Parallel structure capacitors and their fault repair methods

Abstract

This invention relates to a parallel-structure capacitor and its fault repair method. In the parallel-structure capacitor, at least one capacitor branch has a variable resistor connected in series with the capacitor unit. The variable resistor comprises a phase change material. The resistance of the variable resistor increases when the phase change material changes from a crystalline state to an amorphous state. When a short-circuit fault occurs in a capacitor branch with a variable resistor, the resistance can be increased by changing the phase change material from a crystalline state to an amorphous state, thereby changing the short-circuit state of the corresponding capacitor branch and achieving fault repair. Furthermore, the variable resistor does not require additional substrate area, eliminating the need for metal fuses, avoiding cumbersome manufacturing processes, and preventing impacts on product design and miniaturization, thus contributing to improved product yield and production efficiency. The fault repair method for the parallel-structure capacitor provided by this invention has similar advantages to the aforementioned parallel-structure capacitor.

Description

Technical Field

[0001] This invention relates to the field of capacitors, and more particularly to a parallel structure capacitor and a fault repair method for a parallel structure capacitor. Background Technology

[0002] Compared to ordinary capacitors, parallel capacitors offer advantages such as increased capacitance, improved filtering, enhanced circuit stability, reduced line losses, and reduced harmonics. However, because multiple capacitor branches are connected in parallel, a short circuit in any of these branches can cause the entire parallel capacitor structure to fail, resulting in a lower product yield.

[0003] To improve product yield and enable parallel capacitors to continue operating when some branches are short-circuited, existing technologies incorporate metal fuses (such as one-time programmable memories) into each parallel capacitor branch. When a branch is short-circuited, the corresponding metal fuse is burned out to shield the faulty branch for repair. However, the metal fuse has a complex structure, a complicated manufacturing process, and requires a large substrate area, which affects product design and miniaturization. Summary of the Invention

[0004] In order to repair parallel structure capacitors when short circuits occur in some branches, improve product yield, and avoid cumbersome manufacturing processes, product design and miniaturization, this invention provides a parallel structure capacitor and a fault repair method for a parallel structure capacitor.

[0005] On one hand, the present invention provides a parallel structure capacitor, the parallel structure capacitor including at least two capacitor branches arranged in parallel, each capacitor branch having a capacitor unit, wherein at least one capacitor branch also has a variable resistor connected in series with the capacitor unit, the variable resistor including a phase change material, the variable resistor increasing in resistance when the phase change material changes from a crystalline state to an amorphous state.

[0006] Optionally, in the at least two capacitor branches, each capacitor branch has a variable resistor connected in series with the corresponding capacitor unit.

[0007] Optionally, in the capacitor branch provided with the variable resistor, the capacitor unit includes a first plate and a second plate; wherein the variable resistor is disposed on one side of the first plate and / or one side of the second plate.

[0008] Optionally, the parallel structure capacitor is an on-chip capacitor.

[0009] Optionally, the parallel capacitor structure includes:

[0010] A capacitor unit includes a first electrode plate, a capacitor dielectric layer, and a second electrode plate formed on a substrate.

[0011] An interlayer dielectric layer covers the capacitor unit;

[0012] At least one first contact plug is formed in the interlayer dielectric layer and connected to the first electrode plate;

[0013] At least one second contact plug is formed in the interlayer dielectric layer and connected to the second electrode plate;

[0014] An electrode connection pad layer is formed in the interlayer dielectric layer, the electrode connection pad layer including a connecting pad that connects the at least one first contact plug and the at least one second contact plug respectively.

[0015] Optionally, in the electrode connection pad layer, at least one of the connection pads includes the variable resistor.

[0016] Optionally, the capacitor unit is a MIM capacitor or a PIP capacitor.

[0017] On the other hand, the present invention provides a fault repair method for the above-mentioned parallel structure capacitor. The fault repair method includes: applying a DC voltage across the capacitor branch where a short-circuit fault occurs, causing the resistance of the variable resistor to increase due to the phase change material therein changing from a crystalline state to an amorphous state, and detecting the resistance across the capacitor branch where a short-circuit fault occurs, so that the resistance across the capacitor branch where a short-circuit fault occurs is greater than a set value.

[0018] Optionally, the DC voltage is a DC pulse.

[0019] Optionally, the parallel structure capacitor is used to transmit AC signals. In the parallel structure capacitor, the capacitor branches other than the capacitor branch that has experienced a short-circuit fault form a parallel capacitor impedance when transmitting AC signals of the target frequency. The set value is greater than or equal to the parallel capacitor impedance.

[0020] In the parallel structure capacitor provided by this invention, at least one of the capacitor branches has a variable resistor connected in series with the capacitor unit. The variable resistor comprises a phase change material. The resistance of the variable resistor increases when the phase change material changes from a crystalline state to an amorphous state. When a short-circuit fault occurs in the capacitor branch with the variable resistor, the resistance of the variable resistor can be increased by changing the phase change material from a crystalline state to an amorphous state, thereby changing the short-circuit state of the corresponding capacitor branch and achieving fault repair. The variable resistor can be formed in the region of the capacitor unit without occupying additional substrate area. The parallel structure capacitor eliminates the need for metal fuses, avoiding cumbersome manufacturing processes, preventing impact on product design and miniaturization, and helping to improve product yield and production efficiency. The fault repair method for the parallel structure capacitor provided by this invention has similar advantages to the above-mentioned parallel structure capacitor. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the circuit structure of a parallel capacitor according to an embodiment of the present invention.

[0022] Figure 2 This is a partial cross-sectional schematic diagram of a parallel structure capacitor formed on a substrate in one embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a short-circuit fault occurring in part of the capacitor branch of a parallel capacitor in one embodiment of the present invention.

[0024] Figure 4 Yes Figure 3 The diagram shows a fault repair procedure for a parallel capacitor structure. Detailed Implementation

[0025] The parallel structure capacitor and its fault repair method of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be understood that the drawings in this specification are all in a very simplified form and use non-precise scales, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. It should be noted that the order of the steps in the method presented herein is not necessarily the only order in which these steps are performed; some steps may be omitted and / or some other steps not described herein may be added to the method. It should be understood that spatial relative terms are intended to include different orientations in use or operation other than the orientation of the device as depicted in the figures. For example, if the structure in the figures is inverted or otherwise positioned (e.g., rotated), the exemplary term "on" may also include "below" and other orientational relationships.

[0026] Figure 1The circuit structure of a parallel capacitor according to an embodiment of the present invention is shown. (Refer to...) Figure 1 According to an embodiment of the present invention, the parallel structure capacitor 100 includes at least two capacitor branches connected in parallel, each of the capacitor branches having a capacitor unit Cx (e.g., ...). Figure 1 The capacitor units C1~C4 shown are provided, wherein at least one of the capacitor branches also has a variable resistor (e.g., a variable resistor connected in series with the capacitor unit Cx) Figure 1 The variable resistors R1~R4 are shown.

[0027] The variable resistor can be set in some or all of the capacitor branches as needed. For example... Figure 1 As shown, as an example, each capacitor branch of the parallel capacitor 100 has a variable resistor connected in series with the corresponding capacitor unit Cx. The parallel capacitor 100 can transmit electrical signals; one end of the parallel capacitor 100 is connected to both the input and output signals, and the other end is grounded.

[0028] In this embodiment of the invention, the variable resistor in the parallel capacitor 100 includes a phase change material (PCM). The PCM refers to a material capable of undergoing a phase change within a specific temperature range. The resistance increases when the PCM changes from a crystalline to an amorphous state; that is, the resistance of the variable resistor can be changed through the phase change process of the PCM. Utilizing this variable resistor, when a short-circuit fault occurs in the capacitor branch with the variable resistor, the parallel capacitor 100 can increase the resistance by causing the PCM to change from a crystalline to an amorphous state, thereby changing the short-circuit state of the corresponding capacitor branch and achieving fault repair.

[0029] The position of the variable resistor in the capacitor branch can be set as needed. In some embodiments, in the capacitor branch where the variable resistor is provided, the capacitor unit Cx includes a first plate and a second plate, and the variable resistor is disposed on one side of the first plate, and / or, the variable resistor is disposed on one side of the second plate. Figure 1 As shown, as an example, the first plate of the capacitor unit Cx in each capacitor branch is grounded, the second plate is opposite to the first plate, and the variable resistor is set on one side of the second plate of the corresponding capacitor unit Cx.

[0030] The aforementioned parallel capacitor 100 is, for example, an on-chip capacitor, which is a capacitor integrated within an integrated circuit using integrated circuit manufacturing processes. On-chip capacitors offer advantages such as reduced circuit board area, reduced electromagnetic interference, and improved system performance, contributing to higher integration and better performance.

[0031] Each capacitor branch in the aforementioned parallel capacitor 100 is integrated, for example, on a substrate. The substrate can be any material used to form semiconductor devices, such as a silicon substrate. Based on this substrate, only the parallel capacitor 100 can be formed, or other components can be formed in addition to the parallel capacitor 100. The capacitor unit Cx of each capacitor branch can be a MIM (metal-dielectric-metal) capacitor or a PIP (polysilicon-dielectric-polysilicon) capacitor. The capacitor unit Cx can also be a parallel plate capacitor, a trench capacitor, or other types of capacitors.

[0032] Figure 2 A partial cross-sectional structure of a parallel capacitor 100 formed on a substrate in one embodiment is shown. (Refer to...) Figure 2 In one embodiment, the capacitor branch of the parallel structure capacitor 100 includes a capacitor unit Cx formed on a substrate 10. The substrate 10 has a trench TR. An isolation layer 11 covers the surface of the substrate 10 and the inner wall of the trench TR. The capacitor unit Cx includes a first electrode 12 with the isolation layer 11 formed on the substrate 10 and the inner wall of the trench TR, a capacitor dielectric layer 13 formed on the surface of the first electrode 12, and a second electrode 14 formed on the surface of the capacitor dielectric layer 13.

[0033] like Figure 2 As shown, the parallel capacitor 100 may further include an interlayer dielectric layer 15 (e.g., including silicon oxide) covering the capacitor unit Cx, at least one first contact plug 15a, at least one second contact plug 15b, and a plate connecting pad layer 16; the first contact plug 15a is formed in the interlayer dielectric layer 15 and connected to the first plate 12, the second contact plug 15b is formed in the interlayer dielectric layer 15 and connected to the second plate 14, and the plate connecting pad layer 16 is formed in the interlayer dielectric layer 15, for example, on the surface of the interlayer dielectric layer 15, and includes connecting pads that respectively connect the first contact plug 15a and the second contact plug 15b. The connecting pads are used to connect the first plate 12 and the second plate 14 of the capacitor unit Cx to external signals.

[0034] As an example, the aforementioned variable resistor, provided on the capacitor branch of the parallel structure capacitor 100, is located at the connecting pad. In the plate connecting pad layer 16, at least one of the connecting pads includes a variable resistor (Rx). Optionally, each of the connecting pads is provided with the variable resistor. For example, the plate connecting pad layer 16 includes a phase change material layer 161 and a metal layer 162 stacked on the surface of the phase change material layer 161, and each of the connecting pads includes a portion of the phase change material layer 161 and a portion of the metal layer 162 located on the phase change material layer 161. The invention is not limited thereto; for example, in some embodiments, a phase change material layer may be formed on the surface of the first plate 12 and / or the second plate 14 to serve as the variable resistor.

[0035] In the parallel capacitor 100 described in the above embodiments, at least a portion of the capacitor branches are provided with a variable resistor connected in series with the capacitor unit Cx. When a short-circuit fault occurs in a capacitor branch with the variable resistor, the resistance value of the variable resistor can be increased by changing the phase change material in the variable resistor from a crystalline state to an amorphous state, thereby changing the short-circuit state of the corresponding capacitor branch and achieving fault repair. Additionally, as... Figure 2 As shown, the variable resistor can be formed in the region of the capacitor unit Cx without occupying an additional substrate area 10. It will not have a significant adverse impact on the structure, process, and design of the product containing the parallel structure capacitor 100. The parallel structure capacitor 100 can eliminate the need for metal fuses, which helps to avoid cumbersome manufacturing processes, avoid affecting product design and miniaturization, and help improve product yield and production efficiency.

[0036] This invention also relates to a fault repair method for a parallel structure capacitor, wherein the parallel structure capacitor for fault repair is the parallel structure capacitor 100 described in the above embodiments.

[0037] According to an embodiment of the present invention, a fault repair method for a parallel capacitor includes: applying a DC voltage across the capacitor branch where a short-circuit fault occurs, causing the resistance of the variable resistor to increase due to the phase change material therein changing from a crystalline state to an amorphous state, and detecting the impedance across the capacitor branch where the short-circuit fault occurs, so that the resistance across the capacitor branch where the short-circuit fault occurs is greater than a set value.

[0038] For example, when the parallel capacitor 100 fails during factory testing or use after leaving the factory, fault information can be obtained through testing. When a short-circuit fault occurs, further detection can be used to obtain information about the specific capacitor branch where the short circuit occurred. In some embodiments, it may not be necessary to detect information about the specific capacitor branch where the short circuit occurred. As an example, see [reference needed]. Figure 1 and Figure 3 If the first capacitor branch L1, located on the far left of the circuit in the parallel capacitor 100, is short-circuited, while the other capacitor branches are normal, the short circuit of the first capacitor branch L1 will cause the other capacitor branches to also be unable to work properly because the capacitor branches are connected in parallel.

[0039] Reference Figure 4 During fault repair, a DC voltage is applied to the capacitor branch experiencing a short circuit fault, such as the first capacitor branch L1. Since the capacitor branches are connected in parallel, this DC voltage can be applied to the parallel nodes of each capacitor branch. However, this is not the only possibility. In some embodiments, a switch can be provided between the capacitor branches, allowing the voltage to be applied only to the capacitor branch experiencing the short circuit fault, as needed. Optionally, the DC voltage is a DC pulse. The peak voltage and pulse width of the DC pulse can be adjusted as needed.

[0040] Under the influence of the DC voltage, current flows through the capacitor branch that experienced a short circuit fault, such as the first capacitor branch L1. The phase change material in the variable resistor on the first capacitor branch L1 gradually changes from a crystalline state to an amorphous state under the thermal effect of the current, simultaneously increasing its resistance. Consequently, the resistance of the variable resistor increases from R1 to R1' (R1'>R1). The resistance across the first capacitor branch L1 becomes, for example, equal to the resistance of the variable resistor. Because the resistance of the variable resistor increases, the resistance of the corresponding capacitor branch also increases, and it is no longer in a short-circuit state. By increasing the resistance of the variable resistor to a value greater than a set value, the impact of the short-circuit fault on the normal operation of other capacitor branches (those that experienced a short circuit fault) is minimal, allowing them to operate normally.

[0041] The aforementioned parallel capacitor structure 100, for example, includes M capacitor branches, of which N capacitor branches experienced short-circuit faults and were repaired using the method described above. M and N are positive integers, with M being greater than N. After repair, the total capacitance of the remaining (MN) capacitor branches is (MN)*C, where C is the capacitance of each capacitor branch's capacitor unit.

[0042] As an example, the parallel capacitor 100 described above is used to transmit AC signals during operation. For the repaired parallel capacitor 100, the (MN) capacitor branches other than the N capacitor branches that experienced short-circuit faults can form a parallel capacitor impedance when transmitting AC signals during operation. When the signal input to the parallel capacitor 100 is an AC signal, as the frequency of the AC signal increases, the capacitor units Cx in these (MN) capacitor branches begin to charge and discharge, and current flows through them. As the frequency of the AC signal continues to increase, the parallel capacitor impedance gradually decreases. Furthermore, as the frequency of the AC signal increases, the parallel capacitor impedance can gradually decrease to a level close to the impedance state of the N capacitor branches that experienced short-circuit faults. Therefore, as the frequency of the AC signal gradually increases, the influence of the N capacitor branches that experienced short-circuit faults gradually decreases. When the parallel capacitor impedance formed by the (MN) capacitor branches is less than the resistance value of the N capacitor branches that experienced short-circuit faults, the influence of the N capacitor branches can be ignored, and the (MN) capacitor branches return to normal operation. In some embodiments, when the resistance value of the variable resistor is increased to a value greater than a set value using the above-described fault repair method, the set value can be set according to the target AC signal frequency when the (MN) capacitor branches are working normally. For example, if the parallel capacitor impedance formed when the (MN) capacitor branches are working normally at the target AC signal frequency is Rb, then the set value is set to be greater than or equal to Rb. In this way, when the (MN) capacitor branches are working normally at the target AC signal frequency, the corresponding parallel capacitor impedance Rb is less than the current resistance value of the N capacitor branches that have experienced short-circuit faults, and is therefore basically unaffected by the N capacitor branches.

[0043] Using the fault repair method for parallel structure capacitors described in the above embodiments, a parallel structure capacitor 100 with short-circuit faults in N capacitor branches can be repaired. After repair, the parallel structure capacitor 100 can be regarded as a parallel circuit of (MN) capacitor branches and can still be used as a capacitor, which helps to improve product yield.

[0044] It should be noted that the embodiments in this specification are described in a progressive manner, with each part focusing on the differences from other embodiments, and relevant parts can be understood by referring to them.

[0045] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A parallel-connected capacitor, characterized in that, The parallel structure capacitor includes at least two capacitor branches arranged in parallel, each capacitor branch having a capacitor unit. At least one capacitor branch also has a variable resistor connected in series with the capacitor unit. The variable resistor includes a phase change material. The resistance of the variable resistor increases when the phase change material changes from a crystalline state to an amorphous state. For a capacitor branch with the variable resistor, when the capacitor unit is short-circuited, the impact of the short circuit on the normal operation of capacitor branches other than the capacitor branch where the short circuit occurred is reduced by increasing the resistance of the variable resistor to a value greater than a set value.

2. The parallel structure capacitor as described in claim 1, characterized in that, In the at least two capacitor branches, each capacitor branch has a variable resistor connected in series with the corresponding capacitor unit.

3. The parallel structure capacitor as described in claim 1, characterized in that, In the capacitor branch equipped with the variable resistor, the capacitor unit includes a first plate and a second plate; wherein the variable resistor is disposed on one side of the first plate and / or one side of the second plate.

4. The parallel structure capacitor as described in claim 1, characterized in that, The parallel structure capacitor is an on-chip capacitor.

5. The parallel-connected capacitor as described in any one of claims 1 to 4, characterized in that, include: A capacitor unit includes a first electrode plate, a capacitor dielectric layer, and a second electrode plate formed on a substrate. An interlayer dielectric layer covers the capacitor unit; At least one first contact plug is formed in the interlayer dielectric layer and connected to the first electrode plate; At least one second contact plug is formed in the interlayer dielectric layer and connected to the second electrode plate; An electrode connection pad is formed in the interlayer dielectric layer, the electrode connection pad including a connecting pad that connects the at least one first contact plug and the at least one second contact plug respectively.

6. The parallel structure capacitor as described in claim 5, characterized in that, In the electrode connection pad layer, at least one of the connection pads includes the variable resistor.

7. The parallel-structure capacitor as described in any one of claims 1 to 4, characterized in that, The capacitor unit is a MIM capacitor or a PIP capacitor.

8. A method for repairing faults in a parallel-connected capacitor as described in any one of claims 1 to 7, characterized in that, The fault repair method includes: A DC voltage is applied across the capacitor branch where a short-circuit fault occurs, causing the resistance of the variable resistor to increase as the phase change material therein changes from a crystalline to an amorphous state. The resistance across the capacitor branch where the short-circuit fault occurs is detected, and the resistance across the capacitor branch where the short-circuit fault occurs is made greater than a set value, so as to reduce the impact of the short-circuit fault on the normal operation of capacitor branches other than the capacitor branch where the short-circuit fault occurred.

9. The fault repair method as described in claim 8, characterized in that, The DC voltage is a DC pulse.

10. The fault repair method as described in claim 8 or 9, characterized in that, The parallel structure capacitor is used to transmit AC signals. In the parallel structure capacitor, the capacitor branches other than the capacitor branch that has experienced a short circuit fault form a parallel capacitor impedance when transmitting AC signals of the target frequency. The set value is greater than or equal to the parallel capacitor impedance.

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