CN-121994404-A - Capacitive film vacuum gauge and method for measuring gas pressure

Abstract

The embodiment of the application discloses a capacitive film vacuum gauge and a method for measuring gas pressure, which comprises a mobile sealing system, a ceramic electrode, a guide structure, a film electrode and a control system, wherein in the use process, when measuring different process gas pressures, the control system sets corresponding polar plate distances according to a measuring range, selects a capacitive data processing mode according to the process gas pressure, opens a measuring range port, selects a corresponding measuring range according to the process gas pressure, the control system controls the power source of the movable sealing system to adjust the height of the ceramic electrode, so that the distance between the ceramic electrode and the film electrode is changed, high-precision measurement of gas pressure of each pressure section is realized.

Inventors

• LIU RUIQI
• YUAN YAN
• LI CHAOBO
• ZHANG XINQIANG
• SU TAO
• GAO CHENXI
• XU YAHUI
• SUN XIAOMENG
• LIN LIN
• ZHANG SHA
• ZHENG XU

Assignees

• 中国科学院微电子研究所

Dates

Publication Date

20260508

Application Date

20241106

Claims (10)

1. 1. A capacitive film vacuum gauge, comprising: The movable sealing system comprises a power source, and the movable sealing system realizes the ascending and descending of the output end through the power source; The ceramic electrode is connected to the output end of the movable sealing system, and the ceramic electrode is driven by the movable sealing system to realize axial displacement; The guide structure is communicated with the movable sealing system, the ceramic electrode is connected with the guide structure, and the guide structure limits the movement of the ceramic electrode; the thin film electrode is arranged inside the guide structure; And the control system is electrically connected with the movable sealing system and is used for controlling the movable sealing system. The guide structure comprises two support rings, wherein one support ring is arranged between the membrane electrode and the ceramic electrode, the other support ring is arranged on one side of the ceramic electrode, which is away from the membrane electrode, and the support rings are made of compressible materials.
2. 2. The capacitive thin film vacuum gauge of claim 1, wherein the mobile sealing system further comprises: The connecting rod is connected to the guide structure in a sleeved mode, and the ceramic electrode is movably connected to one end of the connecting rod sleeved guide structure; The sealing ring is arranged at the joint of the connecting rod and the guide structure and has an axial movement function; The power source is arranged at the other end of the connecting rod, and the power source drives the connecting rod to ascend or descend.
3. 3. The capacitive thin film vacuum gauge of claim 1, wherein the ceramic electrode comprises: The movable sealing system drives the linkage end to adjust the distance between the ceramic electrode and the thin film electrode; the electrode end is disc-shaped and is connected to the other end of the linkage end.
4. 4. A capacitive film vacuum gauge according to claim 3, wherein the guide structure comprises: the thin film electrode is arranged on one side of the mounting cavity close to the bottom surface, and the top surface of the mounting cavity is provided with a connecting hole; One end of the connecting pipe is communicated with the cavity of the mounting cavity through a connecting hole, and the other end of the connecting pipe is sleeved with the movable sealing system; the electrode end of the ceramic electrode is arranged in the mounting cavity; The linkage end of the ceramic electrode stretches into one end of the connecting pipe connected with the mounting cavity.
5. 5. The capacitive thin film vacuum gauge of claim 4, wherein: the section of the support ring is Z-shaped, the support ring comprises an upper support surface, a lower support surface and a support inclined surface, the upper edge of the support inclined surface is connected with the inner ring of the upper support surface, and the lower edge of the support inclined surface is connected with the outer ring of the lower support surface; The side of the inside of installation cavity is equipped with annular rectangle installation step, the raised surface of annular rectangle installation step conflict in the outer loop side of supporting ring.
6. 6. The capacitive thin film vacuum gauge of claim 5, wherein: The periphery of the electrode end of the ceramic electrode is provided with a first annular bulge, the thickness of the first annular bulge is smaller than that of the electrode end of the ceramic electrode, the first annular bulge is abutted to the upper part/lower part of the supporting ring, and the periphery of the electrode end of the ceramic electrode is abutted to the inner ring side of the supporting ring; The side wall of the mounting cavity is provided with a plurality of movable sliding grooves; guide blocks are arranged on the periphery of the first annular bulge of the ceramic electrode at intervals, and correspond to and fit with the movable sliding groove.
7. 7. The capacitive thin film vacuum gauge of claim 5, wherein: a plurality of air holes are formed in the support ring at intervals; The support ring is formed by one-time processing.
8. 8. The capacitive thin film vacuum gauge of claim 4, wherein the guide structure further comprises: the air suction assembly is arranged in the mounting cavity and is used for exhausting the cavity of the mounting cavity; the airflow channel is arranged on the side wall of the inner part of the installation cavity and is communicated with the air suction component.
9. 9. The capacitive thin film vacuum gauge of claim 1, wherein the control system comprises: The number of the detectors is two, and the intervals between the ceramic electrodes and the thin film electrodes at different positions are respectively monitored; the number of the first signal eductors is two, and the first signal eductors are respectively and electrically connected with the two detectors; The number of the second signal extractors is two, and the second signal extractors are respectively connected with the ceramic electrode and are used for extracting capacitance data of the ceramic electrode; the central processing unit is electrically connected with the first signal extractor and the second signal extractor.
10. 10. A method of measuring gas pressure applied to a capacitive thin film vacuum gauge as claimed in any one of claims 1 to 9, comprising: The control system sets the corresponding distance between the ceramic electrode and the thin film electrode and the capacitance data processing mode according to the measuring range, and the measuring range port is selected in an open mode; The control system selects a corresponding measuring range according to the pressure of the process gas; The movable sealing system automatically adjusts the distance between the ceramic electrode and the thin film electrode according to the measuring range; and the control system recovers the capacitance data and processes the capacitance data by using a corresponding capacitance data processing mode.

Description

Capacitive film vacuum gauge and method for measuring gas pressure Technical Field The embodiment of the application relates to the technical field of semiconductors, in particular to a capacitive film vacuum gauge and a method for measuring gas pressure. Background The principle of the capacitance film vacuum gauge is that a strain diaphragm is used as one electrode, a ceramic substrate forms a conductive film layer as another electrode, when the strain diaphragm is subjected to pressure difference to generate displacement, the capacitance between the diaphragm and the ceramic electrode is changed, and the pressure is measured by measuring the capacitance change. Because of the characteristics that the measurement result of the capacitance film type vacuum gauge is irrelevant to the component types of the measured gas, the capacitance film type vacuum gauge has wide application in the field of vacuum measurement, in particular in the semiconductor industry, and is a key part of process equipment. As can be seen from the capacitance formula c=aεr εo/d (where a is the electrode corresponding area, εr is the relative permittivity of the material, εo is the vacuum permittivity, and d is the bipolar plate spacing), the capacitance value is mainly dependent on the d value with the electrode area and permittivity fixed. The d value in the existing structure is regulated by installing one or more gaskets with different shapes and thicknesses, so that fine adjustment of the electrode spacing in the micron-scale range is realized, and the structure is limited by the fact that the capacitance thin film type vacuum gauge is divided into 0.1Torr, 1Torr, 10Torr, 100Torr and 1000Torr according to the measurement schedule, and the capacitance thin film type vacuum gauge with one specification cannot cover high-precision measurement of pressure in the range of 0.1-1000 Torr. Meanwhile, the measurement precision and stability of the capacitive film vacuum gauge depend on the processing precision of the micron level of the gasket, the processing difficulty and error of the micron level gasket are high, the zero point adjustment difficulty of high-precision vacuum measurement is increased by the error, nonlinear errors are generated, and the pressure measurement precision and stability are directly affected. In particular to the semiconductor industry, the process size is nano-scale, the capacitor film vacuum gauge is used as a key part of process equipment, the requirements on the measurement precision, sensitivity and stability of the capacitor film vacuum gauge are higher, the measurement precision and stability of the capacitor film vacuum gauge are influenced by the gasket structure, and the improvement of the measurement performance of the capacitor film vacuum gauge is limited. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art or related art. To this end, a first aspect of the invention provides a capacitive thin film vacuum gauge. A second aspect of the invention provides a method of measuring gas pressure. In view of this, a first aspect of an embodiment of the present application provides a capacitive thin film vacuum gauge, including: The movable sealing system comprises a power source, and the movable sealing system realizes the ascending and descending of the output end through the power source; The ceramic electrode is connected to the output end of the movable sealing system, and the ceramic electrode is driven by the movable sealing system to realize axial displacement; The guide structure is communicated with the movable sealing system, the ceramic electrode is connected with the guide structure, and the guide structure limits the movement of the ceramic electrode; the thin film electrode is arranged inside the guide structure; And the control system is electrically connected with the movable sealing system and is used for controlling the movable sealing system. The guide structure comprises two support rings, wherein one support ring is arranged between the membrane electrode and the ceramic electrode, the other support ring is arranged on one side of the ceramic electrode, which is away from the membrane electrode, and the support rings are made of compressible materials. In one possible embodiment, the mobile sealing system comprises: the connecting pipe is sleeved and connected with the guide structure, and the ceramic electrode is movably connected with one end of the connecting rod sleeved and connected with the guide structure; The sealing ring is arranged at the joint of the connecting rod and the guide structure and has an axial movement function; The power source is arranged at the other end of the connecting rod, and the power source drives the connecting rod to ascend or descend. In one possible embodiment, the ceramic electrode includes: The movable sealing system drives the linkage end to adjust the distance between the c