A semiconductor irradiation detector for total dose effect loss

Abstract

The present invention discloses a semiconductor radiation detector for total dose effect loss, and relates to the field of radiation detection technology. The semiconductor radiation detector includes: a semiconductor field effect tube, and a capacitor module arranged at the top rear end of the semiconductor field effect tube; the capacitor module is configured to drift the voltage across the capacitor module after pre-charging as the total dose effect continues to accumulate, and the gate voltage applied to the semiconductor field effect tube drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect tube is determined; the semiconductor field effect tube is configured to determine the radiation dose change based on the drain current change, so that the semiconductor field effect tube can increase the radiation dose through the capacitor module while ensuring a thick gate oxide layer, so that the semiconductor radiation detector can be integrated into the complementary metal oxide semiconductor manufacturing process, and the cost of integrating the semiconductor radiation detector on the chip is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of radiation detection, and in particular to a semiconductor radiation detector for total dose effect loss. Background Art

[0002] Radiation dose detection equipment is one of the indispensable equipment in the field of radiation medicine and aerospace. As the sensing component of radiation dose detection equipment, the sensitivity, total dose that can be detected and size of the radiation detector will directly restrict the performance and size of the radiation dose detection equipment.

[0003] At present, radiation detectors can be divided into three types: ionization chamber radiation detectors, fiber optic radiation detectors and semiconductor radiation detectors. Among them, ionization chamber radiation detectors, also known as ion chambers, are composed of electrodes at different potentials and a medium between the electrodes. Ionizing radiation produces ionized ion pairs in the medium. Under the action of the electric field, the ions drift to the two poles respectively, forming a current proportional to the radiation dose. Fiber optic radiation detectors work by using the characteristics of scintillators that ionize or excite to produce photons after being irradiated. During its operation, it converts radiation particles into photons, which generate electrons through the photoelectric effect. The movement of electrons forms a current, and the radiation dose is calculated by the change in the current. However, the ionization chamber has the problem of high voltage required for operation and large equipment size, which makes it impossible to miniaturize and integrate the equipment. Fiber optic radiation detectors are mostly used to calibrate other radiation detectors, but their total measurable dose is small, and they are close to saturation when the dose reaches 50-100 krad.

[0004] For semiconductor radiation detectors, they use the property that semiconductor materials will produce a large number of electron holes after being irradiated to detect radiation dose. The minimum radiation dose that can be measured is 10krad, and threshold voltage drift will occur after being irradiated. Generally, semiconductor radiation detectors use a constant current source reading method during use, keep the detector working current constant, read the threshold voltage drift, and calculate the radiation dose. When the traditional Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is used as a radiation sensor, it is also called a Radiation-Sensitive Field Effect Transistor (RADFET). Generally, P-type MOSFET can be used for radiation measurement. Its sensitive part is the MOS structure in the device. In order to improve the sensitivity of the device and measure a larger total dose, PMOS radiation detectors often require thick gate oxide layers and high gate bias voltages. This makes it impossible to integrate PMOS RADFET manufacturing into the complementary metal oxide semiconductor (CMOS) manufacturing process, resulting in the radiation detector being unable to be integrated into chips manufactured using ordinary processes, requiring additional processes to increase manufacturing costs. Summary of the invention

[0005] The object of the present invention is to provide a semiconductor radiation detector for total dose effect loss, so as to solve the problem that the existing radiation detector cannot be integrated on a chip of ordinary manufacturing process and requires additional process to increase manufacturing cost.

[0006] In a first aspect, the present invention provides a semiconductor radiation detector for total dose effect loss, the semiconductor radiation detector comprising: a semiconductor field effect transistor, and a capacitor module arranged at the top rear end of the semiconductor field effect transistor;

[0007] The capacitor module is configured such that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined;

[0008] The semiconductor field effect transistor is configured to determine a change in irradiation dose based on the change in drain current.

[0009] In the case of adopting the above technical solution, the embodiment of the present application provides a semiconductor radiation detector for total dose effect loss, the semiconductor radiation detector includes: a semiconductor field effect tube, and a capacitor module arranged at the top rear end of the semiconductor field effect tube; the capacitor module is configured so that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, and the gate voltage applied to the semiconductor field effect tube drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect tube is determined; the semiconductor field effect tube is configured to determine the radiation dose change based on the drain current change, so that the semiconductor field effect tube can increase the radiation dose through the capacitor module while ensuring a thick gate oxide layer, so that the semiconductor radiation detector can be integrated into the CMOS manufacturing process, reducing the cost of integrating the semiconductor radiation detector on the chip.

[0010] In a possible implementation manner, the capacitor module includes at least one capacitor.

[0011] In a possible implementation, the capacitor module includes a plurality of capacitors of different qualities and / or capacitance values, and the plurality of capacitors are configured to perform radiation detection with multiple ranges and multiple precisions in combination with the semiconductor field effect transistor.

[0012] In a possible implementation, the area and thickness of the capacitor are determined based on the size of the total dose.

[0013] In a possible implementation, the capacitor includes a first metal plate, and a metal dielectric layer and a second metal plate sequentially disposed on the first metal plate.

[0014] In a possible implementation, the semiconductor field effect transistor includes: a source, a drain, and a substrate, and a gate oxide layer, a gate, and a metal through-hole metal layer arranged on the source, the drain, and the substrate.

[0015] In a possible implementation manner, the first metal plate is disposed above the metal through-hole metal layer.

[0016] In a possible implementation, the metal via metal layer includes a first metal layer, a second metal layer and a third metal layer which are sequentially arranged away from the source / drain and the substrate;

[0017] A first portion of the first metal layer is disposed on the source / drain and the substrate, and a second portion of the first metal layer is disposed on the gate.

[0018] In a possible implementation, the semiconductor field effect transistor further includes an interlayer insulating dielectric layer, and the interlayer insulating dielectric layer is disposed inside the semiconductor field effect transistor.

[0019] In a possible implementation manner, the semiconductor field effect transistor is further configured to determine the sensitivity of the semiconductor radiation detector based on the radiation dose variation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic diagram of a process flow of a semiconductor irradiation detector for total dose effect loss provided by an embodiment of the present application is shown;

[0022] Figure 2 A schematic flow chart of another semiconductor irradiation detector for total dose effect loss provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0024] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0025] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0026] Figure 1 FIG. 4 shows a schematic diagram of the structure of a semiconductor irradiation detector for total dose effect loss provided by an embodiment of the present application. Figure 1 As shown, the semiconductor irradiation detector for total dose effect loss includes:

[0027] A semiconductor field effect transistor 10, and a capacitor module 20 disposed at the top and rear end of the semiconductor field effect transistor 10;

[0028] The capacitor module 20 is configured such that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined;

[0029] The semiconductor field effect transistor 10 is configured to determine a change in irradiation dose based on the change in drain current.

[0030] In summary, the semiconductor radiation detector for total dose effect loss provided in the embodiment of the present application includes: a semiconductor field effect transistor, and a capacitor module arranged at the top rear end of the semiconductor field effect transistor; the capacitor module is configured so that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, and the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined; the semiconductor field effect transistor is configured to determine the radiation dose change based on the drain current change, so that the semiconductor field effect transistor can increase the radiation dose through the capacitor module while ensuring a thick gate oxide layer, so that the semiconductor radiation detector can be integrated into the CMOS manufacturing process, thereby reducing the cost of integrating the semiconductor radiation detector on the chip.

[0031] Figure 2 FIG. 4 shows a schematic diagram of the structure of another semiconductor irradiation detector for total dose effect loss provided by an embodiment of the present application. Figure 2 As shown, semiconductor irradiation detectors for total dose effect loss include:

[0032] A semiconductor field effect transistor 10, and a capacitor module 20 disposed at the top and rear end of the semiconductor field effect transistor 10;

[0033] The capacitor module 20 is configured such that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined;

[0034] The semiconductor field effect transistor 10 is configured to determine a change in irradiation dose based on the change in drain current.

[0035] Optionally, the semiconductor field effect transistor is further configured to determine the sensitivity of the semiconductor radiation detector based on the radiation dose variation.

[0036] For the radiation-sensitive field effect transistor (RADFET), which is the semiconductor field effect transistor in this application, the sensitive unit is the MOS structure in the transistor, and the dose of radiation radiation can also be sensed by using a metal-oxide-metal (MOM) capacitor or a metal-insulator-metal (MIM) capacitor.

[0037] The semiconductor irradiation detector for total dose effect loss in the present application is that after the capacitor module is pre-charged, as the total dose effect (Total Ionizing Dose, TID) continues to accumulate, the capacitance-voltage curve will gradually drift with the accumulation of radiation dose. When the voltage across the capacitor module drifts, the voltage applied to the gate of the semiconductor field effect transistor will also drift, thereby causing a large change in the drain current of the semiconductor field effect transistor.

[0038] Specifically, formula (1) and formula (2) are respectively the expressions of the drain current in the saturation region and the working region of the semiconductor field effect tube:

[0039]

[0040]

[0041] Among them, I DSis the device channel current, μ n is the carrier mobility in the device; C ox is the gate oxide capacitance; W and L are the width and gate length of the device; V DS is the voltage difference between drain and source; V th is the device threshold voltage; V GS is the voltage difference between gate and source.

[0042] By measuring the change in drain current, the change in radiation dose sensed by the radiation detector can be calculated. At this time, the sensitivity (S) can be expressed by formula (3):

[0043]

[0044] Among them, ΔI DS is the drift of the drain current of the semiconductor field effect tube, and D is the radiation dose received by the detector. The voltage with a small change can be converted into a parameter with a large change through the current parameter, which improves the sensitivity of the detector to a certain extent.

[0045] Optional, see Figure 2 The capacitor module 20 includes at least one capacitor C.

[0046] In the present application, the capacitor module includes multiple capacitors of different qualities and / or capacitance values. The multiple capacitors are configured to perform radiation detection with multiple ranges and multiple accuracies in combination with the semiconductor field effect transistor, so that a semiconductor radiation detector can be used in multiple scenarios.

[0047] In the present application, the area and thickness of the capacitor are determined based on the size of the total dose.

[0048] See also Figure 2 The capacitor C includes a first metal plate 201 , and a metal dielectric layer 202 and a second metal plate 203 sequentially arranged on the first metal plate 201 .

[0049] In the present application, the semiconductor field effect transistor can be an ordinary MOSFET or a MOSFET with a structure such as Silicon on Insulator (SOI), so as to realize the integrated application of new semiconductor irradiation detectors at small size nodes such as 28 nanometers. The embodiments of the present application do not limit the specific type and structure of the semiconductor field effect transistor, and can be adjusted according to the actual application scenario.

[0050] Optional, see Figure 2 The semiconductor field effect transistor 10 includes: a source, a drain and a substrate 101 , and a gate oxide layer 102 , a gate 103 and a metal through-hole metal layer 104 arranged on the source, the drain and the substrate 101 .

[0051] Optionally, the first metal electrode plate 201 is disposed above the metal through-hole metal layer 104 .

[0052] Optionally, the metal via metal layer 104 includes a first metal layer 1041, a second metal layer 1042 and a third metal layer 1043 which are sequentially arranged away from the source / drain and the substrate 101;

[0053] A first portion of the first metal layer 1041 is disposed on the source / drain and the substrate 101 , and a second portion of the first metal layer 1041 is disposed on the gate 103 .

[0054] Optionally, the semiconductor field effect transistor 10 further includes an interlayer insulating dielectric layer 105 , and the interlayer insulating dielectric layer 105 is disposed inside the semiconductor field effect transistor 10 .

[0055] In summary, the semiconductor radiation detector for total dose effect loss provided in the embodiment of the present application includes: a semiconductor field effect transistor, and a capacitor module arranged at the top rear end of the semiconductor field effect transistor; the capacitor module is configured so that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, and the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined; the semiconductor field effect transistor is configured to determine the radiation dose change based on the drain current change, so that the semiconductor field effect transistor can increase the radiation dose through the capacitor module while ensuring a thick gate oxide layer, so that the semiconductor radiation detector can be integrated into the CMOS manufacturing process, thereby reducing the cost of integrating the semiconductor radiation detector on the chip.

[0056] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0057] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A semiconductor irradiation detector for total dose effect loss, characterized in that: The semiconductor radiation detector comprises: a semiconductor field effect tube, and a capacitor module arranged at the top and rear end of the semiconductor field effect tube; the capacitor module comprises at least one capacitor; The capacitor module is configured such that after pre-charging, as the total dose effect continues to accumulate, the voltage across the capacitor module drifts, the gate voltage applied to the semiconductor field effect transistor drifts based on the drift of the voltage across the capacitor module, and the drain current change of the semiconductor field effect transistor is determined; The semiconductor field effect transistor is configured to determine the amount of change in irradiation dose based on the amount of change in the drain current; The capacitor comprises a first metal plate, and a metal dielectric layer and a second metal plate sequentially arranged on the first metal plate; The semiconductor field effect transistor comprises: a source, a drain and a substrate, and a gate oxide layer, a gate and a metal through-hole metal layer arranged on the source, the drain and the substrate; The first metal plate is disposed above the metal through-hole metal layer; The metal via metal layer comprises a first metal layer, a second metal layer and a third metal layer which are sequentially arranged away from the source / drain and the substrate; A first portion of the first metal layer is disposed on the source / drain and the substrate, and a second portion of the first metal layer is disposed on the gate.

2. The semiconductor irradiation detector for total dose effect loss according to claim 1, characterized in that: The capacitor module includes a plurality of capacitors of different masses and / or capacitance values. The plurality of capacitors are configured to perform radiation detection with multiple ranges and multiple precisions in combination with the semiconductor field effect transistor.

3. The semiconductor irradiation detector for total dose effect loss according to claim 1, characterized in that: The area and thickness of the capacitor are determined based on the size of the total dose.

4. The semiconductor irradiation detector for total dose effect loss according to claim 3, characterized in that: The semiconductor field effect transistor further comprises an interlayer insulating dielectric layer, and the interlayer insulating dielectric layer is arranged inside the semiconductor field effect transistor.

5. The semiconductor radiation detector for total dose effect loss according to claim 1, characterized in that: The semiconductor field effect transistor is further configured to determine the sensitivity of the semiconductor radiation detector based on the radiation dose variation.

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