Defense circuit of semiconductor device and semiconductor device including the same

A semiconductor device includes a sensing circuit including a first semiconductor element configured to generate a first current in response to externally incident light, a compensation circuit including a semiconductor element configured to generate a second current depending on an ambient temperature and to remove the second current from the first current to generate a third current, a detection circuit configured to convert the third current into a photovoltage and to compare the photovoltage with a predetermined reference voltage to determine whether an external attack has occurred, and a defense circuit configured to control the semiconductor device to perform a predetermined defense operation, based on a result of the determination.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2020-0001864, filed on Jan. 7, 2020 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

Exemplary embodiments of the inventive concept relate to a defense circuit of a semiconductor device and a semiconductor device including the defense circuit.

DISCUSSION OF RELATED ART

Physical attacks for extracting data from a semiconductor device may be classified into non-invasive attacks, semi-invasive attacks, and invasive attacks, depending on whether the semiconductor device is damaged. An invasive attack refers to an attack method of directly observing and analyzing the inside of a semiconductor device. Representative examples of an invasive attack are a de-packaging attack, a probing attack, or the like. An invasive attack is a significantly powerful attack method to directly access a circuit element, a metal wiring, or the like, inside of a semiconductor device.

SUMMARY

According to an exemplary embodiment of the inventive concept, a semiconductor device includes a sensing circuit including a first semiconductor element configured to generate a first current in response to externally incident light, a compensation circuit including a second semiconductor element configured to generate a second current, depending on an ambient temperature, and to remove the second current from the first current to generate a third current, a detection circuit configured to convert the third current into a photovoltage and to compare the photovoltage with a predetermined reference voltage to determine whether an external attack has occurred, and a defense circuit configured to control the semiconductor device to perform a predetermined defense operation, based on a result of the determination.

According to an exemplary embodiment of the inventive concept, a defense circuit of a semiconductor device includes a first diode connected to a first node, a second diode connected to a second node, an input resistor connected between a power supply node configured to supply a power supply voltage and the second node, a first operational amplifier having the first node as an inverting input node and the second node as a non-inverting input node, and a second operational amplifier having an output node of the first operational amplifier as a non-inverting input node. The first operational amplifier includes a feedback resistor connected between the first node and the output node of the first operational amplifier.

According to an exemplary embodiment of the inventive concept, a defense circuit of a semiconductor device includes a sensing circuit including a first semiconductor element configured to generate a first current based on externally incident light and an ambient temperature, a compensation circuit configured to remove current depending on the ambient temperature from the first current to generate a second current, a first operational amplifier configured to output a photovoltage corresponding to the second current, and a second operational amplifier configured to compare the photovoltage with a predetermined reference voltage to generate a comparison result, and to output an event signal indicating whether an external attack has occurred based on a comparison result. The compensation circuit includes a second semiconductor element having substantially the same characteristics as the first semiconductor element and is disposed adjacent to the first semiconductor element. A level of a reverse bias voltage applied to the first semiconductor element is substantially the same as a level of a reverse bias voltage applied to the second semiconductor element.

According to an exemplary embodiment of the inventive concept, a defense circuit of a semiconductor device includes a detection circuit including a first operational amplifier and a second operational amplifier, a sensing circuit including a first diode, and a compensation circuit including a second diode. The first and second diodes are connected to at least one input node of the first operational amplifier. The second operational amplifier is configured to compare an output of the first operational amplifier with a predetermined reference voltage to generate a comparison result, and to output an event signal indicating whether an external attack has occurred based on the comparison result. The first diode generates photocurrent in response to externally incident light and first leakage current depending on ambient temperature. The second diode only generates second leakage current depending on the ambient temperature. The first and second leakage currents are substantially the same.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the inventive concept provide a defense circuit of a semiconductor device, which may sense externally incident light to accurately detect a physical attack, and a semiconductor device including the defense circuit.

Hereinafter, exemplary embodiments of the inventive concept will be described with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout this application.

FIG.1is a schematic block diagram illustrating a configuration of a semiconductor device according to an exemplary embodiment of the inventive concept.

Referring toFIG.1, a semiconductor device1according to an exemplary embodiment of the inventive concept may include a defense circuit10and a defense unit20. The defense unit20may also be a circuit.

The defense circuit10may sense light, incident inwardly of (or towards) a semiconductor chip, to detect a physical attack on the semiconductor chip. In exemplary embodiments of the inventive concept, the physical attack may include a case in which packaging is damaged by a de-packaging attack on a semiconductor chip or other abnormal situations.

The defense circuit10may include a sensing unit11, a compensation unit13, and a detection unit15. According to an exemplary embodiment of the inventive concept, the sensing unit11, the compensation unit13, and the detection unit15may be circuits.

The sensing unit11may generate a photocurrent in response to light incident inwardly of the semiconductor chip. The sensing unit11may include a photosensitive device such as a photodiode, a phototransistor, or the like.

A semiconductor device may operate at a significantly high temperature according to a system environment, an operating condition, or the like. For example, since an electronic control unit (ECU) of a vehicle is disposed adjacent to an engine to be thermally connected to various engine components, the ECU generally operates at a high temperature. The sensing unit11, included in a high-temperature ECU, may generate a predetermined leakage current depending on (or due to) an ambient temperature even when external light does not penetrate therethrough. The generation of such leakage current may significantly reduce physical attack detection accuracy of the defense circuit10. To address such an issue, the compensation unit13may remove the leakage current depending on the ambient temperature generated by the sensing unit11.

In exemplary embodiments of the inventive concept, the compensation unit13may be implemented using the same semiconductor element as the sensing unit11. For example, the compensation unit13may include a photosensitive element such as a photodiode, a phototransistor, or the like. Unlike the sensing unit11, the compensation unit13may be optically shielded to not receive externally incident light. Accordingly, the compensation unit13may generate only leakage current depending on the ambient temperature, and may compensate for the leakage current, generated by the sensing unit11, using the generated leakage current. In other words, the sensing unit11generates a first current (e.g., current including a first leakage current), and the compensation unit13generates a second current (e.g., a second leakage current). The first and second leakage currents (the leakage current) may be substantially the same. The compensation unit13performs compensation by removing the second current from the first current to generate a third current (e.g., the photocurrent that excludes the leakage current).

The detection unit15may convert the photocurrent, generated by the sensing unit11and the compensation unit13, into an optical voltage, and may compare the optical voltage with a predetermined reference voltage to determine whether a physical attack has occurred on a semiconductor chip. For example, when the converted optical voltage is higher than or equal to a predetermined reference voltage, the detection unit15may output an event signal indicating occurrence of the physical attack on the semiconductor chip. Meanwhile, when the converted optical voltage is lower than the predetermined reference voltage, the detector15may output an event signal indicating non-occurrence of the physical attack on the semiconductor chip. In exemplary embodiments of the inventive concept, the event signal may be a voltage signal having a logic high level when the physical attack has occurred on the semiconductor chip, and may be a voltage signal having a logic low level when the physical attack has not occurred on the semiconductor chip.

The defense unit20may control the semiconductor device to perform a predetermined defense operation when the physical attack has occurred on the semiconductor chip. For example, the defense unit20may control the semiconductor device to perform operations such as data initialization, data scrambling, data output blocking, or the like when an event signal indicating the occurrence of the physical attack is received from the defense circuit10.

The defense unit20may be included in a specific semiconductor chip to be protected with the defense circuit10. In addition, the defense circuit10may be included in a specific semiconductor chip to be protected, and the defense unit20may be included in another semiconductor chip, for example, an application processor (AP). In other words, the defense circuit10including the sensing unit11, the compensation unit13, and the detection unit15may be included in a first semiconductor chip, the defense unit20may be included in a second semiconductor chip, and the first and second semiconductor chips are separate.

FIG.2is a circuit diagram of a defense circuit according to an exemplary embodiment of the inventive concept.FIGS.3A and3Bare circuit diagrams illustrating a sensing unit inFIG.2according to exemplary embodiments of the inventive concept.

Referring toFIG.2, a defense circuit100according to an exemplary embodiment of the inventive concept may include a sensing unit110, a compensation unit130, and a detection unit150including a first operational amplifier AMP1and a second operational amplifier AMP2.

The sensing unit110may have a first diode D1connected between an inverting input node N (e.g., a first node) of the first operational amplifier AMP1and a second power supply node for supplying a second power supply voltage, for example, a grounding node.

The first diode D1may include at least one photosensitive element generating a photocurrent in response to incident light. In exemplary embodiments of the inventive concept, the photosensitive element may be a photodiode. Alternatively, as illustrated inFIG.3A, the photosensitive element may be a phototransistor. Alternatively, as illustrated inFIG.3B, the photosensitive element may be a combination of a transistor and a photodiode.

A level of a first reverse bias voltage VN, applied to the first diode D1, may vary depending on an ambient temperature of the defense circuit100. For example, as the ambient temperature is increased, the first diode D1may generate more leakage current, and the first reverse bias voltage VNmay be increased or decreased in inverse proportion to the amount of generated leakage current.

The compensation unit130may include an input resistor R connected between a first power node for supplying a first power supply voltage DVDD and a non-inverting input node P (e.g., a second node) of the first operational amplifier AMP1, and a second diode D2connected between the non-inverting input node P of the first operational amplifier AMP1and the second power supply voltage node, for example, a grounding node.

The second diode D2may have substantially the same current-voltage characteristics as the first diode Dl. In addition, the second diode D2may be disposed adjacent to the first diode D1. Therefore, the magnitude of leakage current, generated by the first diode D1based on the ambient temperature, may be substantially the same as the magnitude of the leakage current generated by the second diode D2.

Unlike the first diode D1, the second diode D2may allow incident light to be blocked by a light shielding film such as a metal. Therefore, unlike the first diode D1, the second diode D2may generate only leakage current depending on the ambient temperature.

A second reverse bias voltage VP, applied to the second diode D2, may be determined by the first power supply voltage DVDD and an input resistance of the input resistor R. The higher the second reverse bias voltage VP, the more amount of current may be generated by the second diode D2from the same number of electron-hole pairs. As a result, the compensation unit130may be increased in sensitivity to a change in the ambient temperature, to detect the amount of leakage current more accurately. Accordingly, in exemplary embodiments of the inventive concept, the first power supply voltage DVDD may have a maximum level at which the first power supply voltage DVDD may be applied to the second diode D2.

A level of the second reverse bias voltage VPmay vary depending on the ambient temperature. For example, the level of the second reverse bias voltage VPmay be increased or decreased in inverse proportion to the amount of leakage current generated by the first diode D1depending on the ambient temperature.

The first operational amplifier AMP1may convert the photocurrent, generated by the first diode D1, into an output voltage VTat an output node T. In exemplary embodiments of the inventive concept, an operating voltage AVDD of the first operational amplifier AMP1may have a magnitude greater than a magnitude of the first power supply voltage DVDD.

A feedback resistor RFmay be connected between the output node T and the non-inverting input node N of the first operational amplifier AMP1. In exemplary embodiments of the inventive concept, the feedback resistor RFmay have substantially the same magnitude as the input resistor R. In addition, the leakage current, generated by the first diode D1, may have substantially the same magnitude as the leakage current generated by the second diode D2. Therefore, the first reverse bias voltage VNmay maintain substantially the same level as the second reverse bias voltage VPin spite of a change in the ambient temperature. As a result, since an influence of the change in the ambient temperature on the output voltage VTof the first operational amplifier AMP1may be eliminated, the defense circuit100may more accurately sense externally incident light to determine whether an external attack has occurred.

The second operational amplifier AMP2may receive the output voltage VTof the first operational amplifier AMP1through a non-inverting input terminal, and may receive a predetermined reference voltage VREFthrough an inverting input terminal. The second operational amplifier AMP2may compare the output voltage VTof the first operational amplifier AMP1with the predetermined reference voltage VREFto output a comparison result VOUT.

The reference voltage VREFmay be set to an appropriate value to prevent an unnecessary protection operation from being performed by dark current, which may be temporarily generated in a normal operation of the semiconductor chip, by inspection light incident in a testing process of a semiconductor chip, or the like.

When sizes of the first diode D1, the second diode D2, the input resistance R, and the feedback resistor RFare decreased to decrease a size of the defense circuit100, light detection sensitivity of the defense circuit100may be reduced. To prevent this, in exemplary embodiments of the inventive concept, the reference voltage VREFmay be set to a relatively low value. Thus, the defense circuit100may accurately detect a physical attack even when a photodiode manufactured by a typical CMOS process is used as the first diode Dl.

FIGS.4A to4Dare cross-sectional views illustrating an arrangement relationship between a first diode and a second diode inFIG.2according to exemplary embodiments of the inventive concept.

Referring first toFIG.4A, the first diode D1and the second diode D2according to an exemplary embodiment of the inventive concept may be disposed to be adjacent to each other.

The first diode D1may be formed by implanting an N-type first semiconductor material230into a P-type semiconductor substrate210. The second diode D2may be formed by implanting an N-type second semiconductor material250, adjacent to the first semiconductor material230, into the semiconductor substrate210. In exemplary embodiments of the inventive concept, the first semiconductor material230and the second semiconductor material250may be implanted with substantially the same doping concentration and substantially the same size.

The first diode D1may generate a photocurrent in response to incident light. Meanwhile, the second diode D2cannot generate a photocurrent because a light shielding film B formed of a metal, or the like, is disposed on the second diode D2.

However, since the first diode D1and the second diode D2are formed of the same material and with substantially the same size in regions adjacent to each other, characteristics thereof may be substantially the same. Therefore, the amount of leakage current generated by the first diode D1based on the ambient temperature may be substantially the same as the amount of leakage current generated by the second diode D2. A defense circuit according to an exemplary embodiment of the inventive concept may offset an influence of the leakage current, generated by the first diode D1, using the leakage current, generated by the second diode D2, to more accurately detect whether an external attack has occurred.

Referring toFIG.4B, the first diode D1may be formed by implanting an N-type first semiconductor material330into a P-type semiconductor substrate310. The second diode D2may be formed by implanting an N-type second semiconductor material350into a lower portion of the first diode D1. In exemplary embodiments of the inventive concept, the first semiconductor material330and the second semiconductor material350may be implanted with the same doping concentration and substantially the same size. UnlikeFIG.4A, as the second diode D2is disposed below the first diode D1, light incident on the second diode D2may be effectively blocked by the first diode D1. Accordingly, an additional light shielding film for blocking light incident on the second diode D2may not be required.

Referring toFIG.4C, the first diode D1and the second diode D2may be formed using P-type semiconductor material layers470and430, respectively, and N-type semiconductor material layers490and450, respectively, sequentially disposed on a semiconductor substrate410. The second diode D2may be disposed adjacent to the first diode D1on the semiconductor substrate410, and the light shielding film B surrounding the second diode D2may be formed to block incident light. The light shielding film B may surround the P-type semiconductor material layer430and the N-type semiconductor material layer450of the second diode D2.

Referring toFIG.4D, the first diode D1and the second diode D2may be formed using P-type semiconductor material layers570and530, respectively, disposed on a first surface of a first substrate510, and N-type semiconductor material layers590and550, respectively, disposed on a first surface of a second substrate520. The first surface of the first substrate510may face the first surface of the second substrate520. An empty space between the first surface of the first substrate510and the first surface of the second substrate520may be filled with an insulating material such as silicon oxide. The light shielding film B may be disposed on a region in which light is incident from the outside to block the incident light. For example, the light shielding film B may be disposed on a second surface of the second substrate520, opposite to the first surface of the second substrate520, to block light incident onto the second diode D2. In other words, externally incident light is blocked from reaching the second diode D2.

FIG.5is a timing diagram illustrating a method of operating a defense circuit according to an exemplary embodiment of the inventive concept.

Referring to bothFIG.5andFIG.2for ease of description, the operating voltage AVDD of the first operational amplifier AMP1may have a level higher than a level of the first power supply voltage DVDD.

As the first power supply voltage DVDD is applied, the second reverse bias voltage VPmay be applied to the second diode D2.

As the ambient temperature of the defense circuit100is changed during first to third periods P1to P3, the second reverse bias voltage VPand the first reverse bias voltage VNmay be changed in inverse proportion to the change in the ambient temperature. For example, the first reverse bias voltage VNand the second reverse bias voltage VPmay be decreased during the first period P1in which the ambient temperature is increased. In contrast, the first reverse bias voltage VNand the second reverse bias voltage VPmay be increased during the third period P3in which an operating temperature of the defense circuit100is decreased. However, since the first diode D1and the second diode D2have substantially the same characteristics and the feedback resistor RFand the input resistor R have substantially the same resistance, the first reverse bias voltage VNand the second reverse bias voltage VPmay be maintained at substantially the same level.

Since the first reverse bias voltage VNand the second reverse bias voltage VPare maintained at substantially the same level, leakage currents, respectively generated by the first diode D1and the second diode D2, may offset each other due to a change in ambient temperature. Thus, the output voltage VTof the first operational amplifier AMP1and the comparison result (or output) VOUTof the second operational amplifier AMP2may be constantly maintained during first to fourth periods P1to P4in which external light does not penetrate therethrough.

During a fifth period P5, light may penetrate into packaging of the semiconductor chip. In this case, the first diode D1may generate a photocurrent in response to the penetrating light, and the first operational amplifier AMP1may convert the photocurrent, generated by the first diode D1, into the output voltage VT(or a photovoltage VT) to output.

The second operational amplifier AMP2may compare the photovoltage VT, output by the first operational amplifier AMP, with the predetermined reference voltage VREF, and may output the comparison result VOUT. In exemplary embodiments of the inventive concept, when the photovoltage VToutput from the first operational amplifier AMP is higher than or equal to the predetermined reference voltage VREF, the second operational amplifier AMP2may output the comparison result VOUThaving a logic high level. In contrast, when the photovoltage VToutput from the first operational amplifier AMP is lower than the predetermined reference voltage VREF, the second operational amplifier AMP2may output the comparison result VOUThaving a logic low level. Accordingly, the second operational amplifier AMP2may output the comparison result VOUThaving a logic high level during the fifth period P5, in which light penetrates into the packaging of the semiconductor chip.

FIG.6is a circuit diagram of a defense circuit according to an exemplary embodiment of the inventive concept.

Configurations similar to that of the defense circuit100, described with reference toFIG.2, will not be described or will be simply described.

Referring toFIG.6, a defense circuit600according to an exemplary embodiment of the inventive concept may include a sensing unit610, a compensation unit630, and a detecting unit650including the first operational amplifier AMP1and the second operational amplifier AMP2.

The sensing unit610may include the first diode D1connected between the inverting input node N of the first operational amplifier AMP1and a second power supply node for supplying a second power supply voltage, for example, a grounding node.

The first diode D1may include at least one photodiode sensing incident light to generate a photocurrent. The first diode D1may be replaced with various photosensitive elements such as a phototransistor, a combination of a transistor and a photodiode, or the like, in addition to a photodiode.

The compensation unit630may include the second diode D2connected between a first power supply node for supplying the first power supply voltage AVDD and the inverting input node N of the first operational amplifier AMP1. In other words, the first diode D1and the second diode D2may be commonly connected to the inverting input node N of the first operational amplifier AMP1.

The second diode D2may include a semiconductor element having substantially the same characteristics as the first diode D1. The second diode D2may be disposed adjacent to the first diode D1. Unlike the first diode D1, the second diode D2may be optically shielded by a shielding film such as a metal. As a result, unlike the first diode D1, the second diode D2may generate only a leakage current depending on an ambient temperature.

Since the first diode D1and the second diode D2have substantially the same characteristics and are disposed adjacent to each other, the amount of leakage current generated by the first diode D1depending on the ambient temperature may be substantially the same as the amount of leakage current generated by the second diode D2depending on the ambient temperature. Accordingly, the leakage current generated by the first diode D1and the leakage current generated by the second diode D2may offset each other. Thus, the voltage VNon the inverting input node N of the first operational amplifier AMP1may be constantly maintained irrespective of a change in the ambient temperature. In addition, since the influence of the change in the ambient temperature on the output voltage VTof the first operational amplifier AMP1may be eliminated, the defense circuit600may more accurately sense externally incident light.

The first operational amplifier AMP1may convert the photocurrent, generated by the first diode D1, into the photovoltage VT. The feedback resistor RFmay be connected between the output node T and the non-inverting input node N of the first operational amplifier AMP1.

A voltage VREF1on the non-inverting input node of the first operational amplifier AMP1may be set to an appropriate value which does not saturate the first operational amplifier AMP1within the range of a preset amplification gain. For example, the voltage VREF1on the non-inverting input node of the first operational amplifier AMP1may be half of the first power supply voltage AVDD. The voltage VREF1on the non-inverting input node of the first operational amplifier AMP1may be set to an appropriate value in consideration of the operating voltage AVDD of the first operational amplifier AMP1, power consumption, or the like. For example, when the operating voltage AVDD of the first operational amplifier AMP1is relatively low, the voltage VREF1in the non-inverting input node of the first operational amplifier AMP1may be set to a relatively high value to increase the magnitude of the output voltage VT. In addition, the voltage VREF1on the non-inverting input node of the first operational amplifier AMP1may be set to a relatively low value to significantly reduce the power consumption of the defense circuit600. The voltage VREF1on the non-inverting input node of the first operational amplifier AMP1may be adjusted to an appropriate value under the control of an external circuit during operation of the defense circuit600.

The second operational amplifier AMP2may receive the output voltage VTof the first operational amplifier AMP1through the non-inverting input node, and may receive a predetermined reference voltage VREF2through the inverting input terminal. The second operational amplifier AMP2may compare the output voltage VTof the first operational amplifier AMP1with the predetermined reference voltage VREF2to output the comparison result VOUT.

The reference voltage VREF2may be set to an appropriate value to prevent an unnecessary protection operation from being performed by dark current, which may be temporarily generated in a normal operation of the semiconductor chip, by inspection light incident in a testing process of the semiconductor chip, or the like. When sizes of the first diode D1, the second diode D2, and the feedback resistor RFneed to be decreased, the predetermined reference voltage VREF2may be set to be a relatively low value to prevent light detection sensitivity of the defense circuit600from being reduced.

FIGS.7A to8Bare perspective views illustrating an arrangement of a defense circuit according to exemplary embodiments of the inventive concept.

Referring toFIG.7A, a defense circuit700according to an exemplary embodiment of the inventive concept may be implemented as a single module, including a photocurrent generation unit710and a detection unit730, to be disposed in one region of a semiconductor chip SC.

The photocurrent generation unit710may include a sensing unit generating a photocurrent in response to light penetrating into packaging of the semiconductor chip SC, and a compensation unit removing leakage current depending on an ambient temperature or the like. The details of the elements are the same as described above with reference toFIGS.1to6.

In exemplary embodiments of the inventive concept, the photocurrent generation unit710may be disposed in a region in which light, penetrating into the packaging of the semiconductor chip SC, may be better received.

The detection unit730may convert the photocurrent, generated by the photocurrent generation unit710, into a photovoltage, and may compare the photovoltage with a predetermined reference voltage to detect whether an external attack has occurred.

InFIG.7A, one defense circuit700is illustrated as being disposed on the semiconductor chip SC. However, the number of defense circuits may be variously changed. For example, referring toFIG.7B, a plurality of defense circuits800ato800dmay be disposed in different regions of the semiconductor chip SC to more accurately detect whether an external attack has occurred on the semiconductor chip SC. The plurality of defense circuits800ato800dmay include a plurality of photocurrent generation units810ato810d,respectively, and a plurality of detection units830ato830d,respectively.

On the other hand, a plurality of photocurrent generation units may share a single detection unit. For example, referring toFIG.8A, a defense circuit900may include a plurality of photocurrent generation units910ato910dand a single detection unit930. The plurality of photocurrent generation units910ato910dmay be distributed in a plurality of regions of the semiconductor chip SC.

In exemplary embodiments of the inventive concept, the detection unit930may obtain an average value from the photocurrents received from the plurality of photocurrent generation units910ato910d,and may determine whether an attack has occurred on the semiconductor chip SC, using the obtained average value. To this end, the detection unit930may further include an operational unit configured to obtain an average value from the photocurrents received from the plurality of photocurrent generation units910ato910d.

In exemplary embodiments of the inventive concept, the detection unit930may sequentially process the respective photocurrents, received from the plurality of photocurrent generation units910ato910d,to determine whether an external attack has occurred on the semiconductor chip SC. To this end, the detection unit930may further include a first-in first-out (FIFO) buffer configured to sequentially process the respective photocurrents received from the plurality of photocurrent generation units910ato910d.

The arrangement of the plurality of photocurrent generation units910ato910dand the detection unit930may be changed in various ways. For example, the detection unit930may be disposed in the center of the plurality of photocurrent generation units910ato910dto significantly reduce a routing length between the plurality of photocurrent generation units910ato910dand the detection unit930. Alternatively, as illustrated inFIG.8B, a plurality of photocurrent generation units1010ato1010dmay be densely disposed in a region, in which a de-packaging attack has occurred more easily, to more accurately detect a physical attack on the semiconductor chip SC, using a detection unit1030.

FIG.9is a flowchart illustrating a method of operating a defense circuit according to an exemplary embodiment of the inventive concept.

Referring to bothFIG.9andFIG.2for ease of description, a sensing unit may generate a photocurrent in response to light penetrating from the outside of packaging of a semiconductor chip (S10). The sensing unit may include a photosensitive element, for example, a photodiode, a phototransistor, a combination of a photodiode and a junction transistor, or the like.

A compensation unit may remove a leakage current component depending on an ambient temperature from the photocurrent generated by the sensing unit (S20). The compensation unit may include a semiconductor element having substantially the same characteristics as the sensing unit and disposed adjacent thereto. The semiconductor element, included in the compensation unit, may generate only the leakage current depending on the ambient temperature because light is blocked by an optical shielding layer. Since the leakage current generated by the compensation unit may be substantially the same as the leakage current generated by the sensing unit, the leakage currents may offset each other.

The detection unit may convert the photocurrent, generated by the sensing unit and the compensation unit, into a photovoltage (S30).

The detection unit may compare the converted photovoltage with a predetermined reference voltage to determine whether an external attack has occurred on a semiconductor chip (S40). For example, when the converted photovoltage is higher than or equal to the predetermined reference voltage, the detection unit may output an event signal indicating the occurrence of the external attack on the semiconductor chip. In contrast, when the converted photovoltage is lower than the predetermined reference voltage, the detection unit may output an event signal indicating non-occurrence of the external attack on the semiconductor chip.

FIG.10is a schematic block diagram of an electronic device including a defense circuit according to an exemplary embodiment of the inventive concept.

Referring toFIG.10, an electronic device1100according to an exemplary embodiment of the inventive concept may include a memory1110, a security module1120, a processor1130, and a communications module1140.

Among the components illustrated inFIG.10, the communications module1140may be a device provided for the electronic device1100to communicate with a video card, sound card, memory card, universal serial bus (USB) device, or the like. The electronic device1100may be a device including a smartphone, a tablet personal computer (PC), a smart wearable device, or the like, in addition to a general desktop computer or a laptop computer.

The memory1100may be a storage medium storing data for the operation of the electronic device1100, multimedia data, or the like. The memory1100may include a storage device based on a nonvolatile memory. In addition, the memory1100may include at least one of a solid-state drive (SSD) a hard disk drive (HDD), or an optical disk drive (ODD), as a storage device.

The processor1130may perform specific operations, commands, tasks, or the like. The processor1130may be a central processing unit (CPU), a microprocessor unit (MCU), a system on chip (SoC), or the like. Via a bus1150, the processor1130may communicate with not only the memory1110and the security module1120but also other devices connected to the electronic device1100via the communication module1140.

The security module1120may be a semiconductor device including a defense circuit according to exemplary embodiments of the inventive concept described with reference toFIGS.1to9. The security module1120may include at least one semiconductor chip for storing confidential information. For example, the security module1120may include a memory chip for encrypting and storing an authentication key. The defense circuit may sense light penetrating through the semiconductor chip in the security module1120to detect whether a physical attack has occurred.

When a physical attack has occurred on the security module1120, the security module1120may perform a predetermined defense operation such as data initialization, data scrambling, data output blocking, or the like. The defense operation of the security module1120may be internally performed based on a detection result of the defense circuit. In addition, the defense operation of the security module1120may be performed based on the detection result of the defense circuit under the control of the processor1130.

FIG.11illustrates a smart card including a defense circuit according to an exemplary embodiment of the inventive concept.

Referring toFIG.11, a smart card1200may include first and second base members1210and1220, a contact portion1230, an IC circuit1240, and an antenna1250.

The first and second base members1210and1220may be formed of plastic or a similar material to form an exterior of the smart card1200.

The IC circuit1240may be disposed between the first and second base members1210and1220. The IC circuit1240may be a smart card chip included in the smart card1200. The contact portion1230, including a plurality of pins, may be formed on the first base member1210. The contact unit1230may be an interface in direct contact with an external device, such as a card terminal to exchange data.

The antenna1250may be formed as a coil between the first and second base members1210and1220. The antenna1250may transmit and receive a wireless signal having a predetermined frequency to and from the external device.

In the IC circuit1240, a defense circuit according to exemplary embodiments of the inventive concept described with reference toFIGS.1to9may be formed. The defense circuit may detect light, incident from the outside of the IC circuit1240, to detect a hacking attempt.

FIG.12is a block diagram illustrating a vehicular electronic device including a defense circuit according to an exemplary embodiment of the inventive concept.

Referring toFIG.12, a vehicle system2000according to an exemplary embodiment of the inventive concept may include a processor2100, a first communications module2200, a second communications module2300, a sensor module2400, and a memory2500.

The processor2100may control at least one of the other components of the vehicle system2000, and may perform various data processing or operations. For example, as a portion of the data processing or operations, the processor2100may load a command or data, received from other components into a volatile memory, and may process the command or the data loaded into the volatile memory to store result data in the volatile memory.

The processor2100may control the overall operation of the vehicle system2000. The processor2100may include a first processor2110and a second processor2120.

The first processor2110may control the operation of the vehicle system2000and may include a central processing unit (CPU), an application processor (AP), or the like.

The second processor2120may perform a self-diagnosis of a vehicle and may include a micro controller unit (MCU) or the like.

The first processor2110and the second processor2120may transmit and receive data through a security module2130. For example, the first processor2110may encrypt command data for obtaining status information of the vehicle through the security module2130, and may transmit the encrypted command data to the second processor2120. The second processor2120may obtain the status information of the vehicle in response to the received encrypted command data, and may encrypt the obtained status information through the security module2130and transmit the encrypted status information to the first processor2110. The security module2130may include a command transmission target list and may block the transmission of command data that does not correspond to the command transmission target list.

The security module2130may include defense circuits according to exemplary embodiments of the inventive concept described with reference toFIGS.1to9. The defense circuit may sense light, penetrating from the outside of the security module2130, to detect whether a physical attack has occurred, irrespective of an operating temperature. When the defense circuit detects a physical attack, the security module2130may block the transmission of command data from the first processor2110to the second processor2120.

The first communications module2200and the second communications module2300may communicate with other electronic devices inside or outside of the vehicle in a wired or wireless communication manner. For example, the first communications module2200may communicate with an external electronic device, and the second communications module2300may communicate with other electronic devices inside of the vehicle.

The first communications module2200may include, for example, a Wi-Fi module2210, a Bluetooth module2220, a cellular communications module2230, and the like. The vehicle system2000may perform short-range wireless communication with an external mobile device using the Wi-Fi module1121or the Bluetooth module2220. In addition, the vehicle system2000may perform wireless communication with an external server using the cellular communications module2230. The cellular communications module2230may perform communication according to communication standards such as standards of Institute of Electrical and Electronics Engineers (IEEE), 3rd Generation (3G), 3rd Generation Partnership Project (3GPP), or Long-Term Evolution (LTE).

The second communications module2300may include, for example, a K-Line communications module2310, an RS-232 communications module2320, and a CAN communications module2330. The second communications module2300may perform wired communication with other electronic devices inside of the vehicle, using the K-Line communications module2310or the like.

The sensor module2400may include various sensors for detecting a state of the vehicle system2000and a state of the vehicle. For example, the sensor module2400may include an acceleration sensor, a gyro sensor, an illumination sensor, a proximity sensor, a pressure sensor, a noise sensor, a video sensor, a temperature sensor, a shock sensor, or the like.

The sensor module2400may detect a state of charge of a battery, a temperature, a moving speed of the vehicle, whether an impact has occurred in a vehicle, an operating state of the vehicle system2000itself, etc., using various sensors.

The memory2500may store various types of software and data, executed and processed in the vehicle system2000, and may include at least one of a volatile memory and a nonvolatile memory. For example, the memory2500may store the status information of the vehicle or the vehicle system2000. In addition, the memory2500may store a list of external devices which may exchange data.

FIG.13is a block diagram of a server device including a defense circuit according to an exemplary embodiment of the inventive concept.

Referring toFIG.13, a mobile system3000according to an exemplary embodiment of the inventive concept may include a camera3100, a display3200, an audio processing unit3300, a modem3400, DRAMs3600aand3600b,flash memory devices3700aand3700b, input/output (I/O) devices3800aand3800b,and an application processor (AP)3900.

The mobile system3000may be implemented as a laptop computer, a mobile phone, a smartphone, a tablet personal computer (PC), a wearable device, a healthcare device, an Internet-of-Things (IoT) device, or the like. Additionally, the mobile system2000may be implemented as a server or a PC.

The camera3100may take a still image or a video under a user's control. The mobile system3000may obtain specific information using a still image/video taken by the camera3100, or may convert and store the still image/video into other types of data such as text. Alternatively, the mobile system3000may recognize a character string included in the still image/video taken by the camera3100, and may provide a text or audio translation corresponding to the character string. As described above, the camera3100in the mobile system3000tends to be used in various fields of application. In exemplary embodiments of the inventive concept, the camera3100may transmit data such as still image/video to the AP3900according to a D-PHY or C-PHY interface defined in the MIPI Standard.

The display3200may be implemented in various forms such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an active-matrix organic light emitting diode (AMOLED) display, a plasma display panel (PDP), a field emission display (FED), an electronic paper, or the like. In an exemplary embodiment of the inventive concept, the display3200may provide a touchscreen function to be also used as an input device of the mobile system3000. In addition, the display3200may be integrated with a fingerprint sensor or the like, to provide a security function for the mobile system3000. The AP3900may transmit image data, to be displayed on the display3200, to the display3200according to a D-PHY or C-PHY interface defined in the MIPI Standard.

The audio processing unit3300may process audio data, stored in the flash memory devices3700aand3700b,or audio data included in contents externally received through the modem3400or the I/O devices3800aand3800b.For example, the audio processing unit3300may perform various processes such as encoding/decoding, amplification, noise filtering, or the like, on the audio data.

The modem3400may modulate a signal and transmit the modulated signal to transmit and receive wired/wireless data, and may demodulate an externally received signal to restore an original signal.

The I/O devices3800aand3800bmay provide digital input and output, and may include an input device, such as a port connectable to an external recording medium, a touchscreen, or a mechanical button key, and an output device capable of outputting a vibration in a haptic manner. In certain examples, the I/O devices3800aand3800bmay be connected to an external recording medium through a port such as a USB, a lightning cable, a Secure Digital (SD) card, a micro SD card, a DVD, a network adapter, or the like.

The AP3900may control the overall operation of the mobile system3000. For example, the AP3900may control the display3200to display a portion of the contents, stored in the flash memory devices3700aand3700b,on a screen. In addition, the AP3900may perform a control operation corresponding to a user input when the user input is received through the I/O devices3800aand3800b.

The AP3900may be provided as a system-on-chip (hereinafter referred to as “SoC”) driving an application program, an operating system (OS), or the like. In addition, the AP3900may be included in a single semiconductor package together with other devices included in the mobile system3000, for example, the DRAMs3600aand3600b,a flash memory3720(included in the flash memory devices3700aand3700b), and/or a controller3710(included in the flash memory devices3700aand3700b). For example, the AP3900and at least one device may be provided in a package form such as Package on Package (PoP), Ball Grid Arrays (BGAs), Chip Scale Packages (CSPs), System In Package (SIP), Multi Chip Package (MCP), Wafer-level Fabricated Package (WFP), Wafer-Level Processed Stack Package (WSP), or the like. A kernel of the operating system, driven on the AP3900, may include an input/output scheduler and a device driver for controlling the flash memory devices3700aand3700b.The device driver may control access performance of the flash memory devices3700aand3700bwith reference to the number of synchronous queues managed by the input/output scheduler, or may control a CPU mode inside the SoC, a dynamic voltage and frequency scaling (DVFS) level, or the like.

In exemplary embodiments of the inventive concept, the AP3900may include a processor block, executing an operation or driving an application program and/or an operating system, and various other peripheral elements connected to the processor block through a system block and a system bus. The peripheral elements may include a memory controller, an internal memory, a power management block, an error detection block, a monitoring block, or the like. The processor block may include one or more cores. When a plurality of cores are included in the processor block, each of the cores includes a cache memory, and a common cache, shared by the cores, may also be included in the processor block.

In exemplary embodiments of the inventive concept, the AP3900may include an accelerator block3920, a specific-purpose circuit for AI data operation. Alternatively, according to exemplary embodiments of the inventive concept, a separate accelerator chip may be provided to be separated from the AP3900, and the DRAM3600bmay be additionally connected to the accelerator block3920or the accelerator chip. The accelerator block3920may be a functional block specialized in performing specific functions of the AP3900, and may include a graphic processing unit (GPU) serving as a functional block specialized in processing graphics data, a neural processing unit (NPU) serving as a functional block specialized in performing AI computation and inference, a data processing unit (DPU) serving as a functional block specialized in transmitting data, or the like.

According to exemplary embodiments of the inventive concept, the mobile system3000may include a security module3500for storing confidential information. The security module3500may store an authentication key, an encryption code, or the like. The security module3500may be a semiconductor device including a defense circuit according to exemplary embodiments of the inventive concept described with reference toFIGS.1to9. The defense circuit mounted on the security module3500may detect light, penetrating into the security module3500, to detect whether an external attack has occurred. The defense circuit mounted on the security module3500may generate leakage current depending on an ambient temperature, and may include a semiconductor element having substantially the same characteristics as the light sensing element to more accurately detect whether an external attack has occurred, based on only the light penetrating into the security module3500.

In exemplary embodiments of the inventive concept, when a physical attack has occurred on the security module3500, the security module3500may perform predetermined defense operations such as data initialization, data scrambling, data output blocking, or the like. The defense operations of the security module3500may be internally performed based on a detection result of the defense circuit. In addition, the defense operations of the security module3500may be performed under the control of the AP3900based on the detection result of the defense circuit.

According to exemplary embodiments of the inventive concept, the mobile system3000may include a plurality of DRAMs3600aand3600b.In exemplary embodiments of the inventive concept, the AP3900may include a controller3910for controlling the DRAMs3600aand3600b,and the DRAM3600amay be directly connected to the AP3900.

The AP3900may set a command and a mode register set (MRS) command according to the JEDEC standards to control a DRAM, or may set specifications and functions required by the mobile system3000, such as a low voltage, high speed, and reliability, and a DRAM interface protocol for CRC/ECC to perform communication. For example, the AP3900may communicate with the DRAM3600athrough an interface, conforming to the JEDEC standards, such as LPDDR4, LPDDR5, or the like. Alternatively, the AP3900may set a new DRAM interface protocol to control the DRAM3600bfor an accelerator, in which the accelerator block3920or an accelerator chip provided independently of the AP3900has a higher bandwidth than the DRAM3600b,to perform communication.

Only the DRAMs3600aand3600bare illustrated inFIG.13, but a configuration of the mobile system3000is not necessarily limited thereto. According to bandwidth and reaction speed of the AP3900or the accelerator block3920, voltage conditions, or the like, memories other than the DRAMS3600aand3600bmay also be included in the mobile system3000. As an example, the controller3910and/or the accelerator block3920may control various memories such as phase-change random access memory (PRAM), static RAM (SRAM), magnetic RAM (MRAM), resistive RAM (RRAM), ferroelectric RAM (FRAM), Hybrid RAM, or the like. The DRAMs3600aand3600bhave relatively lower latency and higher bandwidth than the I/O devices3800aand3800bor the flash memory devices3700aand3700b.The DRAMs3600aand3600bmay be initialized at a point in time when the mobile system3000is powered on. When an operating system and application data are loaded, the DRAMs3600aand3600bmay be used as temporary storages, in which the operating system and application data are temporarily stored, or as spaces in which various software codes are executed.

Four fundamental arithmetic operations such as addition, subtraction, multiplication, and division, and a vector operation, an address operation, or Fast Fourier Transform (FFT) operation data may be stored in the DRAMs3600aand3600b.In an exemplary embodiment of the inventive concept, the DRAMs3600aand3600bmay be provided as a processing in memory (PIM) having an operational function. As an example, a function used in inference may be performed in the DRAMs3600aand3600b.In this case, the inference may be performed in a deep learning algorithm using an artificial neural network. The deep learning algorithm may include a training step, in which a model is learned through various data, and an inference step in which data is recognized with the trained model. For example, a function used in the inference may include a hyperbolic tangent function, a sigmoid function, a rectified linear unit (ReLU) function, or the like.

According to an exemplary embodiment of the inventive concept, an image taken by a user through the camera3100may be signal-processed and stored in the DRAM3600b,and the accelerator block3920or the accelerator chip may perform an AI data operation using the data stored in the DRAM3600band the function used in the inference to recognize data.

According to exemplary embodiments of the inventive concept, the mobile system3000may include a plurality of storages or a plurality of flash memory devices3700aand3700bhaving a capacity higher than a capacity of the DRAMs3600aand3600b.

The flash memory devices3700aand3700bmay include the controller3710and the flash memory3720. The controller3710may receive a control command and data from the AP3900, and may write data to the flash memory3720in response to the control command or may read data stored in the flash memory3720and transmit the read data to the AP3900.

According to an exemplary embodiment of the inventive concept, the accelerator block3920or the accelerator chip may perform a training step and an AI data operation using the flash memory devices3700aand3700b.In exemplary embodiments of the inventive concept, a block capable of performing a predetermined operation may be implemented in the flash memory devices3700aand3700b.Instead of the AP3900and/or the accelerator block3920, the implemented block may perform at least a portion of the training step and the AI data operation, performed by the AP3900and/or the accelerator block3920, using the data stored in the flash memory3720.

In exemplary embodiments of the inventive concept, the AP3900may include an interface3930. Accordingly, the flash memory devices3700aand3700bmay be directly connected to the AP3900. For example, the AP3900may be implemented as an SoC, the flash memory device3700amay be implemented as a chip independently of the AP3900, and the AP3900and the flash memory device3700amay be mounted in a single package. However, the inventive concept is not limited thereto, and the plurality of flash memory devices3700aand3700bmay be electrically connected to the mobile system3000through a connection.

The flash memory devices3700aand3700bmay store data such as a still image/video, taken by the camera3100, or data received through a communications network and/or ports included in the I/O devices3800aand3800b.For example, the flash memory devices3700aand3700bmay store augmented reality/virtual reality, high definition (HD), or ultra high definition (UHD) content.

As described above, a defense circuit of a semiconductor device according to exemplary embodiments of the inventive concept may sense light, penetrating into the semiconductor device, to determine whether a physical attack has occurred.

In addition, a defense circuit of a semiconductor device according to exemplary embodiments of the inventive concept may determine whether a physical attack has occurred using only photocurrent and excluding leakage current that depends on an ambient temperature, and thus, may further improve physical attack detection accuracy.

Furthermore, a defense circuit of a semiconductor device according to exemplary embodiments of the inventive concept may be implemented with a plurality of modules, distributed in the semiconductor device, to further improve physical attack detection accuracy.

While the inventive concept has been shown and described above with reference to exemplary embodiments thereof, it will be apparent to those of ordinary skill in the art that modifications and variations in form and details could be made thereto without departing from the spirit and scope of the inventive concept as set forth by the appended claims.