JPH07254734A - Method of adjusting superconducting device and its adjusting equipment - Google Patents

Abstract

PURPOSE:To provide the method adjusting of a superconducting device and its adjusting equipment which can easily adjust frequency characteristics and prevent deterioration of super-conducting characteristics, by continuously performing the measurement and the adjustment working of a superconducting device in the same circumstance of a cooling state. CONSTITUTION:The title equipment is provided with the following; a vacuum chamber (holding vessel) 12 which accommodates a bandpass filter (superconducting device) 11 in which an electrode pattern is formed, and keeps the filter at a superconduction realizing temperature realizing a superconducting state, a network analyzer (measuring means) 13 which measures electric characteristics of the bandpass filter 11 in the vacuum chamber 12, a glass window (laser light incidence port) 17 formed in the vacuum chamber 12, and an excimer laser oscillator (laser light irradiating means) 14 which irradiates laser light L from the glass window 17 toward an electrode pattern. By irradiating the laser light L, the electrode pattern is worked, and electric characteristics are adjusted to be in a desired value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for adjusting electric characteristics of a superconducting device.

[0002]

2. Description of the Related Art Conventionally, there is known a method of adjusting electrical characteristics of a superconducting device for obtaining desired frequency characteristics when forming an oxide superconductor device, particularly a high frequency device. Since a superconductor has a significantly lower surface resistance than a normal conductor, when a superconductor is applied to a high frequency device, a high frequency device with low loss and strong frequency selectivity may be realized. Research is being conducted with the aim of application to resonators, bandpass filters, high-frequency filters, and the like.

By the way, adjustment is indispensable in order to obtain a desired frequency characteristic, but it goes without saying that the frequency characteristic of a superconducting device should be measured unless it is in a low temperature state where a superconducting state is realized. I can't. Further, when adjusting the frequency characteristics, it is necessary to directly touch the superconducting device to perform mechanical and physical operations. That is, when adjusting the frequency characteristics of the superconducting device, the superconducting device after the formation process is mounted in a measurement system and cooled to a superconducting state, and then its transmission characteristics are measured using a network analyzer, Check whether the required specifications based on the design values are met.

When the frequency characteristic does not meet the required specifications, the adjustment pattern prepared in advance in the electrode pattern is processed to adjust the frequency characteristic, and then cooled again to be in a superconducting state. And then measure again. After that, the above operation is repeated until the frequency characteristic falls within a desired range.

[0005]

However, in the conventional adjustment of the frequency characteristic of the superconducting device, the measuring step of measuring the frequency characteristic of the superconducting device and the adjustment processing step of adjusting the adjustment pattern of the electrode are separately performed. Therefore, it has to be mounted and cooled each time, and it takes a lot of time and labor to adjust the frequency characteristics of the superconducting device to a desired value.

At the same time, since the superconducting device is repeatedly subjected to thermal cycles at room temperature and low temperature, there is a problem that the superconducting characteristics are deteriorated. The present invention has been made in view of the above problems, and an object thereof is to perform measurement and adjustment processing of a superconducting device continuously in the same environment in a cooled state, thereby facilitating adjustment of frequency characteristics. An object of the present invention is to provide a method for adjusting a superconducting device and an adjusting apparatus for the same, which can prevent deterioration of superconducting properties while performing the method.

[0007]

[Means for Solving the Problems] The above-mentioned object is a measurement for holding a superconducting device having an electrode pattern at a superconducting realization temperature for realizing a superconducting state, and measuring electrical characteristics of the superconducting device. A step of adjusting the electrical characteristics to desired values by irradiating the superconducting device with a laser beam to process the electrode pattern while maintaining the superconducting realization temperature. It is achieved by the method for adjusting a superconducting device.

Further, a holding container for accommodating the superconducting device on which the electrode pattern is formed and holding the superconducting device at a superconducting realization temperature for realizing a superconducting state, and the electrical characteristics of the superconducting device in the holding container are measured. Measuring means, a laser light incident port provided in the holding container, and a laser light irradiation means for irradiating a laser beam from the laser light incident port toward the electrode pattern, by irradiation of the laser beam This is achieved by a superconducting device adjusting apparatus characterized by processing the electrode pattern to adjust the electrical characteristics to desired values.

[0009]

According to the present invention, a superconducting device having an electrode pattern formed thereon is maintained at a superconducting realization temperature for realizing a superconducting state, and a measuring step for measuring the electrical characteristics of the superconducting device, While maintaining the superconducting realization temperature, the superconducting device is irradiated with laser light to process the electrode pattern, and an adjusting step of adjusting the electrical characteristics to desired values is performed, thereby measuring the superconducting device. And adjustment processing can be performed continuously in the same environment while maintaining the superconducting realization temperature, electrical characteristics can be adjusted in a short time with high accuracy, and deterioration of superconducting characteristics can be prevented. it can.

Further, a holding container for accommodating the superconducting device on which the electrode pattern is formed and holding the superconducting device at a superconducting realization temperature for realizing a superconducting state, and electric characteristics of the superconducting device in the holding container are measured. To hold the superconducting device by having a measuring means, a laser light entrance provided in the holding container, and a laser light irradiating means for irradiating the laser light from the laser light entrance toward the electrode pattern. While maintaining the superconducting realization temperature in the container, the electrical characteristics of the superconducting device are measured by the measuring means, and the laser light emitted by the laser light irradiating means is irradiated onto the superconducting device from the laser light entrance to the electrode. The pattern can be processed to adjust the electrical characteristics to desired values.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A superconducting device adjusting apparatus according to an embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a superconducting device adjusting apparatus 10 includes a vacuum chamber (holding container) 12 that houses a bandpass filter (superconducting device) 11, and a network analyzer that measures the electrical characteristics of the bandpass filter 11. (Measuring means) 1
3 and an excimer laser oscillator (laser light irradiation means) 14 for irradiating the electrode pattern of the bandpass filter 11 with laser light.

The bandpass filter 11 is a high frequency device using an oxide superconductor and has a very strong frequency dependence. Other examples of such a high frequency device include a resonator and a high pass filter. On the bandpass filter 11, an electrode pattern based on a desired design specification value is formed. As shown in FIG. 2, the electrode pattern is a superconducting film (Y-Ba-Cu-O) formed on a substrate 11a made of magnesium oxide (MgO).
Is coated with a resist, patterning is performed by a photolithography technique, and then the superconducting film is patterned by ion milling with argon (Ar).

This electrode pattern includes, for example, an element 11c formed at the tip of the input microstrip line 11b, and an element 11e formed at the tip of the output microstrip line 11d located in the direction opposite to the element 11c. , Both elements 11c, 11e
It has the element 11f pinched | interposed between and arranged in parallel.

The vacuum chamber 12 is formed by a closed container having an exhaust port 16 communicating with a high vacuum exhaust system 15, and a glass window (laser light) incorporated in a part of an outer wall 12a separating an indoor space from an outdoor space. It has an entrance 17). The inside of the vacuum chamber 12 can be maintained in a vacuum state by the high vacuum exhaust system 15. Also, the vacuum chamber 1
A cooling stage 18 on which the bandpass filter 11 can be placed is installed inside the chamber 2 so as to face the glass window 17, and the cooling stage 18 is provided outside the chamber 12.
9 is connected. Through this cooling stage 18,
The bandpass filter 11 can be cooled to and maintained at the superconducting realization temperature at which the superconducting state is realized.

The network analyzer 13 includes an oscillator 2
The frequency characteristic (transmission characteristic and reflection characteristic) of the bandpass filter 11 which has 0 and is in the operating state by the operation signal input from the oscillator 20 is analyzed and measured. A measurement jig 21 is connected to the oscillator 20, and the measurement jig 2
1, the bandpass filter 11 can be fixedly held, and the bandpass filter 11 can be mounted on the cooling stage 18 in the vacuum chamber 12 via the opening / closing part (not shown) of the vacuum chamber 12. it can.

Further, the measuring jig 21 has a connecting portion (not shown) capable of connecting the bandpass filter 11 to the oscillator 20 by connecting an electrode (not shown) of the bandpass filter 11. It is provided. The excimer laser oscillator 14 emits laser light L toward the electrode pattern. The emitted laser light L is applied to the vacuum chamber 12
After passing through the glass window 17 through the mirror 22 installed outside,
The bandpass filter 11 is introduced into the vacuum chamber 12.
The tip of the element 11f is irradiated.

By irradiating this laser beam L, the superconducting film is converted into an insulator, so that the element 11
Since the effective length of f is shortened, the transmission frequency band can be shifted to the high frequency side. Therefore, by irradiating the laser beam L, the electrode pattern can be processed to adjust the frequency characteristic of the bandpass filter 11 to a desired value. The element 11f is preliminarily formed in a long electrode pattern so as to be adjustable.

Next, a method for adjusting a superconducting device will be described with reference to FIG.
This will be described with reference to the flowchart in FIG. First, the bandpass filter 11 is mounted on the measurement jig 21, and after the connection part and the electrode of the bandpass filter 11 are connected, the measurement jig 21
Is set in the vacuum chamber 12, and the bandpass filter 11 is mounted and fixed on the cooling stage 18 (step S
1).

Subsequently, the vacuum chamber 12 is evacuated to a high vacuum state, and then cooled to a superconducting realization temperature at which the superconducting state is realized (vacuum drawing and cooling), and the bandpass filter 1
1 is maintained in a cooled state of, for example, 77.3K (step S2). After that, the oscillator 20 is operated, and the transmission characteristic of the bandpass filter 11 is measured by the network analyzer 13 (step S3). The transmission characteristic (transmission characteristic a before adjustment) as the measurement result is shown in FIG. In the figure, the vertical axis represents transmission loss (S parameter) and the horizontal axis represents frequency.

Here, the frequency characteristic of the bandpass filter 11 in the superconducting state is measured. Next, the measurement result is compared with the design value (desired transmission characteristic b, see FIG. 4) (step S4), and it is determined whether the bandpass filter 11 of the sample satisfies the specifications (step S).
5).

If the result of the determination is that the specifications are not satisfied, the bandpass filter 11 for irradiating the laser beam L to correct the electrode pattern is processed (step S6). Laser light L
After the irradiation, the temperature of the bandpass filter 11 is stabilized and the transmission characteristics are measured again (step S3).
Then, it is compared with the design value (step S4) to determine whether or not the specifications are satisfied (step S5). If the frequency characteristic is still shifted to the low frequency side,
The bandpass filter 11 is adjusted by repeating the correction and measurement until the measurement result reaches the desired state.

On the other hand, if the result of the determination satisfies the specifications,
The adjustment of the bandpass filter 11 is completed (step S
7). Here, the modification of the electrode pattern will be described.
As a result of the determination, it was confirmed that the transmission characteristic a before the adjustment, which is the measurement result, is deviated to the low frequency side as compared with the desired transmission characteristic b which is the design value (see FIG. 4). The part is irradiated with laser light L. Excimer laser oscillator 14
Then, when the laser beam L emitted toward the bandpass filter 11 in the vacuum chamber 12 irradiates the tip of the element 11f, the superconducting film is converted into an insulator (FIG. 2, FIG.
The shaded portion) The effective length of the element 11f is shortened, and the transmission frequency band can be shifted to the high frequency side. As a result, it is possible to obtain the adjusted transmission characteristic c (see FIG. 4) that satisfies the specifications.

At this time, the bandpass filter 11 to which the laser beam L is irradiated is still arranged in the vacuum chamber 12 and, following the measuring step in which the cooling state is maintained, the adjustment processing is performed while maintaining the cooling state. It goes through the process.
Therefore, the bandpass filter 11 is used in the vacuum chamber 12
Laser light L while maintaining the superconducting realization temperature inside
Can be irradiated to process the electrode pattern and adjust the frequency characteristic to a desired value.

As described above, the measurement process of evaluating the electrical characteristics while the bandpass filter 11 is maintained at the superconducting realization temperature at which the superconducting state is realized, and the adjustment processing step of making the electric characteristics desired. By continuously performing and, the time and process required for the adjustment can be significantly reduced. Furthermore, since the electrode pattern is processed by irradiating the laser beam L, it is not necessary to directly touch the superconducting device to perform mechanical and physical operations when adjusting the frequency characteristics, and therefore it takes a lot of time for adjustment. Not only does this save time and labor, but the accuracy of adjustment can be dramatically improved.

Moreover, in the measurement and adjustment processing steps,
Since the bandpass filter 11 need only be cooled once and no extra heat cycle is applied, deterioration of the characteristics of the bandpass filter 11 can be prevented. Note that the present invention is not limited to the above-described embodiments and can be variously modified. For example, the present invention can be applied to a high-frequency device using an oxide superconductor such as a resonator or a high-pass filter instead of a bandpass filter. You can

[0026]

As described above, according to the present invention, the frequency characteristics can be easily adjusted and the superconducting characteristics can be easily adjusted by continuously measuring and adjusting the superconducting device in the same environment in a cooled state. Can be prevented from deteriorating.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a bandpass filter adjusting apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory plan view of a bandpass filter.

FIG. 3 is a flowchart showing a method of adjusting a bandpass filter.

FIG. 4 is an explanatory diagram showing transmission characteristics of a bandpass filter.

[Explanation of symbols]

 10 ... Adjustment device for superconducting device 11 ... Bandpass filter (superconducting device) 11a ... Substrate 11b ... Input microstripline 11c ... Element 11d ... Output microstripline 11e ... Element 11f ... Element 12 ... Vacuum chamber (holding) Container 12a ... Outer wall 13 ... Network analyzer (measuring means) 14 ... Excimer laser oscillator (laser light irradiation means) 15 ... High-vacuum exhaust system 16 ... Exhaust port 17 ... Glass window (laser light incident port) 18 ... Cooling stage 19 ... Refrigerator 20 ... Oscillator 21 ... Measuring jig 22 ... Mirror L ... Laser light a ... Transmission characteristics before adjustment b ... Desired transmission characteristics c ... Transmission characteristics after adjustment

Claims (2)

[Claims] 1. A superconducting device on which an electrode pattern is formed is maintained at a superconducting temperature for realizing a superconducting state,
Measuring step of measuring the electrical characteristics of the superconducting device, while maintaining the superconducting realization temperature, irradiating the superconducting device with laser light to process the electrode pattern, the electrical characteristics to a desired value. An adjusting method for a superconducting device, comprising: 2. A holding container for accommodating a superconducting device having an electrode pattern formed thereon and holding the superconducting device at a superconducting realization temperature for realizing a superconducting state, and measuring electrical characteristics of the superconducting device in the holding container. Measuring means, a laser beam entrance provided in the holding container, and a laser beam irradiating means for irradiating a laser beam from the laser beam entrance to the electrode pattern, by irradiating the laser beam A device for adjusting a superconducting device, characterized by processing the electrode pattern to adjust the electrical characteristics to desired values.