Device structure for improving voltage division uniformity of radio frequency device and manufacturing method thereof

Abstract

The invention provides a device structure for improving voltage division uniformity of a radio frequency device. The device structure comprises an SOI substrate; the multi-stage series radio frequency switch device is formed on the SOI substrate; the grounding common resistor is arranged in a metal connecting line path between each level of shunt test structure and the metal bonding pad; the to-ground common resistor is used for blocking a radio frequency signal leakage path. According to the invention, the ground common resistor is arranged to significantly improve the voltage distribution balance of the multi-stage device, and the voltage gradient difference caused by the step-by-step leakage of signals is effectively reduced; the integration scheme of the resistor structure is completely compatible with an existing semiconductor manufacturing process, and additional process steps or the number of layers of photomasks is avoided.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a device structure and manufacturing method for improving the voltage division uniformity of radio frequency devices. Background Technology

[0002] As a core component of the front-end module of a mobile terminal, the design of its multi-stage series structure (such as...) Figure 1 As shown, this directly affects key performance indicators such as radio frequency breakdown voltage (RFBV) and harmonic characteristics. In an SOI substrate architecture, the AC signal of the RF device will leak through substrate coupling. This step-by-step leakage effect leads to uneven voltage distribution within the device, specifically, the voltage drop is largest near the antenna end and attenuates further away (e.g., ...). Figure 2 As shown in the figure, this severely weakens the RFBV performance of the device.

[0003] Existing technologies mainly employ two improvement schemes: Please refer to Figure 3 The first approach compensates for the voltage division near the antenna end by adding a feedforward capacitor, but this requires an additional photomask layer, significantly increasing manufacturing costs; please refer to [link to relevant documentation]. Figure 4 The second approach employs an asymmetric transistor size design (i.e., different width / length ratios), but this disrupts the symmetry of the device structure, leading to deterioration of harmonic characteristics. While both methods improve voltage division uniformity, they negatively impact the linearity of the device, failing to meet the stringent requirements of RF switches in high-frequency applications such as 5G communication. The existing test structure is shown in Figure 5 / 6.

[0004] For example, existing technologies for RF switches with cascaded structures of four or more stages have significant shortcomings in controlling the voltage divider difference. Test data shows that the RFBV difference between the one-stage and four-stage structures reaches 0.4V, which directly leads to a decrease in the device's power handling capability. Furthermore, traditional solutions have limited effectiveness in suppressing signal leakage; simulation data shows that their parasitic capacitance leakage is generally high, severely affecting the quality of high-frequency signal transmission.

[0005] To address the aforementioned issues, a novel device structure manufacturing method is needed to improve the voltage division uniformity of radio frequency devices. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a device structure and manufacturing method for improving the voltage division uniformity of radio frequency devices, in order to solve the problem that the design of multi-stage series structures in the prior art will have a negative impact on the linearity of the device and cannot meet the strict requirements of radio frequency switches for high-frequency application scenarios such as 5G communication.

[0007] To achieve the above and other related objectives, the present invention provides a device structure for improving the voltage division uniformity of radio frequency devices, comprising:

[0008] SOI substrate;

[0009] Multi-stage series radio frequency switching devices formed on the SOI substrate;

[0010] A common ground resistor is set in the metal interconnect path between each shunt test structure and the metal pad.

[0011] The common resistor to ground is used to block the leakage path of radio frequency signals.

[0012] Preferably, the common resistor to ground is located at a secondary position in the metal interconnect path from the shunt test structure to the metal pad.

[0013] Preferably, the resistance value of the common resistor to ground is configured to be 0.1-100kΩ.

[0014] Preferably, the voltage difference between adjacent series-connected radio frequency switching devices is reduced to below 0.2V.

[0015] Preferably, the common resistance to ground is formed by a conductive material layer in a semiconductor manufacturing process, and the conductive material layer and the designated functional layer of the transistor are formed synchronously in the same photomask layer.

[0016] Preferably, the device structure improves the second harmonic performance by 2 to 7 dB while keeping the third harmonic performance unchanged.

[0017] Preferably, the common resistor reduces the radio frequency signal leakage of the parasitic capacitance by 20 to 60 fF.

[0018] The present invention also provides a method for manufacturing the above-mentioned device structure for improving the voltage division uniformity of radio frequency devices, comprising:

[0019] Step 1: Provide an SOI substrate and form a multi-stage series radio frequency switching device on the SOI substrate;

[0020] Step 2: Set a common resistor to ground in the metal interconnect path between the shunt test structure and the metal pad of each device.

[0021] Step 3: Block the leakage path of the radio frequency signal through the common resistor to ground, thereby reducing the voltage difference between the multi-stage series radio frequency switching devices.

[0022] Preferably, the common resistor to ground in step two is located at a secondary position in the metal interconnect path from the shunt test structure to the metal pad.

[0023] Preferably, the resistance value of the common resistor to ground in step two is configured to be 0.1-100kΩ.

[0024] Preferably, the common resistance to ground in step two is formed by a conductive material layer in the semiconductor manufacturing process, and the conductive material layer and the designated functional layer of the transistor are formed synchronously in the same photomask layer.

[0025] Preferably, the voltage difference in step three is reduced to below 0.2V.

[0026] Preferably, the method improves the second harmonic index by 2 to 7 dB while keeping the third harmonic index unchanged.

[0027] Preferably, the device structure manufacturing method for improving the voltage division uniformity of radio frequency devices according to claim 1 is characterized in that: the setting of the common resistor reduces the radio frequency signal leakage of parasitic capacitance by 20 to 60 fF.

[0028] As described above, the device structure and manufacturing method of the present invention for improving the voltage division uniformity of radio frequency devices have the following beneficial effects:

[0029] This invention significantly improves the voltage distribution balance of multi-stage devices by setting a common resistor to ground, effectively reducing voltage gradient differences caused by signal leakage at each stage; the integrated solution of the resistor structure is fully compatible with existing semiconductor manufacturing processes, avoiding the need for additional process steps or photomask layers. Attached Figure Description

[0030] Figure 1 The diagram shows a multi-stage series structure of existing technology.

[0031] Figure 2 This diagram illustrates the existing technology where the voltage division is greatest near the antenna end and attenuates at the far end.

[0032] Figure 3 The diagram shows a prior art technique that compensates for voltage division near the antenna end by adding a feedforward capacitor.

[0033] Figure 4 The diagram shown is a schematic of a prior art transistor size design.

[0034] Figure 5 , 6 The diagram shows a test structure diagram of the prior art;

[0035] Figure 7 The diagram shown is a test structure schematic of the present invention;

[0036] Figure 8 The diagram shows a method for manufacturing a device structure that improves the voltage division uniformity of radio frequency devices according to the present invention. Detailed Implementation

[0037] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0038] This invention provides a device structure for improving the voltage division uniformity of radio frequency devices, comprising:

[0039] An SOI substrate is used to form a multi-stage series radio frequency switching device.

[0040] For example, the multi-level structure includes at least four levels of transistor units connected in series through a copper interconnect layer. The gate width of the unit near the antenna end is the same as that of the unit away from the antenna end, ensuring the geometric symmetry of the device structure.

[0041] A common ground resistor is integrated into the metal interconnect path between each shunt test structure and the metal pad, which is directly connected between the test unit output and the ground node.

[0042] In some embodiments, please refer to Figure 7 The ground common resistor is located at a secondary position in the metal interconnect path from the shunt test structure to the pad. It should be noted that in other implementations, the ground common resistor can also be located at other positions. The ground common resistor is constructed using a conductive material layer in the semiconductor manufacturing process, which is formed synchronously with the designated functional layer of the transistor on the same photomask layer. The resistor structure can be made of polysilicon and formed synchronously with the transistor gate layer, without requiring additional photomask layers.

[0043] In some embodiments, the resistance value of the common resistor to ground is configured to be in the range of 0.1-100kΩ.

[0044] In some embodiments, the device structure improves the second harmonic performance by 2 to 7 dB while keeping the third harmonic performance unchanged.

[0045] Simulation results show that this resistance configuration also reduces parasitic capacitance leakage by 20 to 60 fF, for example, 40 fF.

[0046] Actual test data shows that the voltage difference between adjacent device stages using the 4-stage split structure is stably controlled below 0.2V, and the second harmonic distortion is improved by 5dB.

[0047] Please see Figure 8The present invention also provides a method for manufacturing a device structure that improves the voltage division uniformity of radio frequency devices, comprising:

[0048] Step 1: Provide an SOI substrate and form a multi-stage series RF switching device on the SOI substrate;

[0049] For example, the multi-level structure includes at least four levels of transistor units connected in series through a copper interconnect layer. The gate width of the unit near the antenna end is the same as that of the unit away from the antenna end, ensuring the geometric symmetry of the device structure.

[0050] Step 2: Set a common resistor to ground in the metal interconnect path between the shunt test structure and the metal pad of each device.

[0051] In some embodiments, a common ground resistor is integrated into the metal interconnect path between each shunt test structure and the metal pad, which is directly connected between the test unit output and the ground node.

[0052] In some embodiments, please refer to Figure 7 The ground common resistor is located at a secondary position in the metal interconnect path from the shunt test structure to the pad. It should be noted that in other implementations, the ground common resistor can also be located at other positions. The ground common resistor is constructed using a conductive material layer in the semiconductor manufacturing process, which is formed synchronously with the designated functional layer of the transistor on the same photomask layer. The resistor structure can be made of polysilicon and formed synchronously with the transistor gate layer, without requiring additional photomask layers.

[0053] In some embodiments, the resistance value of the common resistor to ground is configured to be in the range of 0.1-100kΩ.

[0054] Step 3: Block the leakage path of the radio frequency signal by using a common resistor to ground, thereby reducing the voltage difference between multiple series-connected radio frequency switching devices.

[0055] In some embodiments, the device structure improves the second harmonic performance by 2 to 7 dB while keeping the third harmonic performance unchanged.

[0056] Simulation results show that this resistance configuration also reduces parasitic capacitance leakage by 40fF.

[0057] Actual test data shows that the voltage difference between adjacent device stages using the 4-stage split structure is stably controlled below 0.2V, and the second harmonic distortion is improved by 5dB.

[0058] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0059] In summary, this invention significantly improves the voltage distribution uniformity of multi-stage devices by setting a common resistor to ground, effectively reducing voltage gradient differences caused by signal leakage at each stage. The integrated resistor structure is fully compatible with existing semiconductor manufacturing processes, avoiding the need for additional process steps or photomask layers. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial applicability.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A device structure for improving the voltage division uniformity of radio frequency devices, characterized in that, include: SOI substrate; Multi-stage series radio frequency switching devices formed on the SOI substrate; A common ground resistor is set in the metal interconnect path between each shunt test structure and the metal pad. The common resistor to ground is used to block the leakage path of radio frequency signals.

2. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The common ground resistor is located at a secondary position in the metal interconnect path from the shunt test structure to the metal pad.

3. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The resistance value of the common resistor to ground is configured to be 0.1-100kΩ.

4. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The voltage difference between adjacent series-connected RF switching devices is reduced to below 0.2V.

5. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The device structure improves the second harmonic performance by 2 to 7 dB while keeping the third harmonic performance unchanged.

6. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The setting of the common resistor reduces the radio frequency signal leakage of parasitic capacitance by 20 to 60 fF.

7. The device structure for improving the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The ground common resistor is formed by a conductive material layer in the semiconductor manufacturing process, and the conductive material layer and the designated functional layer of the transistor are formed synchronously in the same photomask layer.

8. A method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices, characterized in that, At least including: Step 1: Provide an SOI substrate and form a multi-stage series radio frequency switching device on the SOI substrate; Step 2: Set a common resistor to ground in the metal interconnect path between the shunt test structure and the metal pad of each device. Step 3: Block the leakage path of the radio frequency signal through the common resistor to ground, thereby reducing the voltage difference between the multi-stage series radio frequency switching devices.

9. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 8, characterized in that: The common resistor to ground mentioned in step two is set at a secondary position in the metal interconnect path from the shunt test structure to the metal pad.

10. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 8, characterized in that: The resistance value of the common resistor to ground in step two is configured to be 0.1-100kΩ.

11. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 8, characterized in that: The common resistance to ground mentioned in step two is formed by a conductive material layer in the semiconductor manufacturing process. The conductive material layer and the designated functional layer of the transistor are formed synchronously in the same photomask layer.

12. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 8, characterized in that: The voltage difference in step three is reduced to below 0.2V.

13. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 8, characterized in that: The method improves the second harmonic index by 2 to 7 dB while keeping the third harmonic index unchanged.

14. The method for manufacturing a device structure to improve the voltage division uniformity of radio frequency devices according to claim 1, characterized in that: The setting of the common resistor reduces the radio frequency signal leakage of parasitic capacitance by 20 to 60 fF.

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