Image sensor for side incidence imaging with radiation barrier plate in radiation absorbing layer

Abstract

The present application discloses a system with an image sensor having: M radiation absorbing layers (radiation absorbing layers (i), i = 1,..., M) parallel to a first reference plane, where M is an integer greater than 1; and M radiation barrier layers (radiation barrier layer (i), i = 1,..., M) parallel to the first reference plane. The M radiation absorbing layers and the M radiation blocking layers collectively form a 2 * M layer stack in which the M radiation absorbing layers and the M radiation blocking layers are arranged in an alternating manner. For each value of i, a radiation barrier plate (i, j) (j = 1,..., Ni) is embedded in the radiation absorbing layer (i), where Ni (i = 1,..., M) is a positive integer. The radiation barrier plate (i, j) (i = 1,..., M, and j = 1,..., Ni) is parallel to a second reference plane perpendicular to the first reference plane.

Description

Background Art

[0001] A radiation detector is a device that measures properties of radiation. Examples of properties may include the spatial distribution of intensity, phase, and polarization of the radiation. The radiation measured by the radiation detector may be radiation that has passed through an object. The radiation measured by the radiation detector may be electromagnetic radiation, such as infrared light, visible light, ultraviolet light, X-rays, or gamma rays. The radiation may be of other types, such as alpha rays and beta rays. An imaging system may include one or more image sensors, each of which may have one or more radiation detectors. Summary of the invention

[0002] The present application discloses a system with an image sensor, wherein the image sensor has: M radiation absorbing layers (radiation absorbing layer (i), i=1, ..., M) parallel to a first reference plane, wherein M is an integer greater than 1; and M radiation blocking layers (radiation blocking layer (i), i=1, ..., M) parallel to the first reference plane. The M radiation absorbing layers and the M radiation blocking layers together form a stack of 2×M layers, in which the M radiation absorbing layers and the M radiation blocking layers are arranged in an alternating manner. For each value of i, a radiation blocking plate (i, j) (j=1, ..., Ni) is embedded in the radiation absorbing layer (i), wherein Ni (i=1, ..., M) is a positive integer. The radiation blocking plate (i, j) (i=1, ..., M, and j=1, ..., Ni) is parallel to a second reference plane perpendicular to the first reference plane.

[0003] In one aspect, each of the M radiation blocking layers is configured to block X-rays, and each of the radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., Ni) is configured to block X-rays.

[0004] In one aspect, each of the M radiation blocking layers comprises tungsten or lead, and each of the radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., Ni) comprises tungsten or lead.

[0005] In one aspect, each of the M radiation blocking layers is electrically isolated.

[0006] In one aspect, each of the radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., Ni) is electrically isolated.

[0007] In one aspect, each of the radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., Ni) is in direct physical contact with one of the M radiation blocking layers.

[0008] In one aspect, each of the radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., Ni) is not in direct physical contact with any radiation absorbing layer of the M radiation blocking layers.

[0009] On the one hand, Ni (i=1, ..., M) are the same, and for each value of j, there exists a plane (j) that: (A) is parallel to the second reference plane and (B) intersects all radiation blocking plates (i, j) (i=1, ..., M).

[0010] In one aspect, the system further includes a radiation source. A straight line intersecting both the radiation source and the image sensor is parallel to the first reference plane and the second reference plane.

[0011] On the one hand, the image sensor also includes an electronic layer, which is configured to process signals generated in the M radiation absorption layers, and any straight line segment including a first endpoint located on the radiation source and a second endpoint located on any of the M radiation absorption layers does not intersect the electronic layer; and the electronic layer is not in the stack.

[0012] In one aspect, the stack is located between the radiation source and the electron layer.

[0013] In one aspect, for each combination of values ​​of i and j, a straight line segment including a first endpoint located on the radiation source and a second endpoint located on the radiation blocking plate (i, j) does not intersect the radiation absorbing layer (i).

[0014] On the one hand, for each value of i, the radiation absorbing layer (i) includes a first surface (i) and a second surface (i), wherein the first surface (i) and the second surface (i) are parallel to a first reference plane, and the first surface (i) is opposite to the second surface (i); and for each combination of values ​​of i and j, the radiation blocking plate (i, j) does not extend completely from the first surface (i) to the opposite side of the second surface (i).

[0015] In one aspect, for each value of i, all radiation blocking plates (i, j), j=1, ..., Ni extend substantially from the first surface (i) to the second surface (i).

[0016] On the one hand, for each value of i, and for any two adjacent radiation blocking plates (a first radiation blocking plate and a second radiation blocking plate) of radiation blocking plates (i, j), j=1, ..., Ni, the first radiation blocking plate substantially extends from the first surface (i) to the second surface (i), and the second radiation blocking plate substantially extends from the second surface (i) to the first surface (i).

[0017] In one aspect, for each combination of values ​​of i and j, the radiation blocking plate (i, j) extends at least 50% of the distance between the first surface (i) and the second surface (i) in a direction perpendicular to the first reference plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A radiation detector according to an embodiment is schematically shown.

[0019] Figure 2 A simplified cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0020] Figure 3 A detailed cross-sectional view of a radiation detector according to an embodiment is schematically shown.

[0021] Figure 4 A detailed cross-sectional view of a radiation detector according to an alternative embodiment is schematically shown.

[0022] Figure 5A-Figure 6 Different views of an imaging system according to an embodiment are schematically shown.

[0023] Figure 7 Schematically shows Figure 6 Another example of a structure of . DETAILED DESCRIPTION

[0024] Radiation Detectors

[0025] As an example, Figure 1 The radiation detector 100 is schematically shown. The radiation detector 100 may include an array of pixels 150 (also referred to as sensing elements 150). The array may be a rectangular array (e.g. Figure 1 as shown), a honeycomb array, a hexagonal array, or any other suitable array. Figure 1 The array of pixels 150 in the example of FIG. 1 has 4 rows and 7 columns; however, in general, the array of pixels 150 may have any number of rows and any number of columns.

[0026] Each pixel 150 can be configured to detect radiation from a radiation source (not shown) incident thereon, and can be configured to measure characteristics of the radiation (e.g., energy, wavelength, and frequency of the particles). Radiation may include radiation particles such as photons (X-rays, gamma rays, etc.) and subatomic particles (alpha particles, beta particles, etc.). Each pixel 150 can be configured to count the number of radiation particles incident thereon over a period of time and whose energy falls into a plurality of energy bins. All pixels 150 can be configured to count the number of radiation particles incident thereon and falling into a plurality of energy bins over the same period of time. When the incident radiation particles have similar energies, the pixel 150 can be simply configured to count the number of radiation particles incident thereon over a period of time without measuring the energy of each radiation particle.

[0027] Each pixel 150 can have its own analog-to-digital converter (ADC) configured to digitize an analog signal representing the energy of an incident radiation particle into a digital signal, or to digitize an analog signal representing the total energy of multiple incident radiation particles into a digital signal. The pixels 150 can be configured to operate in parallel. For example, when one pixel 150 measures an incident radiation particle, another pixel 150 may be waiting for the radiation particle to arrive. The pixels 150 do not have to be individually addressable.

[0028] The radiation detector 100 described herein may be applied to applications such as: X-ray telescopes, X-ray mammography, industrial X-ray defect detection, X-ray microscopy or microradiography, X-ray casting inspection, X-ray nondestructive testing, X-ray weld inspection, X-ray digital subtraction angiography, etc. It may be appropriate to use this radiation detector 100 instead of a photographic plate, photographic film, a photostimulated phosphor plate (PSP plate), an X-ray image intensifier, a scintillator, or another semiconductor X-ray detector.

[0029] Figure 2 Schematically illustrating the Figure 1 2-2. Specifically, the radiation detector 100 may include a radiation absorbing layer 110 and an electronic layer 120 (which may include one or more ASICs or application specific integrated circuits), and the electronic layer 120 is used to process and analyze the electrical signal generated in the radiation absorbing layer 110 by the incident radiation. The radiation detector 100 may or may not include a scintillator (not shown). The radiation absorbing layer 110 may include a semiconductor material such as silicon, germanium, GaAs, CdTe, CdZnTe or a combination thereof. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest.

[0030] As an example, Figure 3 Schematically shows Figure 1 Detailed cross-sectional view of the radiation detector 100 along line 2-2. Specifically, the radiation absorbing layer 110 may include one or more diodes (e.g., pin or pn) formed by one or more discrete regions 114 of the first doping region 111, the second doping region 113. The second doping region 113 may be separated from the first doping region 111 by an optional intrinsic region 112. The discrete regions 114 may be separated from each other by the first doping region 111 or the intrinsic region 112. The first doping region 111 and the second doping region 113 may have opposite types of doping (e.g., the first doping region 111 is p-type and the second doping region 113 is n-type; or the first doping region 111 is n-type and the second doping region 113 is p-type). Figure 3 In the example of , each discrete region 114 of the second doped region 113 forms a diode with the first doped region 111 and the optional intrinsic region 112. That is, in Figure 3 In the example of FIG. 1 , the radiation absorbing layer 110 has a plurality of diodes (more specifically, 7 diodes corresponding to Figure 1 The array has 7 pixels in one row 150, for simplicity, in Figure 3 Only two pixels 150 are marked in FIG. 1 . A plurality of diodes may have an electrode 119A as a shared (common) electrode. The first doped region 111 may also have a plurality of discrete portions.

[0031] The electronic layer 120 may include an electronic system 121 suitable for processing or interpreting signals generated by radiation incident on the radiation absorption layer 110. The electronic system 121 may include analog circuits such as filter networks, amplifiers, integrators, and comparators, or digital circuits such as microprocessors and memories. The electronic system 121 may include one or more ADCs (analog-to-digital converters). The electronic system 121 may include components shared by multiple pixels 150 or components dedicated to a single pixel 150. For example, the electronic system 121 may include an amplifier dedicated to each pixel 150 and a microprocessor shared between all pixels 150. The electronic system 121 may be electrically connected to the pixel 150 through the through hole 131. The space between the through holes may be filled with a filling material 130, which may increase the mechanical stability of the connection of the electronic layer 120 to the radiation absorption layer 110. Other bonding techniques may connect the electronic system 121 to the pixel 150 without using the through hole 131.

[0032] When radiation from a radiation source (not shown) strikes the radiation absorption layer 110 including the diode, the radiation particles may be absorbed and generate one or more carriers (e.g., electrons, holes) through a variety of mechanisms. The carriers may drift to one of the electrodes of the diodes under the action of an electric field. The electric field may be an external electric field. The electrical contact 119B may include a plurality of discrete portions, each of which is in electrical contact with the discrete region 114. The term "electrical contact" may be used interchangeably with the term "electrode". In one embodiment, the carriers may drift in a plurality of directions, and the carriers generated by a single radiation particle are substantially not shared by two different discrete regions 114 (here, "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of these carriers flow to a discrete region 114 different from the discrete region to which the remaining carriers flow). The carriers generated by radiation particles incident around the footprint of one of the discrete regions 114 are substantially not shared by another of the discrete regions 114. A pixel 150 associated with a discrete region 114 may be an area around the discrete region 114 in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the carriers generated by radiation particles incident therein flow toward the discrete region 114. That is, less than 2%, less than 1%, less than 0.1%, or less than 0.01% of the carriers flow out of the pixel 150.

[0033] Figure 4 Schematically illustrating an alternative embodiment Figure 1 Detailed cross-sectional view of radiation detector 100 along line 2-2. More specifically, radiation absorbing layer 110 may include resistors of semiconductor materials such as silicon, germanium, GaAs, CdTe, CdZnTe, or combinations thereof, but not diodes. The semiconductor material may have a high mass attenuation coefficient for the radiation of interest. In one embodiment, Figure 4 The electronic layer 120 is similar in structure and function to Figure 3 The electron layer is 120.

[0034] When radiation strikes the radiation absorbing layer 110, which includes a resistor but does not include a diode, it can be absorbed and generate one or more carriers through a variety of mechanisms. One radiation particle can generate 10 to 100,000 carriers. The carriers can drift to the electrical contacts 119A and 119B under the action of the electric field. The electric field can be an external electric field. The electrical contact 119B can include multiple discrete portions. In one embodiment, the carriers can drift in multiple directions and make the carriers generated by a single radiation particle substantially not shared by two different discrete portions of the electrical contact 119B (here "substantially not shared by..." means that less than 2%, less than 0.5%, less than 0.1% or less than 0.01% of these carriers flow to a discrete portion of the multiple discrete portions that is different from the discrete portion to which the remaining carriers flow). The charge carriers generated by radiation particles incident on the footprint of one of the discrete portions of the electrical contact 119B are substantially not shared by another of the discrete portions of the electrical contact 119B. A pixel 150 associated with a discrete portion of the electrical contact 119B may be an area around the discrete portion in which substantially all (greater than 98%, greater than 99.5%, greater than 99.9%, or greater than 99.99%) of the charge carriers generated by radiation particles incident therein flow toward the discrete portion of the electrical contact 119B. That is, less than 2%, less than 0.5%, less than 0.1%, or less than 0.01% of the charge carriers flow out of the pixel associated with the discrete portion of the electrical contact 119B.

[0035] Imaging System

[0036] Figure 5A and Figure 5B Schematically shows a perspective view of the same imaging system 500 according to an embodiment. In an embodiment, the imaging system 500 may include an image sensor 505 and a radiation source 590. Note that Figure 5A and Figure 5B The same imaging system 500 is shown; however, for ease of viewing, Figure 5A The sensing element 150 shown in FIG. Figure 5B In the display, and Figure 5B The radiation blocking plate 540 shown in FIG. Figure 5A Displayed in.

[0037] Image Sensor

[0038] Radiation absorbing layer of image sensor

[0039] In one embodiment, for illustration, the image sensor 505 may include three radiation absorbing layers 510 a , 510 b , and 510 c . In one embodiment, the three radiation absorbing layers 510 (ie, 510 a , 510 b , and 510 c ) may be parallel to the first reference plane 561 .

[0040] In one embodiment, each of the three radiation absorbing layers 510 may be similar in structure and function to Figure 2-Figure 4 For example, radiation absorbing layer 510a may include a 4×7 array of sensing elements 150 (or simply 4×7 sensing elements 150). Similarly, radiation absorbing layer 510b may include 4×7 sensing elements 150; and radiation absorbing layer 510c may include 4×7 sensing elements 150 (e.g. Figure 5A shown).

[0041] Radiation blocking layers for image sensors

[0042] In one embodiment, for illustration, the image sensor 505 may further include three radiation blocking layers 530a, 530b, and 530c. In one embodiment, the three radiation blocking layers 530 (i.e., 530a, 530b, and 530c) may be parallel to the first reference plane 561. In one embodiment, each of the three radiation blocking layers 530 may be configured to block X-rays. In one embodiment, each of the three radiation blocking layers 530 may include a heavy metal such as tungsten or lead.

[0043] Layer stack in image sensor

[0044] In one embodiment, the three radiation absorbing layers 510 and the three radiation blocking layers 530 may together form a stack of six layers (as shown), with all six layers of the stack being parallel to the first reference plane 561 .

[0045] In one embodiment, in a stack, three radiation absorbing layers 510 and three radiation blocking layers 530 may be arranged in an alternating manner, i.e., from right to left, the radiation absorbing layer 510, then the radiation blocking layer 530, then the radiation absorbing layer 510, then the radiation blocking layer 530, and so on.

[0046] Electronic layer of image sensor

[0047] In one embodiment, the image sensor 505 may further include an electronic layer 520 for processing the signals generated in the 4×7×3 sensing elements 150 of the three radiation absorbing layers 510. In one embodiment, the electronic layer 520 may be similar in structure and function to Figure 2-Figure 4 The electron layer is 120.

[0048] Radiation blocking plates for image sensors

[0049] In one embodiment, the image sensor 505 may further include one or more radiation blocking plates 540 embedded in each radiation absorbing layer 510. For example, Figure 5B As shown, the image sensor 505 may include (A) radiation blocking plates 540a1 and 540a2 embedded in the radiation absorbing layer 510a, (B) radiation blocking plates 540b1 and 540b2 embedded in the radiation absorbing layer 510b, and (C) radiation blocking plates 540c1 and 540c2 embedded in the radiation absorbing layer 510c.

[0050] In one embodiment, all six radiation blocking plates 540 (i.e., 540a1, 540a2, 540b1, 540b2, 540c1, and 540c2) of the image sensor 505 may be parallel to a second reference plane 562 that is perpendicular to the first reference plane 561. In one embodiment, each of the six radiation blocking plates 540 of the image sensor 505 may be configured to block X-rays. In one embodiment, each of the six radiation blocking plates 540 of the image sensor 505 may include a heavy metal such as tungsten or lead.

[0051] In one embodiment, each of the six radiation blocking plates 540 of the image sensor 505 may be in direct physical contact with one of the three radiation blocking layers 510. For example, the radiation blocking plate 540a1 may be in direct physical contact with the radiation blocking layer 530a. For another example, the radiation blocking plate 540b2 may be in direct physical contact with the radiation blocking layer 530b.

[0052] In an alternative embodiment, each of the six radiation blocking plates 540 of the image sensor 505 may not be in direct physical contact with any radiation blocking layer 530. For example, the radiation blocking plate 540a1 may not be in direct physical contact with any radiation blocking layer 530 (including the radiation blocking layer 530a). For another example, the radiation blocking plate 540b2 may not be in direct physical contact with any radiation blocking layer 530 (including the radiation blocking layer 530b).

[0053] In one embodiment, the six radiation blocking plates 540 of the image sensor 505 may be arranged in rows and columns (e.g., as shown in FIG. Figure 5B In one embodiment, three radiation blocking plates 540 in different rows but in the same column may be aligned along a plane parallel to the second reference plane 562 (eg, Figure 5B shown).

[0054] For example, the three radiation blocking plates 540a1, 540b1, and 540c1 may be aligned along a plane parallel to the second reference plane 562 (as shown). Similarly, the three radiation blocking plates 540a2, 540b2, and 540c2 may be aligned along a plane parallel to the second reference plane 562 (as shown).

[0055] In other words, if the six radiation blocking plates 540 of the image sensor 505 are identified as radiation blocking plates (i, j) (i=1, ..., M, and j=1, ..., N (M=3, N=2)), then for each value of j, there exists a plane (j) that (A) is parallel to the second reference plane 562 and (B) intersects with all radiation blocking plates (i, j) (i=1, ..., M).

[0056] Radiation sources for imaging systems

[0057] In an embodiment, radiation source 590 may have any size and shape (i.e., not necessarily a point source). In an embodiment, radiation source 590 may be arranged relative to image sensor 505 such that imaging system 500 is used for side-incidence imaging. In an embodiment, a straight line (not shown) intersecting both radiation source 590 and image sensor 505 may be parallel to first reference plane 561 and second reference plane 562 (as shown).

[0058] In one embodiment, radiation source 590 may generate radiation beam 592 toward object 550 and image sensor 505, with object 550 located between radiation source 590 and image sensor 505 (as shown). In one embodiment, image sensor 505 may capture an image of object 550 based on the interaction between radiation beam 592 and object 550. In one embodiment, radiation beam 592 may be a parallel beam or a diverging beam.

[0059] The interaction between the radiation beam 592 and the object 550 may include scenarios such as: (A) some radiation particles of the radiation beam 592 incident on the object 550 are blocked by the object 550, (B) some radiation particles of the radiation beam 592 incident on the object 550 travel through the object 550 without changing their direction, and (C) some radiation particles of the radiation beam 592 incident on the object 550 collide with atoms of the object 550 and thereby change their direction.

[0060] The term "image" in this patent application (including claims) is not limited to the spatial distribution of radiation characteristics (such as intensity). For example, the term "image" can also include the spatial distribution of the density of a substance or element.

[0061] Other embodiments

[0062] The radiant barrier / radiant barrier is electrically isolated

[0063] In one embodiment, reference Figure 5A and Figure 5B , each of the three radiation blocking layers 530 of the image sensor 505 can be electrically isolated. In one embodiment, each of the six radiation blocking plates 540 of the image sensor 505 can be electrically isolated. Here, in this application (including the claims), "electrically isolated" means configured to not help or interfere with the flow of charge in any sensing element 150 of the image sensor 505. For example, in one embodiment, the three radiation blocking layers 530 and the six radiation blocking plates 540 of the image sensor 505 are not electrically connected to any electrode (119A or 119B) of any sensing element 150 of the image sensor 505.

[0064] The relative position of the electron shell

[0065] In one embodiment, reference Figure 5A and Figure 5B , the electron layer 520 may be positioned such that any straight line segment having a first endpoint located on the radiation source 590 and a second endpoint located on any one of the three radiation absorbing layers 510 does not intersect the electron layer 520. Therefore, the electron layer 520 does not interfere with the image sensor 505 imaging the object 550 using the radiation beam 592 from the radiation source 590.

[0066] In one embodiment, the electronic layer 520 may not be in the stack described above. In one embodiment, the stack may be located between the radiation source 590 and the electronic layer 520 (as shown).

[0067] The radiation source "sees" the radiation barrier

[0068] In one embodiment, for each radiation blocking plate 540, there exists a straight line segment that: (A) has a first endpoint located on the radiation source 590 and a second endpoint located on each radiation blocking plate 540, and (B) does not intersect the radiation absorbing layer 510 in which each radiation blocking plate 540 is embedded.

[0069] For example, for the radiation blocking plate 540a1, there is a straight line segment (not shown): (A) has a first endpoint located on the radiation source 590 and a second endpoint located on the radiation blocking plate 540a1, and (B) does not intersect with the radiation absorbing layer 510a. For another example, for the radiation blocking plate 540b2, there is a straight line segment (not shown): (A) has a first endpoint located on the radiation source 590 and a second endpoint located on the radiation blocking plate 540b2, and (B) does not intersect with the radiation absorbing layer 510b.

[0070] Radiant barrier panels do not extend all the way to the bottom

[0071] Figure 6 Schematically illustrating the Figure 5B 5. A top view of image sensor 505 (ie, viewed from radiation source 590).

[0072] In one embodiment, reference Figure 6 The radiation absorbing layer 510a may include a first surface 510a' and a second surface 510a", both of which are parallel to the first reference plane 561, and the first surface 510a' is opposite to the second surface 510a".

[0073] Similarly, in one embodiment, the radiation absorbing layer 510b may include a first surface 510b′ and a second surface 510b″, both of which are parallel to the first reference plane 561, and the first surface 510b′ is opposite to the second surface 510b″.

[0074] Similarly, in one embodiment, the radiation absorbing layer 510c may include a first surface 510c′ and a second surface 510c″, both of which are parallel to the first reference plane 561, and the first surface 510c′ is opposite to the second surface 510c″.

[0075] In one embodiment, each radiation blocking plate 540 may extend incompletely from the first surface to the second surface of the radiation absorbing layer 510 in which each radiation blocking plate 540 is embedded. For example, the radiation blocking plate 540a1 may extend incompletely from the first surface 510a′ to the second surface 510a″ of the radiation absorbing layer 510a (as shown in the figure). For another example, the radiation blocking plate 540b2 may extend incompletely from the first surface 510b′ to the second surface 510b″ of the radiation absorbing layer 510b (as shown in the figure).

[0076] The radiation blocking panels in each radiation absorbing layer extend substantially from the same surface

[0077] In one embodiment, reference Figure 6 For each radiation absorbing layer 510 , all radiation blocking plates 540 in each radiation absorbing layer 510 may substantially extend from the same surface of the first surface and the second surface of each radiation absorbing layer 510 to the remaining surfaces of the first surface and the second surface of each radiation absorbing layer 510 .

[0078] For example, for the radiation absorbing layer 510a, all the radiation blocking plates 540a1 and 510a2 in the radiation absorbing layer 510a may substantially extend from the first surface 510a' to the second surface 510a". For another example, for the radiation absorbing layer 510b, all the radiation blocking plates 540b1 and 510b2 in the radiation absorbing layer 510b may substantially extend from the first surface 510b' to the second surface 510b".

[0079] Note that in this application (including the claims), the phrase "extending substantially from one surface" means "extending from one surface or almost extending from one surface". The phrase "extending almost from one surface" may be defined as starting from a point whose distance relative to the surface does not exceed 5% of the distance between the first surface and the second surface of the corresponding radiation absorbing layer 510 in a direction perpendicular to the first reference plane 561.

[0080] For example, assuming that the distance between the first surface 510a' and the second surface 510a" of the radiation absorbing layer 510a along the direction perpendicular to the first reference plane 561 is 100μm, and the radiation blocking plate 540a1 starts from a point 4μm (not more than 5% of 100μm) away from the first surface 510a' and extends toward the second surface 510a", it is considered that the radiation blocking plate 540a1 basically extends from the first surface 510a' to the second surface 510a".

[0081] Each radiant barrier extends at least 50%

[0082] In one embodiment, reference Figure 6 , each radiation blocking plate 540 may extend at least 50% of the distance between the first surface and the second surface of the corresponding radiation absorbing layer 510 in the direction perpendicular to the first reference plane 561. For example, assuming that the distance between the first surface 510a′ and the second surface 510a″ of the radiation absorbing layer 510a in the direction perpendicular to the first reference plane 561 is 100 μm, the radiation blocking plate 540a1 may extend at least 50 μm.

[0083] Two adjacent radiation barrier panels extend from different surfaces

[0084] Figure 7 Schematically shows Figure 6 Another example of image sensor 505 . Figure 7 The image sensor 505 may be similar to Figure 6 The image sensor 505 is different in that Figure 7The image sensor 505 includes five radiation blocking plates 540 located in each radiation absorbing layer 510. For example, five radiation blocking plates 540a1, 540a2, 540a3, 540a4, and 540a5 are located in the radiation absorbing layer 510a.

[0085] In one embodiment, reference Figure 7 For each radiation absorbing layer 510 of the image sensor 505, and for any two adjacent radiation blocking plates 540 (referred to as the first radiation blocking plate and the second radiation blocking plate) in each radiation absorbing layer 510, the first radiation blocking plate can basically extend from the first surface of each radiation absorbing layer 510 to the second surface of each radiation absorbing layer 510, and the second radiation blocking plate can basically extend from the second surface of each radiation absorbing layer 510 to the first surface of each radiation absorbing layer 510.

[0086] For example, for the radiation absorbing layer 510a, and for two adjacent radiation blocking plates 540a1 and 540a2, the radiation blocking plate 540a1 basically extends from the first surface 510a' to the second surface 510a", and the radiation blocking plate 540a2 basically extends from the second surface 510a" to the first surface 510a' (as shown in the figure).

[0087] Image sensor formation

[0088] In one embodiment, reference Figure 5A-Figure 7 , the image sensor 505 can be formed as follows. First, a groove can be formed in each radiation absorbing layer 510. Then, in one embodiment, the groove in each radiation absorbing layer 510 can be filled with a material that blocks X-rays, thereby obtaining a radiation blocking plate 540 embedded in each radiation absorbing layer 510. Then, in one embodiment, three radiation absorbing layers 510 (with radiation blocking plates 540 embedded therein) and three radiation blocking layers 530 can be combined together to form a stack. Then, in one embodiment, the electronic layer 520 can be combined to the stack to obtain the image sensor 505.

[0089] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the appended claims.

Claims

1. A system comprising an image sensor, the image sensor comprising: M radiation absorbing layers (radiation absorbing layer (i), i=1, ..., M) parallel to the first reference plane, wherein M is an integer greater than 1; M radiation blocking layers (radiation blocking layer (i), i=1, ..., M) parallel to the first reference plane, wherein the M radiation absorbing layers and the M radiation blocking layers together form a stack of 2×M layers, in which the M radiation absorbing layers and the M radiation blocking layers are arranged in an alternating manner; and For each value of i, a radiation blocking plate (i, j), j=1, ..., Ni, embedded in said radiation absorbing layer (i), wherein Ni, i=1, ..., M is a positive integer, Wherein, the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni, are parallel to a second reference plane perpendicular to the first reference plane.

2. The system according to claim 1, in, Each of the M radiation blocking layers is configured to block X-rays, and Among them, each of the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni is configured to block X-rays.

3. The system according to claim 2, in, Each of the M radiation blocking layers comprises tungsten or lead, and Wherein, each of the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni comprises tungsten or lead.

4. The system of claim 1, wherein: Each of the M radiation blocking layers is electrically isolated.

5. The system of claim 1, wherein: Each of the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni, is electrically isolated.

6. The system of claim 1, wherein: Each of the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni, is in direct physical contact with one radiation absorbing layer among the M radiation blocking layers.

7. The system of claim 1, wherein: Each of the radiation blocking plates (i, j), i=1, ..., M, and j=1, ..., Ni, is not in direct physical contact with any radiation absorbing layer among the M radiation blocking layers.

8. The system of claim 1, in, Ni, i = 1, ..., M are the same, and Therein, for each value of j, there exists a plane (j) that is (A) parallel to the second reference plane and (B) intersects all of the radiation blocking plates (i, j), i=1, ..., M.

9. The system of claim 1, further comprising a radiation source, wherein: A straight line intersecting both the radiation source and the image sensor is parallel to the first reference plane and the second reference plane.

10. The system of claim 9, in, The image sensor further includes an electronic layer configured to process signals generated in the M radiation absorbing layers, wherein any straight line segment including a first endpoint located on the radiation source and a second endpoint located on any radiation absorbing layer of the M radiation absorbing layers does not intersect the electron layer, and Wherein, the electronic layer is not in the stack.

11. The system of claim 10, wherein: The stack is located between the radiation source and the electron layer.

12. The system of claim 9, wherein: For each combination of values ​​of i and j, a straight line segment including a first endpoint located on the radiation source and a second endpoint located on the radiation blocking plate (i, j) does not intersect the radiation absorbing layer (i).

13. The system of claim 1, in, For each value of i, the radiation absorbing layer (i) comprises a first surface (i) and a second surface (i), the first surface (i) and the second surface (i) are both parallel to the first reference plane, and the first surface (i) is opposite to the second surface (i), and Therein, for each combination of values ​​of i and j, the radiation blocking plate (i, j) does not extend completely from the first surface (i) to the second surface (i).

14. The system of claim 13, wherein: For each value of i, all said radiation blocking plates (i, j), j=1, ..., Ni extend substantially from said first surface (i) to said second surface (i).

15. The system of claim 13, wherein: For each value of i, and for any two adjacent radiation blocking plates (first radiation blocking plate and second radiation blocking plate) among the radiation blocking plates (i, j), j=1, ..., Ni, the first radiation blocking plate basically extends from the first surface (i) to the second surface (i), and the second radiation blocking plate basically extends from the second surface (i) to the first surface (i).

16. The system of claim 13, wherein: For each combination of values ​​of i and j, the radiation blocking plate (i, j) extends at least 50% of the distance between the first surface (i) and the second surface (i) in a direction perpendicular to the first reference plane.

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