A shielding probe device, a cryogenic probe station and a cryogenic probe system

Abstract

A shielding probe device, a cryogenic probe station and a cryogenic probe system provided by the present invention provide electromagnetic shielding and thermal radiation shielding for signal transmission lines. A conductive layer is provided on the outer surface of the shielding component as a signal ground layer and is connected to the outer conductor of the signal connector, so that the electromagnetic shielding of the conductive component is complete, which can reduce the influence of electromagnetic interference and is conducive to the accurate measurement of sample characteristic parameters. The conductive component is placed in the shielding inner cavity of the shielding component, and the outer surface of the shielding component has a heat insulation layer, which can reduce the thermal radiation between the shielding probe device and the probe-sample contact area, thereby increasing temperature stability.

Description

Technical Field

[0001] The present invention relates to the field of low-temperature testing of semiconductor devices, and more specifically, to a shielding probe device, a cryogenic probe station, and a cryogenic probe system. Background Art

[0002] A cryogenic probe station is a platform that provides low-temperature and vacuum environmental conditions for non-destructive electrical characterization and measurement of wafer, device, and material samples. It generally consists of a vacuum chamber, a sample stage, a thermal radiation screen, a probe arm, a probe assembly, a cryogenic and vacuum acquisition assembly, etc. Among them, the probe assembly is installed in the vacuum chamber through the probe arm, and makes non-destructive contact with the sample through the tip to accurately measure the characteristic parameters of the sample. The measurement accuracy of the existing probe assembly is relatively low.

[0003] The existing probe assemblies include ZN50R and ZN50C standard probes and ZN50R-CVT probes. The structures of the ZN50R and ZN50C standard probes include: an SMA connector, a conductive microstrip, a tip, and a probe holder. The probe holder is a ceramic sheet, with a conductive microstrip bonded on one side as the probe signal transmission line, and a conductive film plated on the other side as the signal ground. The ZN50R-CVT probe assembly includes: an SMA connector, a tip, a probe holder, and a metal elastic component. Among them, the metal elastic component is used to compensate for the relative displacement between the tip and the sample caused by temperature changes, and also serves as part of the signal transmission line. Summary of the Invention

[0004] In order to solve at least one of the above problems, a first aspect of the present invention provides a shielding probe device, including:

[0005] A probe for detecting a detection signal generated by a sample to be measured;

[0006] A conductive component, one end of which is coupled to the probe for transmitting the detection signal;

[0007] A signal connector, the inner conductor of which is coupled to the other end of the conductive component for transmitting the detection signal to an external host computer; and

[0008] A shielding component, the shielding component includes a shielding inner cavity, the probe is inserted into the shielding inner cavity, the conductive component is placed in the shielding inner cavity, and the outer surface of the shielding component is covered with a conductive layer and a heat insulation layer; wherein, the conductive layer is electrically isolated from the conductive component and the probe; the conductive layer is coupled to the outer conductor of the signal connector for forming a complete electromagnetic shielding between the signal connector and the shielding component.

[0009] Preferably, the conductive component includes a conductive bar and an electrical connection terminal. A through hole is formed in the electrical connection terminal. One end of the probe is inserted into the through hole, and the other end of the conductive bar is inserted into the through hole and abuts against the probe; a gap is formed between the conductive layer and the probe, thereby forming the electrical isolation.

[0010] Preferably, the shielding component is in a flat plate shape. There are two conductive layers. The conductive component includes a conductive bar and two connection terminals. The probe and the conductive bar are inserted into the gap between the two connection terminals and abut against each other; the two conductive layers are respectively located on one side of a connection terminal, and a gap is formed between the conductive layer and the connection terminal on the same side, thereby forming the electrical isolation.

[0011] Preferably, the outer surfaces of the conductive layer and the connection terminal on the same side are in the same plane.

[0012] Preferably, the heat insulation layer includes at least one unit layer. The unit layer has a double-layer structure, with its inner layer being a polyester mesh and its outer layer being a double-sided aluminized polyester film.

[0013] Preferably, the conductive layer includes a wire mesh formed by alternately interweaving a plurality of metal wires.

[0014] Preferably, the signal connector is an SMA connector.

[0015] Preferably, the shielded probe device further includes a grounding wire, and one end of the grounding wire is fixed on the outer surface of the heat insulation layer of the shielding component.

[0016] In a second aspect of the present invention, a cryogenic probe station is provided, including the shielded probe device, a vacuum component, a probe arm, and a thermal radiation component according to any one of the above;

[0017] The vacuum component includes a vacuum chamber and a vacuum acquisition component; the shielded probe device is fixed in the vacuum chamber, and the shielded probe device is fixedly connected to the probe arm.

[0018] In a third aspect of the present invention, a cryogenic probe system is provided, including the cryogenic probe station and a host computer described above.

[0019] Advantages of the present invention

[0020] Compared with the traditional probe components of existing low-temperature probe stations, a shielding probe device provided by the present invention provides electromagnetic shielding and thermal radiation shielding for signal transmission lines. A conductive layer is provided on the outer surface of the shielding component as a signal ground layer and is connected to the outer conductor of the signal connector, so that the electromagnetic shielding of the conductive component is complete, which can reduce the influence of electromagnetic interference on the measurement accuracy and is conducive to the accurate measurement of sample characteristic parameters. The conductive component is placed in the shielding inner cavity of the shielding component, and the outer surface of the shielding component has a heat insulation layer, which can reduce the thermal radiation between the shielding probe device and the probe-sample contact area, thereby increasing the temperature stability of the shielding probe device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic structural diagram of the shielding probe device in the embodiment of the present invention;

[0023] Figure 2 It is a schematic structural diagram of the probe and the shielding component of the shielding probe device in the embodiment of the present invention;

[0024] Figure 3 It is a schematic structural diagram of the probe and the flat shielding component of the shielding probe device in the embodiment of the present invention;

[0025] Figure 4 It is a schematic side view structural diagram of the shielding probe device in the embodiment of the present invention.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS: 1. Signal connector; 2. Signal connector slot; 3. Shielding component; 4. Fixed position of the shielding probe device on the low-temperature probe station; 5. Connection terminal; 6. Conductive component; 7. Connection terminal; 8. Probe; 9. Conductive layer; 10. Polyester mesh; 11. Heat insulation layer; 12. Tip welding area; 13. Copper rivet; 14. Heat insulation layer ground wire. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0028] In order to improve the accuracy of measuring the characteristic parameters of semiconductor samples, the present invention provides a shielding probe device. Refer to Figure 1 , including:

[0029] A probe 8 for detecting a detection signal generated by a sample to be measured;

[0030] A conductive component 6, one end of which is coupled to the probe 8 for transmitting the detection signal;

[0031] A signal connector 1, which is coupled to the other end of the conductive component 6 for transmitting the detection signal to an external host computer; and

[0032] A shielding component 3, the shielding component 3 includes a shielding inner cavity, the probe 8 is inserted into the shielding inner cavity, the conductive component 6 is placed in the shielding inner cavity, and the outer surface of the shielding component 3 is covered with a conductive layer 9 and a heat insulation layer 11; wherein, the conductive layer 9 is electrically isolated from the conductive component 6 and the conductive layer 9 is electrically isolated from the probe 8.

[0033] It can be understood that the basic principle of electromagnetic shielding is: using a conductor material with low resistance, and using the reflection of electromagnetic waves on the surface of the shielding conductor, the absorption in the conductor and the loss during the transmission process to hinder the continuous transmission of electromagnetic wave energy, thus playing a shielding role. There are two factors affecting the shielding effectiveness of the shielding body: one is that the entire surface of the shielding body must be electrically continuous, and the other is that there cannot be a conductor directly penetrating the shielding body.

[0034] In a specific embodiment, the existing probes have the defect of incomplete shielding in terms of both electromagnetic interference and thermal radiation. The standard probe holder uses a single-piece ceramic, with a conductive microstrip bonded on one side and a conductive thin film plated on the other side as the signal ground. It can be seen that the electromagnetic shielding of the conductive microstrip, which is part of the signal transmission line, is missing, resulting in the accurate measurement of weak signals being easily affected by electromagnetic interference. The metal elastic component of the probe assembly, as part of the signal transmission line, is not electromagnetically shielded, which will cause the accurate measurement of weak signals to be easily affected by electromagnetic interference. The probe holder ceramic piece of the probe assembly has good thermal conductivity and is not shielded from thermal radiation, which will affect the temperature stability of the tip-sample contact area, thereby causing the accurate measurement of weak signals to be easily affected by thermal radiation.

[0035] Therefore, due to the factors of partial absence of electromagnetic shielding and impedance discontinuity in the probe signal transmission line, electromagnetic interference is likely to be coupled into the signal transmission line via the probe assembly in the form of conduction or radiation, affecting the accurate measurement of weak current or voltage signals. The shielded probe device mainly transfers heat through two ways: heat conduction and radiation. To reduce heat loss, a thermal radiation shield is installed in the vacuum cavity where the shielded probe device is located to reduce thermal radiation. However, the shielding component is most easily overlooked in thermal radiation protection. Since it is close to the sample and there is a strong thermal radiation coupling between it and the sample, it is likely to affect the temperature stability of the contact area between the tip and the sample, affecting the accuracy of measurement.

[0036] Preferably, in this embodiment, the probe 8 and the signal connector 1 are connected through the conductive component 6. The conductive component 6 is placed inside the shielding cavity of the shielding component 3. A conductive layer 9 is covered on the outer surface of the shielding component 3. The surface conduction of the shielding component 3 is continuous. The conductive layer 9 forms electromagnetic shielding for the conductive component 6, blocking electromagnetic interference from entering the signal transmission line and making the electromagnetic shielding of the conductive component 6 complete; heat insulation layers 11 are provided on the outer surface of the conductive layer 9 and the outer surface of the signal connector 1. The heat insulation layer 11 adopts an adiabatic multi-layer coating structure, which can reduce the thermal radiation between the probe support and the tip-sample contact area, thereby increasing temperature stability. The outer surface of the shielding component 3 is provided with a conductive layer and a heat insulation layer, blocking electromagnetic interference and reducing thermal radiation, which is beneficial to the accurate measurement of sample characteristic parameters. For the cross-sectional structure diagram of the shielded probe device, see Figure 1 , and for the side structure diagram, see Figure 4 . The signal connector 1 is fixed on a ceramic chip bracket with multi-layer film deposition. The ceramic chip bracket with multi-layer film deposition has an alumina ceramic chip as the substrate. The conductive component 6 is located on one side of the substrate. A layer of silicon dioxide film is deposited on a part of the surface of the ceramic chip substrate on the side with the conductive component 6 as an insulating layer to completely cover the conductive component 6. Aluminum films are deposited on both sides of the ceramic chip substrate, completely covering both sides of the ceramic chip substrate and the deposited part of the silicon dioxide film. A layer of silicon dioxide film is deposited on the outer surface of the aluminum films deposited on both sides of the ceramic chip substrate. The aluminum film and the silicon dioxide film form a stacked structure. The deposited aluminum film can be used as the conductive layer 9 to shield electromagnetic interference. At the same time, the aluminum film can also be used as a thermal radiation reflection layer. The silicon dioxide film deposited on the outer surface of the aluminum film is used as a thermal isolation layer. The aluminum film and the silicon dioxide film isolation layer are alternately deposited and stacked, and are symmetrically distributed on both sides of the substrate, forming a ceramic bracket with multi-layer film deposition with the ceramic chip substrate.

[0037] As can be seen from the above description, a shielding probe device provided by the present invention provides electromagnetic shielding and thermal radiation shielding for a signal transmission line. A conductive layer is provided on the outer surface of the shielding component as a signal ground and is connected to the shielding housing of the signal connector, so that the electromagnetic shielding of the conductive component is complete, which can reduce the influence of electromagnetic interference and is conducive to the accurate measurement of sample characteristic parameters. The conductive component is placed in the shielding inner cavity of the shielding component, and the outer surface of the shielding component has a heat insulation layer, which can reduce the thermal radiation between the shielding component and the probe contact area, thereby increasing temperature stability. Moreover, due to the thermal radiation protection of the heat insulation layer, the flexibility of the shielding component material selection is increased, and it is not limited to traditional ceramics.

[0038] In some specific embodiments, referring to Figure 2 , the conductive component 6 includes a conductive strip and a connection terminal 7. A through hole is formed in the connection terminal 7. One end of the probe 8 is inserted into the through hole, and the conductive strip is inserted into the other end of the through hole and abuts against the probe 8; a gap is formed between the conductive layer 9 and the probe 8, thereby forming the electrical isolation.

[0039] In this embodiment, the shielding component 3 includes a support frame and a shielding carrier. The shielding component 3 can be columnar. The shielding carrier surrounds the circumferential side of the conductive component 6. The outer surface of the shielding carrier is provided with a conductive layer 9 and a heat insulation layer 11. In some other embodiments, the conductive layer 9 and the heat insulation layer 11 can also be provided on the inner surface of the shielding inner cavity of the shielding carrier. The conductive component 6 extends outward to form two electrical connection terminals 5 and 7. The electrical connection terminal 5 of the conductive component 6 is connected to the central jack of the signal connector 1, and the other electrical connection terminal 7 is connected to the probe 8 to form a signal transmission line. A gap is formed between the shielding carrier and the conductive component 6, so that the conductive layer 9 is insulated from the probe 8 and the conductive component 6.

[0040] In some specific embodiments, referring to Figure 2 , the shielding component 3 is flat. There are two conductive layers 9. The conductive component 6 includes a conductive strip and two connection terminals 7. The probe 8 and the conductive strip are inserted into the gap between the two connection terminals 7 and abut against each other; each of the two conductive layers 9 is located on one side of a connection terminal 7, and a gap is formed between the conductive layer 9 and the connection terminal 7 on the same side, thereby forming the electrical isolation.

[0041] In this embodiment, the shielding component 3 is in the shape of a cuboid flat plate. The shielding component 3 includes a support frame and two shielding carriers. The shielding carriers are arranged oppositely. The geometric shapes, sizes, and materials of the two shielding carriers are the same. The distance between the two shielding carriers is greater than the width of the conductive component 6. Each shielding carrier can completely cover the conductive component 6. The conductive component 6 is located between the two shielding carriers, forming a sandwich structure. The outer surface of the shielding carrier is provided with a conductive layer 9 and a heat insulation layer 11. In some other embodiments, the conductive layer 9 and the heat insulation layer 11 can also be provided on the inner surface of the shielding carrier. One end of the conductive component 6 extends outward to form an electrical connection terminal 5. The electrical connection terminal 5 of the conductive component 6 is connected to the central jack of the signal connector 1. The other end includes two electrical connection terminals 7. A gap is formed between the two electrical connection terminals. The conductive strip and the probe 8 are placed in this gap and connected to each other to form a signal transmission line. A gap is formed between the shielding carrier and the conductive component 6. Furthermore, the conductive layer 9 is insulated from the probe 8 and from the conductive component 6.

[0042] In some specific embodiments, referring to Figure 3 , the outer surfaces of the conductive layer 9 and the connection terminal 7 on the same side are in the same plane;

[0043] In this embodiment, since the shielding component 3 is in the shape of a cuboid flat plate and the shielding carriers are arranged oppositely on the two surfaces with the largest area of the shielding component 3, the fact that the outer surfaces of the conductive layer 9 and the connection terminal 7 are in the same plane can make the shielding component 3 more flat, improve the electromagnetic shielding effect of the shielding component 3, and improve the sample measurement accuracy of the shielding probe device.

[0044] In some specific embodiments, the heat insulation layer includes at least one unit layer. The unit layer is a double-layer structure, with its inner layer being a polyester mesh and its outer layer being a double-sided aluminized polyester film.

[0045] In this embodiment, the heat insulation layer 11 is located on the outer surface of the shielding component 3 and the signal connector 1, or on the inner surface of the shielding component 3 and the outer surface of the signal connector 1. The heat insulation layer 11 can use the method of alternately depositing and stacking an aluminum film and a silicon dioxide film to reduce heat radiation, or can use the method of alternately thermally controlling multiple layers of double-sided aluminized polyester films and polyester meshes to reduce heat radiation. The heat insulation layer 11 includes multiple unit layers. Each unit layer is a double-layer structure. The innermost layer of the unit layer is a polyester mesh 10, and the outermost layer is a double-sided aluminized polyester film. In Figure 1 the shown embodiment, the heat insulation layer 11 wraps 10 unit layers. Each unit is composed of 1 layer of 6μm thick double-sided aluminized polyester film and 1 layer of polyester mesh.

[0046] In some specific embodiments, the conductive layer includes a metal wire mesh formed by alternately interweaving multiple metal wires.

[0047] In some specific embodiments, the signal connector is an SMA connector.

[0048] In some specific embodiments, referring to Figure 1 , the shielding probe device further includes a grounding wire, one end of which is fixed on the outer surface of the heat insulation layer 11 of the shielding component 3.

[0049] In this embodiment, a grounding wire 14 is led out from the heat insulation layer 11 through a copper rivet 13 and connected to the ground of the probe arm of the cryogenic probe station. Electrodes are processed on the surface of the deposited aluminum film for grounding. Each layer of the aluminum film leads out a ground wire through the electrode and is connected to the cold ground of the sample stage of the cryogenic probe station.

[0050] In some specific embodiments, referring to Figure 1 , the probe 8 is welded to the bottom end of the shielding component 3, and the welding area is 12, which is connected to the connection terminal 7, that is, the signals on the probe 8, the welding area 12, and the connection terminal 7 are connected. The conductive layer 9 plated on the outer surface of the shielding component 3 does not completely cover the outer surface of the shielding component 3, and the area 4 fixedly connected to the probe arm of the cryogenic probe station is reserved.

[0051] In addition, the second aspect of the present invention further provides a cryogenic probe station, including the shielding probe device, vacuum component, probe arm, and thermal radiation component described in any one of the above;

[0052] The vacuum component includes a vacuum chamber and a vacuum acquisition component; the shielding probe device is fixed in the vacuum chamber, and the shielding probe device is fixedly connected to the probe arm.

[0053] It can be understood that the cryogenic temperature in this aspect refers to the detection environment temperature of the sample, generally at minus 5 °C. Of course, the present invention is not limited thereto, as long as the sample can be detected.

[0054] In this embodiment, the cryogenic probe station is composed of a vacuum chamber, a sample stage, a thermal radiation screen, a probe arm, a shielding probe device, cryogenic and vacuum acquisition components, etc. Among them, the shielding probe device is installed in the vacuum chamber through the probe arm, and makes non-destructive contact with the sample through the probe 8 to accurately measure the characteristic parameters of the sample.

[0055] In addition, the third aspect of the present invention further provides a cryogenic probe system, including the cryogenic probe station described above and a host computer.

[0056] It can be understood that the host computer is coupled to the SMA connector 1 in the cryogenic probe station and can receive detection signals to measure the characteristics of the sample.

[0057] In summary, for the low-temperature probe station and the low-temperature probe system provided by the present invention, a shielded probe device provided with a conductive layer and a heat insulation layer is used to obtain the detection signal generated by the sample to be measured. During the process of obtaining the detection signal, the conductive layer can reduce the influence of electromagnetic interference, which is beneficial to the accurate measurement of the characteristic parameters of the sample by the low-temperature probe station. The heat insulation layer can reduce the thermal radiation between the shielding component and the probe-sample contact area, thereby increasing the temperature stability of the probe-sample contact area and avoiding the accurate measurement of the detection signal being easily affected by thermal radiation.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of this specification. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example.

[0059] In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. The above is only the embodiments of the embodiments of this specification and is not used to limit the embodiments of this specification. For those skilled in the art, various changes and modifications can be made to the embodiments of this specification. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of this specification shall be included within the scope of the claims of the embodiments of this specification.

Claims

1. A shielding probe device, characterized in that, Comprising: A probe for detecting a detection signal generated by a sample to be measured; A conductive component, one end of which is coupled to the probe for transmitting the detection signal; A signal connector, the inner conductor of which is coupled to the other end of the conductive component for transmitting the detection signal to an external host computer; And A shielding component, the shielding component includes a shielding inner cavity, the probe is inserted into the shielding inner cavity, the conductive component is placed in the shielding inner cavity, and the outer surface of the shielding component is covered with a conductive layer and a heat insulation layer; wherein, the conductive layer is electrically isolated from the conductive component and the conductive layer is electrically isolated from the probe; the conductive layer is coupled to the outer conductor of the signal connector for forming a complete electromagnetic shielding between the signal connector and the shielding component; Wherein, the surface conduction of the shielding component is continuous; the heat insulation layer adopts an adiabatic multi-layer coating structure, including at least one unit layer, the unit layer is a double-layer structure, the inner layer thereof is a polyester mesh, and the outer layer thereof is a double-sided aluminized polyester film.

2. The shielding probe device according to claim 1, wherein The conductive component includes a conductive strip and an electrical connection terminal, a through hole is formed on the electrical connection terminal, one end of the probe is inserted into the through hole, and the conductive strip is inserted into the other end of the through hole and abuts against the probe; a gap is formed between the conductive layer and the probe, thereby forming the electrical isolation.

3. The shielding probe device according to claim 1, wherein The shielding component is in a flat plate shape, there are two conductive layers, the conductive component includes a conductive strip and two connection terminals, the probe and the conductive strip are inserted into the gap between the two connection terminals and abut against each other; the two conductive layers are respectively located on one side of a connection terminal, and a gap is formed between the conductive layer and the connection terminal on the same side, thereby forming the electrical isolation.

4. The shielded probe device according to claim 3, characterized in that, The outer surfaces of the conductive layer and the connection terminal on the same side are in the same plane.

5. The shielding probe device according to claim 1, wherein The conductive layer includes a wire mesh formed by alternately intertwining a plurality of metal wires.

6. The shielding probe device according to claim 1, characterized in that, The signal connector is an SMA connector.

7. The shielding probe device according to claim 1, wherein The shielding probe device further includes a heat insulation layer grounding wire, one end of which is fixed on the outer surface of the heat insulation layer of the shielding component.

8. A low-temperature probe station, characterized in that, Comprising the shielding probe device according to any one of claims 1 to 7, a vacuum component, a probe arm and a thermal radiation component; The vacuum component includes a vacuum chamber and a vacuum acquisition component; the shielding probe device is fixed in the vacuum chamber, and the shielding probe device is fixedly connected to the probe arm.

9. A cryogenic probe system, characterized in that, Comprising the cryogenic probe stage according to claim 8 and a host computer.

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