JPH0620158B2 - Semiconductor radiation distribution detector - Google Patents

Description

The present invention relates to a semiconductor device for detecting radiation such as an electron beam, a particle beam, and a light beam, particularly a two-dimensional distribution of an electron beam.

(B) Conventional technology Conventionally, when measuring weak light or radiation,
Electrons, multipliers or multi-channel electrontrons that apply the principle of secondary electron emission are used. In particular, with the development of microfabrication technology, multichannel tunneltrons have come to be obtained as thin microchanneltrons having an outer diameter of several tens of microns.

More recently, a so-called two-dimensional observation microchannel plate has been developed in which tens of thousands to hundreds of thousands of microchannels are bundled into a plate shape.

FIG. 5 is an example thereof, and FIG. 5 (a) is a schematic diagram of a microchannel plate bundled in a disc shape.
(b) is a model showing how incident radiation is amplified in a channel tron having a high-resistance semiconductor film. Here, (1) is the incident radiation, (2) is the microchannel plate, (3) is the secondary electron that is width-doubled and emerges from the microchannel plate (2), (4),
(5) is an electrode, (6) is a secondary electron, (7) is a power supply voltage source for applying a bias voltage to the channel plate (2) via the electrodes (4) and (5), and (8) is an increase. It is a power supply that applies voltage to the collector (9) that collects the secondary electrons (3) that are multiplied and output. Usually, a gain of about 10 ³ to 10 ⁵ can be obtained on the microchannel plate.

When a weak input signal is finally obtained as a visible light image using the microchannel plate with such a configuration, it can be easily realized by using an optical lens system and a fluorescent plate. The image can be easily processed as two-dimensional information by means of a TV camera or the like.

However, in general, when the two-dimensional information of the input radiation is to be directly captured as a two-dimensional image using this microchannel plate, a problem arises in the measurement system on the output side. That is, in the case of direct two-dimensional observation of radiation, it is required to detect the intensity and position information of the input signal quantitatively and without time delay.

By the way, as an example of the conventional device for detecting the secondary distribution of the electron beam appearing on the output side of the microchannel plate, as shown in FIG. 6, two-dimensionally on the output side of the microchannel plate (2). Providing a plurality of collectors (10) arranged. However, with this method, it is difficult to reduce the shape of the collector, and the two-dimensional position resolution is not easily improved. Also, collector 1
Since an external measurement system is used for each one, peripheral equipment is quite difficult. This hinders the miniaturization of the entire microchannel plate and its wide application.

There are also known ones that detect a two-dimensional distribution of radiation such as an electron beam and a particle beam by using a semiconductor element, but all of these are photolithographic methods using a photomask on the surface of one semiconductor substrate. The method of arranging the radiation detectors in a two-dimensional array by the method described above, and in this case also, similarly to the case of the array of collectors, there is a limit to reducing the size of each detector. There is
It also requires large peripherals.

In addition to the demand for improving the resolution of the collector electrode or the detector and reducing the size of peripheral devices, real-time measurement is strongly required (the method of emitting light from the fluorescent plate causes a time lag and is not practical).

(C) Problems to be solved by the invention and objects thereof The present invention has these problems of the prior art, namely, the position resolution of the two-dimensional distribution of radiation such as electron beam, ion beam, particle beam, ray, and X-ray. Therefore, the object of the present invention is to solve the problems of the conventional ones such as low power consumption, large peripheral equipment, and difficulty in real-time measurement. Is to provide a semiconductor radiation two-dimensional distribution detection device that can detect a two-dimensional distribution of radiation such as a high resolution, quantitatively and in real time, and that requires only a small peripheral device. Includes not only light rays and X-rays but also broadly includes electron beams, ion beams, particle beams and the like.

(D) Means for Solving the Problems In order to achieve this object, in the semiconductor radiation two-dimensional distribution detection device of the present invention, a plurality of semiconductor devices having the end face as the incident surface are provided in the vicinity of one end of the same semiconductor substrate. The radiation detectors of the above are provided in parallel, and the preamplifier circuits for the respective radiation detectors are provided on the same semiconductor difference plate, and a plurality of semiconductor substrates are laminated via an insulating layer into a block shape. The radiation detectors are arranged in a two-dimensional array on one side of the block body.

In a preferred embodiment, the radiation detector is arranged to detect an electron beam, in particular an electron beam emerging from the microchannel plate, which is a surface barrier detector or a pn junction detector. You can pay. The preamplifier circuit is, for example, a RUSH type high speed amplifier (see, for example, "Electronic Science", November 1978, pp. 39-41), a charge-sensitive amplifier.

(E) Action In the present invention, a plurality of radiation detectors provided in parallel at one end of the same semiconductor substrate so that the end faces serve as the incident planes of radiation detect the distribution of radiation in a one-dimensional direction. The two-dimensional distribution can be detected by stacking these. Moreover, the resolution can be enhanced as a characteristic of the laminated type. Further, since each radiation detector is integrally provided with the preamplifier circuit, it is possible to detect in real time and the peripheral device becomes small. Further, it is easy to fabricate a main amplifier, a waveform shaping circuit, an A-D conversion circuit, a delay line, a memory, etc. on the same chip as necessary. In some cases, a CPU is also provided on the same chip. You can also

(F) Embodiment One embodiment of the present invention will be described below with reference to the drawings. In this embodiment, an electron beam emitted from the microchannel plate is described as an example of radiation to be detected, but the present invention is not limited to this, and other radiation such as ion beam, particle beam, It will be apparent from the following description that it can be applied to the detection of a two-dimensional distribution of rays, X-rays and the like.

FIG. 1 is a conceptual diagram for explaining an embodiment of the present invention. (1) indicates the incoming direction of the incident radiation as described above,
(2) is a microchannel plate. (11) is a flat semiconductor substrate that is a main component of the detection device (100) according to the present embodiment, and (12) is an insulation formed to keep the semiconductor substrate (11) in an electrically insulated state. Membrane (eg S _i O ₂
Membrane). A required number of semiconductor substrates (11) and insulating films (12) are alternately laminated to form an integral block body. This semiconductor substrate (11) will be described in more detail.

As an example, the structure of this substrate is shown in FIG. (11) is a semiconductor substrate (for example, high-purity silicon, 100 μm to 30 μm)
It is a flat plate having a thickness of 0 μm). This semiconductor substrate
As for (11), it is simple to use a high-purity silicon material as described above, and it can be widely applied in view of cost. Of course, a material having a large atomic number, which has a strong mutual interference with charged particles, such as an organic semiconductor which has been recently developed, can also be used. The following elements are formed on this substrate (11). That is, for example, the radiation detector (1 that is arranged close to the output side of the microchannel plate
3) (which is configured as an electron beam detector in this embodiment) and is electrically connected to the radiation detector (13) by a thin film electrode (14), and a signal is output from the detector (13). Preamplifier circuit (15) to be input, and further this preamplifier circuit
Terminal (pad) for supplying the required power supply voltage to (15)
(16) and a terminal (1 that extracts the output signal of the preamplifier circuit (15)
7) and Further, the detection parts (13) are provided in parallel with each other, but each of them is a thin groove (18) for separation on the substrate.
It is taken into consideration that they do not interfere with each other (made by etching).

The preamplifier circuit (15) shown in FIG. 2 is integrated and provided on the substrate (11). In FIG. 3, the npn transistor of the first stage input section is shown as a model. npn
A vapor-deposited aluminum wiring (20) extends from the emitter side (19) of the transistor to the tip of the substrate (11) to form a surface electrode. The size of this surface becomes a factor that determines the volume of the radiation detecting portion (for example, it is determined so as to have a width of 3 to 4 times the microchannel plate). Then the substrate (11)
Gold vapor deposition (21) is applied to the opposite surface on the opposite side to the surface barrier potential is formed between the two, and a semiconductor radiation detecting portion is formed in this portion.

A bias voltage is applied to the semiconductor radiation detection section through the electrodes (20) and (21) to leave a full depletion layer. By doing so, for example, the secondary electron group (3) emitted from the microchannel plate generates an electron-ion pair (22), (23) due to the interaction with the silicon atom in this semiconductor detection part. . The total number of this electron-ion pair is proportional to the magnitude and total amount of the energy of the incident secondary electrons. Therefore, in this embodiment, by keeping the high voltage bias of the microchannel plate constant, the total number of electron-ion pairs is proportional to only the total amount of incident secondary electrons. In this way, the current value of the electron-ion pair can be amplified to a required signal level via the preamplifier circuit.

Needless to say, if a waveform shaping circuit, an A-D conversion circuit, etc. are formed on one chip, the signal processed accordingly can be taken out. In this embodiment, the surface barrier type detector is adopted as the radiation detector (13), but it is also possible to use other semiconductor radiation detectors (for example, pn junction type detector). . Further, from the above description, the radiation that generates the electron-ion pair (22), (23) in the depletion layer of the semiconductor is not limited to the electron beam, but may be an ion beam, a particle beam, a light beam, an X-ray or the like. It is clear from the property theory that it is good. Therefore, the semiconductor radiation secondary distribution detecting device of the present invention is not limited to detecting the two-dimensional distribution of the electron beam.

Now, the preamplifier circuit (15) used here is required to have a rise time of 0.1 to 1 nsec, a fast response, and a low noise property for handling a weak signal. FIG. 4 shows an embodiment for that purpose, in which the detecting portion (13) is indicated by a diode symbol. The circuit is mainly based on the RUSH type high-speed system, and the detection unit is on the emitter side of the npn transistor (24) in the input stage.
(13) is connected through the bias circuits (26) and (27). These circuits will be integrated as the preamplifier circuit (15) of FIG. In addition, when mainly considering low noise, a charge sensitive amplifier or the like can be used.

(G) Effects of the Invention As described above through the embodiments, the semiconductor radiation distribution detecting apparatus of the present invention, since a minute radiation detector is formed in parallel by a method such as photolithography at the substrate end, Compared with other electron beam detection devices, higher position resolution is possible, real-time detection is also possible, and by incorporating a preamplifier circuit, etc., peripheral devices that perform signal processing are small. Become. Further, since the preamplifier circuit and the like are integrally formed, the manufacturing of the entire device is simplified. In addition, the detection device of the present invention can measure the two-dimensional distribution of radiation by a method of scanning one substrate and scanning in the direction perpendicular to the surface thereof, and also by stacking a plurality of substrates, the two devices can be simultaneously paralleled. In addition, it is possible to measure the two-dimensional distribution of the radiation, and by detecting the two-dimensional distribution of the radiation, it can be used for various measuring methods and can also be used as a conversion element for an image of a radiation such as an electron beam.

Furthermore, when the detection device of the present invention is used in combination with a microchannel plate, it enables realization of two-dimensional weak light measurement, which has been difficult to realize in the past, and a high-speed signal converted into an electrical signal is a real-time image. It also enables processing. Further, in the vertical arrangement method of the present invention, the detection unit and the preamplifier circuit are integrally incorporated, and the number of laminated layers can be made variable according to the required two-dimensional size of the microchannel plate. Therefore, it is possible to obtain an arbitrary size of the two-dimensional surface.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an example of a semiconductor radiation two-dimensional distribution detector of the present invention used in combination with a microchannel plate, and FIG. 2 is a semiconductor substrate which is a main part of the detector of FIG. FIG. 3, FIG. 3 is a partial sectional view showing a part of the AA ′ section of FIG. 2, FIG. 4 is a circuit diagram of an example of a preamplifier circuit formed on a semiconductor substrate, and FIG.
The figure is an illustration of the microchannel plate.
Figure (a) is a schematic perspective view, Figure 5 (b) is an explanatory view showing how electrons are multiplied in one microchannel tron, and Figure 6 shows the relationship between the microchannel plate and the collector. It is a fragmentary sectional view shown. 1: incident radiation, 2: microchannel plate,
3, 6: Secondary electron group, 4, 5: Electrodes 7, 8: Bias power supply, 9, 10: Collector, 11: Semiconductor substrate, 12: Insulating film 13: Radiation (electron beam) detector 14: Vapor deposition electrode, 15: preamplifier circuit 16, 17: terminal, 18: isolation groove, 19: emitter of npn transistor, 20, 21: vapor deposition electrode, 22,
23: Electron-ion pair 24, 25: Transistor, 26, 31: Capacitor, 27-30: Resistor 32-34: Terminal, 100: Detection device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H01L 27/14

Claims (10)

[Claims] 1. A plurality of radiation detectors each having an end face as a radiation incident surface are formed in parallel in the vicinity of one end of the same semiconductor substrate, and a preamplifier circuit for each of the radiation detectors is provided. A plurality of semiconductor substrates each having a signal processing circuit including the same formed on the same semiconductor substrate are laminated with an insulating layer interposed therebetween so that the radiation incident surfaces are aligned to form a block, and a radiation detector is provided on one side surface of the block body. Semiconductor radiation two-dimensional distribution detector characterized in that the two are arranged in a two-dimensional array. 2. The semiconductor radiation two-dimensional distribution detector according to claim 1, wherein the radiation detector is a surface barrier type detector. 3. The semiconductor radiation two-dimensional distribution detector according to claim 1, wherein the radiation detector is a pn junction type detector. 4. The semiconductor radiation two-dimensional distribution detector according to claim 1, wherein the preamplifier circuit is a RUSH type high speed amplifier circuit. 5. The semiconductor radiation two-dimensional distribution detector according to claim 1, wherein the preamplifier circuit is a charge-sensitive amplifier. 6. A microchannel plate and a detection device for detecting an electron beam from the microchannel plate which is arranged immediately after the microchannel plate, the detection device having the end face in the vicinity of one end of the same semiconductor substrate. A plurality of radiation detectors serving as radiation incident surfaces are formed in parallel, and a signal processing circuit including a preamplifier circuit for each of the radiation detectors is formed on the same semiconductor substrate. A plurality of sheets are laminated so that the incident surfaces of the radiation are aligned to form a block, and the radiation detectors are arranged on one side surface of the block in a two-dimensional array corresponding to the microchannel plate. A semiconductor radiation two-dimensional distribution detector characterized in that 7. The semiconductor radiation two-dimensional distribution detector according to claim 6, wherein the radiation detector is a surface barrier type detector. 8. The two-dimensional semiconductor radiation detecting apparatus according to claim 6, wherein the radiation detector is a pn junction type detector. 9. The semiconductor radiation two-dimensional distribution detector according to claim 6, wherein the preamplifier circuit is a RUSH type high speed amplifier circuit. 10. The semiconductor radiation two-dimensional distribution detection device according to claim 6, wherein the preamplifier circuit is a charge-sensitive amplifier.