Compact capacitor, resistor parallel structure for use in mmic
By employing a compact parallel capacitor and resistor structure in a monolithic microwave integrated circuit and using an air bridge to connect the thin film resistor and the metal layer, the coupling effect and loss problems at high frequencies are solved, thus achieving the stability and miniaturization of the MMIC.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF SEMICONDUCTORS - CHINESE ACAD OF SCI
- Filing Date
- 2021-11-12
- Publication Date
- 2026-06-05
AI Technical Summary
In existing monolithic microwave integrated circuits, the transmission lines of passive devices exhibit severe coupling effects and losses at high frequencies, affecting the stability and performance of the circuit.
By employing a compact parallel capacitor and resistor structure, and connecting it to the thin film resistor and metal layer via an air bridge, the use of transmission lines is reduced, coupling effects and losses are decreased, and circuit stability is improved.
This achieves high-frequency stability and miniaturization of the MMIC, reduces coupling effects and losses between transmission lines, and improves the overall performance and flexibility of the circuit.
Smart Images
Figure CN114121930B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of monolithic microwave integrated circuits, and more particularly to a compact capacitor-resistor parallel structure for use in MMICs. Background Technology
[0002] Monolithic microwave integrated circuits (MMICs) are integrated circuits with specific functions formed by directly fabricating active and passive devices and interconnecting microstrip lines on semiconductor substrates such as silicon, gallium arsenide, or gallium nitride using semiconductor integrated circuit fabrication technology. Integrating multiple functional circuits on a single chip reduces costs and, due to the use of internal matching circuits, minimizes the impact of external parasitic effects, thus largely maintaining and improving the performance of millimeter-wave frequency band circuits.
[0003] In monolithic microwave integrated circuits, passive devices realize the matching of MMIC circuits, provide bias voltage, and have the functions of phase shifting and filtering. The passive components commonly used in circuits are: microstrip lines, MIM capacitors, and thin film resistors. Microstrip lines are used as interconnect transmission lines for MMIC circuits to realize the connection between components. In actual impedance matching, the corresponding impedance value can be achieved by adjusting the width and length of the microstrip lines. MIM capacitors adopt the traditional parallel capacitor plate structure, which can achieve a large capacitance value with a small area. They are simple in structure, easy to integrate, and reduce the influence of parasitic inductance and RF loss. They are mainly used for matching networks and bias circuits, playing the roles of matching, filtering, and DC blocking. Since thin film resistors have accurate resistance values and high stability, their main functions in MMICs include: (1) stabilizing the circuit network and improving the stability of devices and circuits; (2) removing the influence from the RF network in the bias circuit; and (3) participating in matching. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] This disclosure provides a compact capacitor-resistor parallel structure for use in MMICs to solve the aforementioned technical problems.
[0006] (II) Technical Solution
[0007] According to one aspect of this disclosure, a compact capacitor-resistor parallel structure for use in an MMIC is provided, comprising:
[0008] Thin-film resistors are fabricated on a substrate.
[0009] A first metal layer is fabricated on the substrate, and the first end of the thin film resistor is connected to the first metal layer;
[0010] A dielectric layer is fabricated on the first metal layer and the thin-film resistor;
[0011] A second metal layer is formed on the dielectric layer;
[0012] An air bridge is provided, with its first end connected to the second end of the thin-film resistor and its second end connected to the second metal layer.
[0013] In some embodiments of this disclosure, the air bridge includes:
[0014] A first air bridge metal layer, one end of which is connected to the second end of the thin film resistor;
[0015] A conductive via is disposed within the dielectric layer, and one end of the conductive via is electrically connected to the other end of the first air bridge metal layer.
[0016] The second air bridge metal layer has one end connected to the other end of the conductive via, and the other end of the second air bridge metal layer is connected to the second metal layer.
[0017] In some embodiments of this disclosure, the thin-film resistor has metal contact pads at both ends, and the thickness of the thin-film resistor is 0.01 μm-10 μm.
[0018] In some embodiments of this disclosure, the dielectric layer is made of one or more of silicon nitride and silicon dioxide; the thickness of the dielectric layer is 0.01 μm-1 μm.
[0019] In some embodiments of this disclosure, the thickness of the first metal layer is 0.01 μm-10 μm; the thickness of the second metal layer is 1-10 μm.
[0020] According to one aspect of this disclosure, a compact capacitor-resistor parallel structure for use in an MMIC is provided, comprising:
[0021] The first metal layer is fabricated on the substrate;
[0022] A dielectric layer is fabricated on the first metal layer;
[0023] A second metal layer is formed on the dielectric layer;
[0024] A thin-film resistor is fabricated on the dielectric layer, and a first end of the thin-film resistor is connected to the second metal layer;
[0025] An air bridge is provided, with its first end connected to the second end of the thin-film resistor and its second end connected to the first metal layer.
[0026] In some embodiments of this disclosure, the air bridge includes:
[0027] A third air bridge metal layer, one end of which is connected to the second end of the thin film resistor;
[0028] A conductive via is provided in the dielectric layer, and one end of the conductive via is electrically connected to the other end of the third air bridge metal layer;
[0029] A fourth air bridge metal layer, one end of which is electrically connected to the other end of the conductive via, and the other end of which is connected to the first metal layer.
[0030] In some embodiments of this disclosure, the thin-film resistor has metal contact pads at both ends, and the thickness of the thin-film resistor is 0.01 μm-10 μm.
[0031] In some embodiments of this disclosure, the dielectric layer is made of one or more of silicon nitride and silicon dioxide; the thickness of the dielectric layer is 0.01 μm-1 μm.
[0032] In some embodiments of this disclosure, the thickness of the first metal layer is 0.01 μm-10 μm; the thickness of the second metal layer is 1-10 μm.
[0033] (III) Beneficial Effects
[0034] As can be seen from the above technical solution, the compact capacitor and resistor parallel structure disclosed herein applied in MMIC has at least one or a portion of the following beneficial effects:
[0035] (1) The compact capacitor and resistor parallel structure provided in this disclosure reduces the use of transmission lines, can reduce the coupling effect between transmission lines at high frequencies, and the loss caused by the skin effect, improve the overall circuit performance, and ensure the stability and reliability of the circuit at high frequencies.
[0036] (2) Due to the greatly reduced spacing between capacitors and resistors, the overall area of the MMIC is miniaturized, while the circuit layout is more flexible and the overall performance of the MMIC is improved.
[0037] (3) This disclosure uses an air bridge to connect with a resistor, which reduces the influence of parasitic parameters, and the parasitic parameters can be adjusted by adjusting the height of the air bridge. Attached Figure Description
[0038] Figure 1 This is a schematic diagram of a compact capacitor and resistor parallel structure used in an MMIC according to an embodiment of the present disclosure.
[0039] Figure 2 This is a top cross-sectional top view of a compact capacitor and resistor parallel structure used in an MMIC according to an embodiment of the present disclosure.
[0040] [Explanation of key component symbols in the accompanying drawings of this disclosure embodiment]
[0041] 1-Thin film resistor;
[0042] 2-MIM capacitors;
[0043] 21 - First metal layer;
[0044] 22-Dielectric layer;
[0045] 23 - Second metal layer;
[0046] 3-Air bridge;
[0047] 31 - First air bridge metal layer;
[0048] 32-Conductive via;
[0049] 33 - Second air bridge metal layer. Detailed Implementation
[0050] This disclosure provides a compact capacitor-resistor parallel structure for use in MMIC, comprising: a thin film resistor, a first metal layer, a dielectric layer, a second metal layer, and an air bridge; the thin film resistor and the first metal layer are respectively fabricated on a substrate, and a first end of the thin film resistor is connected to the first metal layer; the dielectric layer is fabricated on the first metal layer and the thin film resistor; the second metal layer is fabricated on the dielectric layer; a first end of the air bridge is connected to a second end of the thin film resistor, and a second end of the air bridge is connected to the second metal layer.
[0051] The parallel capacitor and resistor structure disclosed herein has a significant impact on the overall circuit performance. For example, connecting a capacitor in series before the gate of each active device can reduce the gate capacitance of the device, increase the cutoff frequency of the gate transmission line, and significantly improve the stability of the circuit. Simultaneously, the parallel resistor acts as a biasing element. Using the parallel capacitor and resistor structure in the matching network can reduce the quality factor of the matching network, expand the bandwidth, compensate for the gain roll-off of the device with frequency, increase inter-stage isolation, and improve the stability of the circuit.
[0052] With increasing demands for miniaturization of MMICs, it is necessary to reduce the physical size and spacing of passive components. However, when MMICs operate at millimeter-wave frequencies or even higher, excessively dense microstrip lines can cause severe coupling effects, significantly degrading high-frequency performance. Furthermore, the skin effect at high frequencies increases signal loss during transmission. Therefore, to ensure both miniaturization and high performance of MMICs, it is necessary to reduce the length of transmission lines.
[0053] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.
[0054] Certain embodiments of this disclosure will be described more fully below with reference to the accompanying drawings, some of which, but not all, will be shown. In fact, various embodiments of this disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable this disclosure to meet applicable legal requirements.
[0055] In a first exemplary embodiment of this disclosure, a compact capacitor-resistor parallel structure is provided for use in an MMIC. Figure 1 This is a schematic diagram of a compact capacitor and resistor parallel structure used in an MMIC according to an embodiment of the present disclosure. Figure 2 This is a top cross-sectional top view of a compact capacitor-resistor parallel structure used in an embodiment of the present disclosure in an MMIC. Figure 1 , Figure 2 As shown, the compact capacitor-resistor parallel structure disclosed herein for use in MMIC includes: a thin-film resistor 1, a first metal layer 21, a dielectric layer 22, a second metal layer 23, and an air bridge 3; the thin-film resistor 1 and the first metal layer 21 are respectively fabricated on a substrate, and the first end of the thin-film resistor 1 is connected to the first metal layer 21; the dielectric layer 22 is fabricated on the first metal layer 21 and the thin-film resistor 1; the second metal layer 23 is fabricated on the dielectric layer 22; the first end of the air bridge 3 is connected to the second end of the thin-film resistor 1, and the second end of the air bridge 3 is connected to the second metal layer 23.
[0056] In this embodiment, the MIM capacitor 2 includes a first metal layer 21, a dielectric layer 22, and a second metal layer 23. Since there is an insulating dielectric between the first metal layer 21 and the second metal layer 23, an air bridge 3 containing a conductive via 32 is used to connect the first metal layer 21 and the second metal layer 23, thereby realizing the parallel connection of the resistor and the capacitor.
[0057] The following is a detailed description of the air bridge 3 used in the compact capacitor-resistor parallel structure of this embodiment. The air bridge 3 includes: a first air bridge metal layer 31, a conductive via 32, and a second air bridge metal layer 33. The first air bridge metal layer 31 is disposed in the same layer as and connected to the second end of the thin-film resistor 1. The second air bridge metal layer 33 is disposed in the same layer as and connected to the second metal layer 23. The conductive via 32 is disposed within the dielectric layer 22, with its lower end connected to the first air bridge metal layer 31 and its upper end connected to the second air bridge metal layer 33.
[0058] In some embodiments of this disclosure, the material selection and manufacturing specifications of the first air bridge metal layer 31 may be similar to or the same as those of the first metal layer 21.
[0059] In some embodiments of this disclosure, the material selection and manufacturing specifications of the second air bridge metal layer 33 may be similar to or the same as those of the second metal layer 23.
[0060] In some embodiments of this disclosure, the thin-film resistor 1 has metal contact pads at both ends, and the thickness of the thin-film resistor 1 can be 0.01μm-10μm.
[0061] In some embodiments of this disclosure, the capacitor may be a capacitor using a metal-insulator-metal (MIM) architecture. The material of the dielectric layer 22, serving as the insulator, may be one or more of silicon nitride (SiN) and silicon dioxide (SiO2). The thickness of the dielectric layer 22 may be 0.01 μm to 1 μm.
[0062] In some embodiments of this disclosure, the thickness of the first metal layer 21 can be 0.01 μm-10 μm; the thickness of the second metal layer 23 can be 1-10 μm.
[0063] In a second exemplary embodiment of this disclosure, a compact capacitor-resistor parallel structure for use in a MMIC is provided. Compared with the compact capacitor-resistor parallel structure for use in a MMIC in the first embodiment, the difference in this embodiment is that the thin-film resistor 1 is not fabricated on a substrate, but on a dielectric layer, that is, it is disposed as the same layer as the second metal layer.
[0064] The structure of the corresponding air bridge will be adjusted. In this embodiment, the air bridge includes: a third air bridge metal layer, a conductive via, and a fourth air bridge metal layer. The third air bridge metal layer is disposed in the same layer as and connected to the second end of the thin film resistor. The fourth air bridge metal layer is disposed in the same layer as and connected to the first metal layer. The conductive via is disposed within the dielectric layer, with its lower end connected to the fourth air bridge metal layer and its upper end connected to the third air bridge metal layer.
[0065] For the purpose of brevity, any technical features described in Embodiment 1 that can be applied in the same way are included here, and there is no need to repeat the same description.
[0066] The embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. It should be noted that implementations not illustrated or described in the drawings or the main text of the specification are forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the various elements and methods described above are not limited to the specific structures, shapes, or methods mentioned in the embodiments, and those skilled in the art can easily modify or substitute them.
[0067] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.
[0068] Furthermore, the shapes and dimensions of the components in the figures do not reflect actual size and proportion, but are merely illustrative of embodiments of this disclosure. Additionally, any reference numerals placed between parentheses in the claims should not be construed as limiting the scope of the claims.
[0069] Unless otherwise stated, the numerical parameters in this specification and the appended claims are approximate values and can be varied according to desired characteristics derived from the content of this disclosure. Specifically, all figures used in the specification and claims to indicate composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Generally, this means that a specific amount varies by ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments.
[0070] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.
[0071] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not imply that the element has any ordinal number, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a named element to be clearly distinguished from another element with the same name.
[0072] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof. However, this approach to disclosure should not be construed as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the aspects of the disclosure consist of fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the disclosure.
[0073] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.
Claims
1. A compact capacitor-resistor parallel structure for use in MMICs, comprising: Thin-film resistors are fabricated on a substrate. A first metal layer is fabricated on the substrate, and the first end of the thin film resistor is connected to the first metal layer; A dielectric layer is fabricated on the first metal layer and the thin-film resistor; A second metal layer is formed on the dielectric layer; An air bridge, wherein a first end of the air bridge is connected to a second end of the thin film resistor, and a second end of the air bridge is connected to the second metal layer; The air bridge includes: A first air bridge metal layer, one end of which is connected to the second end of the thin film resistor; A conductive via is disposed within the dielectric layer, and one end of the conductive via is electrically connected to the other end of the first air bridge metal layer. The second air bridge metal layer has one end connected to the other end of the conductive via, and the other end of the second air bridge metal layer is connected to the second metal layer.
2. The compact capacitor-resistor parallel structure applied in MMIC according to claim 1, wherein, The thin-film resistor has metal contact pads at both ends, and the thickness of the thin-film resistor is 0.01μm-10μm.
3. The compact capacitor-resistor parallel structure applied in MMIC according to claim 1, wherein, The dielectric layer is made of one or more of silicon nitride and silicon dioxide; the thickness of the dielectric layer is 0.01 μm-1 μm.
4. The compact capacitor-resistor parallel structure applied in MMIC according to claim 1, wherein, The thickness of the first metal layer is 0.01 μm-10 μm; the thickness of the second metal layer is 1-10 μm.
5. A compact capacitor-resistor parallel structure for use in MMICs, comprising: The first metal layer is fabricated on the substrate; A dielectric layer is fabricated on the first metal layer; A second metal layer is formed on the dielectric layer; A thin-film resistor is fabricated on the dielectric layer, and a first end of the thin-film resistor is connected to the second metal layer; An air bridge, wherein the first end of the air bridge is connected to the second end of the thin film resistor, and the second end of the air bridge is connected to the first metal layer; The air bridge includes: A third air bridge metal layer, one end of which is connected to the second end of the thin film resistor; A conductive via is provided in the dielectric layer, and one end of the conductive via is electrically connected to the other end of the third air bridge metal layer; A fourth air bridge metal layer, one end of which is electrically connected to the other end of the conductive via, and the other end of which is connected to the first metal layer.
6. The compact capacitor-resistor parallel structure applied in MMIC according to claim 5, wherein, The thin-film resistor has metal contact pads at both ends, and the thickness of the thin-film resistor is 0.01μm-10μm.
7. The compact capacitor-resistor parallel structure applied in MMIC according to claim 5, wherein, The dielectric layer is made of one or more of silicon nitride and silicon dioxide; the thickness of the dielectric layer is 0.01 μm-1 μm.
8. The compact capacitor-resistor parallel structure applied in MMIC according to claim 5, wherein, The thickness of the first metal layer is 0.01 μm-10 μm; the thickness of the second metal layer is 1-10 μm.