KR20220086953A - Separated double-gate transistor with self-destruction and physically unclonable function - Google Patents

Abstract

An isolated double gate transistor having a self-destruct function and a physical copy protection function is disclosed. According to one embodiment, the separated double gate transistor comprises: a semiconductor substrate; a nanowire channel formed on the semiconductor substrate; a source region and a drain region formed at both ends of the nanowire channel; a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and a gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel, wherein the separated double gate transistor includes applying a voltage to the nanowire channel, It is characterized in that it has a self-destructive function by applying a voltage or applying a voltage between the source region and the drain region and the semiconductor substrate.

Description

SEPARATED DOUBLE-GATE TRANSISTOR WITH SELF-DESTRUCTION AND PHYSICALLY UNCLONABLE FUNCTION

The following embodiments relate to an isolated double gate transistor having a self-destruct function and a physical copy protection function.

Artificial Intelligence (AI), self-driving cars, big data, Augmented Reality/Virtual Reality (AR/VR), Internet of Things (IoT), smartphones according to the 4th industrial revolution , the importance and market of the semiconductor industry are growing due to the rapid increase in demand for smart home appliances. At this time, the 4th industrial revolution based on information and communication technology (ICT) requires digitization and interconnection of all devices and massive data processing.

In addition, 5G or 6G, the core infrastructure of the 4th industrial revolution that aims for hyper-connectivity, hyper-intelligence, and hyper-convergence, is converging with other industries to change the communication environment, such as the emergence of new services, diversification of communication devices, and rapid increase in connections between devices. is causing In particular, the IoT industry, which requires the use of a huge number of terminals based on the connection of things, unlike the existing mobile communication consisting of a human-centered network, is expected to develop epoch-making by utilizing the hyper-connectivity of 5G or 6G.

The 4th industrial revolution based on 5G or 6G, which aims for hyper-connectivity, super intelligence, and super convergence, has led the development of the IoT industry. We are faced with the problem that such attacks do not stay in the cyber world, but can threaten human life and property in the real world. In addition, as the functions and types of IoT devices diversify, the importance of security reinforcement is increasing.

On the other hand, representative hardware of an integrated circuit (IC) chip with a security function is a Physically Unclonable Function (PUF), a random number generator (RNG), or a structure of a cryptographic module (Cryptographic module). can have Among them, PUF is a technology that uses the unique microstructure difference of semiconductors produced in the same manufacturing process to generate a security key that cannot be physically copied. It contains unique information such as a kind of fingerprint, and the unique security key value must have a characteristic that cannot be detected from the outside. These PUFs are receiving great attention because they have the advantage of being able to easily apply to IoT devices at low cost while overcoming the fundamental limitations of software (SW)-based security solutions.

In order to realize an ideal PUF, it must have two main characteristics. First, it should be easy to evaluate the value of the output (response) to the challenge, but it should be difficult to predict. This means that the read operation of the made PUF device (hereinafter, PUF device means a device having a physical copy protection function) should be facilitated and secure security from external predictions, etc. should be secured. Second, it should be easy to craft but difficult to replicate. Ease of fabrication is a very important characteristic that increases the productivity of PUF devices that can be integrated into an integrated circuit and reduces costs. However, if it becomes easy to copy while securing ease of manufacture, the security of PUF may be compromised, so the impossibility of copying is still a part to be maintained.

In addition to the two characteristics described, the manufactured PUF device has three characteristics: uniformity, uniqueness (inter-chip Hamming Distance; HDinter), and reliability (intra-chip Hamming Distance; HDintra). Should be. First, uniformity is a characteristic that evaluates whether the ratio of cells having '0' and '1' bits in the PUF array (key) is uniform. It is possible to fabricate a PUF device. Second, uniqueness is an index that evaluates whether a bit value has no causal relationship independently between two PUF arrays (keys), and can be expressed as an inter-chip Hamming Distance (HDinter). The inter-chip Hamming distance is a measure of randomness between different PUF keys when the same input is applied to two PUF devices, and in the case of an ideal PUF device, a value close to 50% should be secured. Finally, reliability is a value indicating whether unique bits of the PUF array are kept constant according to time or external environment change, and is expressed as an intra-chip Hamming Distance (HDintra). The hamming distance within the chip approaches 0% as there is no change according to the external environment and time, and has a value of 0% in an ideal case.

Meanwhile, Metal Oxide Semiconductor Field Effective Transistor (MOSFET) has been established as a basic element of all silicon integrated circuits since it was first developed at Bell Labs in the United States in 1960. In this development process, device miniaturization continued for mass production, and problems such as short-channel effects (SCEs) occurred due to the continued miniaturization. In order to solve this problem, it has evolved into a multiple-gate structure such as a double-gate structure in which the gate covers two sides of the channel and a tri-gate structure in which the gate covers three sides of the channel. .

However, as the device continues to be miniaturized, the process variation gradually increases, which has caused non-uniformity or inconsistency in electrical characteristics between manufactured devices. Typical causes that cause process dispersion in the MOSFET manufacturing process are random dopant fluctuation (RDF), gate insulating film thickness distribution, line edge roughness (LER) in the case of a three-dimensional structure, physical thickness of the channel, or Width and, in the case of polycrystalline materials, the effect of grain size and lattice direction dispersion. As mentioned above, randomly induced dispersion occurs naturally during the MOSFET manufacturing process and causes problems such as yield reduction in terms of mass production, but it has an advantageous aspect by greatly reducing the possibility of physical replication from the perspective of PUF.

In the case of MOSFET-based PUF devices, unlike PUF devices using 2-terminal-based RRAM (Resistive Random Access Memory) and PCRAM (Phase-Change Random Access Memory), etc., they are compatible with existing integrated circuits, so they are easy to manufacture, and the threshold voltage It has the advantage that it can be easily evaluated through various electrical factors such as (Threshold voltage, VT), operating current (On current, Ion), and leakage current (Off current, Ioff).

Accordingly, in order to satisfy the increasing importance of security enhancement in the 4th industrial revolution, it is necessary to propose a technology for a MOSFET device that compensates for the shortcomings in terms of integration by securing multi-level cell characteristics and implementing PUF.

One embodiment intends to propose a separate dual gate transistor that implements a physical copy protection function with electrical characteristics that appear when a voltage is applied to gate regions separated from each other.

In particular, one embodiment intends to propose a separate dual gate transistor that secures multi-level cell characteristics in implementing a physical copy protection function with electrical characteristics that appear when a voltage is applied to gate regions separated from each other.

However, the technical problems to be solved by the exemplary embodiments are not limited to the above problems, and may be variously expanded without departing from the technical spirit and scope of the described examples.

According to one embodiment, the separated double gate transistor comprises: a semiconductor substrate; a nanowire channel formed on the semiconductor substrate; a source region and a drain region formed at both ends of the nanowire channel; a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and a gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel, wherein the separated double gate transistor includes applying a voltage to the nanowire channel, It is characterized in that it has a self-destructive function by applying a voltage or applying a voltage between the source region and the drain region and the semiconductor substrate.

According to one side, the separated double gate transistor may have a self-destruct function based on Joule heat generated by voltage application to the nanowire channel.

According to another aspect, the separated double gate transistor may have a self-destruction function based on a gate dielectric breakdown caused by voltage application to the gate insulating layer.

According to another aspect, the separated double gate transistor has a self-destructive function based on a junction breakdown caused by voltage application between the source region and the drain region and the semiconductor substrate. can do.

According to another aspect, the separated double gate transistor includes a first digit divided according to the magnitude of an electrical characteristic that appears when a voltage is simultaneously applied to the first gate region and the second gate region, and the first Multi-level cell characteristics by combining second digit bits that are distinguished according to a difference in electrical characteristics between the first gate region and the second gate region that appear when a voltage is separately applied to each of the gate region and the second gate region It may be characterized as having this secured, physically unclonable function (PUF).

According to another aspect, in the separated double gate transistor, at least one of a voltage simultaneously applied to the first gate region and the second gate region or a voltage separately applied to each of the first gate region and the second gate region As one voltage is adjusted, it may be characterized in that multi-level cell characteristics of 2 bits or more are secured.

According to another aspect, the separated double gate transistor may be connected to a detection circuit that detects an external security attack, and activates or deactivates the self-destruct function according to the control of the detection circuit.

According to another aspect, the sensing circuit detects the external security attack including at least one of a side channel attack, an electromagnetic radiation analysis, or a physical cloning attack. In this case, it may be characterized in that the self-destructive function is activated.

According to another aspect, the separated double gate transistor includes a buried oxide, a buried n-well, a buried p-well, and a buried SiC ( It may further include a buried insulating layer formed of at least one of Buried SiC) and buried SiGe (Buried SiGe).

According to another aspect, the semiconductor substrate may be formed of at least one of silicon, silicon germanium, tensile silicon, tensile silicon germanium, and silicon carbide.

According to another aspect, the semiconductor substrate may be operable as a back gate.

According to another aspect, the nanowire channel may be formed of at least one of silicon, silicon germanium, tensile silicon, tensile silicon germanium, insulating layer buried silicon, silicon carbide, or a group III-V compound semiconductor. .

According to another aspect, the source region and the drain region are formed in a form in which impurity ions are implanted into the semiconductor material forming the nanowire channel, or at least of Al, W, Ti, Co, Ni, Er, or Pt. It may be formed of a silicide alloy containing any one, or formed of a metal containing at least one of Au, Al, Ag, Mg, Ca, Yb, Cs-ITO, Ti, Cr, or Ni.

According to another aspect, the source region and the drain region formed of p-type silicon or n-type silicon are diffusion, solid-phase diffusion, epitaxial growth, and selective epitaxial growth. It may be characterized in that it is formed by at least one of epitaxial growth, ion implantation, and subsequent heat treatment.

According to another aspect, the first gate region and the second gate region, n-type polysilicon, p-type polysilicon, aluminum (Al), molybdenum (Mo), chromium (Cr), palladium (Pd), platinum (Pt), nickel (Ni), titanium (Ti), tantalum (Ta), tungsten (W), silver (Ag), characterized in that formed of at least one of titanium nitride (TiN) or tantalum nitride (TaN) can

According to another side, the gate insulating film is an oxide film (Silicon oxide), a nitride film (Silicon nitride), an oxynitride film (Silicon oxynitride), aluminum oxide (Aluminum oxide), hafnium oxide (Hafnium oxide), hafnium oxynitride (Hafnium Oxynitride) ), zinc oxide, zirconium oxide, polymer dielectric, or hafnium zirconium oxide (HZO), or formed in a state filled with air (Air ambient) can be done with

According to one embodiment, the separated double gate transistor comprises: a semiconductor substrate; a nanowire channel formed on the semiconductor substrate; a source region and a drain region formed at both ends of the nanowire channel; a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and a gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel, wherein a voltage is applied to the first gate region and the second gate region at the same time. The difference in electrical characteristics between the first digit divided according to the size and the first gate region and the second gate region when a voltage is separately applied to each of the first gate region and the second gate region It is characterized in that it has a physically unclonable function (PUF), in which multi-level cell characteristics are secured by combining the second digit bits distinguished according to each other.

According to one embodiment, a system based on an isolated double gate transistor having a self-destruct function includes: the separated double gate transistor; and a sensing circuit configured to detect an external security attack on the isolated double gate transistor while being connected to the isolated double gate transistor, and to control the isolated double gate transistor according to the detection result, The transistor includes a semiconductor substrate; a nanowire channel formed on the semiconductor substrate; a source region and a drain region formed at both ends of the nanowire channel; a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and a gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel, wherein a voltage is applied to the nanowire channel, a voltage is applied to the gate insulating layer, or the source region and the It is characterized in that it has a self-destruction function by applying a voltage between the drain region and the semiconductor substrate, wherein the sensing circuit activates or deactivates the self-destruction function of the separated double gate transistor according to the detection result characterized.

One embodiment may propose a separate dual gate transistor that implements a physical copy protection function with electrical characteristics that appear when a voltage is applied to gate regions separated from each other.

In particular, embodiments may propose a separate dual gate transistor that secures multi-level cell characteristics in implementing a physical copy protection function with electrical characteristics that appear when a voltage is applied to gate regions separated from each other.

The separated double gate transistor according to an embodiment can be implemented based on CMOS technology, which has already secured technological maturity. Hardware-based security can also be improved.

The exemplary embodiments are not limited to the above effects, and may be variously expanded without departing from the spirit and scope of the described examples.

1A is a perspective view illustrating an isolated double gate transistor according to an exemplary embodiment.
FIG. 1B is a plan view illustrating the isolated double gate transistor shown in FIG. 1A.
1C is a scanning electron microscope (SEM) photograph of the separated double gate transistor shown in FIG. 1A.
1D is a cross-sectional side view of the isolated double gate transistor shown in FIG. 1A;
2A is a perspective view illustrating an isolated double gate transistor according to another exemplary embodiment.
FIG. 2B is a side cross-sectional view illustrating the isolated double gate transistor shown in FIG. 2A.
3A is a diagram for describing multi-level cell characteristics of an isolated double gate transistor according to an exemplary embodiment.
FIG. 3B is a diagram for explaining that 2 bits are divided through a read operation according to multi-level cell characteristics of an isolated double gate transistor according to an embodiment.
FIG. 4 is a diagram for explaining conversion from an arrangement of a separate double gate transistor to a 2-bit bitmap according to an exemplary embodiment.
5A to 5B are diagrams for explaining a measurement result of a security characteristic of a physical copy protection function of an isolated double gate transistor according to an exemplary embodiment.
6 is a flowchart illustrating a process in which a self-destruction function of an isolated double gate transistor is activated according to an exemplary embodiment.
7 is a view for explaining a result of activating a self-destruction function of an isolated double gate transistor according to an exemplary embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the examples. Also, like reference numerals in each figure denote like members.

In addition, the terms (Terminology) used in this specification are terms used to properly express a preferred embodiment of the present invention, which may vary depending on the intention of a user or operator or customs in the field to which the present invention belongs. Accordingly, definitions of these terms should be made based on the content throughout this specification.

1A is a perspective view illustrating an isolated double gate transistor according to an embodiment, FIG. 1B is a plan view illustrating the isolated double gate transistor illustrated in FIG. 1A, and FIG. 1C is the isolated double gate transistor shown in FIG. 1A It is a scanning electron microscope (SEM) photograph taken, and FIG. 1D is a side cross-sectional view showing the separated double gate transistor shown in FIG. 1A.

1A to 1D , an isolated double gate transistor 100 according to an embodiment includes a semiconductor substrate 110 , a nanowire channel 120 , a source region 130 and a drain region 140 , It may include a first gate region 150 and a second gate region 160 , and a gate insulating layer 170 .

The semiconductor substrate 110 is a single crystal semiconductor substrate and may be formed of at least one of silicon, silicon germanium (SiGe), tensile silicon (Strained Si), tensile silicon germanium (Strained SiGe), or silicon carbide (SiC).

The semiconductor substrate 110 may operate as a back gate to which a voltage bias is applied.

The nanowire channel 120 is formed on the semiconductor substrate 110 on single crystalline silicon, poly-crystalline silicon, silicon germanium, tensile silicon, tensile silicon germanium, and insulating layer buried silicon (Silicon-On). -Insulator, SOI), silicon carbide (SiC), or any combination of group III-V compound semiconductors having different energy band gaps may be formed. The nanowire channel 120 is not limited or limited to being formed of the materials of the described examples, and may induce a random dopant fluctuation (RDF) effect, or a dispersion effect due to grain size and lattice direction (polycrystalline material). In the case of ), it can be formed of a material that can cause

The source region 130 and the drain region 140 may be formed at both ends of the nanowire channel 120 . In this case, the source region 130 and the drain region 140 are formed in a form in which impurity ions are implanted into the semiconductor material forming the nanowire channel 120 , or Al, W, Ti, Co, Ni, Er, or Pt. It may be formed of a silicide alloy containing at least one of, or formed of a metal containing at least one of Au, Al, Ag, Mg, Ca, Yb, Cs-ITO, Ti, Cr, or Ni.

For example, the source region 130 and the drain region 140 may be formed of p-type silicon or n-type silicon. In this case, the source region 130 and the drain region 140 are formed of the nanowire channel 120 . It can have a type opposite to the ion type. As a more specific example, when the nanowire channel 120 is p-type, the source region 130 and the drain region 140 may be n-type, and when the nanowire channel 120 is n-type, the source region 130 and the drain region. Region 140 may be p-type.

In addition, when the source region 130 and the drain region 140 are formed of p-type silicon or n-type silicon, the source region 130 and the drain region 140 perform diffusion and solid-phase diffusion. ), epitaxial growth, selective epitaxial growth, ion implantation, or subsequent heat treatment.

When a voltage is applied between the source region 130 and the drain region 140 , Joule heat is generated to implement a self-destruction function. Hereinafter, the application of a voltage between the source region 130 and the drain region 140 means that the voltage is applied to the nanowire channel 120 formed at both ends of the source region 130 and the drain region 140 . .

In addition, when a voltage is applied between the source region 130 and the drain region 140 and the semiconductor substrate 110 , a junction breakdown may occur and a self-destruction function may be implemented.

The first gate region 150 and the second gate region 160 may be formed on both sides of the nanowire channel 120 so as not to contact the source region 130 and the drain region 140 . Accordingly, the first gate region 150 and the second gate region 160 have a structure separated from each other, and the present device including the first gate region 150 and the second gate region 160 has a double separated structure. It may be referred to as a gate transistor 100 .

The separated first and second gate regions 150 and 160 are n-type polysilicon, p-type polysilicon, aluminum (Al), molybdenum (Mo), chromium (Cr), palladium (Pd), platinum ( Pt), nickel (Ni), titanium (Ti), tantalum (Ta), tungsten (W), silver (Ag), titanium nitride (TiN), or tantalum nitride (TaN) may be formed of at least one.

The gate insulating layer 170 is formed between each of the first gate region 150 and the second gate region 160 and the nanowire channel 120 , and the first gate region 150 and the second gate region 160 . Each of the nanowire channels 120 may be insulated from each other. To this end, the gate insulating film 170 is an oxide film (Silicon oxide), a nitride film (Silicon nitride), an oxynitride film (Silicon oxynitride), aluminum oxide (Aluminum oxide), hafnium oxide (Hafnium oxide), hafnium oxynitride (Hafnium Oxynitride), It may be formed of at least one of zinc oxide, zirconium oxide, a polymer dielectric, or hafnium zirconium oxide (HZO), or may be formed in a state filled with air (air ambient).

When a voltage is applied to the gate insulating layer 170 as described above, a gate dielectric breakdown may occur, so that a self-destructive function may be implemented. Hereinafter, application of a voltage to the gate insulating layer 170 means that a voltage is applied between the first gate region 150 and the second gate region 160 having the gate insulating layer 170 interposed therebetween.

When a voltage is applied between the source region 130 and the drain region 140 , Joule heat is generated to implement a self-destruction function. Hereinafter, the application of a voltage between the source region 130 and the drain region 140 means that the voltage is applied to the nanowire channel 120 formed at both ends of the source region 130 and the drain region 140 . .

The separated double gate transistor 100 having the structure described above includes applying a voltage to the nanowire channel 120, applying a voltage to the gate insulating layer 170, or applying a source region 130 and a drain region 140 and a semiconductor substrate ( 110) may be characterized as having a self-destructive function through the application of a voltage between them.

For example, the dual gate transistor 100 separated as described above may implement a self-destruction function based on Joule heat generated by voltage application to the nanowire channel 120 .

As another example, the double gate transistor 100 separated as described above may implement a self-destruction function based on the destruction of the gate insulating film caused by voltage application to the gate insulating film 170 .

As another example, the dual gate transistor 100 isolated as described is based on junction breakdown caused by voltage application between the source region 130 and drain region 140 and the semiconductor substrate 110 . Self-destruction function can be implemented.

Such a self-destruction function may be activated or deactivated according to the control of a sensing circuit (not shown) connected to the separated double gate transistor 100 . In one example, the sensing circuit detects an external security attack comprising at least one of a side channel attack, electromagnetic radiation analysis, or a physical cloning attack, thereby enabling the described external security attack. When this is sensed, the self-destruction function of the isolated double gate transistor 100 may be activated. A detailed description thereof will be described with reference to FIGS. 6 to 7 .

Accordingly, one system (a system based on an isolated double gate transistor having a self-destruct function) can be implemented with the isolated double gate transistor 100 and the sensing circuit of the described structure. In addition, the system includes not only the components described, but also additional components (eg, resistors, capacitors, other transistors, and inverters) for performing read and self-destruct operations on the isolated double gate transistor 100 . may include more.

In particular, the separated double gate transistor 100 may implement a physical copy protection function with electrical characteristics that appear when a voltage is applied to the gate regions (the first gate region 150 and the second gate region 160 ) that are separated from each other. In more detail, in the separated double gate transistor 100 , various dispersions (eg, random dopant fluctuations (RDF)), gate insulating film thickness dispersion, and Line edge roughness (LER) occurring during the manufacturing process. ), and in the case of polycrystalline materials, it is possible to implement a physical copy prevention function with different electrical properties to the effect of grain size and lattice direction dispersion, etc.).

Accordingly, the separated double gate transistor 100 has a first digit and a second digit divided according to the magnitude of electrical characteristics appearing when a voltage is simultaneously applied to the first gate region 150 and the second gate region 160 , Two types are distinguished according to a difference in electrical characteristics between the first gate region 150 and the second gate region 160 that appear when a voltage is separately applied to each of the first gate region 150 and the second gate region 160 . By combining the digit bit, it is possible to implement a physical copy protection function that secures multi-level cell characteristics. A detailed description thereof will be described with reference to FIGS. 3A to 3B, 4, and 5A to 5B below.

In addition, the separated double gate transistor 100 is applied to a voltage simultaneously applied to the first gate region 150 and the second gate region 160 or to each of the first gate region 150 and the second gate region 160 . As at least one of the separately applied voltages is adjusted, multi-bits of 2 bits or more may be implemented to secure multi-level cell characteristics.

In the above, it has been described that the separated double gate transistor 100 is manufactured in a bulk channel structure, but the present invention is not limited thereto and may be manufactured in a floating channel structure. A detailed description thereof will be described with reference to FIGS. 2A to 2B below.

2A is a perspective view illustrating an isolated double gate transistor according to another exemplary embodiment, and FIG. 2B is a side cross-sectional view illustrating the isolated double gate transistor illustrated in FIG. 2A .

2A to 2B , an isolated double gate transistor 100 according to another embodiment has the same function as the separated double gate transistor described with reference to FIGS. 1A to 1D by including the same components, It is different in that it has a floating channel structure rather than a bulk channel structure.

In more detail, the separated double gate transistor 100 may have a floating channel structure in which the nanowire channel 120 is floated by the buried insulating layer 180 formed on the semiconductor substrate 110 .

Here, the buried insulating layer 180 is formed over the semiconductor substrate 100 , the nanowire channel 120 , the source region 130 and the drain region 140 , the first gate region 150 , and the second gate region 160 . , between the lower portion of the gate insulating layer 170 , a buried oxide, a buried n-well, a buried p-well, and a buried SiC (Buried SiC) Or it may be formed of at least one of buried SiGe (Buried SiGe).

FIG. 3A is a diagram for explaining multi-level cell characteristics of an isolated double-gate transistor according to an embodiment, and FIG. 3B is a view for explaining the multi-level cell characteristics of the separated double-gate transistor according to an embodiment through a read operation. It is a diagram for explaining that bits are divided.

Referring to FIG. 3A , when a voltage is simultaneously applied to the first gate region and the second gate region in the separated double gate transistor, the arrangement (Key) of the separated double gate transistor shows the distribution of electrical characteristics for each cell therein This causes non-uniformity to separate the first digit bit (310) (eg, '0x' and '1x'), and when a voltage is applied separately to each of the first gate region and the second gate region, in the cell In , the second digit bit may be distinguished through a difference in electrical characteristics in each of the first gate region and the second gate region ( 320 ) (eg, '00', '01', '10', and '11'). . Accordingly, the multi-level cell characteristics of '00', '01', '10', and '11' may be secured by combining the first digit bit and the second digit bit. That is, a cell configured with the binary bitmap 330 may be expanded into a double binary bitmap 340 having a doubled key size.

As the multi-level cell characteristics are secured as described above, the threshold voltage is different for each cell based on the current density that appears when a voltage is simultaneously applied to the first gate region and the second gate region as shown in FIG. 3B. The first digit is distinguished by , and it is confirmed that current densities are different when a voltage is separately applied to each of the first gate region and the second gate region, so that the second digit bit can be distinguished.

FIG. 4 is a diagram for explaining conversion from an arrangement of a separate double gate transistor to a 2-bit bitmap according to an embodiment.

Referring to FIG. 4 , an array 410 of an isolated double gate transistor having a structure of (2*16) has a quaternary bit as the above-described multi-level characteristic is secured, and when converted to a double binary bit (4 *16) may have an expanded number of cells 420.

As such, the separated double-gate transistor having multi-level cell characteristics may have twice the number of bits compared to a general transistor having the same area having a physical copy protection function. In addition, in the separated double gate transistor, as at least one of a voltage simultaneously applied to the first gate region and the second gate region or a voltage applied separately to each of the first gate region and the second gate region is regulated, physical replication It may have more than double the number of bits compared to a general transistor of the same area with a prevention function.

However, it is not limited or limited now, and the electrical characteristics used by the separated double gate transistor for the expansion of the number of bits include a threshold voltage ( V _th ), an operating current ( I _on ), or an off current (Off current). ; I _off ) may further include electrical characteristics.

5A to 5B are diagrams for explaining a measurement result of a security characteristic of a physical copy protection function of an isolated double gate transistor according to an exemplary embodiment.

5A and 5B, the multi-level cell-based physical copy protection function of the isolated double gate transistor utilizes a polycrystalline silicon nanowire channel among various dispersion-inducing effects to achieve large uniformity through grain size and lattice direction dispersion, It shows that uniqueness and reliability are guaranteed.

6 is a flowchart illustrating a process in which the self-destruction function of the separated double gate transistor is activated according to an embodiment, and FIG. 7 is a result of activating the self-destruction function of the separated double gate transistor according to the embodiment. It is a drawing for explanation.

6 to 7 , a detection circuit included in a system (hereinafter, referred to as a system) based on an isolated double gate transistor having a self-destruct function may detect an external security attack in step S610 .

As a result, if it is detected that an external security attack is being attempted, the sensing circuit activates the self-destruction function of the double-gate transistor isolated in step S620, and in response, the detached double-gate transistor self-destructs in step S630 function can be executed.

Here, the self-destruction function is based on Joule heat generated by voltage application to the nanowire channel, or gate insulating layer destruction caused by voltage application to the gate insulating layer, or the source and drain regions and the semiconductor substrate. It can be based on junction breakdown caused by the application of voltage between them.

1400℃)으로 알려진 조건이 서로 부합되어 도 7의 하단 그래프와 같이 녹는점 근방에서 나노선 채널의 전류 밀도는 급격히 낮아짐을 보이고, 이는 나노선 채널이 도 7의 상단 SEM 사진과 같이 파괴되었음을 나타낸다.Accordingly, the separated double gate transistor may perform self-destruction that destroys the nanowire channel by generating Joule heat by applying a voltage to the nanowire channel in step S630 . As a result of self-destruction, the voltage condition (18V) and the melting point of silicon (

1400° C.), the current density of the nanowire channel is sharply lowered near the melting point as shown in the lower graph of FIG. 7 as shown in the lower graph of FIG.

As another example, the separated double gate transistor may perform self-destruction that destroys the gate insulating film by applying a voltage to the gate insulating film in step S630 .

As another example, the isolated double-gate transistor may perform self-destruction of breaking the junction by applying a voltage between the region and the drain region and the semiconductor substrate in step S630 .

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible from the above description by those skilled in the art. For example, the described techniques are performed in an order different from the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (18)

A separate double gate transistor comprising:
semiconductor substrate;
a nanowire channel formed on the semiconductor substrate;
a source region and a drain region formed at both ends of the nanowire channel;
a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and
A gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel
including,
The separated double gate transistor,
The separated double gate transistor having a self-destruct function by applying a voltage to the nanowire channel, applying a voltage to the gate insulating layer, or applying a voltage between the source region and the drain region and the semiconductor substrate. According to claim 1,
The separated double gate transistor,
The separated double gate transistor, characterized in that it has a self-destructive function based on Joule heat generated by voltage application to the nanowire channel. The method of claim 1,
The separated double gate transistor,
Separated double gate transistor, characterized in that it has a self-destructive function based on the gate dielectric breakdown (Gate dielectric breakdown) caused by the voltage application to the gate insulating layer. According to claim 1,
The separated double gate transistor,
and a self-destructive function based on junction breakdown caused by voltage application between the source region and the drain region and the semiconductor substrate. According to claim 1,
The separated double gate transistor,
A voltage is separately applied to each of the first digit and the first gate region and the second gate region, and the first digit divided according to the magnitude of an electrical characteristic that appears when a voltage is simultaneously applied to the first gate region and the second gate region Physically Unclonable Function (PUF), in which multi-level cell characteristics are secured by combining second digit bits that are distinguished according to differences in electrical characteristics between the first gate region and the second gate region that appear when ), characterized in that it has an isolated double gate transistor. 6. The method of claim 5,
The separated double gate transistor,
When at least one of a voltage simultaneously applied to the first gate region and the second gate region or a voltage separately applied to each of the first gate region and the second gate region is adjusted, a multi-level cell of 2 bits or more Separated double gate transistor characterized in that it secures the characteristics. According to claim 1,
The separated double gate transistor,
Separated double gate transistor, characterized in that it is connected to a detection circuit that detects an external security attack, and activates or deactivates the self-destruct function according to the control of the detection circuit. 8. The method of claim 7,
The sensing circuit is
Activating the self-destruct function when the external security attack including at least one of a side channel attack, electromagnetic radiation analysis, or physical cloning attack is detected isolated double gate transistors. The method of claim 1,
The separated double gate transistor,
At least any of buried oxide, buried n-well, buried p-well, buried SiC (Buried SiC), or buried SiGe (Buried SiGe) A buried insulating film formed as one
Separated double gate transistor comprising a further. According to claim 1,
The semiconductor substrate,
An isolated double gate transistor formed of at least one of silicon, silicon germanium, tensile silicon, tensile silicon germanium, or silicon carbide. According to claim 1,
The semiconductor substrate,
An isolated double gate transistor operable as a back gate. According to claim 1,
The nanowire channel is
An isolated double gate transistor, characterized in that it is formed of at least one of silicon, silicon germanium, tensile silicon, tensile silicon germanium, insulating layer buried silicon, silicon carbide, or a group III-V compound semiconductor. The method of claim 1,
The source region and the drain region are
It is formed in a form in which impurity ions are implanted into the semiconductor material forming the nanowire channel, or formed of a silicide alloy containing at least one of Al, W, Ti, Co, Ni, Er, or Pt, or Au, Al, An isolated double gate transistor formed of a metal comprising at least one of Ag, Mg, Ca, Yb, Cs-ITO, Ti, Cr or Ni. 14. The method of claim 13,
The source region and the drain region formed of p-type silicon or n-type silicon,
Diffusion, solid-phase diffusion, epitaxial growth, selective epitaxial growth, ion implantation, or subsequent heat treatment. Separated double gate transistors. According to claim 1,
the first gate region and the second gate region,
n-type polysilicon, p-type polysilicon, aluminum (Al), molybdenum (Mo), chromium (Cr), palladium (Pd), platinum (Pt), nickel (Ni), titanium (Ti), tantalum (Ta), An isolated double gate transistor formed of at least one of tungsten (W), silver (Ag), titanium nitride (TiN), or tantalum nitride (TaN). The method of claim 1,
The gate insulating film is
Silicon oxide, nitride, silicon oxynitride, aluminum oxide, hafnium oxide, hafnium oxynitride, zinc oxide, zirconium oxide (Zirconium oxide), a polymer dielectric, or at least one of hafnium zirconium oxide (HZO), or formed in a state filled with air (Air ambient), characterized in that the separated double gate transistor. A separate double gate transistor comprising:
semiconductor substrate;
a nanowire channel formed on the semiconductor substrate;
a source region and a drain region formed at both ends of the nanowire channel;
a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and
A gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel
including,
A voltage is separately applied to each of the first digit and the first gate region and the second gate region, and the first digit divided according to the magnitude of an electrical characteristic that appears when a voltage is simultaneously applied to the first gate region and the second gate region Physically Unclonable Function (PUF), in which multi-level cell characteristics are secured by combining second digit bits that are distinguished according to differences in electrical characteristics between the first gate region and the second gate region that appear when ), characterized in that it has an isolated double gate transistor. In a system based on an isolated double gate transistor having a self-destruct function,
the isolated double gate transistor; and
A sensing circuit for detecting an external security attack on the isolated double gate transistor while being connected to the isolated double gate transistor, and controlling the isolated double gate transistor according to the detection result
including,
The separated double gate transistor comprises:
semiconductor substrate;
a nanowire channel formed on the semiconductor substrate;
a source region and a drain region formed at both ends of the nanowire channel;
a first gate region and a second gate region formed on both sides of the nanowire channel so as not to contact the source region and the drain region; and
A gate insulating layer formed between each of the first gate region and the second gate region and the nanowire channel
includes,
It is characterized in that it has a self-destructive function by applying a voltage to the nanowire channel, applying a voltage to the gate insulating layer, or applying a voltage between the source region and the drain region and the semiconductor substrate,
The sensing circuit is
and activating or deactivating the self-destruct function of the separated double gate transistor according to the detection result.

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