Double-buried-oxide silicon-on-insulator total dose irradiation detector

Abstract

The invention discloses a double-buried oxygen silicon-on-insulator total dose irradiation detector, relates to the technical field of power electronics, and is used for solving the problems that the detection linear range of an irradiation detector in the prior art is limited, and the integration level of a dosimeter device and a circuit is relatively low. Comprising a silicon substrate; the second buried oxide layer is formed on the silicon substrate; a configuration layer formed on the second buried oxide layer; the first buried oxide layer is formed on the configuration layer; the configuration layer is led out by an electrode, and a lead-out electrode of the configuration layer is on the front surface; the first buried oxide layer serves as a gate oxide layer of the dosimeter device, and the configuration layer serves as a grid electrode of the dosimeter device. According to the invention, dosimeter devices can be integrated into a circuit. The thick gate oxide used by the dosimeter device does not need to be manufactured by changing a device process any more, and is well compatible with a circuit process; the threshold voltage offset of the dosimeter device is kept in a linear change region by using a bias cycle control measurement technology, the threshold voltage change is not saturated, and the detected dose range can be greatly widened.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a silicon-on-double-buried-oxygen-insulator total dose irradiation detector. Background Art

[0002] As the sensing component of the radiation dose detection equipment, the sensitivity, total dose that can be detected and the 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. However, in the prior art, due to factors such as the structure of the dosimeter device or the radiation resistance of the bulk silicon device, the detection linear range of the radiation detector is limited, and the integration of the dosimeter device and the circuit is low.

[0004] Therefore, there is an urgent need to provide a more reliable total dose irradiation detector. Summary of the invention

[0005] The object of the present invention is to provide a double buried oxygen silicon on insulator total dose radiation detector for solving the problems in the prior art that the detection linear range of the radiation detector is limited and the integration of the dose meter device and the circuit is low.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a double buried oxygen silicon on insulator total dose irradiation detector, comprising at least:

[0008] Silicon substrate;

[0009] a second buried oxide layer formed on the silicon substrate;

[0010] a configuration layer formed on the second buried oxide layer;

[0011] And a first buried oxide layer is formed on the configuration layer; the configuration layer is led out by an electrode, and the lead-out electrode of the configuration layer is on the front side; the first buried oxide layer serves as a gate oxide layer of a dosimeter device, and the configuration layer serves as a gate of the dosimeter device.

[0012] Optionally, the double buried oxide silicon on insulator total dose irradiation detector also includes:

[0013] a functional layer formed on the first buried oxide layer;

[0014] The functional layer includes a source region, a drain region, a channel region, a front gate and a gate oxide layer;

[0015] The isolation between the device structures in the functional layer is performed by shallow trench isolation using oxide, and the isolation between the configuration layers is performed by shallow trench isolation using oxide.

[0016] Optionally, when the dosimeter device is irradiated, electron-hole pairs are generated in the first buried oxide layer, and trapped charges are accumulated in the interface region between the first buried oxide layer and the functional layer, causing the back gate threshold voltage of the dosimeter device to drift.

[0017] Optionally, the gate contact of the dosimeter device is an electrode of the configuration layer;

[0018] The front gate and the first buried oxide layer are grounded;

[0019] The bias voltage of the dosimeter device is applied separately using a double buried oxide silicon-on-insulator structure.

[0020] Optionally, when radiation ions pass through the dosimeter device, they are ionized in the oxide to generate electron-hole pairs; the electrons and holes generated by ionization are evenly distributed in the oxide; the holes form trapped charges in the oxide, changing the trapped charge density in the oxide, causing changes in the electrical parameters of the device.

[0021] Optionally, the bias cycle controlled measurement includes a positive charge accumulation phase and a radiation induced charge neutralization phase;

[0022] In the positive charge accumulation stage, the gate of the dosimeter device is connected to a positive voltage, and the other terminals are grounded;

[0023] When irradiated, the radiation excites electron-hole pairs, and under a positive gate voltage, among the electron-hole pairs that do not recombine, the electrons are swept out of the gate and the holes move toward the functional layer and the silicon substrate;

[0024] In the gate oxide layer, a large number of holes are trapped within a preset distance from the Si / SiO2 interface. Under a constant positive bias, the holes are annealed or tunneled from the functional layer and the silicon substrate to the gate oxide layer and recombined with electrons trapped nearby.

[0025] Optionally, when the bias voltage changes from positive to negative, the movement directions of the electrons and holes are reversed, the tunneling compensation at the Si / SiO2 interface stops, the electrons move toward the functional layer and the silicon substrate, the holes move toward the gate, or are captured by the gate, and the electrons move toward the Si / SiO2 interface.

[0026] Optionally, charge accumulates under positive bias, and a negative shift in the threshold voltage is used to quantify the absorbed dose; when the negative bias is switched, radiation-induced charge neutralization begins, the threshold voltage increases, and a positive shift in the threshold voltage is used to quantify the absorbed dose.

[0027] Optionally, when the circuit is sampling, a dosimeter device is connected to the circuit; the channel corresponding to the dosimeter device is in a region close to the first buried oxide layer, the front gate is grounded, and a parasitic thick gate oxide MOS structure is used.

[0028] Optionally, during irradiation, the drain, front gate and source of the dosimeter device are grounded, and the back gate is connected to a bias voltage; during readout, a current source inputs current from the source to the dosimeter device, the drain, back gate and front gate are grounded, and the output voltage is the threshold voltage of the back gate transistor of the dosimeter device.

[0029] Compared with the prior art, the present invention provides a double buried oxide silicon on insulator total dose irradiation detector, which at least includes: a silicon substrate; a second buried oxide layer formed on the silicon substrate; a configuration layer formed on the second buried oxide layer; and a first buried oxide layer formed on the configuration layer; the configuration layer is led out by an electrode, and the lead-out electrode of the configuration layer is on the front side; the first buried oxide layer serves as the gate oxide layer of the dosimeter device, and the configuration layer serves as the gate of the dosimeter device. The present invention uses the configuration layer as the gate (BG), the first buried oxide layer as the gate oxide layer, and the second buried oxide layer can be operated in isolation. When biasing the dosimeter device, other devices and circuits on the same chip are not affected by the bias, and the dosimeter device can be integrated into the circuit. The thick gate oxide used in the dosimeter device no longer needs to change the device process manufacturing, and can be well compatible with the circuit process; the threshold voltage offset of the dosimeter device is kept in the linear change region by using the bias cycle control measurement technology, and the threshold voltage change is not saturated, which can greatly broaden the detection dose range. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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:

[0031] Figure 1 It is a schematic diagram of a dose meter device of prior art 1;

[0032] Figure 2 It is a schematic diagram of a dose meter device of prior art 2;

[0033] Figure 3 A schematic diagram of the structure of a double-buried-oxygen silicon-on-insulator total dose irradiation detector provided by the present invention;

[0034] Figure 4 A schematic diagram of charge distribution of the dosimeter device provided by the present invention when irradiated without bias voltage;

[0035] Figure 5 A schematic diagram of charge changes of the dosimeter device provided by the present invention when irradiated under positive bias;

[0036] Figure 6 A schematic diagram of charge changes of the dosimeter device provided by the present invention when irradiated under negative bias voltage;

[0037] Figure 7 A schematic diagram of the channel position of the double buried oxygen-on-insulator silicon dosimeter device provided by the present invention when it is connected to a circuit;

[0038] Figure 8 Schematic diagram of the irradiation and readout circuit of the double buried oxygen-on-insulator silicon dosimeter device.

[0039] Reference numerals:

[0040] 101-front gate, 101A-gate oxide layer, 102A-source region, 102B-drain region, 103-channel region, 104A-first buried oxide layer, 104B-second buried oxide layer, 105A-functional layer, 105B-configuration layer, 106-silicon substrate, 107-oxide, 108-electrode, 201-radiation ions, 202-electrons, 203-holes, 301-positive voltage, 302- Ground, 303-sweeping direction, 304A-first electron, 304B-second electron, 401-negative bias, 402-first moving direction, 403-second moving direction, 404-capture direction, 405-recombination direction, 501-target area, 601-drain, 602-gate, 603-source, 604-back gate, 605-bias voltage, 606-current source, 607-output voltage. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] First, the English abbreviations used in the embodiments of this specification are explained:

[0045] BCCM: Bias Controlled CycledMeasurement, bias cycle controlled measurement.

[0046] PCB: Positive Charge Buildups, positive charge accumulation.

[0047] RICN: Radiation Induced Charge Neutralization, radiation induced charge neutralization.

[0048] At present, the solutions in the prior art are as follows:

[0049] Prior art 1:

[0050] The dosimeter device in the prior art is a metal-oxide semiconductor field effect transistor (MOS) dosimeter device prepared by a standard complementary metal oxide semiconductor (CMOS) process, and a thick field oxide (FOX) is used to isolate the field region in the chip as the gate oxide of the sensor. The device structure is as follows Figure 1 As shown. Usually, FOX devices have a very high absolute value of threshold voltage, often higher than 20V, in order to achieve its isolation function and prevent the operating voltage on the conductive line located on the thick gate oxide layer from accidentally inducing a conductive channel in the underlying silicon. The drain (Drain) and source (Source) regions of the N-channel FOXFET adopt a doping concentration lower than the N+ region. However, one of the prior arts is to use field oxide (FieldOxide) as the gate oxide layer, and increasing the thickness of the gate oxide layer improves the sensitivity to the dose. This results in a very high threshold voltage of the dosimeter device, and a high-voltage control dosimeter device is required when integrated in the circuit, and its power supply voltage (VDD) is greater than 15V. When the dosimeter device is integrated with the readout circuit, a high-voltage CMOS process is required, and the circuit power consumption is high. The power supply voltage of the logic control circuit part is generally less than 5V, and an additional circuit is required for level conversion.

[0051] In addition, the radiation resistance of the bulk silicon device in the prior art is very poor, and the circuit and the dosimeter device need to be manufactured separately. During irradiation, the dosimeter device is irradiated separately, and after the irradiation is completed, it is connected to the circuit for reading. Since the readout circuit is easily affected by irradiation and causes circuit malfunction, in order to be able to read the dose detected by the dosimeter device during irradiation, the readout circuit needs to be isolated from the radiation source.

[0052] Prior art 2:

[0053] A silicon-on-insulator (SOI) device is used as a dosimeter device, the buried oxide layer (BOX) is used as the radiation detection area, and the back silicon substrate (Sub) is used as the gate electrode of the device. The structure is as follows Figure 2 As shown. During irradiation, electron-hole pairs are generated in the buried oxide layer, resulting in an increase in radiation-induced trapped charges in the buried oxide layer and a change in the back gate threshold voltage of the device. However, the dosimeter device in the second prior art uses a silicon substrate as a gate. When integrated with a readout circuit, the bias state of the dosimeter device affects the circuit. Therefore, the silicon substrate of the dosimeter device can only be grounded during irradiation, which limits the detection range of the dosimeter device.

[0054] In order to solve the above problems in the prior art, the present invention provides a double buried oxygen silicon on insulator total dose irradiation detector. Next, the solution provided in the embodiment of this specification is described in conjunction with the accompanying drawings:

[0055] like Figure 3 As shown, the structure may include:

[0056] Silicon substrate 106;

[0057] A second buried oxide layer 104B formed on the silicon substrate 106;

[0058] A configuration layer 105B formed on the second buried oxide layer 104B;

[0059] And a first buried oxide layer 104A is formed on the configuration layer 105B; the configuration layer 105B is led out by the electrode 108, and the lead-out electrode of the configuration layer 105B is on the front side; the first buried oxide layer 104A serves as the gate oxide layer of the dosimeter device, and the configuration layer 105B serves as the gate of the dosimeter device.

[0060] Figure 3 The structure includes: a silicon substrate; a second buried oxide layer formed on the silicon substrate; a configuration layer formed on the second buried oxide layer; and a first buried oxide layer formed on the configuration layer; the configuration layer is led out by an electrode, and the lead-out electrode of the configuration layer is on the front side; the first buried oxide layer serves as a gate oxide layer of the dosimeter device, and the configuration layer serves as a gate of the dosimeter device. The present invention uses the configuration layer as a gate (BG), the first buried oxide layer as a gate oxide layer, and the second buried oxide layer can be operated in isolation. When biasing the dosimeter device, other devices and circuits on the same chip are not affected by the bias, and the dosimeter device can be integrated into the circuit. The thick gate oxide used in the dosimeter device no longer needs to change the device process manufacturing, and can be well compatible with the circuit process; the threshold voltage offset of the dosimeter device is kept in the linear change region by using the bias cycle control measurement technology, and the threshold voltage change is not saturated, which can greatly broaden the detection dose range.

[0061] based on Figure 3 The present specification also provides some specific implementation structures of the structure, which will be described below.

[0062] More specifically, the double buried oxygen silicon on insulator total dose irradiation detector further includes:

[0063] A functional layer 105A formed on the first buried oxide layer 104A;

[0064] The functional layer 105A includes a source region 102A, a drain region 102B, a channel region 103, a front gate 101 and a gate oxide layer 101A;

[0065] The isolation between the device structures in the functional layer 105A is performed by shallow trench isolation using oxide, and the isolation between the configuration layers 105B is performed by shallow trench isolation using oxide 107 .

[0066] like Figure 3As shown, the configuration layer 105B is located on the first buried oxide layer 104A, and the functional layer 105A is located on the first buried oxide layer 104A, including the source region 102A, the drain region 102B, the channel region 103, the front gate 101 and the gate oxide layer 101A. The device structures in the functional layer 105A are isolated by shallow trench isolation through oxide 107, and the configuration layers are also isolated by shallow trench isolation using oxide 107. When the dosimeter device is irradiated, electron-hole pairs are generated in the first buried oxide layer 104A, and trapped charges are accumulated in the interface region between the first buried oxide layer 104A and the functional layer 105A, causing the back gate threshold voltage of the dosimeter device to drift.

[0067] The present invention provides Figure 3 In the structure, since the dosimeter device used has a thick gate oxide layer, it can be used as the first buried oxide layer 104A of the gate oxide layer, and no additional process is required to make the thick gate oxide layer. The isolated back gate-configuration layer 105B can apply different voltages without affecting other circuits. At the same time, the double buried oxide silicon on insulator structure has the characteristics of radiation resistance when making circuits, and is less affected by radiation than the bulk silicon structure. The gate contact of the dosimeter device is the electrode 108 of the configuration layer 105B, and the gate oxide layer is the first buried oxide layer 104A. The front gate 101 and the gate oxide layer 101A are grounded and do not act as gates. The double buried oxide silicon on insulator structure can apply the bias voltage of the dosimeter device separately without affecting other circuits. At the same time, the lead electrode 108 of the configuration layer 105B is on the front side and does not need to be led out separately from the back side, which is convenient for integration with the circuit. The isolation of the configuration layer 105B can realize independent voltage bias between each region, which not only suppresses the opening of the back gate, but also compensates for the influence of the radiation-induced trap charge of the insulating layer on the front gate. In addition, unlike the PN junction isolation of the fully depleted silicon-on-insulator (FDSOI) structure, the independent back-gate control characteristics of the DSOI device can improve the flexibility of the circuit radiation hardening design.

[0068] When the dosimeter device is irradiated, electron-hole pairs are generated in the first buried oxide layer, and trapped charges are accumulated in the interface region between the first buried oxide layer and the functional layer, causing the back gate threshold voltage of the dosimeter device to drift.

[0069] As an optional implementation, the gate contact of the dosimeter device is the electrode of the configuration layer; the front gate and the first buried oxide layer are grounded; and the bias voltage of the dosimeter device is applied separately using a double buried oxide silicon-on-insulator structure.

[0070] When radiation ions pass through the dosimeter device, they are ionized in the oxide to generate electron-hole pairs; the electrons and holes generated by ionization are evenly distributed in the oxide; the holes form trapped charges in the oxide, changing the trapped charge density in the oxide and causing changes in the electrical parameters of the device.

[0071] The bias cycle controlled measurement includes a positive charge accumulation phase and a radiation-induced charge neutralization phase;

[0072] In the positive charge accumulation stage, the gate of the dosimeter device is connected to a positive voltage, and the other terminals are grounded;

[0073] When irradiated, the radiation excites electron-hole pairs, and under a positive gate voltage, among the electron-hole pairs that do not recombine, the electrons are swept out of the gate and the holes move toward the functional layer and the silicon substrate;

[0074] In the gate oxide layer, a large number of holes are trapped within a preset distance from the Si / SiO2 interface. Under a constant positive bias, the holes are annealed or tunneled from the functional layer and the silicon substrate to the gate oxide layer and recombined with electrons trapped nearby.

[0075] When the bias voltage changes from positive to negative, the moving directions of the electrons and holes are reversed, the tunneling compensation at the Si / SiO2 interface stops, the electrons move toward the functional layer and the silicon substrate, the holes move toward the gate, or are captured by the gate, and the electrons move toward the Si / SiO2 interface.

[0076] Under positive bias, charge accumulates and the negative shift of threshold voltage is used to quantify absorbed dose; under negative bias switching, radiation-induced charge neutralization begins, the threshold voltage increases, and the positive shift of threshold voltage is used to quantify absorbed dose.

[0077] When the circuit is sampling, the dosimeter device is connected to the circuit; the channel corresponding to the dosimeter device is in the area close to the first buried oxide layer, the front gate is grounded, and a parasitic thick gate oxide MOS structure is used.

[0078] During irradiation, the drain, front gate and source of the dosimeter device are grounded, and the back gate is connected to a bias voltage; during readout, a current source inputs current from the source to the dosimeter device, the drain, back gate and front gate are grounded, and the output voltage is the threshold voltage of the back gate transistor of the dosimeter device.

[0079] In order to further illustrate the technical effects corresponding to the technical solutions provided by the present invention, next, based on Figure 4-8 To explain:

[0080] The electron-hole pair distribution generated by the DSOI dosimeter device provided by the present invention when irradiated without bias is as follows: Figure 4 As shown:

[0081] When the radiation ions 201 pass through the device, they will ionize and generate electron-hole pairs in the oxide. Since there is no bias voltage, the electrons 202 and holes 203 generated by ionization will be evenly distributed in the oxide. These holes 203 generated by ionization will form trapped charges in the oxide, change the trapped charge density in the oxide, and cause changes in the electrical parameters of the device. When the radiation dose accumulates to a certain amount, the number of trapped charges is maintained at a certain level. At this time, the change in the electrical parameters of the device also tends to a saturated state and no longer changes with the increase of the dose.

[0082] Further, as an optional implementation, in order to increase the detection range and linear region, a bias cycle control measurement technology is used to apply different voltages to the configuration layer 105B of the dosimeter device to control the threshold voltage drift caused by irradiation. The bias cycle control measurement is divided into two states, the positive charge accumulation stage (PCB) and the radiation induced charge neutralization stage (RICN).

[0083] Specifically, Figure 5 As shown, in the positive charge accumulation stage, the gate of the dosimeter device is connected to a positive voltage 301, and the other terminals are grounded 302. When irradiated, the radiation excites electron-hole pairs. Under the positive voltage 301, 70% to 90% of the electron-hole pairs do not recombine, and the electrons are quickly swept out of the configuration layer 105B. The sweeping direction is shown as 303, and the holes slowly move toward the functional layer 105A and the silicon substrate 106. In the gate oxide layer (the first buried oxide layer 104A and the second buried oxide layer 104B), a large number of holes are captured within 10nm from the Si / SiO2 interface. Under a constant positive bias, these holes are annealed or tunneled from the functional layer 105A and the silicon substrate 106 to the first buried oxide layer 104A and are captured nearby. The first electron 304A and the second electron 304B recombine.

[0084] When the bias voltage changes from positive bias voltage to negative bias voltage 401, the direction of electron and hole movement is reversed, such as Figure 6 As shown:

[0085] Tunneling compensation at the Si / SiO2 interface stops, and electrons move toward the functional layer 105A and the silicon substrate 106. The first moving direction is shown as 402, and holes move toward the configuration layer 105B. The second moving direction is shown as 403, or they are captured (the capture direction is shown as 404) in the configuration layer 105B. At this time, the threshold shift caused by holes can even be ignored. Electrons move toward the Si / SiO2 interface. If the electrons encounter holes near the Si / SiO2 interface, they are captured or directly recombined (the recombination direction is shown as 405), reducing the drift caused by the oxide trap charge.

[0086] Charge accumulates under positive bias, and the threshold voltage is negatively shifted to quantify the absorbed dose; when the negative bias is switched, radiation-induced charge neutralization begins, the threshold voltage increases, and the threshold voltage is positively shifted to quantify the absorbed dose. By switching different bias states, the threshold voltage of the dosimeter device can be maintained within a specified window to ensure stable sensitivity throughout the measurement process. While maintaining the same sensitivity, the measurement range can be expanded by more than a thousand times.

[0087] When the circuit is sampling, the dosimeter device is connected to the circuit, such as Figure 7 As shown:

[0088] The channel used by the DSOI dosimeter device is in the target area 501 near the first buried oxide layer 104A, the front gate 101 is grounded, and a parasitic thick gate oxide (i.e., the first buried oxide layer 104A) MOS structure is used. Except for the high voltage required for controlling the configuration layer 105B of the DSOI dosimeter device, the remaining sources and drains all use the same power supply voltage as the circuit, which greatly reduces the power consumption of the dosimeter device and its circuit. After the first buried oxide layer is thinned and the back gate control voltage is reduced to within the circuit voltage range, the dosimeter device and its circuit no longer require an additional high-voltage power supply or boost circuit module, and can be well integrated in other processing circuits, greatly improving the integration of the dosimeter device and reducing the volume of the dose detection equipment.

[0089] The circuits of DSOI dosimeter devices during irradiation and readout are as follows Figure 8 As shown:

[0090] During irradiation, the drain 601, gate 602, and source 603 of the dosimeter device are grounded, and the back gate 604 is connected to a bias voltage 605; during readout, a current source 606 inputs current to the dosimeter device from the source 603, and the drain 601, back gate 604, and gate 602 are grounded. The output voltage 607 is the threshold voltage of the back gate transistor of the dosimeter device. The change in the threshold voltage can clearly indicate the total radiation dose to which the device is exposed.

[0091] The present invention provides a dosimeter device for improving the integration of a total dose detector and expanding the detection range of a dosimeter device. The device uses a double buried oxide silicon on insulator device as a dosimeter device, utilizes the first layer of buried oxygen of the double buried oxide silicon on insulator as the gate oxide layer of the dosimeter device, and uses a configuration layer as the gate of the dosimeter device. The detection range of the dosimeter device is expanded by applying different voltages to the configuration layer. The doping type of the configuration layer is configurable, and the saturation interval detected by the dosimeter device and the amplitude of the drift of the threshold voltage as the dose increases are changed by changing the doping type. More specifically, the technical effects that can be achieved by the solution provided by the present invention include at least the following:

[0092] 1) Using a PMOS dosimeter device based on the DSOI process, the configuration layer is used as the gate (BG), the first buried oxide layer is used as the gate oxide layer, and the second buried oxide layer can be operated in isolation, so that when the dosimeter device is biased, other devices and circuits on the same chip are not affected by the bias, and the dosimeter device can be integrated into the circuit. In addition, the thick gate oxide used in the dosimeter device no longer needs to change the device process manufacturing, and can be well compatible with the circuit process.

[0093] 2) Using bias cycle control measurement technology to keep the threshold voltage offset of the dosimeter device in the linear change region and prevent the threshold voltage change from saturating can greatly broaden the detected dose range.

[0094] 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.

[0095] 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 double buried oxygen silicon on insulator total dose irradiation detector, characterized in that: At least: Silicon substrate; a second buried oxide layer formed on the silicon substrate; a configuration layer formed on the second buried oxide layer; And a first buried oxide layer is formed on the configuration layer; the configuration layer is led out by an electrode, and the lead-out electrode of the configuration layer is on the front side; the first buried oxide layer serves as a gate oxide layer of a dosimeter device, and the configuration layer serves as a gate of the dosimeter device.

2. A double buried oxygen silicon on insulator total dose irradiation detector according to claim 1, characterized in that: The double buried oxygen-on-insulator total dose irradiation detector also includes: a functional layer formed on the first buried oxide layer; The functional layer includes a source region, a drain region, a channel region, a front gate and a gate oxide layer; The isolation between the device structures in the functional layer is performed by shallow trench isolation using oxide, and the isolation between the configuration layers is performed by shallow trench isolation using oxide.

3. A double buried oxygen silicon on insulator total dose irradiation detector according to claim 2, characterized in that: When the dosimeter device is irradiated, electron-hole pairs are generated in the first buried oxide layer, and trapped charges are accumulated in the interface region between the first buried oxide layer and the functional layer, causing the back gate threshold voltage of the dosimeter device to drift.

4. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 1, characterized in that: The gate contact of the dosimeter device is an electrode of the configuration layer; The front gate and the first buried oxide layer are grounded; The bias voltage of the dosimeter device is applied separately using a double buried oxide silicon-on-insulator structure.

5. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 1, characterized in that: When radiation ions pass through the dosimeter device, they are ionized in the oxide to generate electron-hole pairs; the electrons and holes generated by ionization are evenly distributed in the oxide; the holes form trapped charges in the oxide, changing the trapped charge density in the oxide and causing changes in the electrical parameters of the device.

6. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 2, characterized in that: The bias cycle controlled measurement includes a positive charge accumulation phase and a radiation-induced charge neutralization phase; In the positive charge accumulation stage, the gate of the dosimeter device is connected to a positive voltage, and the other terminals are grounded; When irradiated, the radiation excites electron-hole pairs, and under a positive gate voltage, among the electron-hole pairs that do not recombine, the electrons are swept out of the gate and the holes move toward the functional layer and the silicon substrate; In the gate oxide layer, a large number of holes are trapped within a preset distance from the Si / SiO2 interface. Under a constant positive bias, the holes are annealed or tunneled from the functional layer and the silicon substrate to the gate oxide layer and recombined with electrons trapped nearby.

7. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 6, characterized in that: When the bias voltage changes from positive to negative, the moving directions of the electrons and holes are reversed, the tunneling compensation at the Si / SiO2 interface stops, the electrons move toward the functional layer and the silicon substrate, the holes move toward the gate, or are captured by the gate, and the electrons move toward the Si / SiO2 interface.

8. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 7, characterized in that: Under positive bias, charge accumulates and the negative shift of threshold voltage is used to quantify absorbed dose; under negative bias switching, radiation-induced charge neutralization begins, the threshold voltage increases, and the positive shift of threshold voltage is used to quantify absorbed dose.

9. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 1, characterized in that: When the circuit is sampling, the dosimeter device is connected to the circuit; the channel corresponding to the dosimeter device is in the area close to the first buried oxide layer, the front gate is grounded, and a parasitic thick gate oxide MOS structure is used.

10. The double buried oxygen silicon on insulator total dose irradiation detector according to claim 1, characterized in that: During irradiation, the drain, front gate and source of the dosimeter device are grounded, and the back gate is connected to a bias voltage; during readout, a current source inputs current from the source to the dosimeter device, the drain, back gate and front gate are grounded, and the output voltage is the threshold voltage of the back gate transistor of the dosimeter device.

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