JP2005098807A - Two-dimensional radiation detector and method of two-dimensional radiation measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the incident position of radiation with high positional resolution in real time. <P>SOLUTION: The detector 10 is constituted of the upper film 11 and the lower film 12, and when the radiation incident on the upper film 11 and the lower film 12, energy is generated, while diffusing toward the heat bath 15. The temperature-time variation is measured by the microthermometers 13, 14 arranged on the 4 edges of upper film 11 and 4 edges of the lower film 12. The incident position of the radiation is determined from the difference in the responses of the microthermometers 13, and 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation two-dimensional detector and a radiation two-dimensional detection method.

  Various detectors for detecting a radiation incident position two-dimensionally have been developed so far, and examples include an imaging plate (position resolution: 50 μm) and a microstrip gas detector (position resolution: 100 μm). be able to. Such detectors are used in the medical field and the physical experiment field of large accelerators. However, the above-described conventional detector can only achieve a position resolution of 1 μm or more, and a detector that achieves the original resolution of non-destructive inspection by radiation (the wavelength of X-ray of 10 keV is about 0.1 mm). It has not been realized yet.

  In recent years, a detector that realizes a positional resolution of 100 nm by combining a plastic track detector (CR-39) and an intermolecular force microscope (AFM) has been developed. However, this detector makes the track detector sensitize the radiation that has passed through the object to be imaged, and reads out an image obtained later by the intermolecular force microscope. Therefore, although the position resolution is high, real-time imaging is impossible.

  An object of this invention is to detect the incident position of a radiation in real time with high position resolution.

In order to achieve the above object, the present invention provides:
An upper thin film composed of a predetermined material;
A lower thin film provided to face the upper thin film;
A plurality of micro thermometers provided at a plurality of positions on the upper thin film and the lower thin film;
A heat bath connected to the upper thin film and the lower thin film;
The present invention relates to a two-dimensional radiation detector having a membrane structure.

The present invention also provides:
A step of arranging an upper thin film and a lower thin film made of a predetermined material to face each other;
Arranging a micro thermometer at a plurality of positions on the upper thin film and the lower thin film;
Connecting a heat bath to the upper thin film and the lower thin film;
Sequentially applying radiation to the upper thin film and the lower thin film;
A plurality of positions on the upper thin film and the lower thin film are measured with respect to time changes in temperature when thermal energy generated when the radiation is incident on the upper thin film and the lower thin film is diffused toward the heat bath. Identifying the incident position of the radiation based on the difference in the responsiveness of the fine thermometers arranged at the respective positions.
It is related with the radiation two-dimensional detection method characterized by comprising.

  According to the present invention, the upper thin film and the lower thin film connected to the heat bath are arranged so as to face each other, and the micro thermometers are arranged at a plurality of positions on these thin films. It is composed. Radiation primarily enters the upper thin film, and components transmitted through the upper thin film enter the lower thin film.

  Specifically, when the radiation is composed of photons such as X-rays and γ-rays, the photons are converted into electrons by photoelectric conversion in the upper thin film, and pass through the upper thin film while applying energy to the upper thin film. To the lower thin film. When the energy of the electrons is high, it passes through the lower thin film, but when the energy is relatively low, it stops in the lower thin film. Regardless of whether the electrons are transmitted or stopped, the electrons impart energy to the lower thin film in such operations.

  When the radiation is composed of charged particles, the charged particles pass through the upper thin film while applying energy to the upper thin film, and reach the lower thin film. Also in this case, when the energy of the charged particles is high, it passes through the lower thin film, but when the energy is relatively low, it stops in the lower thin film. In either case, the charged particles impart energy to the lower thin film.

  The energy imparted to the upper thin film and the lower thin film by the radiation is converted into thermal energy, and the thermal energy diffuses toward the heat bath. As described above, since the fine thermometers are provided at a plurality of positions on the upper thin film and the lower thin film, the temporal change in temperature caused by the thermal energy differs among the fine thermometers. Therefore, the incident position of the radiation with respect to the detector can be identified by detecting the difference in responsiveness of each micro thermometer.

  According to the detector and detection method of the present invention described above, the target radiation incident position can be identified in real time with a position resolution of 100 nm.

  In a preferred embodiment of the present invention, the upper thin film has a thickness of 1 μm or less. In this case, the struggling effect on the track when the radiation is composed of light particles such as an electron beam can be sufficiently suppressed.

  In another preferred embodiment of the present invention, the fine thermometer is composed of a single electron transistor. In this case, the size of the micro thermometer can be reduced to the order of several hundred nm, and the influence on the diffusion of the thermal energy described above can be reduced. Therefore, the position resolution with respect to the radiation can be further improved.

  As described above, according to the radiation two-dimensional detector and the radiation two-dimensional detection method of the present invention, the radiation incident position can be detected in real time with high position resolution.

Hereinafter, the present invention will be described in detail based on embodiments of the invention.
FIG. 1 is a side view showing an example of the radiation two-dimensional detector of the present invention, and FIG. 2 is a top plan view of the radiation two-dimensional detector shown in FIG.

  In the radiation two-dimensional detector 10 shown in FIGS. 1 and 2, the upper thin film 11 and the lower thin film 12 are arranged so as to face each other with a predetermined gap 16 therebetween. Further, fine thermometers 13 are arranged at the four end portions of the upper thin film 11, and although not clearly shown in the figure, the fine temperatures are also provided at positions corresponding to the fine thermometer 13 at the four end portions of the lower thin film 12. A total of 14 are arranged. A bulk-like member 15 resulting from the production method of these thin films is continuously provided at the end portions of the upper thin film 11 and the lower thin film 12, and functions as a heat bath for the thin films 11 and 12 due to their heat capacity. .

  When radiation enters the detector 10 shown in FIGS. 1 and 2, when the radiation is composed of photons such as X-rays and γ-rays, the photons are converted into electrons by photoelectric conversion in the upper thin film 11, and While giving energy to the thin film 11, it passes through the upper thin film 11 and reaches the lower thin film 12. When the energy of the electrons is high, the light passes through the lower thin film 12, but when the energy is relatively low, it stops in the lower thin film 12. Regardless of whether the electrons are transmitted or stopped, the electrons also apply energy to the lower thin film 12 in this operation.

  When the radiation is composed of charged particles, the charged particles pass through the upper thin film 11 while applying energy to the upper thin film 11 and reach the lower thin film 12. Even in this case, when the energy of the charged particles is high, the light passes through the lower thin film 12, but when the energy is relatively low, the charged particles stop in the lower thin film 12. In either case, the charged particles impart energy to the lower thin film 12.

  The energy applied to the upper thin film 11 and the lower thin film 12 by the radiation is converted into thermal energy, and this thermal energy diffuses toward the heat bath 15. As described above, since the micro thermometers 13 and 14 are provided at the four end portions on the upper thin film 11 and the four end portions on the lower thin film 12, the time change of the temperature due to the thermal energy is as follows. It becomes different for each fine thermometer. Therefore, the incident position of the radiation with respect to the detector 10 can be identified by detecting the difference in responsiveness of each micro thermometer.

  The thicknesses of the upper thin film 11 and the lower thin film 12 are appropriately set according to the type and energy of radiation to be detected. When the thickness t1 of the upper thin film 11 is 1 μm or less, even when the radiation is a light particle such as an electron beam, the struggling effect of the track can be suppressed, and the incident position of the light particle can be increased. It can be identified with position resolution.

  If the thickness t2 of the lower thin film 12 is 6 μm or more, most of the radiation can be stopped in the film, and the radiation energy is efficiently absorbed to generate relatively large thermal energy. Can do. As a result, the detection accuracy in each fine thermometer increases, and the position resolution with respect to the radiation can be increased.

  In addition, although the magnitude | size (length of one side) of the upper thin film 11 and the lower thin film 12 is not specifically limited, When the thickness of these thin films is set as mentioned above, one side of the thin films 11 and 12 The length L is about 10 μm. At this time, the fine thermometers 13 and 14 are disposed at positions away from the ends of the thin films 11 and 12 by about 2 μm in the length direction and the width direction, respectively.

  The gap 16 is provided to electrically and thermally insulate the upper thin film 11 and the lower thin film 12, and the thickness W in the width direction is preferably set to 1 μm to 2 μm. Instead of forming such a gap, a member having a sufficiently large electrical and thermal insulating property can be interposed between the upper thin film 11 and the lower thin film 12.

  As the fine thermometers 13 and 14, any kind of thermometer can be used. However, it preferably comprises a single electron transistor. In this case, the size of the micro thermometers 13 and 14 can be reduced to the order of several hundred nm, specifically, a thickness of 300 nm, a width of 500 nm, and a length of 500 nm. Can be reduced. Therefore, the position resolution with respect to the radiation can be further improved.

  As described above, the upper thin film 11 and the lower thin film 12 facing each other through the gap 16 can be formed by thinning a predetermined single crystal member through etching. At this time, the bulk member constituting the heat bath 15 can be constituted by the etching residual portion of the single crystal member. Therefore, the detector 10 as shown in FIGS. 1 and 2 can be easily manufactured.

The upper thin film 11 and the lower thin film 12 have been used for many years in the field of semiconductors and the like, and can be composed of single crystal Si having high reliability and achievements. In this case, the detector 10 shown in FIGS. 1 and 2 prepares a single crystal Si member, and etches it with KOH or the like to form an upper thin film 11 and a lower thin film 12, and forms a heat bath 15. To make.
However, the detector 10 can be composed of a member other than single crystal Si, and a member used in the semiconductor field and other device fields can be appropriately used.

  As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and all modifications and changes are made without departing from the scope of the present invention. It can be changed.

  The radiation two-dimensional detector and detection method of the present invention can be suitably used for non-destructive imaging of microstructures that require particularly high position resolution. For example, each component of a single cell can be imaged alive.

It is a side view which shows an example of the radiation two-dimensional detector of this invention. FIG. 2 is a top plan view of the radiation two-dimensional detector shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Two-dimensional radiation detector 11 Upper thin film 12 Lower thin film 13, 14 Fine thermometer 15 Heat bath (bulk member)
16 Air gap

Claims (18)

An upper thin film composed of a predetermined material;
A lower thin film provided to face the upper thin film;
A plurality of micro thermometers provided at a plurality of positions on the upper thin film and the lower thin film;
A heat bath connected to the upper thin film and the lower thin film;
A two-dimensional radiation detector with a membrane structure, characterized by comprising:   The two-dimensional radiation detector according to claim 1, wherein the upper thin film has a thickness of 1 μm or less.   The radiation two-dimensional detector according to claim 1, wherein a thickness of the lower thin film is 6 μm or more.   The radiation two-dimensional detector according to any one of claims 1 to 3, wherein the upper thin film and the lower thin film are disposed with a distance of 1 µm to 2 µm.   The radiation two-dimensional detector according to any one of claims 1 to 4, wherein at least one of the upper thin film and the lower thin film is formed by etching a single crystal member.   The radiation two-dimensional detector according to claim 5, wherein the single crystal member is single crystal Si.   The radiation two-dimensional detector according to claim 5, wherein the heat bath is constituted by an etching residue of the single crystal member.   The two-dimensional radiation detector according to claim 7, wherein the micro thermometer is formed at each of four ends of the upper thin film and the lower thin film.   The two-dimensional radiation detector according to any one of claims 1 to 8, wherein the micro thermometer comprises a single electron transistor. A step of arranging an upper thin film and a lower thin film made of a predetermined material to face each other;
Arranging a micro thermometer at a plurality of positions on the upper thin film and the lower thin film;
Connecting a heat bath to the upper thin film and the lower thin film;
Sequentially applying radiation to the upper thin film and the lower thin film;
A plurality of positions on the upper thin film and the lower thin film are measured with respect to time changes in temperature when thermal energy generated when the radiation is incident on the upper thin film and the lower thin film is diffused toward the heat bath. Identifying the incident position of the radiation based on the difference in the responsiveness of the fine thermometers arranged at the respective positions.
A radiation two-dimensional detection method characterized by comprising:   The radiation two-dimensional detection method according to claim 10, wherein a thickness of the upper thin film is 1 μm or less.   The radiation two-dimensional detection method according to claim 10 or 11, wherein the thickness of the lower thin film is 6 µm or more.   The radiation two-dimensional detection method according to any one of claims 10 to 12, wherein the upper thin film and the lower thin film are disposed at a distance of 1 µm to 2 µm.   14. The radiation two-dimensional detection method according to claim 10, wherein the micro thermometer is formed at each of four ends of the upper thin film and the lower thin film.   The radiation two-dimensional detection method according to claim 10, wherein the micro thermometer is constituted by a single electron transistor.   The radiation two-dimensional detection method according to claim 10, wherein at least one of the upper thin film and the lower thin film is formed by etching a single crystal member.   The radiation two-dimensional detection method according to claim 16, wherein the single crystal member is single crystal Si.   The radiation two-dimensional detection method according to claim 16 or 17, wherein the heat bath is constituted by an etching residue of the single crystal member.

Images