Figure 8 shows a schematic diagram of the structure of a random phase-triggered (RP) optically coupled three-terminal bidirectional AC switch device 500 without a specially provided current-limiting resistor for comparison. In Figures 8 to 10, the component symbols or abbreviations that are the same as those in Figures 4 and 5 refer to the same components, materials, etc., and will not be repeated hereafter.

[0049] In one embodiment, the resistive layer 150 of FIG9 is formed on the isolation layer 145 or oxide layer in the form of poly resistance, and is connected to other doped electrical regions and externally connected endpoints (as shown in T1 and T2) by a metal interconnect layer 160. By varying the doping degree, for example, poly material at low doping concentration can act as a resistor, in the electrical regions of the first and second endpoint regions in FIG9, and between the externally connected endpoints T1 and T2, the resistive layer 150 is disposed between the conductive metal interconnect layer 160 to serve as the resistance of the semiconductor structure itself. It should be noted that the poly resistance can be disposed anywhere on the layout, as long as a similar electrical function can be achieved, and is not limited to being formed and disposed between the electrical regions of the first and second endpoint regions as shown in FIG9.

[0050] In one embodiment, the resistive layer of FIG10 is formed on the substrate 110 or oxide layer by means of implant resistance. Specifically, the resistive layer 150 is formed by embedding a well region PW of a P-type semiconductor layer therein, and a low-concentration N-type semiconductor region (as shown by N-) is formed in the well region PW of the P-type semiconductor layer by means of implantation, and thus serves as a resistor. In this way, between the electrical regions of the first and second endpoint regions on the left and right sides of FIG7, and the externally connected endpoints T1 and T2, the resistive layer 150 is disposed between the conductive metal interconnect layer 160, thereby serving as the resistance of the semiconductor structure itself. It should be noted that the poly resistance can be placed anywhere on the layout, as long as a similar function can be achieved electrically, and is not limited to being formed and disposed between the electrical regions of the first and second endpoint regions as shown in FIG10.

[0051] Please refer to Figures 5 to 10 and 11. For example, the left half of the semiconductor structure 200 of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor shown in Figure 5 has been described exemplarily above. Correspondingly, the semiconductor structure 200 of the optocoupled three-terminal bidirectional AC switching device with current-limiting resistor shown in Figure 5 includes two sets of NPN transistors, which can be connected to the T1 and T2 terminals respectively by the metal interconnect layer 160, which is equivalent to the T1 and T2 terminals shown in Figure 11. In addition, the arrangement of the resistor layer 150 and its related semiconductor structure is equivalent to the equivalent current-limiting resistor R shown in Figure 7, and the circuit element markings of the NPN transistors in Figure 11 are equivalent to the NPN transistor semiconductor structure shown in Figure 6.

[0052] Therefore, through the semiconductor structures shown in Figures 5, 6, 7, 9, and 10, a semiconductor structure 200 of an optocoupled three-terminal bidirectional AC switch device with a current-limiting resistor can be formed, achieving the effect of directly integrating the current-limiting resistor into the optocoupled three-terminal bidirectional AC switch device itself through semiconductor manufacturing process.

[0053] In summary, by employing the manufacturing method and specific structure of this invention, which incorporates a resistive layer into the semiconductor structure of an optocoupled three-terminal bidirectional AC switching device, along with the arrangement of the resistive layer and its structural configuration with surrounding layers (e.g., the configuration of regions of the P-type semiconductor layer and the N-type semiconductor layer, and the relative relationships of the gate layer, resistive layer, and isolation layer), the structure of the optocoupled three-terminal bidirectional AC switching device can be directly integrated with a built-in current-limiting resistor. This provides protection against damage caused by excessive current, eliminating the need for an additional current-limiting resistor in the trigger circuit of the optocoupled three-terminal bidirectional AC switching device. Simultaneously, the characteristics and function of the current-limiting resistor are preserved, resulting in improved overall system integration, space saving, cost reduction, and enhanced applicability. Furthermore, through semiconductor manufacturing processes, without the need for additional external configuration, the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor can be manufactured simultaneously with the optocoupled three-terminal bidirectional AC switching device.

[0054] The present invention has been disclosed above with reference to preferred embodiments. However, those skilled in the art should understand that these embodiments are merely illustrative of the invention and should not be construed as limiting its scope. It should be noted that all variations and substitutions equivalent to these embodiments should be considered within the scope of the present invention, and the above embodiments can be combined and modified in any way. Therefore, the scope of protection of the present invention should be determined by the claims as defined in the patent applications.

[0055] 10: Optically coupled three-terminal bidirectional AC switching device 20: Current-limiting resistor 80: Commonly known optically coupled three-terminal bidirectional AC switching devices 90: Current-limiting resistor 100: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device 110:Substrate 120: P-type semiconductor layer 130: N-type semiconductor layer 131: First N-type semiconductor region 132: Second N-type semiconductor region 133: Third N-type semiconductor region 134: Fourth N-type semiconductor region 140: Gate layer 145: Isolation layer 150: Resistive layer 160: Metal bonding layer 200: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. 300: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. 400: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. 500: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. 600: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. 700: Semiconductor structure of an optically coupled three-terminal bidirectional AC switching device with current-limiting resistor. R: Equivalent current-limiting resistor T1: Endpoint T2: Endpoint S100~S200: Steps S110~S180: Steps S260: Steps

Claims

1. A method for manufacturing an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: providing a semiconductor structure of an optically coupled three-terminal bidirectional AC switching device; and providing a resistive layer in the semiconductor structure of the optically coupled three-terminal bidirectional AC switching device.

2. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 1, wherein, The resistive layer is formed on a gate layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

3. The method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 2, further comprising: Provide a substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; a gate layer is formed on the N-type semiconductor layer; a resistive layer is formed on the gate layer; an isolation layer is formed between adjacent N-type semiconductor layers and the gate layer; and a metal interconnect layer is formed to electrically connect regions of the same electrical properties.

4. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 3, wherein: The P-type semiconductor layer includes a well region, a body region, and a contact region; the N-type semiconductor layer includes a first N-type semiconductor region, a second N-type semiconductor region, a third N-type semiconductor region, and a fourth N-type semiconductor region; the first N-type semiconductor region, the second N-type semiconductor region, and the third N-type semiconductor region are formed in the well region, and the fourth N-type semiconductor region is formed in the body region; the gate layer is formed between the first N-type semiconductor region and the second N-type semiconductor region, and partially covers the first N-type semiconductor region and the second N-type semiconductor region; the isolation layer is formed and covers the first N-type semiconductor region, the second N-type semiconductor region, and the gate layer at their adjacent locations, and is also formed and covers a portion of the first N-type semiconductor region, the second N-type semiconductor region, the third N-type semiconductor region, and the fourth N-type semiconductor region.

5. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 1, wherein, The resistive layer is formed on an isolation layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

6. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 5, further comprising: Provide a substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; a gate layer is formed on the N-type semiconductor layer; an isolation layer is formed, wherein at least a portion of the isolation layer is formed on a first endpoint region and a second endpoint region; a resistive layer is formed on the isolation layer formed on the first endpoint region and the second endpoint region; a metal interconnect layer is formed to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

7. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 5, further comprising: Provide a substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; an isolation layer is formed, wherein at least a portion of the isolation layer is formed in a first endpoint region and a second endpoint region; a resistive layer is formed on the isolation layer formed in the first endpoint region and the second endpoint region; a metal interconnect layer is formed to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

8. A method for manufacturing the optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 1, wherein, The resistive layer is embedded in the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device.

9. A method for manufacturing the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 8, further comprising: Provide a substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; an isolation layer is formed, wherein at least a portion of the isolation layer is formed in a first endpoint region and a second endpoint region; a resistive layer is formed in the first endpoint region and the second endpoint region; a metal interconnect layer is formed to electrically connect the same electrical regions, wherein at least a portion of the metal interconnect layer is formed on the resistive layer.

10. A method for manufacturing the optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 9, further comprising: A well region is formed to form a P-type semiconductor layer; A low-concentration N-type semiconductor region is formed in the well region of the P-type semiconductor layer.

11. A structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: an optically coupled three-terminal bidirectional AC switching device semiconductor structure; and a resistive layer formed within the optically coupled three-terminal bidirectional AC switching device semiconductor structure, wherein, The resistive layer is formed on a gate layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

12. The structure of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 11, further comprising: One substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; an isolation layer is formed between the adjacent N-type semiconductor layer and the gate layer; a metal interconnect layer is formed on the isolation layer and electrically connects the same electrical regions; wherein the gate layer is formed on the N-type semiconductor layer; wherein the resistive layer is formed on the gate layer.

13. The structure of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 12, wherein: The P-type semiconductor layer includes a well region, a body region, and a contact region; the N-type semiconductor layer includes a first N-type semiconductor region, a second N-type semiconductor region, a third N-type semiconductor region, and a fourth N-type semiconductor region; the first N-type semiconductor region, the second N-type semiconductor region, and the third N-type semiconductor region are formed in the well region, and the fourth N-type semiconductor region is formed in the body region; the gate layer is formed between the first N-type semiconductor region and the second N-type semiconductor region, and partially covers the first N-type semiconductor region and the second N-type semiconductor region; the isolation layer is formed and covers the first N-type semiconductor region, the second N-type semiconductor region, and the gate layer at their adjacent locations, and is also formed and covers a portion of the first N-type semiconductor region, the second N-type semiconductor region, the third N-type semiconductor region, and the fourth N-type semiconductor region.

14. A structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: an optically coupled three-terminal bidirectional AC switching device semiconductor structure; and a resistive layer formed within the optically coupled three-terminal bidirectional AC switching device semiconductor structure, wherein, The resistive layer is formed on an isolation layer of the semiconductor structure of the optocoupled three-terminal bidirectional AC switching device, and the resistive layer is a low-doped polycrystalline silicon material.

15. The structure of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 14, further comprising: One substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; a gate layer is formed on the N-type semiconductor layer; a metal interconnect layer, at least a portion of which is formed on the resistive layer and electrically connects the same electrical regions; wherein at least a portion of the isolation layer is formed in a first endpoint region and a second endpoint region; wherein the resistive layer is formed on the isolation layer formed in the first endpoint region and the second endpoint region.

16. The structure of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 14, further comprising: One substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; a metal interconnect layer is formed on the resistive layer, and electrically connects the same electrical regions; wherein at least a portion of the isolation layer is formed in a first endpoint region and a second endpoint region; wherein the resistive layer is formed on the isolation layer formed in the first endpoint region and the second endpoint region.

17. A structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: an optically coupled three-terminal bidirectional AC switching device semiconductor structure; and a resistive layer formed within the optically coupled three-terminal bidirectional AC switching device semiconductor structure, wherein, The resistive layer is embedded in the semiconductor structure of the optocoupled three-terminal bidirectional AC switch device.

18. The structure of the optocoupled three-terminal bidirectional AC switching device with a current-limiting resistor as described in claim 17, further comprising: One substrate; An oxide layer is formed on the substrate; A P-type semiconductor layer is formed on the substrate; An N-type semiconductor layer is formed in the P-type semiconductor layer; an isolation layer is formed at least a portion therein in a first endpoint region and a second endpoint region, wherein the resistive layer is formed in the first endpoint region and the second endpoint region; a metal interconnect layer is formed at least a portion therein on the resistive layer, and electrically connects the same electrical regions.

19. A structure of an optically coupled three-terminal bidirectional AC switching device with a current-limiting resistor, comprising: an optically coupled three-terminal bidirectional AC switching device semiconductor structure; a resistive layer formed in the optically coupled three-terminal bidirectional AC switching device semiconductor structure; a well region of a P-type semiconductor layer; and a low-concentration N-type semiconductor region formed in the well region of the P-type semiconductor layer.

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