JP4346348B2 - Semiconductor radiation detector - Google Patents

Description

【００３７】
上部アルミニウム電極３を−５０Ｖに保持して、エネルギー１ＭｅＶのアルファ線が半導体検出器の中央に垂直方向に入射した状況を、シミュレーションにより解析した。その結果、ＭＯＳ構造を有する本発明の実施例のデバイス構造では、従来のＭＯＳ構造を有しない場合に比較して信号強度である電荷量が２０％多いという結果を得た。このシミュレーション例では、有感領域の開口部の面積に対し、ＭＯＳ構造の領域は３６％を占めるが、実際の半導体放射線検出器の面積は、この例よりも大きく、１％程度の面積の増加でも、２０％程度の信号増強効果が得られる。
【００３８】
【発明の効果】
以上詳述したように、本発明によれば、デバイス構造を複雑にすることなく、また製造コストを上昇させることなく、放射線の検出感度を著しく高感度にすることができる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態に係る半導体放射線検出器を示す断面図である。
【図２】本発明の動作原理を説明するためのシミュレーションに関するＭＯＳ構造を示す断面図である。
【図３】本発明の動作原理を説明するためのシミュレーションに関する印加電圧を示すグラフ図である。
【図４】本発明の第２の実施形態に係る半導体放射線検出器を示す断面図である。
【図５】本発明の半導体放射線検出器の各層の平面レイアウト形状の一例を示す模式図である。
【図６】本発明の半導体放射線検出器の各層の平面レイアウト形状の他の例を示す模式図である。
【図７】従来の半導体放射線検出器を示す断面図である。
【符号の説明】
１、２１、３１、６１；ｎ型シリコン基板
２、２２、３２；ｐ型拡散層
３、２３、３３、６３；上部アルミニウム電極
４、２４、３４、６２；シリコン酸化膜
５、２５；チャネルストッパー
６、７、２６、３６、３７；空乏層
８、２７、３８、６４；下部アルミニウム電極
３５；フィールドプレート
４１、５１；有感領域
４２、５２；素子分離領域
４３、５３；上部アルミニウム電極成膜領域
４４、５４；ＭＯＳ構造形成領域
７１；シミュレーションで上部電極に印加した電圧[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor radiation detector having a radiation sensitive part composed of a pn junction or a Schottky junction.
[0002]
[Prior art]
FIG. 7 is a cross-sectional view showing a conventional semiconductor radiation detector. In the conventional semiconductor detector, for example, a p-type diffusion layer 22 is formed on the surface of an n-type silicon substrate 21, and a silicon oxide film 24 is formed on the substrate surface excluding a portion on the p-type diffusion layer 22. Is formed. An upper aluminum electrode 23 is formed on the silicon oxide film 24 and the silicon substrate 21. Accordingly, the upper aluminum electrode 23 is in ohmic contact with the diffusion layer 22. In this case, the portion where the upper aluminum electrode 23 is connected to the diffusion layer 22 corresponds to a radiation sensitive region. The portion on the silicon substrate 21 other than the sensitive region is covered with the silicon oxide film 24, and the upper aluminum electrode 23 is insulated from the silicon substrate 21 by the silicon oxide film 24 in the portion other than the sensitive region (diffusion layer 22). Has been. An n-type diffusion layer having a higher concentration than the silicon substrate 21 is formed as a channel stopper 25 on the outer periphery of the diffusion layer 22. An aluminum electrode 27 is formed on the lower surface of the silicon substrate 21.
[0003]
In the semiconductor radiation detector configured as described above, when a voltage at which the aluminum electrode 23 becomes negative is applied between the aluminum electrode 23 and the aluminum electrode 27, the n-type silicon substrate 21 connected to the aluminum electrode 27. A reverse bias is applied between the p-type diffusion layer 22 and the p-type diffusion layer 22 ohmically connected to the aluminum electrode 23, and a depletion layer 26 extends under the p-type diffusion layer 22. When radiation is incident on the depletion layer 26, the radiation generates carriers (charges) of electron / hole pairs in the depletion layer 26, and the generated electron / hole pairs are separated by the electric field of the depletion layer 26. A current flows through the electrodes 23 and 27 and is detected.
[0004]
Although the above description is for the case where the silicon substrate 21 is n-type, the polarity of the diffusion layer 22 and the channel stopper 25 (n-type diffusion layer) and the polarity of the applied voltage are changed even when the silicon substrate 21 is p-type. Thus, a semiconductor radiation detector having a similar function can be obtained.
[0005]
[Problems to be solved by the invention]
In semiconductor radiation detectors as described above, the number of electron-hole pairs generated with the incidence of radiation is determined by the energy of the incident radiation. In this method, the electron-hole pairs generated by controlling the spread width or electric field of the depletion layer are separated efficiently, and the recombination and trapping of defects are reduced to prevent the electron-hole pairs from disappearing. It is necessary to. However, there are limits to these measures, and measures close to this limit have already been taken.
[0006]
On the other hand, as a method of increasing the detection signal, the generated electrons and holes are accelerated by a high electric field, and as a result, electrons and holes that have obtained sufficiently high energy collide with Si atoms, thereby creating new electrons and holes. Although generation of hole pairs has been devised, it is not desirable in terms of signal level stability and long-term reliability.
[0007]
The present invention has been made in view of such problems, and it is an object of the present invention to provide a semiconductor radiation detector capable of increasing detection sensitivity without complicating the device structure and without increasing the cost. Objective.
[0008]
[Means for Solving the Problems]
A semiconductor radiation detector according to the present invention includes a first conductivity type semiconductor substrate , an element isolation region that is formed on the surface of the semiconductor substrate and partitions an element formation region , and a pn junction formed in the element formation region or a radiation sensible region consisting Schottky junction, the electrode for signal detection in contact with the sensible area, before SL signal detecting electrode and electrically connected to the wiring electrode, the semiconductor and the wiring electrode An insulating film provided between the substrate and the element isolation region is a channel stopper which is a diffusion layer having the same first conductivity type as the semiconductor substrate and a higher concentration than the semiconductor substrate; on the opposite side area of the isolation region and the sensible area than the surface of the semiconductor substrate, the wiring electrode, the insulating film and the and the semiconductor substrate are MOS structure formed by the incident radiation Also it characterized in that a depletion layer is formed in the MOS structure when a depletion layer formed in Kieu sense region.
[0010]
Another semiconductor radiation detector according to the present invention includes a first conductivity type semiconductor substrate, an element isolation region formed on the surface of the semiconductor substrate and partitioning an element formation region, and a pn junction formed in the element formation region. A radiation sensitive region comprising a portion or a Schottky junction, a signal detection electrode in contact with the sensitive region, a wiring electrode electrically connected to the signal detection electrode, the wiring electrode and the An isolation film provided between the semiconductor substrate, and the element isolation region is a field plate that is insulated from the semiconductor substrate via the insulation film and is applied with the same potential as the semiconductor substrate. A MOS structure is formed from the wiring electrode, the insulating film, and the semiconductor substrate in a region opposite to the sensitive region from the element isolation region on the surface of the semiconductor substrate, Also it characterized in that a depletion layer is formed in the MOS structure when a depletion layer formed in the sensible area by.
[0011]
Note that the fact that the element formation region is partitioned by the element isolation region does not mean that the element formation region is surrounded by the element isolation region. That is, the element isolation region does not necessarily surround the sensitive region, and the element isolation region may not be provided in a direction where element isolation is not required, for example, a depletion layer does not extend. However, it is necessary to provide an element isolation region between the MOS structure and the sensitive region.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a semiconductor radiation detector according to an embodiment of the present invention. A p-type diffusion layer 2 is provided on the surface of the n-type silicon substrate 1, and a silicon oxide film 4 is formed on the surface of the silicon substrate 1 excluding the upper portion of the p-type diffusion layer 2. An upper aluminum electrode 3 is formed on the silicon oxide film 4 and the silicon substrate 1, and since the silicon oxide film 4 is not formed on the diffusion layer 2, the upper aluminum electrode 3 is formed on the diffusion layer 2. On the other hand, it is in ohmic contact. In this case, a portion where the upper aluminum electrode 3 is in ohmic contact with the diffusion layer 2 corresponds to a radiation sensitive region. Therefore, the silicon substrate 1 other than the sensitive region is covered with the silicon oxide film 4, and the upper aluminum electrode 3 is insulated from the silicon substrate 1 by the silicon oxide film 4 in the portion other than the sensitive region. Yes.
[0013]
Further, an n-type diffusion layer having a higher concentration than the silicon substrate 1 is formed as a channel stopper 5 so as to surround the diffusion layer 2. A region surrounded by the channel stopper 5 is an element formation region in which elements are separated by the channel stopper 5. The aluminum electrode 3 is formed to extend to the outside of the channel stopper 5 on the surface of the silicon substrate 1, that is, to a region on the opposite side of the diffusion layer 2, and a region adjacent to the channel stopper 5 in the silicon substrate 1. It is formed up to the top. As a result, a MOS structure including the upper aluminum electrode 3, the silicon oxide film 4, and the silicon substrate 1 is formed in a region outside the channel stopper 5. A lower aluminum electrode 8 is formed on the lower surface of the silicon substrate.
[0014]
Next, the operation of the semiconductor radiation detector of the present embodiment configured as described above will be described. When a reverse bias is applied between the n-type silicon substrate 1 in contact with the lower aluminum electrode 8 and the p-type diffusion layer 2, the depletion layer 6 extends under the diffusion layer 2. At this time, the voltage applied to the upper aluminum electrode 3 is a negative voltage when the lower aluminum electrode 8 is grounded and the silicon substrate 1 is grounded (set to 0 V). When the radiation is incident on the depletion layer 6, the radiation generates carriers (charges) of electron / hole pairs in the depletion layer 6, and the generated electron / hole pairs are separated by the electric field of the depletion layer 6, A current flows between the aluminum electrodes 3 and 8 to generate a detection signal.
[0015]
As described above, when the reverse bias voltage is applied to operate the semiconductor detector, the MOS structure constituted by the upper aluminum electrode 3, the silicon oxide film 4, and the silicon substrate 1 is surrounded by the channel stopper 5. The depletion layer 7 also spreads on the surface of the silicon substrate 1 outside the formed element formation region. When the applied voltage of the upper aluminum electrode 3 exceeds the threshold voltage of the MOS structure, that is, when the absolute value of the applied voltage is larger than the absolute value of the threshold voltage, an inversion layer is formed on the surface of the depletion layer 7. Even if a voltage is further applied (the absolute value is increased), the depletion layer 7 does not expand any more.
[0016]
Next, the operation principle that the radiation detection sensitivity can be improved by the semiconductor radiation detector of the present invention as described above will be described. The basic principle of a semiconductor radiation detector in which electron-hole pairs generated when radiation enters a sensitive region of a semiconductor generates a detection signal is the same as in the prior art. However, in the present invention, the effect of the MOS structure provided in the region adjacent to the channel stopper 5 which is an element isolation region that partitions the radiation sensitive region is added.
[0017]
The electrical characteristics of semiconductor elements are numerically analyzed by semiconductor device simulation technology (for example, “Edited by Dan Ryo, published by Sangyo Tosho Co., Ltd., process / device simulation technology”). The results of analysis by the present inventors using a device simulator in this device simulation method will be described with reference to FIGS. The device structure used for the analysis is as follows. A silicon oxide film 62 having a thickness of 400 nm is formed on the surface of an n-type silicon substrate 61 having a thickness of 500 μm and a resistivity of 250 Ω · cm. An aluminum electrode 63 is formed on the silicon oxide film 62. Is formed. An aluminum electrode 64 is in ohmic contact with the lower surface of the silicon substrate 61.
[0018]
Then, a voltage 71 is applied to the upper aluminum electrode 63 of the MOS structure as shown in FIG. At this time, the lower aluminum electrode 64 is set to zero potential (ground). The applied voltage 71 to the upper aluminum electrode 63 is -50V, -49.9V for time zero (0), 1 nano (1n) second, 2 nano (2n) second, 3 nano (3n) second, and thereafter. -49.9V and -50V, and a transient analysis was performed using a semiconductor simulator. This transient analysis was performed up to 10 microseconds as a sufficient time to return to the steady state when the applied voltage 71 of FIG. 3 was applied. As a result, the charge obtained by integrating the current flowing through the upper electrode 63 with time is about 24 pico C / square centimeter (pico is 10 to the power of 12) per unit area of the surface area in the plan view of the device. The current flows out from the MOS structure to the outside. However, the direction of the current is not constant and changes from the direction in which the current flows into the MOS structure from the upper electrode to the direction in which it flows out to the outside. When the current was integrated over time, as a result, the charge flowing out from the MOS structure through the upper electrode 63 prevailed. Furthermore, in general, a signal detection unit of a semiconductor radiation detector has a configuration in which a resistor and a capacitor (capacitor) are connected in parallel. Since this capacitance component acts as a low-pass filter, a high-frequency component of the signal is used. Since the current component flowing into the MOS structure from the upper electrode contains a higher frequency component, the current component flowing into the MOS structure from the upper electrode has a smaller contribution to the detection signal, and as a result, passes through the upper electrode. The current component flowing out from the MOS structure contributes to the detection signal and acts more effectively.
[0019]
The above description explains the operation of the MOS structure itself. Next, the operation of the semiconductor radiation detector of the present invention provided with this MOS structure will be described. In the semiconductor radiation detector of this embodiment shown in FIG. 1, when the n-type silicon substrate 1 is grounded and, for example, −50 V is applied to the upper aluminum electrode 3, the depletion layer 6 expands. When radiation such as alpha rays enters the depletion layer 6, electron / hole pairs are generated and separated by the electric field of the depletion layer 6, and the generated holes pass through the p-type diffusion layer 2 and pass through the upper aluminum electrode 3. To leak. On the other hand, the generated electrons flow out of the aluminum electrode 8 on the lower surface of the substrate. Since the generated electrons flow out from the lower surface of the substrate, the current flows from the aluminum electrode 8 toward the aluminum electrode 3 in the direction opposite to the electrons. With this current, the voltage at the top of the silicon substrate 1 is lower than the bottom of the substrate (0 V). That is, it becomes a negative potential. If the voltage of the upper aluminum electrode 3 is fixed at −50 V, the MOS structure is composed of the upper aluminum electrode 3 / the silicon oxide film 4 / the silicon substrate 1 and will be described with reference to FIGS. As described above, a pulse voltage is applied to the upper electrode 3 in the same direction as the voltage 71 shown in FIG. Furthermore, generally, a voltage is applied to the upper aluminum electrode 3 through a resistor. When a fixed voltage of −50 V is applied to the outside of the resistor, the upper electrode 3 becomes a voltage shallower than −50 V (a negative voltage whose absolute value is smaller than 50) due to the current flowing out to the outside. This corresponds to the application of a pulse voltage in the same direction as the applied voltage 71 of FIG. Therefore, the same phenomenon as described in FIGS. 2 and 3 occurs in the MOS structure constituted by the upper aluminum electrode 3 / silicon oxide film 4 / silicon substrate 1 in FIG. The shape of the pulse voltage (time, pulse voltage height) is expected to be different from the simulation performed in FIGS. 2 and 3, but the aluminum electrode 3 in FIG. A displacement current signal in the same direction from the MOS structure is added to the current, and the radiation signal detected from the upper aluminum electrode is enhanced.
[0020]
As described above, in this embodiment, the depletion layer 6 is formed in the element formation region and the depletion layer 7 is also formed outside the element formation region, so that the radiation detection current is amplified and the detection sensitivity is increased. Can be increased.
[0021]
In the first embodiment, the silicon substrate 1 is n-type, but the polarity of the diffusion layer 2 and the channel stopper 5 (n-type diffusion layer) and the applied voltage can be applied even when the silicon substrate 1 is p-type. By changing the polarity of the semiconductor radiation detector, a semiconductor radiation detector having the same function can be obtained.
[0022]
In the first embodiment, the upper electrode 3 is an aluminum wiring. However, the upper electrode 3 is not limited to this, and any wiring material that can form an ohmic contact with the diffusion layer 2 may be used.
[0023]
In the first embodiment, the entire surface of the diffusion layer 2 is covered with the upper aluminum electrode 3. However, as long as electrical connection with the diffusion layer 2 can be established, the diffusion layer 2 is covered not in its entirety but in part. The aluminum electrode 3 may be formed.
[0024]
In the first embodiment, the pn junction is provided as a means for forming the depletion layer in the sensitive part. However, the present invention is not limited to this, and a Schottky junction may be provided. Specifically, a Schottky junction can be formed by using gold or the like as an upper electrode in the case of an n-type silicon substrate and using aluminum or the like as an upper electrode in the case of a p-type silicon substrate.
[0025]
In the first embodiment, the upper wiring of the depletion layer 7 is formed at the same time as the upper aluminum electrode 3 that is in ohmic contact with the diffusion layer 2. However, as a device structure of the semiconductor radiation detector, these are not necessarily formed at the same time. They may not be formed, and after they are formed in separate steps, they may be electrically connected. However, from the viewpoint of manufacturing cost, it is preferable to use a wiring formed simultaneously with the upper aluminum electrode 3 in ohmic contact with the diffusion layer 2 as the wiring above the depletion layer 7.
[0026]
In the first embodiment, a silicon oxide film is used as the insulating film 4. However, the insulating film 4 is not limited to the silicon oxide film as long as it has an electrical insulating property, and other insulating films such as a silicon nitride film. Alternatively, a stacked film of a plurality of insulators may be used. However, since the insulating film in contact with the surface of the silicon substrate needs to suppress the defect density at the interface, it is preferably a thermally oxidized silicon oxide film.
[0027]
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is different from the embodiment shown in FIG. 1 in that a field plate is used as an element isolation region instead of the channel stopper (diffusion layer) shown in FIG. The configuration other than the element isolation region is the same as that of the first embodiment shown in FIG.
[0028]
A p-type diffusion layer 32 is formed on the surface of the n-type silicon substrate 31, and a silicon oxide film 34 is formed on the surface of the silicon substrate 31 excluding the ohmic contact region between the p-type diffusion layer 32 and the aluminum electrode 33. Is formed. In the silicon oxide film 34, a field plate 35 as an element isolation region is formed at a position surrounding the diffusion layer 32 in plan view. The field plate 35 is usually formed of aluminum, but is not limited to aluminum as long as it is a wiring material, and can be formed of various materials. The aluminum electrode 33 extends from the ohmic contact region with the diffusion layer 32 to the region on the opposite side of the diffusion layer 32 beyond the field plate 35. An aluminum electrode 38 is also formed on the lower surface of the silicon substrate 31.
[0029]
In this embodiment, by applying a voltage having the same potential as that of the silicon substrate 31 to the field plate 35, the field plate 35 exhibits a function of element isolation. Therefore, by applying a reverse bias voltage to the aluminum electrode 34, a depletion layer 36 is formed in the element region separated by the field plate 35, and when radiation enters the depletion layer 36, A pair is generated, and a detection current flows through the aluminum electrode 34. In this case, since the aluminum electrode 33 is also formed outside the element region partitioned by the field plate 35, the depletion layer 37 is also formed in the MOS structure configured in this region.
[0030]
As described above, since the aluminum electrode 33 is formed to extend outside the field plate 35, in the present embodiment, the signal current caused by the holes generated by the radiation is transferred in the same direction from the MOS structure by the above-described action. A displacement current signal is added, so that an amplification effect of the detection current is obtained, and extremely high radiation detection accuracy can be obtained.
[0031]
In order for the field plate 35 to function as an element molecule, a voltage having the same potential as that of the silicon substrate 31 is normally applied to the field plate 35, but it should be a potential that does not invert the silicon substrate 31 directly below the field plate 35. For example, the same potential as that of the silicon substrate 31 is not necessarily required. The voltage of the upper aluminum electrode 33 that inverts the silicon substrate 31 is practically a function of the concentration of the silicon substrate 31, the dielectric constant and film thickness of the insulating film (silicon oxide film 34), and the work function of the upper aluminum electrode 33. Predict with no problem. The polarity of the conductivity type, the type of junction for forming the depletion layer, the material of the upper electrode and the insulator, and the like are the same as in the first embodiment.
[0032]
In the above embodiment, a silicon substrate is used as the semiconductor substrate. However, the present invention is not limited to this silicon substrate, and a semiconductor substrate such as diamond or SiC may be used.
[0033]
Next, an example of a planar layout pattern of each layer of the semiconductor radiation detector of the present invention will be described with reference to FIG. In the example of FIG. 5, the circular region 41 is an opening without a silicon oxide film and is a sensitive region. In regions other than the sensitive region 41, a silicon oxide film is provided on the silicon substrate. An annular region 42 surrounding the sensitive region 41 is an element isolation region. An aluminum electrode is provided on the entire surface surrounded by the thick frame 43. An annular region 44 adjacent to the annular region 42 is provided outside the annular region 42, and the annular region 44 has a MOS structure. The layout pattern shown in FIG. 5 is circular. However, the layout pattern is not limited to this, and other shapes such as a rectangle may be used as long as it is disposed outside the annular element isolation region 44 surrounding the sensitive region 41. You may comprise.
[0034]
Moreover, with reference to FIG. 6, the other example of the planar layout pattern of each layer of the semiconductor radiation detector of this invention is demonstrated. A region 51 to be a sensitive region is rectangular and is an opening provided in an insulating film (silicon oxide film). In a region other than the region 51, a silicon oxide film is provided on the silicon substrate. An aluminum electrode is provided on the entire surface of the region 53 surrounded by the thick frame, and the region provided with the aluminum electrode extends in one direction from one side of the sensitive region 51. An element isolation region 52 is provided between the extension region and the sensitive region 51. A MOS structure is provided in a region 54 extending outside the element isolation region 52. As shown in FIG. 6, the element isolation region 52 and the MOS structure do not necessarily need to surround the sensitive region 51.
[0035]
【Example】
Hereinafter, the simulation results of the effects of the embodiments falling within the scope of the present invention will be described. The structure of the semiconductor radiation detector used for this simulation is shown in FIG. This semiconductor simulation was performed under the conditions shown in Table 1 below. Further, the planar layout shape of each layer is concentric as shown in FIG.
[0036]
[Table 1]

[0037]
The situation where the upper aluminum electrode 3 was held at −50 V and an alpha ray with an energy of 1 MeV was vertically incident on the center of the semiconductor detector was analyzed by simulation. As a result, in the device structure of the example of the present invention having the MOS structure, the charge amount as the signal intensity is 20% larger than that in the case where the conventional MOS structure is not provided. In this simulation example, the area of the MOS structure occupies 36% of the area of the opening of the sensitive area, but the actual area of the semiconductor radiation detector is larger than this example and the area is increased by about 1%. However, a signal enhancement effect of about 20% can be obtained.
[0038]
【The invention's effect】
As described above in detail, according to the present invention, the detection sensitivity of radiation can be made extremely high without complicating the device structure and without increasing the manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a semiconductor radiation detector according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a MOS structure related to a simulation for explaining the operating principle of the present invention.
FIG. 3 is a graph showing an applied voltage related to a simulation for explaining an operation principle of the present invention.
FIG. 4 is a cross-sectional view showing a semiconductor radiation detector according to a second embodiment of the present invention.
FIG. 5 is a schematic view showing an example of a planar layout shape of each layer of the semiconductor radiation detector of the present invention.
FIG. 6 is a schematic view showing another example of the planar layout shape of each layer of the semiconductor radiation detector of the present invention.
FIG. 7 is a cross-sectional view showing a conventional semiconductor radiation detector.
[Explanation of symbols]
1, 21, 31, 61; n-type silicon substrates 2, 22, 32; p-type diffusion layers 3, 23, 33, 63; upper aluminum electrodes 4, 24, 34, 62; silicon oxide films 5, 25; channel stoppers 6, 7, 26, 36, 37; depletion layers 8, 27, 38, 64; lower aluminum electrode 35; field plates 41, 51; sensitive regions 42, 52; element isolation regions 43, 53; Regions 44 and 54; MOS structure formation region 71; voltage applied to upper electrode in simulation

Claims (2)

A semiconductor substrate , an element isolation region formed on the surface of the semiconductor substrate and defining an element formation region , a radiation sensitive region including a pn junction or a Schottky junction formed in the element formation region , and Yes electrode for signal detection in contact with the sensitive area, before Symbol electrodes and wiring electrically connected to electrodes for signal detection, and an insulating film provided between the wiring electrode and the semiconductor substrate The element isolation region is a channel stopper that is a diffusion layer having the same conductivity type as the semiconductor substrate and having a higher concentration than the semiconductor substrate, and is more sensitive to the sensitive region than the element isolation region on the surface of the semiconductor substrate. the MOS structure on the opposite side region, said wiring electrodes, the when the insulating film and are MOS structure formed from the semiconductor substrate, the depletion layer to the sensible region upon incidence of the radiation are formed Semiconductor radiation detector, characterized in that a depletion layer is also formed in the. A semiconductor substrate , an element isolation region formed on the surface of the semiconductor substrate and defining an element formation region , a radiation sensitive region including a pn junction or a Schottky junction formed in the element formation region , and Yes electrode for signal detection in contact with the sensitive area, before Symbol electrodes and wiring electrically connected to electrodes for signal detection, and an insulating film provided between the wiring electrode and the semiconductor substrate The element isolation region is a field plate that is insulated from the semiconductor substrate via an insulating film and is applied with the same potential as the semiconductor substrate, and is present more than the element isolation region on the surface of the semiconductor substrate. on the opposite side of the region of the sensitive area, the wiring electrode, the insulating film and the MOS structure from the semiconductor substrate is formed, prior to when the depletion layer in the sensible area is formed by the incident radiation Semiconductor radiation detector, characterized in that a depletion layer is also formed in the MOS structure.

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