JP6281268B2 - Radiation detector using gas amplification - Google Patents

Description

  The present invention relates to a radiation detector using gas amplification by a pixel-type electrode.

  Conventionally, a pixel type radiation detector has been used as a radiation detector utilizing gas amplification. In this radiation detector, for example, a strip-like cathode electrode is formed on the surface of a double-sided printed circuit board, an anode strip is formed on the back surface, and openings are formed at regular intervals in the strip-like cathode electrode. A cylindrical anode electrode connected to the rear anode strip, that is, a pixel electrode is formed at the center of the portion.

  In addition, the said radiation detector is arrange | positioned, for example in the mixed gas of He and methane. In addition, a voltage of +600 V, for example, is applied to the pixel electrode.

  In the radiation detector, when predetermined radiation is incident on the detector, the gas is ionized to generate electrons, and the electrons are applied between the strip-like cathode electrode and the pixel electrode. Electron avalanche amplification is caused by a large electric field and a strong electric field generated due to the shape (shape anisotropy) of the pixel electrode as a point electrode. On the other hand, positive ions generated by the electron avalanche amplification drift toward the surrounding strip-like cathode electrode.

  As a result, holes and electrons are charged to the target strip-like cathode electrode and pixel electrode, respectively. Therefore, by detecting the positions of the strip-like cathode electrode and pixel electrode in which charges are generated in this way, the incident position in the radiation detector can be specified, and radiation can be detected (Patent Document). 1).

  In the above-described radiation detector, when the voltage applied to the pixel electrode is increased, the intensity of the generated electric field also increases, and the above-described electron avalanche amplification becomes significant. Therefore, the charges generated in the strip-like cathode electrode and the pixel electrode are increased. The amount is increased and the sensitivity (gas amplification factor) of radiation is improved. On the other hand, when the voltage applied to the pixel electrode is increased, the pixel electrode may be damaged due to abnormal discharge caused by the shape of the pixel electrode or foreign matter in the atmosphere. Further, when the voltage applied to the pixel electrode is reduced, the above-described abnormal discharge is reduced, but the degree of the above-mentioned electronic avalanche amplification is also reduced, and the radiation detection sensitivity is lowered.

  From such a point of view, instead of increasing the voltage applied to the pixel electrode, attempts have been made to narrow the pixel electrode and improve the strength of the generated electric field. However, since the pixel electrode is formed by via fill plating in the through hole formed in the printed circuit board, it is necessary to narrow the through hole in order to narrow the pixel electrode. On the other hand, if the through hole is narrowed, the via fill plating cannot be performed uniformly in the through hole, and a uniform pixel electrode cannot be formed. This may cause problems such as an increase in sensitivity pixels. Therefore, the narrowing of the pixel electrode is naturally limited depending on the manufacturing method (Patent Document 2).

  Similarly, instead of increasing the voltage applied to the pixel electrode, it has been attempted to attach a GEM (Gas Electron Multiplier) to the radiation detector. There is also a problem that radiation cannot be stably detected.

  As a result, there is a problem that the sensitivity (gas amplification factor) of the pixel-type radiation detector cannot be sufficiently improved at present.

JP 2002-6047 JP2012-13383A

  An object of this invention is to provide the radiation detector using the gas amplification by the pixel-type electrode which has sufficiently high sensitivity (gas amplification factor), and its manufacturing method.

In order to achieve the above object, the present invention provides:
A first electrode pattern formed on a first surface of a semiconductor substrate having an oxide film formed on the surface and having a plurality of circular openings;
A plurality of through holes formed on the second surface opposite to the first surface of the semiconductor substrate and formed from the second surface of the insulating member toward the first surface A second electrode pattern having a plurality of via conductor layers formed in each of them,
The present invention relates to a radiation detector using gas amplification, wherein upper end portions of the plurality of via conductor layers are exposed at central portions of the plurality of openings of the first electrode pattern.

  The inventors of the present invention have intensively studied to achieve the above object. As a result, the reason why the sensitivity (gas amplification factor) of the conventional pixel type radiation detector cannot be sufficiently improved is that the via conductor layer in the second electrode pattern constituting the pixel electrode is replaced with the radiation detector. After forming a through-hole with respect to the insulating member to comprise, it discovered that it was because it formed in this through-hole by via fill plating.

  Generally, when a filled via is formed in an insulating member, the inner wall surface of the through hole becomes less smooth and uneven as the aspect ratio becomes higher. For this reason, when via fill plating is performed, voids are easily generated in the obtained filled vias, and defects such as non-attachment of filled vias are likely to occur, and a uniform pixel electrode cannot be formed. Therefore, a through hole having a high aspect ratio cannot be formed, and the thickness of the insulating member is relatively reduced.

  As a result, the distance between the first electrode pattern and the second electrode pattern formed on the opposing surfaces is necessarily close, and the pixel electrode, that is, between the first electrode pattern and the second electrode pattern. When a voltage is applied, an electric field (lines of electric force) is also generated between the first electrode pattern and the second electrode pattern formed on the first surface and the second surface of the insulating member via the insulating member. The electric field (electric field lines) based on the voltage is not concentrated between the pixel electrode and the first electrode pattern existing on the outer peripheral edge of the opening where the pixel electrode is located. I found out that is the cause.

  Therefore, in the present invention, a semiconductor substrate is used instead of an insulating member as a substrate constituting the radiation detector, and after forming an oxide film on the surface of the semiconductor substrate, a so-called TSV (through silicon via) technique is used. Through holes are formed in the semiconductor substrate. A via conductor layer is formed in the through hole by performing a plating process in the through hole.

  According to the TSV technique, the through hole can be formed so that the inner wall surface is smooth. Therefore, voids are not generated in the obtained via conductor layer, and defects such as non-attachment of the via conductor layer are unlikely to occur, and a uniform pixel electrode can be formed. As a result, a through-hole with a high aspect ratio can be formed, and the thickness of the semiconductor substrate constituting the radiation detector and having the oxide film formed on the surface can be sufficiently increased.

  As a result, the distance between the first electrode pattern and the second electrode pattern formed on both surfaces of the semiconductor substrate can be sufficiently increased. Therefore, when a voltage is applied between the first electrode pattern and the second electrode pattern, an electric field (lines of electric force) generated between the first electrode pattern and the second electrode pattern can be suppressed. The electric field (electric field lines) based on the voltage is applied between the pixel electrode constituted by the upper end portion of the via conductor layer and the first electrode pattern existing on the outer periphery of the opening where the pixel electrode is located Can concentrate. For this reason, the sensitivity (gas amplification factor) of the radiation detector can be improved in a state in which complication of the apparatus due to the use of GEM (Gas Electron Multiplier) is suppressed.

  In the present invention, since a semiconductor is used as the base material of the radioactive detector, the radiation transmittance is high. For example, by arranging an ETCC (Electron Tracking Compton Camera) around the radiation detector, Detection can be performed. Accordingly, the scattered gamma rays can be detected three-dimensionally, and the tracks of the scattered gamma rays can be monitored.

  As described above, the thickness of the semiconductor substrate can be increased, and as a result of the formation of a smooth inner wall surface through-hole by the TSV technique, the aspect ratio of the through-hole is 2 or more, and further 8 This can be done.

  In an example of the present invention, the central portion in the length direction of the via conductor layer can be hollow. In one example of the present invention, the via conductor layer can be formed so as to bury the through hole. In the present invention, the above-described effects can be obtained in any of these forms.

  In one example of the present invention, the height of the upper end portion of the via conductor layer can be made equal to the horizontal level of the first surface of the semiconductor substrate. In this case, the width (diameter) of the upper end portion of the via conductor layer can be made substantially equal to the diameter of the through hole. That is, since the width (diameter) of the upper end portion of the via conductor layer can be narrowed, it is configured from the upper end portion of the via conductor layer when a voltage is applied between the first electrode pattern and the second electrode pattern. The electric field (electric lines of force) based on the voltage can be more concentrated between the pixel electrode and the first electrode pattern existing on the outer peripheral edge of the opening where the pixel electrode is located. The sensitivity of the detector can be further improved.

  In one example of the present invention, an insulating resin layer can be disposed between the first electrode pattern and the first surface of the semiconductor substrate. The oxide film formed on the surface of the semiconductor substrate has low insulation, and a leak current of, for example, several nA to several tens of nA is generated, depending on the voltage applied between the first electrode pattern and the second electrode pattern. In addition, a discharge may occur between the oxide film and the upper end portion of the via conductor layer, and a crack may be formed in the oxide film. As a result, the electric field based on the voltage is concentrated between the pixel electrode formed from the upper end portion of the via conductor layer and the first electrode pattern existing on the outer peripheral edge of the opening where the pixel electrode is located. In some cases, the sensitivity of the radiation detector of the present invention is lowered.

  However, as described above, by disposing the insulating resin layer between the first electrode pattern and the first surface of the semiconductor substrate, the oxide film is covered with the insulating resin layer. Therefore, the exposure ratio of the oxide film is reduced. Therefore, the above-described problem of leakage current can be avoided, and the sensitivity of the radiation detector of the present invention can be improved.

  The insulating resin layer can be disposed so as to extend to the inside of each of the plurality of through holes in a state where the via conductor layer is embedded in each of the plurality of through holes. In this case, when the plurality of via conductor layers are formed so as to be embedded in the plurality of through holes, the end portions of the insulating resin layer exist inside the plurality of through holes. The layer narrows the upper end of each of the plurality of via conductor layers. Therefore, when a voltage is applied between the first electrode pattern and the second electrode pattern, the pixel electrode formed from the upper end portion of the via conductor layer and the outer peripheral edge of the opening where the pixel electrode is located exist. The electric field (electric field lines) based on the voltage can be concentrated between the first electrode pattern and the sensitivity of the radiation detector of the present invention can be improved.

  The “center portion” of the present invention refers to an allowable range of manufacturing error because the upper end portion of the via conductor layer is not positioned at the center portion of the opening of the first electrode pattern due to a manufacturing error or the like. It also includes the case where it deviates from the central part.

  As described above, according to the present invention, it is possible to provide a radiation detector using gas amplification by a pixel electrode having sufficiently high sensitivity (gas amplification factor), and a method for manufacturing the same.

It is a perspective view showing a schematic structure of a radiation detector using gas amplification in a 1st embodiment. It is sectional drawing which expands and shows the pixel electrode peripheral part of the radiation detector shown in FIG. It is sectional drawing which shows the modification of the radiation detector using the gas amplification in 1st Embodiment. It is sectional drawing which expands and shows the pixel electrode peripheral part of the radiation detector in 2nd Embodiment. It is sectional drawing which expands and shows the pixel electrode peripheral part of the radiation detector in 3rd Embodiment. It is sectional drawing which expands and shows the pixel electrode peripheral part of the radiation detector in 4th Embodiment. It is process drawing in the manufacturing method of the radiation detector of 1st Embodiment. It is process drawing in the manufacturing method of the radiation detector of 1st Embodiment. It is process drawing in the manufacturing method of the radiation detector of 1st Embodiment. It is process drawing in the manufacturing method of the radiation detector of 3rd Embodiment. It is process drawing in the manufacturing method of the radiation detector of 3rd Embodiment. It is process drawing in the manufacturing method of the radiation detector of 3rd Embodiment.

  Hereinafter, the features and other advantages of the present invention will be described based on embodiments for carrying out the invention.

(First embodiment)
FIG. 1 is a perspective view showing a schematic configuration of a radiation detector using gas amplification according to the present embodiment, and FIG. is there.

  As shown in FIG. 1, a radiation detector 10 using gas amplification according to the present embodiment includes a detection panel 1 and an electrode plate 12 provided so as to face each other above the detection panel 11. Yes.

  As shown in FIGS. 1 and 2, the detection panel 11 includes a first electrode having a plurality of circular openings 112A formed on a main surface 111A of a semiconductor substrate 111 having an oxide film 111C on the surface. The pattern 112 and the 2nd electrode pattern 113 formed on the back surface 111B of the semiconductor base material 111 are included. The second electrode pattern 113 has a via conductor layer 114 formed on the inner wall surface of a through hole 111H formed with the semiconductor substrate 111 from the back surface 111B toward the main surface 111A. 114A is exposed at the center of the opening 112A of the first electrode pattern 112.

  The upper end portion 114A of the via conductor layer 114 extends from the through hole 111H onto the main surface 111A of the semiconductor substrate 111, and constitutes a pixel electrode. The semiconductor substrate 111 can be composed of a general-purpose semiconductor.

  Further, the “center portion” of the present embodiment is not allowed because the upper end portion 114A of the via conductor layer 114 is not positioned at the center portion of the opening portion 112A of the first electrode pattern 112 due to a manufacturing error or the like. It is a concept that includes a case where it deviates from the central portion within the range of manufacturing error.

  In addition, in the detection panel 11 of the radiation detector 10 shown in FIG. 1, a total of eight openings 112A are formed in the first electrode pattern 112 and arranged in two rows by four, The upper end portion 14A of the via conductor layer 14 is exposed in the opening 112A, so that a total of eight detection electrodes are formed. However, the number and arrangement method of the detection electrodes can be arbitrarily set as necessary.

  In the radiation detector 10 of this embodiment, in the manufacturing method described below, the semiconductor substrate 111 constituting the radiation detector 10 (detection panel 11) is penetrated using a so-called TSV (through silicon via) technique. After forming the hole 111H, for example, conformal plating is performed in the through hole 111H, whereby a via conductor layer 114 (so-called conformal plating layer, ie, via conductor layer) having a hollow length in the through hole 111H is formed. ), And the upper end portion 114A is exposed at the center of the opening 112A of the first electrode pattern 112.

  According to the TSV technique, the through hole 111H can be formed such that the inner wall surface is smooth. Therefore, it is difficult for voids to be generated in the via conductor layer 114 and problems such as non-attachment of the via conductor layer 114 to occur. As a result, a through hole having a high aspect ratio can be formed, and the thickness of the semiconductor substrate 111 can be sufficiently increased. As a result, the distance between the first electrode pattern 112 and the second electrode pattern 113 formed on both surfaces of the semiconductor substrate 111 can be sufficiently increased.

  Therefore, when a voltage is applied between the first electrode pattern 112 and the second electrode pattern 113, an electric field generated between the first electrode pattern 112 and the second electrode pattern 113 via the semiconductor substrate 111. (Electric lines of force) can be suppressed, and an electric field (electric lines of force) based on the voltage is applied to the upper end portion 114A of the via conductor layer 114 functioning as a pixel electrode and the opening portion 112A where the upper end portion 114A is located. It can concentrate between the 1st electrode pattern 112 which exists in an outer periphery. Therefore, the sensitivity (gas amplification factor) of the radiation detector 10 can be improved in a state in which complication of the apparatus by using GEM (Gas Electron Multiplier) is suppressed.

  Specifically, when the thickness of the semiconductor substrate 111 is t1, and the diameter of the through hole 111H is d1, the aspect ratio t1 / d1 of the through hole 111H can be 2 or more, and more preferably 8 or more. can do. Thereby, for example, the thickness t1 of the semiconductor substrate 111 can be set to 400 μm or more. Therefore, for example, even when a voltage of about 600 V is applied between the first electrode pattern 112 and the second electrode pattern 113, the first electrode pattern 112 and the second electrode pattern 112 between the first and second electrode patterns 112 are interposed. Therefore, the sensitivity (gas amplification factor) of the radiation detector 10 can be sufficiently improved.

  The upper limit of the aspect ratio t1 / d1 of the through hole 111H is not particularly limited, but is about 16 in the current processing technology. However, the upper limit of the aspect ratio t1 / d1 increases with the progress of processing technology.

  Further, the thickness d2 of the via conductor layer 114 can be set to 1 μm or more and 15 μm or less, for example. If the thickness d2 of the via conductor layer 114 is smaller than the lower limit value, voids and the like formed in the layer are exposed on the surface of the via conductor layer 114, resulting in poor shape of the pixel electrode, and the via conductor layer. 114 may not function as a pixel electrode.

  Furthermore, the size (length) of the extending portion 114B of the upper end portion 114A of the via conductor layer 114 can be set to, for example, 5 μm or more and 30 μm or less. If the size of the extending portion 114B is smaller than the lower limit value, the electric field concentration structure that does not depend on the shape of the hole described above cannot be formed, and the size of the extending portion 114B is larger than the upper limit value. In some cases, the upper end portion 114A of the via conductor layer 114 becomes too large, and the via conductor layer 114 does not sufficiently function as a pixel electrode.

  Note that the height (thickness) t4 of the protruding portion of the via conductor layer 114 is substantially equal to the thickness t2 of the first electrode pattern 112 due to the manufacturing method of the radiation detector 10 described below. You may make it mutually differ by devising a manufacturing method.

  As an example of the size of each part, the thickness t2 of the first electrode pattern 112, the thickness t3 of the second electrode pattern 113, and the height t4 of the protruding portion of the via conductor layer 114 are each 5 μm. It can be set to ˜18 μm. Furthermore, the diameter D1 of the opening 112A can be set to, for example, 80 μm to 300 μm.

  FIG. 3 is a cross-sectional view showing a schematic configuration of a modified example of the radiation detector using gas amplification according to the present embodiment, and shows an enlarged peripheral portion of the pixel electrode of the radiation detector.

  The radiation detector 20 (detection panel 21) using the gas amplification of this embodiment shown in FIG. 3 forms the via conductor layer 114 so as to embed the inside of the through hole 111H, and the upper end portion 114A of the via conductor layer 114 is formed in the through hole. It differs from the radiation detector 10 (detection panel 11) of the first embodiment shown in FIG. 2 and the like in that it protrudes from the opening 111S of 111H and extends to the main surface 111A of the semiconductor substrate 111. To do.

  Thus, even if the via conductor layer 114 is formed by performing, for example, a plating process so as to embed the inside of the through hole 111H, the same effect as that obtained when the above-described hollow via conductor layer is used is obtained.

(Second Embodiment)
FIG. 4 is a cross-sectional view showing a schematic configuration of a radiation detector using gas amplification according to the present embodiment, and shows an enlarged peripheral portion of a pixel electrode of the radiation detector.

  In the radiation detector 30 (detection panel 31) using the gas amplification of this embodiment shown in FIG. 4, the height of the upper end portion 114A of the via conductor layer 114 is equal to the horizontal level of the main surface 111A of the semiconductor substrate 111. This is different from the radiation detector 20 (detection panel 21) of the first embodiment shown in FIG. Therefore, hereinafter, operational effects based on such differences will be described.

  In addition, the same code | symbol is used about the structure similar or the same as the component of the radiation detectors 10 and 20 shown in FIGS.

  As described above, in the radiation detector 30 (detection panel 31) of the present embodiment, the height of the upper end portion 114A of the via conductor layer 114 is equal to the horizontal level of the main surface 111A of the semiconductor substrate 111. The width (diameter) of the upper end portion 114A of the via conductor layer 114 is substantially equal to the diameter of the through hole 111H.

  As a result, the width (diameter) of the upper end portion 114A of the via conductor layer 114 can be reduced in accordance with the diameter of the through hole 111H as compared with the embodiment having the extending portion 114B as shown in FIG. Therefore, when a voltage is applied between the first electrode pattern 112 and the second electrode pattern 113, the pixel electrode constituted by the upper end portion 114A of the via conductor layer 114 and the opening portion 112A where the pixel electrode is located. The electric field (electric field lines) based on the voltage can be more concentrated between the first electrode pattern 112 existing on the outer peripheral edge of the electrode and the sensitivity of the radiation detector of the present invention can be further improved.

  Since other features and operational effects are the same as those of the radiation detector 10 (detection panel 11) shown in the first embodiment, description thereof will be omitted.

(Third embodiment)
FIG. 5 is a cross-sectional view showing a schematic configuration of a radiation detector using gas amplification of the present embodiment, and shows an enlarged peripheral portion of a pixel electrode of the radiation detector.

  In the radiation detector 40 (detection panel 41) of the present embodiment shown in FIG. 5, an insulating resin layer 42 such as photosensitive polyimide is provided between the first electrode pattern 112 and the main surface 111A of the semiconductor substrate 111. It differs from the radiation detector 10 (detection panel 11) shown in FIG. Therefore, hereinafter, operational effects based on such differences will be described.

  In addition, the same code | symbol is used about the structure similar or the same as the component of the radiation detectors 10, 20, and 30 shown in FIGS.

  The oxide film 111 </ b> C formed on the main surface 111 </ b> A of the semiconductor substrate 111 has low insulation and depends on the voltage applied between the first electrode pattern 112 and the second electrode pattern 113, for example, several nA to several tens. An nA leakage current may be generated, or a discharge may be generated between the oxide film 111C and the upper end portion 114A of the via conductor layer 114 to cause a crack in the oxide film 111C. As a result, the electric field based on the voltage is applied between the pixel electrode formed by the upper end portion 114A of the via conductor layer 114 and the first electrode pattern 112A existing at the outer peripheral edge of the opening 112A where the pixel electrode is located. In some cases, the sensitivity of the radiation detector 40 (detection panel 41) may be lowered, and the like may occur.

  However, as described above, by disposing the insulating resin layer 42 having a thickness of 1 μm to 20 μm, for example, between the first electrode pattern 112 and the main surface 111A of the semiconductor substrate 111, the oxide film 111C. Is covered with the insulating resin layer 42, the exposure rate of the oxide film 111C is reduced. Therefore, since the insulation of the main surface 111A of the semiconductor substrate 111 is substantially improved, the above-described problem of leakage current can be avoided, and the sensitivity of the radiation detector 40 (detection panel 41) can be reduced. Can be improved.

  In the present embodiment, the insulating resin layer 43 is also formed between the second electrode pattern 113 and the back surface 111B of the semiconductor substrate 111. The insulating resin layer 43 is mainly formed by the radiation detector 40. (Detection panel 41) is provided due to the manufacturing method. However, the presence of the insulating resin layer 43 substantially improves the insulating property of the back surface 111B of the semiconductor substrate 111, and thus, for example, the lower end portion of the via conductor layer 114 and the back surface 111B of the semiconductor substrate 111. A discharge or the like between the side oxide film 111C and the like can be prevented. As a result, the generation of cracks in the oxide film 111C on the back surface 111B side can be suppressed, and the sensitivity of the radiation detector 40 (detection panel 41) can be improved.

  In the radiation detector 40 (detection panel 41) of the present embodiment, the insulating resin layer 42 covers all of the oxide film 111C formed on the main surface 111A of the semiconductor substrate 111. If the insulating resin layer 42 is formed between the first electrode pattern 112 and the main surface 111 </ b> A of the semiconductor substrate 111, the above-described effects can be obtained. However, by covering all of the oxide film 111 </ b> C with the insulating resin layer 42, the above-described operational effects can be more reliably achieved.

  Since other features and operational effects are the same as those of the radiation detector 10 (detection panel 11) shown in the first embodiment, description thereof will be omitted.

(Fourth embodiment)
FIG. 6 is a cross-sectional view showing a schematic configuration of a radiation detector using gas amplification according to the present embodiment, and shows an enlarged peripheral portion of a pixel electrode of the radiation detector.

  The radiation detector 50 (detection panel 51) using the gas amplification of this embodiment shown in FIG. 6 embeds the insulating resin layer 42 in the third embodiment and embeds the via conductor layer 114 in each of the plurality of through holes 111H. In the state formed in such a manner, it is different from the radiation detector 10 (detection panel 11) shown in FIG. 1 in that it is arranged so as to extend to the inside of each of the plurality of through holes 111H. Therefore, hereinafter, operational effects based on such differences will be described.

  In addition, the same code | symbol is used about the structure similar or the same as the component of the radiation detectors 10, 20, 30, and 40 shown in FIGS.

  In the present embodiment, as in the radiation detector 20 (detection panel 21) of the first embodiment shown in FIG. 3, the plurality of through holes 111H are embedded with via conductor layers 114, and the insulating resin layer 42 is further embedded. Is extended to the inside of each of the plurality of through holes 111H.

  In this case, since the end portions of the insulating resin layer 42 exist inside the plurality of through holes 111H, the insulating resin layer 42 narrows the upper end portions 114A of the plurality of via conductor layers 114, respectively. Therefore, when a voltage is applied between the first electrode pattern 112 and the second electrode pattern 113, the pixel electrode constituted by the upper end portion of the via conductor layer 114A and the outside of the opening 112A where the pixel electrode is located The electric field (electric field lines) based on the voltage can be more concentrated between the first electrode pattern 112 existing on the periphery and the sensitivity of the radiation detector 50 can be further improved.

  Since other features and operational effects are the same as those of the radiation detector 10 (detection panel 11) shown in the first embodiment, description thereof will be omitted.

(Fifth embodiment)
In the present embodiment, a method for manufacturing the radiation detector 10 (detection panel 11) of the first embodiment will be described. In the following, the case where silicon is used as the semiconductor substrate 111 will be described in the case of manufacturing using the substruct method. 7 to 9 are process diagrams in the manufacturing method of the present embodiment.

  First, as shown in FIG. 7, for example, deep RIE (Reactive Ion Etching) is performed on the main surface 111A of the semiconductor substrate 111 made of silicon to form a through hole 111H from the main surface 111A toward the back surface 111B. To do. Next, as shown in FIG. 8, the semiconductor substrate 111 is heat-treated in an oxidizing atmosphere to form an oxide film 111 </ b> C on the surface of the semiconductor substrate 111.

  Next, as shown in FIG. 9, after electroless plating is performed on the main surface 111A, the back surface 111B, and the inner wall surface of the through hole 111H of the semiconductor substrate 111, a seed layer is formed, and then the seed layer is used as an electrode. Processing is performed to form plating layers 112X, 113X, and 114X, respectively.

  Thereafter, the plating layers 112X, 113X, and 114X are patterned by photolithography to obtain a first electrode pattern 112, a second electrode pattern 113, and a via conductor layer 114 as shown in FIG. A device 10 (detection panel 11) is obtained.

  Note that the radiation detector 10 (detection panel 11) can be manufactured using a semi-additive method instead of the substruct method.

  Moreover, the radiation detector 20 (detection panel 21) shown in FIG. 3 can be obtained by performing via filling plating instead of the above-described plating treatment.

  Further, the radiation detector 30 (detection panel 31) shown in FIG. 4 performs via filling plating in place of the above-described plating process, and further performs photolithography on the plating layer 112, so that the via conductor layer 114 is formed. It can be obtained by not masking the portion exposed from the through hole 111H.

(Sixth embodiment)
In the present embodiment, a method for manufacturing the radiation detector 40 (detection panel 41) of the third embodiment will be described. In the following, the case where silicon is used as the semiconductor substrate 111 will be described in the case of manufacturing using the substruct method. 10 to 12 are process diagrams in the manufacturing method of this embodiment.

  First, as described in the fifth embodiment, for example, deep RIE (Reactive Ion Etching) is performed on the main surface 111A of the semiconductor substrate 111 made of silicon to penetrate from the main surface 111A toward the back surface 111B. A hole 111H is formed, and then heat treatment is performed on the semiconductor substrate 111 in an oxidizing atmosphere to form an oxide film 111C on the surface of the semiconductor substrate 111 (see FIGS. 7 and 8).

  Next, as shown in FIG. 10, insulating resin films 42X and 43X made of, for example, photosensitive polyimide are laid on the entire main surface 111A and back surface 111B of the semiconductor substrate 111.

  Next, as shown in FIG. 11, the insulating resin layers 42X and 43X are subjected to photolithography to form insulating resin layers 42 and 43 on the main surface 111A and the back surface 111B of the semiconductor substrate 111.

  Next, as shown in FIG. 12, after electroless plating is performed on the main surface 111A, the back surface 111B, and the inner wall surface of the through hole 111H of the semiconductor substrate 111, a seed layer is formed, and then the seed layer is used as an electrode. Processing is performed to form plating layers 112X, 113X, and 114X, respectively.

  Thereafter, the plating layers 112X, 113X, and 114X are patterned by photolithography to obtain a first electrode pattern 112, a second electrode pattern 113, and a via conductor layer 114 as shown in FIG. A device 40 (detection panel 41) is obtained.

  Note that the radiation detector 40 (detection panel 41) can be manufactured using a semi-additive method instead of the substruct method.

  Further, the radiation detector 50 (detection panel 51) shown in FIG. 6 performs via filling plating instead of the above-described plating process, and the end portions of the insulating resin layers 42 and 43 extend into the through hole 111H. Thus, it can obtain by performing photolithography with respect to the insulating resin films 42X and 43X.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

  For example, although it was clearly shown in the above embodiment, in the radiation detector 30 (detection panel 31) of the second embodiment shown in FIG. 4, between the first electrode pattern 112 and the main surface 111A of the semiconductor substrate 111. An insulating resin layer 42 may be disposed on the substrate. As a result, the same operational effects as those of the third embodiment shown in FIG. 5 can be obtained.

10, 20, 30, 40, 50 Radiation detector 11, 21, 31, 41, 51 Detection panel 12 Electrode plate 111 Semiconductor substrate 111
111H Through-hole 112 First electrode pattern 112A Circular opening of first electrode pattern 113 Second electrode pattern 114 Via conductor layer 114A Upper end portion of via conductor layer 114B Extension portion of via conductor layer

Claims (8)

A first electrode pattern formed on a first surface of a semiconductor substrate having an oxide film formed on the surface and having a plurality of circular openings;
A plurality of penetrations formed on a second surface opposite to the first surface of the semiconductor substrate and formed from the second surface of the semiconductor substrate toward the first surface A second electrode pattern having a plurality of via conductor layers formed in each of the holes ;
An insulating resin layer disposed between the first electrode pattern and the first surface of the semiconductor substrate;
A radiation detector using gas amplification, wherein upper end portions of the plurality of via conductor layers are exposed at central portions of the plurality of openings of the first electrode pattern.   The radiation detector using gas amplification according to claim 1, wherein a central portion in the length direction of the via conductor layer is hollow.   The radiation detector using gas amplification according to claim 1, wherein the via conductor layer is formed so as to bury the through hole.   The radiation detector using gas amplification according to claim 3, wherein a height of an upper end portion of the via conductor layer is equal to a horizontal level of the first surface of the semiconductor substrate. The insulating resin layer extends to the inside of each of the plurality of through-holes, characterized in that it constricted the upper end of each of the plurality of via conductors layers, according to claim 3 Radiation detector using gas amplification. The radiation detector using gas amplification according to claim 1 , wherein an aspect ratio of the through hole is 2 or more. The radiation detector using gas amplification according to claim 6 , wherein an aspect ratio of the through hole is 8 or more. The radiation detector using gas amplification according to claim 7 , wherein an aspect ratio of the through hole is 16 or more.

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