WO2017138773A1

WO2017138773A1 - Security semiconductor chip and method for operating same

Info

Publication number: WO2017138773A1
Application number: PCT/KR2017/001491
Authority: WO
Inventors: 고형호; 최병덕
Original assignee: 한양대학교 산학협력단
Priority date: 2016-02-12
Filing date: 2017-02-10
Publication date: 2017-08-17

Abstract

Disclosed is a security semiconductor chip. When a physical attack such as a depackaging attack occurs, the semiconductor chip can detect the physical attack. A semiconductor chip according to one embodiment comprises an energy harvesting element inside a package. The energy harvesting element may comprise, for example, an on-chip photodiode. A depackaging attack causes the generation of a voltage of a photodiode, and thus a change in physical state of the packaging can be detected.

Description

Security semiconductor chip and its operation method

It relates to a security-enhanced semiconductor chip and its operation method, and more particularly to the detection of a physical attack on the semiconductor chip.

Various physical attacks and software attacks on semiconductor chips are threats to products using SoC (System on Chip) and application services using them. Examples of such physical attacks include de-packaging, circuit modifications using focused ion beams (FIBs), micro-probing, power analysis, electromagnetic analysis (EMA), voltage / frequency Various things are known, including fault injection and temperature injection.

Techniques for detecting physical attacks and protecting circuits from them have been introduced, for example, some of the prior art documents described below can help to understand previous attempts.

A highly time sensitive XOR gate for probe attempt detectors (S. Manich, et al., IEEE Trans. Circuits Syst., II: Exp. Briefs, vol. 60, no. 11, pp. 786-790, Nov. 2013) proposes a technique for detecting a probing capacitance delay that occurs when probing an internal data bus after depackaging of a semiconductor chip.

The present invention is to provide a security semiconductor chip for detecting a physical attack, and to perform a countermeasure according to the attack detection and its operation method.

According to one side, the semiconductor chip is packaged together with at least one data bus for transmitting data processed through the semiconductor chip, the at least one data bus is in a state that the light from the outside is blocked by the package, the package A potential generating block for detecting an event that fails to block light from the outside, and a switch for blocking transmission of at least some data of the at least one data bus when the event is detected.

In one embodiment, the potential generating block includes an energy harvesting element that generates energy using the light when exposed to light from the outside.

In one embodiment, the potential generating block comprises at least one photodiode that generates a current when exposed to light from the outside, a capacitor that stores charge by at least a portion of the current, and wherein the charge is from the capacitor. And a pull-down resistor to cause the discharge.

In one embodiment, the switch is turned on by a potential difference across the pull-down resistor during the discharge of the charge through the pull-down resistor to ground at least some data of the at least one data bus. The transmission is interrupted by discharging.

In one embodiment, the pull-down resistor comprises an active device whose resistance value is programmable by setting.

In one embodiment, increasing the pull-down resistance setpoint reduces the amount of discharge current required to turn on the switch so that the switch is turned on relatively easily, and when the pull-down resistance setpoint is lowered The amount of discharge current required to turn on the switch increases, making the switch relatively difficult to turn on.

In one embodiment, the at least one photodiode comprises a plurality of photodiodes that are cascaded at least in part.

In one embodiment, the at least one photodiode includes a plurality of photodiodes hierarchically connected in a tree structure.

In one embodiment, the at least one data bus comprises a plurality of data buses each transmitting data in parallel, the plurality of data buses sharing the potential generating block.

According to another aspect, a protection device embedded in a semiconductor chip packaging includes a potential generating block that detects an event in which the package fails to block light from the outside, and at least some data transmission paths in the semiconductor chip when the event is detected. It includes a switch to cut off.

In one embodiment, the switch is turned on by a potential difference across the pull-down resistor in the process of discharging the charge through the pull-down resistor to ground the transfer path by grounding a portion of the transfer path. Block it.

According to another aspect of the present invention, a method in which a semiconductor chip detects a damage to a packaging may include a pull-down of a potential generating block embedded in an on-chip module form when light penetrates from outside the packaging of the semiconductor chip due to the damage of the packaging. Generating a potential difference across the resistor, and at least a portion of the data transfer path in the semiconductor chip is grounded by the potential difference to block data transfer.

According to the present invention, it is possible to detect a physical attack and to perform a countermeasure according to the attack detection.

1 is a block diagram illustrating a security semiconductor chip according to an embodiment.

2 is a schematic view of a portion of a secure semiconductor chip according to an embodiment.

3 is an exemplary diagram for describing an operation of a security semiconductor chip according to an exemplary embodiment.

4 is an exemplary diagram for describing an operation of a security semiconductor chip according to an exemplary embodiment.

FIG. 5 is a timing diagram illustrating a method of detecting damage to a packaging by a semiconductor chip according to an exemplary embodiment.

6 is a diagram illustrating an example of an on-chip photodiode of a security device of a semiconductor chip according to an embodiment.

7 is a flowchart illustrating a method of detecting damage to a packaging by a semiconductor chip according to an exemplary embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of rights is not limited or limited by these embodiments. Like reference numerals in the drawings denote like elements.

The terminology used in the description below has been selected to be general and universal in the art to which it relates, although other terms may vary depending on the development and / or change in technology, conventions, and preferences of those skilled in the art. Therefore, the terms used in the following description should not be understood as limiting the technical spirit, and should be understood as exemplary terms for describing the embodiments.

In addition, in certain cases, there is a term arbitrarily selected by the applicant, and in this case, the meaning thereof will be described in detail in the corresponding description. Therefore, the terms used in the following description should be understood based on the meanings of the terms and the contents throughout the specification, rather than simply the names of the terms.

Terms such as first or second may be used to describe various components, but such terms should be interpreted only for the purpose of distinguishing one component from another component. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When a component is referred to as being "connected" to another component, it should be understood that there may be a direct connection or connection to that other component, but there may be other components in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, but includes one or more other features or numbers, It is to be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

As mentioned above, various physical attacks and software attacks on a semiconductor chip can be a threat in terms of security or stability of the semiconductor chip. In particular, when accessing the data bus inside the semiconductor chip through depackaging of the semiconductor chip, data may be exposed to hacking, etc. In this case, it is desirable to have a structure that can prevent data leakage.

In general, when depackaging occurs, light from outside the packaging of the semiconductor chip penetrates into the packaging. As a special case, when depackaging occurs in a limited environment such as a dark room, light penetration due to the depackaging itself may not occur, but photons may be detected while accessing the data bus or observing the structure inside the chip.

Therefore, a structure for detecting an abnormal state through a photosensitive device and performing a countermeasure when necessary when a light penetrates inside a semiconductor chip by a depacking attack or other abnormal situation is proposed. For example, semiconductor chips include energy harvesting elements in a package. By way of example, the energy harvesting device may include an on-chip photo diode. The depackaging attack causes the voltage generation of the photodiode to detect the penetration of light into the packaging. Using energy harvesting techniques, energy harvesters accumulate light energy from ambient light to trigger a protective trigger signal even when the package is removed or damaged, even when the chip is not powered. Hereinafter, various embodiments will be described in more detail with reference to the drawings.

1 is a block diagram illustrating a security semiconductor chip according to an embodiment. In one embodiment, the secure semiconductor chip 100 may include a potential generating block 110, a switch 120, and a data bus 130. The security semiconductor chip 100 may detect an abnormal state such as a depackaging attack by collecting optical energy as described above.

In one embodiment, the potential generating block 110 may be configured to generate a potential difference when more than a predetermined level of light energy is collected using a structure capable of collecting light energy. For example, the potential generating block 110 collects the light energy penetrated into the packaging by using an energy harvesting element or a photodiode, and uses at least a portion of the collected light energy to supply a capacitor and a pull-down resistor. The potential difference can be generated by this.

Specifically, the potential generating block 110 includes at least one photodiode that generates a current when exposed to light from outside, a capacitor that stores charge by at least a portion of the current, and a full-charge that causes the charge to be discharged from the capacitor. It may include a down resistor.

In one embodiment, the switch 120 may block the data output of the data bus 130 of the semiconductor chip by using the potential difference generated by the capacitor and the pull-down resistor. For example, the switch 120 is turned off when no light energy is collected to allow the data output of the data bus 130 to proceed normally, and the light energy is collected and depackaged by the potential generating block 110. When an abnormal state such as the like is detected, the data output of the data bus 130 may be blocked so as not to proceed normally.

In one embodiment, when the secure semiconductor chip 100 includes a plurality of data buses 130, one potential generation block 110 may be configured to be shared by the plurality of data buses 130. For example, a structure in which the potential generating block 110 is connected to the plurality of switches 120 corresponding to each of the plurality of data buses 130 may be selected.

2 is a schematic view of a portion of a secure semiconductor chip according to an embodiment. In one embodiment, the secure semiconductor chip may include a potential generation block 210, a switch 220, and a data bus 230.

In one embodiment, the potential generating block 210 may include a photodiode 211, a capacitor 212, and a pull-down resistor 213. For example, when the photodiode 211 generates a current when it is exposed to light from the outside, charge is stored in the capacitor 212 using the generated current. When the voltage at the upper node of the capacitor 212 rises due to the storage of charge, the discharge current by the pull-down resistor 213 is generated by the voltage difference between the upper node of the capacitor 212 and the ground.

Here, when the voltage of the upper node of the capacitor 212 rises above the threshold voltage, the protection circuit for the semiconductor chip may be operated through the switch 220 in consideration of an abnormal state such as depacking in the semiconductor chip. have. For example, when the current generated by the photodiode 211 is greater than the current discharged through the pull-down resistor 213, the voltage at the node of the upper node of the capacitor 212 gradually increases, and the voltage of the upper node of the capacitor 212 is increased. When the voltage is above the threshold voltage, a protective measure may be performed on the semiconductor chip.

In the illustrated embodiment, as an example of a protective measure for the semiconductor chip, a description has been given of blocking the data output of the data bus 230 from being normally performed by the switch 220. When the voltage of the upper node of the capacitor 212 rises and the switch 220 is turned on, for example, the output of the second inverter inv2 is forced to be low so that the outputs of the data bus 230 are all low. can do. In this manner, the PAD output of the internal data may be blocked to prevent the data input 240 of the data bus 230 from being transmitted to the data output 250 so that the data output may not be leaked by an external attack. .

However, the blocking of the data transmission path as described above is one of various embodiments of protection measures performed when a package removal or a damage event occurs, and a package damage or removal situation of a semiconductor chip to a semiconductor chip through optical energy harvesting. There may be other examples of protective measures that differ in electrical state from circuits before the city. For example, as another embodiment of a protective measure for the semiconductor chip, data erasing, data scrambling, destruction or deactivation of the semiconductor chip may be performed. Protection measures are therefore not to be construed as limited to the examples set forth explicitly herein.

If the current difference generated by the photodiode 211 flows through the pull-down resistor 213 is less than a certain level threshold (this threshold may be related to the turn-on threshold of the transistor switch), the protection The circuit may not work. If the charge generated by the energy harvesting is small enough to not make a sufficient potential difference across the capacitor 212, the protection circuit may not operate because it is not regarded as an abnormal state such as depackaging in the semiconductor chip. This operating threshold is related to the sensitivity of how sensitive the circuit is to take protective action. Sensitivity may be set appropriately to prevent the protection circuit from operating unnecessarily by dark current that may temporarily occur during normal operation or by X-rays radiating from outside the semiconductor packaging and penetrating the package. Can be.

In one embodiment, the pull-down resistor 213 is configured to adjust the timing at which the protection circuit starts to operate in accordance with the intensity of light being sensed. For example, when the resistance value of the pull-down resistor 213 increases, the discharge current decreases, so that the data output blocking through the switch 220 may proceed even if the current generated by the photodiode 211 is relatively small. On the contrary, when the resistance value of the pull-down resistor 213 decreases, the discharge current increases, so that the data output blocking through the switch 220 may proceed when the current generated by the photodiode 211 is relatively large.

That is, by operating the pull-down resistor 213 programmable to control the magnitude of the discharge current, the operation timing of the protection circuit may be adjusted according to the magnitude of the current. The size of the resistance value of the pull-down resistor 213 may be designed to a suitable value based on the characteristics of the semiconductor chip, the type of packaging, the environment in which the semiconductor chip is used, and the like.

In one embodiment, when the secure semiconductor chip includes a plurality of data buses 230, one potential generation block 210 may be configured to be shared by the plurality of data buses 230. For example, the structure in which the potential generating block 210 is connected to the plurality of switches 220 corresponding to each of the plurality of data buses 230 may be selected.

3 is an exemplary diagram for describing an operation of a security semiconductor chip according to an exemplary embodiment. The secure semiconductor chip of FIG. 3 may be part of the secure semiconductor chip shown in FIG. 2, for example. In one embodiment, the secure semiconductor chip may include a photodiode 311, a capacitor 312, a pull-down resistor 313, a switch 320, and a data bus 330.

3 exemplarily illustrates an operation of a security semiconductor chip before a security attack such as depacking occurs. In a normal environment in which the packaging is not damaged, since the both ends of the photodiode 311 are substantially the same as the open state, the voltage at the upper node of the capacitor 312 is maintained at a value close to ground. As described above, the voltage at the top node of the capacitor 312 can be maintained at a value close to ground through a structure that is discharged through the pull-down resistor 313 even when a small current is generated temporarily.

That is, since the current generated by the photodiode 211 is designed to be smaller than the current discharged through the pull-down resistor 213 before the security attack such as depacking occurs, the node and the switch (top of the capacitor 312) ( The voltage at the gate terminal of 320 is maintained at a value close to ground.

As a result, since the switch 320 remains turned off, the pulse train provided at the data input 340 of the data bus 330 may be normally transmitted to the pad data output 350 of the internal data. have.

4 is an exemplary diagram for describing an operation of a security semiconductor chip according to an exemplary embodiment. The secure semiconductor chip of FIG. 4 may be part of the secure semiconductor chip shown in FIG. 2, for example. In one embodiment, the secure semiconductor chip may include a photodiode 311, a capacitor 312, a pull-down resistor 313, a switch 320, and a data bus 330, as described in FIG. 3. have.

4 exemplarily illustrates an operation of a secure semiconductor chip after a security attack such as depacking occurs. In the environment where the packaging is damaged and light penetrates into the packaging, the photo energy of the photodiode 311 allows the photosensitive energy to be reduced. Will rise.

That is, when a security attack such as depacking occurs, the current generated by the photodiode 211 is designed to be larger than the current discharged through the pull-down resistor 213, so that the node and the switch 320 at the upper end of the capacitor 312. The voltage at the gate terminal of increases gradually.

When the voltage at the upper node of the capacitor 312 and the gate terminal of the switch 320 rises above the threshold voltage, an abnormal state such as depackaging occurs in the semiconductor chip, and thus, the data bus 230 is assumed through the switch 320. You can block the data output from proceeding normally. That is, when the switch 220 is turned on, for example, the output of the second inverter inv2 may be forced low so that the outputs of the data bus 230 are all low. In this manner, the PAD output of the internal data may be blocked to prevent the data input 440 of the data bus 330 from being transmitted to the data output 450 so that the data output may not be leaked by an external attack. .

By way of example, the PAD outputs PAD0, PAD1, PAD2, and PAD3 of four data buses are shown. V _PD refers to a voltage formed at the upper node of the capacitor using the current generated by the photodiode, and CLK refers to a clock signal.

Illustrated in FIG ever look at the trend of the V _PD shown, the de-photodiode by the packaging attack begins to rise the V _PD at a first time 510 to start generating the current and voltage is raised for a period of time As a result, the rise of V _PD is stopped at the second time point 520 where the current generated by the photodiode is equal to the current discharged through the pull-down resistor.

Here, the threshold voltage may be selected as a value between the V _PD value at the first time point 510 and the V _PD value at the second time point 520. In other words, the switch to cut off the output of the data bus based on the threshold voltage can be turned on. When the disconnect switch is turned on, the output of the data bus can be forced all low as described above. In the illustrated example, it can be seen that the PAD outputs PAD0, PAD1, PAD2, and PAD3 of the four data buses output only low signals without outputting normal data after a certain time due to the operation of the cutoff switch. In this way, the internal data can be prevented from being leaked.

6 is a diagram illustrating an example of an on-chip photodiode of a security device of a semiconductor chip according to an embodiment. The on-chip photodiode of FIG. 6 may be used, for example, to implement the potential generating block 110 of the secure semiconductor chip 100 of FIG. 1.

As shown, the on-chip photo diode according to an embodiment may include a tree structure in which a plurality of photo diodes are cascaded to easily generate a high voltage required for driving a circuit. When the light energy penetrating inside the packaging is collected through such a structure, at least a part of the collected light energy may be transferred to a capacitor to generate a potential difference. By employing the tree-on-chip photodiode, there is an advantage that a voltage required to drive a circuit can be generated without a DC-DC converter.

The photodiode can be replaced or used together with any device that can perform the same or similar function. In addition to the structure explicitly shown in FIG. 6, a structure in which it is applied or modified may be used to suit the embodiment.

As described above, when the current generated by the on-chip photodiode is greater than the current discharged through the pull-down resistor, the voltage at the upper node of the capacitor may increase, so that the cutoff switch may be turned on. Therefore, the photosensitive performance and detailed design of the on-chip photodiode can be optimized in consideration of the characteristics of the pull-down resistor and the disconnect switch.

7 is a flowchart illustrating a method of detecting damage to a packaging by a semiconductor chip according to an exemplary embodiment. For example, the method of FIG. 7 may be implemented as a method of operating the secure semiconductor chip 100 of FIG. 1.

In step 710, light may penetrate from outside the packaging of the semiconductor chip. Since the penetration of light refers to a case in which the packaging of the semiconductor chip is damaged by a depackaging attack or other abnormal situation, it is desirable to take measures to fundamentally block hacking attempts that may occur after the packaging of the semiconductor chip.

As mentioned above, if depackaging occurs in a confined environment such as a darkroom, light infiltration due to the depacking itself may not occur, but photons may be detected in the process of accessing the data bus or observing the structure inside the chip. Can be.

In step 720, a potential difference across the pull-down resistor may be generated by the potential generating block. That is, since it is considered that a security attack such as depacking occurs due to light penetration in step 710, a potential difference for the protection circuit operation may be generated in the potential generating block.

For example, the current generated by the photodiode is designed to be greater than the current discharged through the pull-down resistor, thereby gradually increasing the voltage at the capacitor top node and the gate terminal of the disconnect switch.

In step 730, the data transfer path in the semiconductor chip may be blocked using the potential difference. For example, the pad outputs of each data bus can be forced low so that normal data outputs are not delivered. In addition, as a protective measure for the semiconductor chip, data erase, data scrambling, destruction or deactivation of the semiconductor chip may be performed additionally or alternatively as necessary. As mentioned above, while some embodiments have been described with respect to the method of operating a circuit protection, such as a method of blocking the data output of the data bus, the protection measures for the semiconductor chip are limited to the examples explicitly described herein. It should not be.

According to the exemplary embodiment described above, when a chip package is damaged or removed, an energy harvesting device such as a photo-diode operates a trigger circuit such as to initialize or erase security data by harvesting ambient light energy. In a typical room, the light response of the illuminance and the PN junction of the CMOS is 0.5W / m ² , 0.5A · cm ⁻² / W · cm ^−2, respectively. Assuming an exemplary environment, a 100 μm ² photodiode can generate ^2.5 nA photocurrent. Assuming a supply voltage of 1.8V and a capacitor of 10pF, the time required for the protection circuit operation is about 72ms. When all capacitors are charged, 18uA current is supplied to report to the trigger circuit for 10us. This optical energy harvesting allows protection operations, such as erasing the contents of an SRAM, to be performed in a very short time (eg less than 0.1 second). Thus, physical attack such as removing at least a portion of the package or performing an invasive microprobing attack is effectively prevented by the embodiments described above.

The device described above may be implemented as a hardware component of a memory, a memory as a control software component, and / or a combination of hardware components and software components. For example, the devices and components described in the embodiments may be, for example, processors, controllers, arithmetic logic units (ALUs), digital signal processors, microcomputers, field programmable arrays (FPAs), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions.

The software may include a computer program, code, instructions, or a combination of one or more of the above, and configure the processing device to operate as desired, or process it independently or collectively. You can command the device. Software and / or data may be any type of machine, component, physical device, virtual equipment, computer storage medium or device in order to be interpreted by or to provide instructions or data to the processing device. Or may be permanently or temporarily embodied in a signal wave to be transmitted. The software may be distributed over networked computer systems so that they may be stored or executed in a distributed manner. Software and data may be stored on one or more computer readable recording media.

Memory operation control method according to an embodiment is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Although the embodiments have been described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved. Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the claims that follow.

Claims

In a semiconductor chip,

At least one data bus for transmitting data to be processed through the semiconductor chip;

A potential generating block packaged together with the at least one data bus to detect an event in which light from the outside is blocked by a package and the package fails to block light from the outside; And

A switch to block transmission of at least some data of the at least one data bus when the event is detected

Semiconductor chip comprising a.
The method of claim 1,

The dislocation generating block includes an energy harvesting element that generates energy by using the light when exposed to light from the outside.
The method of claim 1,

The potential generating block,

At least one photodiode generating a current when exposed to light from the outside;

A capacitor that stores charge by at least a portion of the current; And

A pull-down resistor that causes the charge to discharge from the capacitor

Semiconductor chip comprising a.
The method of claim 3,

The switch is turned on by a potential difference across the pull-down resistor during the discharge of the charge through the pull-down resistor to ground the at least some data of the at least one data bus. Semiconductor chip to cut off.
The method of claim 4, wherein

And the pull-down resistor is an active device whose resistance value is programmable by setting.
The method of claim 5,

Increasing the pull-down resistance set point reduces the amount of discharge current required to turn on the switch so that the switch is turned on relatively easily, and turning the switch on when lowering the pull-down resistor set point. The amount of discharge current required to increase the semiconductor chip is relatively difficult to turn on.
The method of claim 3,

And the at least one photodiode comprises a plurality of photodiodes cascaded at least in part.
The method of claim 3,

The at least one photodiode includes a plurality of photodiodes hierarchically connected in a tree structure.
The method of claim 1,

And said at least one data bus comprises a plurality of data buses each transferring data in parallel, said plurality of data buses sharing said potential generating block.
A protective device embedded in a semiconductor chip packaging,

A potential generating block for detecting an event in which the package fails to block light from the outside; And

A switch to block at least some data transmission paths in the semiconductor chip when the event is detected

Device comprising a.
The method of claim 10,

The potential generating block,

At least one photodiode generating a current when exposed to light from the outside;

A capacitor that stores charge by at least a portion of the current; And

A pull-down resistor that causes the charge to discharge from the capacitor

Device comprising a.
The method of claim 11,

And the switch is turned on by a potential difference across the pull-down resistor in the process of discharging the charge through the pull-down resistor to block the transfer path by grounding a portion of the transfer path.
The method of claim 12,

Wherein the pull-down resistor is an active element whose resistance value is programmable by setting.
The method of claim 13,

Increasing the pull-down resistance set point reduces the amount of discharge current required to turn on the switch so that the switch is turned on relatively easily, and turning the switch on when lowering the pull-down resistor set point. The amount of discharge current required to make the switch turn on relatively difficult.
The method of claim 11,

And the at least one photodiode comprises a plurality of photodiodes hierarchically connected in a tree structure.
In the method in which the semiconductor chip detects the damage of the packaging,

When light penetrates from outside the packaging of the semiconductor chip due to the damage of the packaging, the potential generating block embedded in the on-chip module form generating a potential difference across the pull-down resistor; And

At least a portion of the data transfer path in the semiconductor chip is grounded by the potential difference to block data transfer

How to include.