In-situ wireless photomask temperature sensor

Abstract

The application provides an in-situ wireless photomask temperature measuring sensor for measuring the temperature of a photomask (1), characterized in that at least comprising: a photomask (1) integrated with one or more temperature sensors (3); a temperature data processing module (5) connected with and communicating with the temperature sensor (3) to collect the temperature data of the temperature sensor (3); and a battery (6) for providing power to at least the processing module (5). The sensor provided by the application can wirelessly monitor the temperature distribution of the photomask, the shape of the sensor is consistent with that of a common photomask, the sensor can be transferred to a semiconductor chip processing position by a mechanical hand, and wireless temperature measurement can be performed in-situ in an actual process.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor equipment, specifically to the field of semiconductor photomask inspection and temperature measurement technology, and particularly relates to a photomask temperature sensor, especially an in-situ wireless photomask temperature sensor, which can be used to measure the temperature distribution of semiconductor processing equipment. Background Technology

[0002] In semiconductor chip manufacturing, the temperature uniformity of the photomask surface is extremely important, requiring strict temperature measurement and control. With advancements in semiconductor chip manufacturing processes, temperature control requirements in photolithography have reached the mk level, or one-thousandth of a degree Celsius. Accurately measuring the temperature of the photomask is a significant challenge.

[0003] Existing in-situ wired wafer temperature sensors, as described in patents US6190040 and US6915589, use temperature sensors such as thermocouples or resistance temperature detectors as temperature sensing elements, or embed them in blind vias on the wafer, or directly attach them to the wafer with high-temperature resistant adhesives, and then transmit the temperature sensor signal to the outside through wires.

[0004] In the photolithography process, the photomask is in a strong magnetic field environment and moves back and forth at a high speed with an acceleration of several Gs, which is difficult to achieve with traditional lead wire temperature measurement methods.

[0005] To address the quality and cost issues of existing in-situ wired photomask temperature sensors, a novel in-situ wireless photomask temperature sensor is needed. Summary of the Invention

[0006] To address the quality issues and ineffective application problems of existing in-situ wired photomask temperature sensors, this invention provides an in-situ wireless photomask temperature sensor for measuring the temperature of a photomask 1. The sensor comprises at least: a photomask 1, on which one or more temperature sensors 3 are integrated; a temperature data processing module 5, for connecting and communicating with the temperature sensors 3 to collect temperature data from the temperature sensors 3; and a battery 6, for providing power to at least the processing module 5.

[0007] Preferably, the photomask 1 has blind holes, the height and size of which are matched with the temperature sensor 3, the processing module 5, or the battery 6, so that one or more of the temperature sensor 3, the processing module 5, and the battery 6 are placed inside the blind holes.

[0008] Preferably, the blind hole is manufactured using any of the following methods:

[0009] -Dry etching;

[0010] -Wet etching;

[0011] - Laser grooving; or

[0012] - Precision machining technology.

[0013] Preferably, the processing module 5 directly transmits the temperature data to the host computer or is equipped with a memory for storing the temperature data.

[0014] Preferably, the processing module 5 includes a processor 9 and a wireless module 8. The processor 9 is used to control temperature acquisition and the wireless module 8, and the wireless module 8 is used to perform wireless communication and / or wireless charging of the battery 6.

[0015] Preferably, the sensor further includes a flexible circuit board 2, which is disposed on the photomask 1, and the wires inside the flexible circuit board 2 are used to connect the temperature sensor 3 to the circuit of the processing module 5, and to connect the processing module 5 to the circuit of the battery 6.

[0016] Preferably, the thickness of the flexible circuit board 2 is 0.1 to 0.2 mm.

[0017] Preferably, the flexible circuit board 2 has any of the following shapes:

[0018] - A complete circuit board with the same shape as the photomask 1;

[0019] - Cross-shaped;

[0020] - Square shape.

[0021] Preferably, the sensor further includes a photomask box 10, and a controller 11 is disposed inside the photomask box 10. The controller 11 is used to transmit data with the processing module 5.

[0022] Preferably, the sensor further includes a transmission interface, which is connected to the processing module 5 for data communication, and the controller 11 is connected to the transmission interface via a spring electrode for data communication.

[0023] Preferably, the power supply 6 is disposed within the photomask box 10.

[0024] Preferably, the photomask box 10 is further provided with one or more of the following devices on the side or top of its outer shell:

[0025] - A connection port for wired charging of the photomask box 10 and / or transmission of the temperature data;

[0026] - Switch 13, the switch 13 being used to control the activation and deactivation of the photomask box 10; and

[0027] - Display 14, wherein the display 14 is any one of liquid crystal display, digital tube, and LED.

[0028] Preferably, the connection port is any one of USB, DB, SCSI, LEMO, or Ethernet interface.

[0029] Preferably, the temperature sensor 3 is composed of any one or more of the following: a thermocouple temperature sensor, a resistance temperature sensor, or a temperature measuring chip.

[0030] Preferably, the photomask 1 is made of quartz, borosilicate glass or soda glass.

[0031] Preferably, the photomask 1 has a size of 3 inches to 6 inches.

[0032] Compared to existing solutions, this invention provides a wireless photomask temperature measurement system that can wirelessly monitor the temperature distribution of the photomask. The photomask sensor has the same shape as a regular photomask and can be transported to the semiconductor chip processing location by a robotic arm for in-situ wireless temperature measurement. The measured temperature data can be transmitted to a host computer in real time, or stored in a module built into the photomask under electromagnetic shielding and strong electromagnetic interference environments, and then transmitted to the host computer after the test is completed and the photomask is retrieved. Compared to existing temperature sensors, this system can obtain temperature data on the photomask in-situ, wirelessly, and in real time, providing a direct and convenient temperature reference for the photolithography process, allowing engineers to adjust technical parameters and improve process yield. Attached Figure Description

[0033] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1A , Figure 1B The top view and side view of an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention are shown respectively.

[0035] Figure 2 A schematic diagram of a processing module in an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention is shown.

[0036] Figure 3A , Figure 3B The diagrams and side views of the photomask box in an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention are shown respectively.

[0037] Figure 4 Shows a schematic diagram of the working process of an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention.

[0038] Label description:

[0039] 1. Photomask; 2. Flexible circuit board;

[0040] 3. Temperature sensor; 4. Wire;

[0041] 5. Processing module; 6. Battery;

[0042] 7. Antenna; 8. Wireless module;

[0043] 9. Processor; 10. Photomask cassette;

[0044] 11. Controller; 12. Connection port;

[0045] 13. Switch; 14. Display;

[0046] 15. Connecting wire. Specific embodiment

[0047] Those skilled in the art understand that the technical problem to be solved by the present invention is to propose an in-situ wireless photomask temperature sensor for the design defects of the existing in-situ photomask temperature sensor pointed out in the background technology.

[0048] Specifically, Figure 1A 、 Figure 1B Respectively show a top view and a side view of an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention. Among them Figure 1A is the top view, Figure 1B is the side view. The in-situ wireless photomask temperature sensor includes a photomask 1, a flexible circuit board 2, a temperature sensor 3, a processing module 5, and a battery 6. The wire 4 in the flexible circuit board 2 serves as an electrical circuit to connect the circuits of the temperature sensor 3 and the processing module 5, and the circuits of the processing module 5 and the battery 6. Preferably, the thickness of the flexible circuit board is 0.1-0.2 mm, and the material can be selected as polyimide. The shape of the flexible board can be a whole piece the same as the surface of the photomask, or can be designed into any shape according to the circuit routing. For example, in a variant, the flexible board is in the shape of a "cross" or a "square", and such variants are all within the protection scope of the present invention.

[0049] The photomask 1, as a raw material for semiconductor processing and manufacturing, can be made of materials such as quartz, borosilicate glass, and soda ash glass; variations in these materials are all within the scope of protection of this invention. Furthermore, the size of the photomask 1 is preferably between 3 and 6 inches, and in some applications, it can exceed this size range; these variations are all within the scope of protection of this invention. The shape of the photomask 1 is preferably square, but it can also be circular, elliptical, triangular, rectangular, etc.; these variations are all within the scope of protection of this invention. Preferably, the surface of the photomask 1 can be uncoated, single-sided chrome-plated, or double-sided chrome-plated; these variations are all within the scope of protection of this invention. In the technical solution provided by this invention, the photomask 1 is the object to be measured, and the temperature sensor 3 is used to measure its temperature.

[0050] The photomask 1 has blind holes, preferably with dimensions matching the temperature sensor, processing module, and battery. For example, preferably, the depth of the blind hole is slightly larger than the height of the temperature sensor, processing module, and battery, such as 0.01 mm larger. Preferably, the temperature sensor, processing module, and battery are all placed within the blind holes of the photomask. The blind holes can be fabricated using dry or wet etching, laser grooving, or precision machining.

[0051] Preferably, the temperature sensor 2 can be any of the following: resistive temperature detector (RTD), thermocouple (TC), or temperature sensing chip (IC). The RTD can be a thermistor with a negative temperature coefficient (NTC) or a platinum resistance thermometer with a positive temperature coefficient (PTC), depending on the specific circumstances. These variations are all within the protection scope of this invention.

[0052] The number of temperature sensors 3 can be [number missing]. Figure 1A The 16 shown could also be other numbers, such as 1, 9, or 64; in other variations, the number of temperature sensors 3 could be 4, 6, 12, etc. The distribution of the temperature sensors 3 can also be arbitrary, or a relatively uniform distribution can be made according to the number of temperature sensors 3, so that the temperature sensors 3 can contact as many different positions of the photomask 1 as possible. These variations are all within the protection scope of this invention.

[0053] Preferably, the battery 6 can be a lithium battery or a rechargeable button battery, etc. When the sensor provided by this invention is working, the battery 6 provides power to the processing module 5 and the temperature sensor 3.

[0054] Preferably, the processing module 5 is used to collect and store the temperature data of the temperature sensor 3, and transmit it to the host computer wirelessly. Figure 1A(Not shown in the image). Preferably, the processing module 5 includes a processor 9 and a wireless module 8 circuit. The processor 9 is used to store and run programs, and to control temperature acquisition and control the wireless module 8. Preferably, the wireless module 8 includes wireless communication and wireless charging. The wireless communication method used by the wireless module 8 can be Bluetooth, WiFi, ZigBee, Near Field Communication (NFC), etc. Similar variations are within the scope of protection of this invention and will not be described further.

[0055] Figure 2 A schematic diagram of a processing module 5 in an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention is shown. The processing module 5 may be composed of a flexible printed circuit board (FPC), or two rigid printed circuit boards (PCBs) and an FPC, wherein preferably the FPC serves as a flexible, bendable connecting wire to connect the two PCBs. The wireless module 8 and the processor 9 are located in... Figure 2 On the circular PCB or FPC shown, there is another antenna 7 on another PCB or FPC, which is connected to the wireless module 8 via the FPC. Preferably, the PCB or FPC containing the antenna 7 can be folded onto the PCB or FPC containing the wireless module and the processor, thus reducing the area occupied by the processing module 5 on the photomask 1.

[0056] Preferably, a magnetic isolation sheet or shielding film may be provided between the antenna 7 and the wireless module 8 and the processor 9 to protect the wireless module 8 and the processor 9.

[0057] Preferably, the antenna 7 can be drawn on a flexible circuit board or use an external coil. Multiple antennas 7 can be provided, and can be used for wireless charging or as wireless communication antennas, such as Bluetooth or WiFi antennas. The antenna 7 can also be placed directly on the back of the circuit boards of the wireless module 8 and the processor 9, thus constituting another variation in antenna arrangement and reducing area; these variations are all within the protection scope of this invention.

[0058] Figure 3A , Figure 3B The diagram shows a schematic and a side view of the photomask box 10 in an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention, wherein the left side... Figure 3A This is an overall schematic diagram of the photomask box 10, with the right side showing... Figure 3B This is a side view of the photomask box 10.

[0059] Preferably, the photomask box 10 has the same external dimensions as a conventional photomask box, i.e., preferably the same external shape, which facilitates the use of the in-situ wireless photomask temperature sensor provided by the present invention in the production system. Furthermore, those skilled in the art will understand that the photomask box provided by the present invention has a controller 11 internally configured, which can... Figure 1A , Figure 1B The in-situ wireless photomask temperature sensor shown can be used for data transmission or charging. Data transmission and charging between the controller 11 and the in-situ wireless photomask temperature sensor can be wireless or wired. Preferably, when using a wired connection, the in-situ wireless photomask temperature sensor has a transmission interface, such as a signal output terminal on the flexible plate 2. The controller 11 inside the photomask housing 10 can connect to the transmission interface of the in-situ wireless photomask temperature sensor provided by this invention using a connector such as a spring electrode, thereby transmitting data or charging.

[0060] Preferably, a battery is optionally provided inside the photomask box 10 to provide power to the controller 11.

[0061] Preferably, the photomask cassette 10 has a connection port 12, a switch 13, and a display 14 on its outer shell, which can be placed on the side or top of the photomask cassette 10; these variations are all within the scope of protection of this invention. The connection port 12, switch 13, and display 14 are preferably connected to the controller 11 via a connecting cable 15.

[0062] Furthermore, preferably, the connection port 12 is used to charge the photomask box 10 in a wired manner and transmit temperature data. It can use interfaces such as USB, DB, SCSI, LEMO, and Ethernet. These variations are all within the protection scope of this invention.

[0063] Furthermore, preferably, the switch 13 is used to control the start and stop of the photomask box 10, that is, to control the start and stop of the in-situ wireless photomask temperature sensor provided by the present invention.

[0064] Furthermore, the display 14 is used to display the operating status of the photomask box 10, and can be an LCD screen, digital tube, LED, etc.

[0065] Furthermore, the in-situ wireless photomask temperature sensor also includes a host computer (not shown in Figure 3). The host computer communicates wirelessly with the wireless module 8 within the processing module 5 of the in-situ wireless photomask temperature sensor, or communicates with the photomask box 10 via wireless / wired means. The host computer can be an industrial control computer or a regular computer, and it contains a control program corresponding to the in-situ wireless photomask temperature sensor. When the host computer communicates with or charges the photomask box 10 via a wired connection, it can be connected to the photomask box 10 through the connection port 12.

[0066] Figure 4 This diagram illustrates the workflow of an in-situ wireless photomask temperature sensor according to a specific embodiment of the present invention. First, in step S1, the photomask temperature measurement device is started and powered on. Then, in step S2, the operating mode is selected; online mode proceeds to step S3, and offline mode proceeds to step S8. If step S3 is entered, the robotic arm transfers the photomask sensor to the process node requiring temperature measurement, such as a photolithography exposure stage or a photoresist spin coater. Then, in step S4, the host computer sends a wireless signal to notify the photomask sensor to begin measurement, awaiting the test results. Then, in step S5, after the photomask sensor completes the measurement, it wirelessly transmits the results to the host computer. Finally, in step S6, the test is completed, the robotic arm retrieves the photomask sensor, and the device is powered off.

[0067] If the process proceeds to step S7, the delay start-up time of the photomask sensor is set on the host computer, or the start-up trigger condition, such as the start-up temperature, is set, and the recording time interval and duration are set.

[0068] Then, in step S8, the robot arm transfers the photomask sensor to the process node where temperature measurement is required.

[0069] Then proceed to step S9, where the delay start-up time of the photomask sensor ends or the start-up condition is triggered, and the photomask sensor begins measurement.

[0070] Then proceed to step S10, where the photomask sensor measurement time ends, the robotic arm retrieves the photomask sensor and sends the measurement results back to the host computer, and then shuts down.

[0071] Furthermore,

[0072] The in-situ wireless photomask temperature sensor integrates multiple temperature sensors, a temperature data processing module circuit, and a battery on a photomask. The photomask serves as the substrate supporting the sensors, is the object being measured, and is also the photomask used in semiconductor photolithography. Its materials include quartz, borosilicate glass, and soda ash glass. Its size varies from 3 to 6 inches. It is square in shape and has surfaces with no coating, single-sided chrome plating, or double-sided chrome plating.

[0073] Blind vias are formed on the photomask, with the via dimensions matched to the temperature sensor, processing module, and battery. The temperature sensor, processing module, and battery are all housed within the blind vias of the photomask. Blind via fabrication can be performed using dry or wet etching, laser grooving, or precision machining.

[0074] The temperature sensor is a device used to measure the temperature of a wafer, and can be a thermocouple (TC), a resistance temperature detector (RTD), a temperature sensing chip (IC), or other temperature sensors.

[0075] The processing module is used to collect and store temperature data from the temperature sensor and wirelessly transmit it to the host computer. It includes a processor and a wireless module circuit. The processor stores and runs programs, controlling the temperature acquisition and wireless module. The wireless module includes wireless communication and wireless charging capabilities. Wireless communication methods include Bluetooth, WiFi, ZigBee, and NFC (Near Field Communication).

[0076] The battery powers the processing module and accepts wireless charging from the wireless module. The battery can be a lithium battery or a rechargeable button cell battery.

[0077] A flexible board is placed on top of the photomask. The wires inside the flexible board are used to connect the temperature sensor to the processing module circuitry, and the processing module to the battery circuitry. The flexible board is 0.1–0.2 mm thick and can be made of polyimide. The flexible board can be a single sheet identical to the photomask surface, or it can be designed into any shape according to the circuit routing.

[0078] The in-situ wireless photomask temperature sensor also includes a photomask housing, which has the same external dimensions as a standard photomask housing, but contains a controller that can transmit data with the photomask sensor or charge it. Data transmission and charging between the controller and the photomask sensor can be wireless or wired. In the wired configuration, the photomask sensor has a transmission interface, and the controller inside the photomask housing can connect to this interface using spring electrodes.

[0079] The photomask box may optionally include a battery to power it.

[0080] The photomask housing also has connectors, switches, and displays, which can be placed on the side or top of the box.

[0081] The connector is used for wired charging of the photomask box and transmission of temperature data, and can be used with interfaces such as USB, DB, SCSI, LEMO, and Ethernet.

[0082] The switch is used to control the start and stop of the photomask box.

[0083] The display is used to show the operating status of the photomask box, and can be an LCD screen, digital tube, LED, etc.

[0084] The in-situ wireless photomask temperature sensor also includes a host computer. The host computer communicates wirelessly with the wireless module within the photomask processing module, or communicates with the photomask box via wireless / wired connection. The host computer can be an industrial computer or a PC.

[0085] The in-situ wireless photomask temperature sensor can operate in two modes: online and offline. In online mode, the photomask sensor wirelessly transmits temperature data to the host computer in real time. In offline mode, the photomask sensor collects temperature data and then wirelessly transmits the data to the host computer. Users can set the start-up delay, running time, and sampling interval.

[0086] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. An in-situ wireless photomask temperature sensor for measuring the temperature of a photomask (1), characterized in that, At least including: A photomask (1) has multiple blind holes on its surface; Flexible circuit board (2), the flexible circuit board (2) is disposed on the photomask (1); Multiple temperature sensors (3) are embedded in blind holes whose height and size match those of the temperature sensors (3) for in-situ measurement of the temperature of the photomask (1); A temperature data processing module (5) is embedded in a blind hole whose height and size match the temperature data processing module (5) for connecting and communicating with the temperature sensor (3) and collecting temperature data from the temperature sensor (3); and A battery (6) is embedded in a blind hole whose height and size match that of the battery (6) for providing power to at least the processing module (5); The wires inside the flexible circuit board (2) are used to connect the temperature sensor (3) to the circuit of the processing module (5) and to connect the processing module (5) to the circuit of the battery (6). The processing module (5) includes a processor (9) and a wireless module (8). The processor (9) is used to control temperature acquisition and the wireless module (8). The wireless module (8) is used to perform wireless communication and / or wireless charging of the battery (6). The processing module (5) is composed of two rigid printed circuit boards (PCBs) and a flexible circuit board (FPC). The FPC is used as a flexible bendable connecting line to connect the two PCBs. The wireless module (8) and the processor (9) are located on one of the PCBs. There is also an antenna (7) on the other PCB. The PCB where the antenna (7) is located can be folded onto the PCB where the wireless module and the processor are located.

2. The sensor according to claim 1, characterized in that, The blind hole is manufactured using any of the following methods: -Dry etching; -Wet etching; - Laser grooving; or - Precision machining technology.

3. The sensor according to claim 1 or 2, characterized in that, The processing module (5) directly transmits the temperature data to the host computer or has a memory for storing the temperature data.

4. The sensor according to claim 1, characterized in that, The thickness of the flexible circuit board (2) is 0.1 to 0.2 mm.

5. The sensor according to claim 1, characterized in that, The flexible circuit board (2) has any of the following shapes: - A whole circuit board with the same shape as the photomask (1); - Cross-shaped; - Square shape.

6. The sensor according to claim 1 or 2, characterized in that, It also includes a photomask box (10), in which a controller (11) is provided, and the controller (11) is used to transmit data with the processing module (5).

7. The sensor according to claim 6, characterized in that, It also includes a transmission interface, which is connected to the processing module (5) for data communication, and the controller (11) is connected to the transmission interface via a spring electrode for data communication.

8. The sensor according to claim 7, characterized in that, The battery (6) is disposed inside the photomask box (10).

9. The sensor according to claim 7 or 8, characterized in that, The photomask box (10) is further provided with one or more of the following devices on its outer side or top: - A connection port for charging the photomask box (10) and / or transmitting the temperature data in a wired manner; - Switch (13), the switch (13) is used to control the start and stop of the photomask box (10); as well as - Display (14), wherein the display (14) is any one of liquid crystal display, digital tube, and LED.

10. The sensor according to claim 9, characterized in that, The connection port is any one of USB, DB, SCSI, LEMO, or Ethernet interfaces.

11. The sensor according to claim 1 or 2, characterized in that, The temperature sensor (3) is composed of any one or more of the following: thermocouple temperature sensor, resistance temperature sensor, or temperature measuring chip.

12. The sensor according to claim 1 or 2, characterized in that, The photomask (1) is made of quartz, borosilicate glass or soda glass.

13. The sensor according to claim 1 or 2, characterized in that, The photomask (1) is 3 to 6 inches in size.

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