TW201723467A - Optical systems and methods of characterizing high-k dielectrics - Google Patents

Abstract

The disclosed technology generally relates to characterization of semiconductor structures, and more particularly to optical characterization of high-k dielectric materials. A method includes providing a semiconductor structure comprising a semiconductor and a high-k dielectric layer formed over the semiconductor, wherein the dielectric layer has electron traps formed therein. The method additionally includes at least partially transmitting an incident light having an incident energy through the high-k dielectric layer and at least partially absorbing the incident light in the semiconductor. The method additionally includes measuring a nonlinear optical spectrum resulting from the light having the energy different from the incident energy, the nonlinear optical spectrum having a first region and a second region, wherein the first region changes at a different rate in intensity compared to the second region. The method further includes determining from the nonlinear optical spectrum one or both of a first time constant from the first region and a second time constant from the second region, and determining a trap density in the high-k dielectric layer based on the one or both of the first time constant and the second time constant.

Description

Method for characterizing high dielectric constant dielectric and optical system thereof

The present invention relates to a method of characterizing a semiconductor structure and an optical system thereof, and more particularly to a method of characterizing a high dielectric constant dielectric.

As the complementary metal-oxide-semiconductor (CMOS) technology continues to evolve, the market's performance requirements for various components of metal oxide semiconductor (MOS) transistors continue to increase. One such component is MOS. The gate dielectric layer of the transistor. Since the physical thickness of the gate dielectric layer made of thermally grown ruthenium dioxide is continuously thinned, unacceptable current leakage has occurred. In order to solve the problem of current leakage, the industry is working to study the application of a high dielectric constant (high-k) dielectric layer in a gate dielectric layer based on cerium oxide in a MOS. With a dielectric layer of the same thickness, a higher dielectric constant provides a higher gate capacitance of the dielectric. By using a high-k dielectric, the thickness of the gate dielectric layer can be thickened while maintaining the same capacitance to reduce leakage current. A number of high-k dielectric layers have been developed to inherit the gate dielectric layer of germanium dioxide, including, for example, aluminum oxide (Al ₂ O ₃ ) and hafnium oxide (HfO ₂ ). The high-k dielectric layer, because these two materials not only have a high dielectric constant, but also have a certain degree of thermal stability when in contact with ruthenium, these two materials are currently quite popular materials.

Despite the necessary requirements for high-k dielectrics, certain electrical properties of high-k dielectric layers make them quite challenging when applied to high-order MOS transistors. And difficulties. Some structural defects such as fixed negative charge, interface state, and charge trap center affect the characteristic performance and yield of the high-k dielectric layer, such as negative bias temperature instability, threshold voltage shift, and gate. Leakage, etc., thereby limiting its application. For further research, development, and manufacturing, systems and methods that can be used to quickly, quantitatively, and non-destructively characterize structural defects in high-k dielectrics are becoming increasingly important. Existing characterization techniques have their shortcomings: the methods of characterizing electrical properties such as capacitance and voltage (CV), current and voltage (IV) measurements, most of which are performed using instrument structures that have been manufactured and manufactured. Not only time-consuming, but also difficult to introduce into the production process; and some ways to characterize physical and optical properties such as X-ray electron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), infrared spectroscopy (FTIR) and optical absorption/diverging Spectroscopy, etc., although chemical or optical properties can be used to characterize structural defects, but such methods do not necessarily exhibit electrical activity defects, which may cause unpredictable equipment or yield problems. In addition to the above disadvantages, many detection methods are not only destructive, but also time consuming and difficult to introduce into the production process. To address the above problems and disadvantages, the present invention provides a method of characterizing a high-k dielectric that is quantifiable, fast, non-destructive, and easy to import into a production process.

In one aspect, a method of characterizing a semiconductor structure of the present invention includes: providing a semiconductor structure comprising a semiconductor and a high-k dielectric layer formed on the surface of the semiconductor, wherein the high dielectric constant The dielectric layer has an electron trap that is mostly formed therein. The method of the present invention additionally includes causing incident light having incident energy to at least partially penetrate the high-k dielectric layer and at least a portion of the incident energy is absorbed by the semiconductor. The incident energy is sufficient to cause a portion of the electrons to be transferred from the semiconductor to the electron traps and temporarily trapped by the electron traps. The incident energy is sufficient for the electrons to temporarily fill the electron traps, and generate an energy light whose energy is different from the incident energy, and the light is generated It is based on nonlinear optical effects. The method of the present invention additionally includes measuring a spectrum generated from the light having an energy different from the incident energy, wherein the nonlinear spectrum includes a first region and a second region, the first region being compared to the The second region varies in intensity at different rates. The method further includes determining, by the spectrum, a first time constant of a first region or a second time constant of a second region, or a combination thereof, and determining from the first time constant or the second time constant or a combination thereof The density of the electron traps in the high dielectric constant dielectric layer.

In another aspect, a method of characterizing a semiconductor structure of the present invention includes: providing a semiconductor structure including a semiconductor body, and a high-k dielectric layer formed on a surface of the semiconductor substrate, wherein the high dielectric layer The electrical coefficient dielectric layer is provided with an electronic trap that is mostly formed therein. The method of the present invention additionally includes: causing at least a portion of the incident light having incident energy to penetrate the high-k dielectric layer, and at least a portion of the incident energy is absorbed by the semiconductor substrate, wherein the incident energy is sufficient to cause a portion of the electrons from the semiconductor The substrate is transferred to the electronic traps and temporarily trapped by the electronic traps. The incident energy is sufficient for the electrons to temporarily fill the electron traps and produce a harmonic generation (SHG). The method further includes measuring a second harmonic spectrum generated by the frequency doubling effect, wherein the second harmonic spectrum comprises a first region and a second region, wherein the first region has a higher rate of change than the second region The area is fast. The method of the present invention further includes determining, by the second harmonic spectrum, a first time constant of a first region, or a second time constant of a second region, or a combination thereof, and from the first time constant or the first The two time constants or a combination thereof determines the density of the electron traps in the high-k dielectric layer.

In another aspect, a system for characterizing a semiconductor structure of the present invention includes a light source that emits incident light having incident energy, wherein the incident light is at least partially penetrated to form a surface of a semiconductor substrate. A high-k dielectric layer is at least partially absorbed by the semiconductor body, wherein the high-k dielectric layer has an electron trap formed therein. The incident energy is sufficient to make the part Sub-electrons are transferred from the semiconductor structure to the electron traps and temporarily trapped by the electron traps. The incident energy is sufficient for the electrons to temporarily fill the electron traps and generate an energy ray having an energy different from the incident energy, and the light is generated based on a nonlinear optical effect. The system further includes a sensor for detecting a spectrum of the light, wherein the spectrum is a nonlinear spectrum, the spectrum comprising a first region and a second region, wherein the first region has a rate of change of intensity compared to the first region The second area is fast. The system further includes an electronic device for determining a first time constant of a first region, or a second time constant of a second region, or a combination thereof, and from the first time constant or the second time constant or In combination, the density of the electron traps in the high-k dielectric layer is determined.

In another aspect, a system for characterizing a semiconductor structure of the present invention includes a light source that emits incident light having incident energy, wherein the incident light is at least partially penetrated to form a surface of a semiconductor substrate. A high-k dielectric layer is at least partially absorbed by the semiconductor body, wherein the high-k dielectric layer is provided with an electron trap formed therein. The incident energy is sufficient to cause a portion of the electrons to be transferred from the semiconductor substrate to the electron traps and temporarily trapped by the electron traps. Wherein the incident energy is sufficient for the electrons to temporarily fill the electron traps and produce a frequency multiplication effect. The system further includes a sensor for measuring a second harmonic spectrum generated by the frequency doubling effect, wherein the second harmonic spectrum has a first region and a second region, and wherein the first region The intensity changes at a faster rate than the second region. The system further includes a time constant measuring unit for determining a first time constant of a first region, or a second time constant of a second region or a combination thereof from the second harmonic spectrum, and from the first The density of the electron traps in the high-k dielectric layer is determined by a time constant or the second time constant or a combination thereof.

100‧‧‧ method

104, 108, 112, 116, 120‧‧‧ steps

200a‧‧‧ system

200b, 200c‧‧‧ can bring schematic diagram

202‧‧‧Semiconductor structure

204‧‧‧Semiconductor substrate

208‧‧‧ interface layer

212‧‧‧High dielectric constant dielectric layer

216‧‧‧Light source

220‧‧‧ incident light

224‧‧‧ reflected light

228‧‧‧second harmonic light

232‧‧‧Sensor

238a, 238b‧‧ arrows

240‧‧‧Electronics

242‧‧‧Arrow

244‧‧‧ holes

246‧‧‧Time constant measuring unit

248‧‧‧Electronic trap

250‧‧‧Electronic trap density measuring unit

260‧‧‧Electronic devices

400‧‧‧ second harmonic spectrum diagram

404‧‧‧Secondary harmonic spectrum

408, 412‧‧‧ second harmonic signal

404a‧‧‧First area

404b‧‧‧Second area

500, 600, 700, 800‧‧‧ charts

504‧‧‧Second harmonic spectrum of the embodiment

508‧‧‧ mode matching

Second harmonic spectrum of samples 604, 608, 704, 712‧‧

604a, 608a, 704a, 712a‧‧‧ first area

604b, 608b, 704b, 712b‧‧‧ second area

Figure 1 is a flow chart of a method for characterizing the structural defects of a high-k dielectric with a frequency doubling effect.

2A is a schematic diagram of a system that characterizes structural defects of a high dielectric constant dielectric with frequency doubling effects.

2B and 2C are schematic views of the energy band of the semiconductor structure of FIG. 2A in different stages of implementation of FIG. 1.

Figure 3 is a schematic diagram of the second harmonic spectrum of the time constant and the density of structural defects measured by the frequency doubling effect.

Figure 4 is an example of an experimental second harmonic spectroscopy time constant and a density of the high dielectric constant dielectric structure defect compared to a spectral model.

Figures 5 and 6 are examples of the determination of the time constant of different samples and the density of high dielectric constant dielectric structure defects by frequency doubling effect.

Figure 7 is a graph showing the relationship between the thickness and the time constant of a high dielectric constant dielectric in the embodiment.

The embodiments provided by the present invention address the market's need for characterization techniques that are relatively fast, non-destructive, and easy to introduce into the fabrication process of semiconductor devices and quantify the electroactive structural features or electron traps of high-k dielectrics. In particular, the following specific embodiments utilize nonlinear optical effects induced by laser light in a solid.

When the light propagates in a solid, the electromagnetic wave of the light interacts with the dipole of the solid, thereby producing a nonlinear optical effect, wherein the dipole is produced by the nucleus and electrons of the solid. When the electromagnetic wave of the light interacts with the dipole of the solid to cause vibration, the dipole that generates vibration becomes a source that generates electromagnetic waves. When the amplitude of the vibration is small, the electromagnetic waves emitted by the dipole will have the same frequency as the incident light. In some embodiments of the present invention, when the illuminance of the incident light is sufficiently high, the illuminance and the amplitude of the vibration are converted into a nonlinear relationship, so that the dipole of the vibration generates a harmonic of a specific frequency, so-called frequency doubling or two. Subharmonic. As the illuminance of the incident light continues to increase, even higher order frequency effects may be produced. The polarization (or dipole moment per unit volume) P can be expressed as a power series expansion of the applied electric field E as: P = ε ₀ ( χE + χ ₂ E ² + χ ₃ E ³ +...). [1]

In equation [1], the linear sensitivity of the lanthanide, χ ₂ , χ ₃ ... is a nonlinear optical constant. The applied electric field E is expressed by the sine function E of electromagnetic waves E = E ₀ sin ωt , and the equation [1] can be rewritten as:

In equation [2], 2ω represents an electromagnetic wave having twice the incident frequency of a frequency system. When the applied electric field is relatively increased, for example, using a laser, the size of 2ω becomes relatively significant. The second harmonic can be observed in a non-central symmetry solid. In a symmetrical solid, an applied electric field causes the dipole to produce the same magnitude but opposite polarization, resulting in a weak overall net polarization, even without net polarization. Therefore, some centrally symmetric semiconductors, such as germanium, cannot produce frequency doubling effects. However, in the embodiments provided by the present invention, the electric field through the interface of the semiconductor and the dielectric layer can cause the generation of a frequency doubling effect.

Method and system for characterizing electron trap in high dielectric constant dielectric by frequency doubling effect

Referring to Figure 1, a method 100 for characterizing structural defects in a high-k dielectric in a multi-frequency effect in accordance with an embodiment of the present invention is illustrated. Referring to Fig. 2A, a system 200a that is erected in conjunction with method 100 is illustrated. More clearly, the individual optical elements in accordance with embodiments of the present invention are described in detail with reference to FIG. 2A.

Referring to FIG. 1, the method 100 includes a step 104 of providing a semiconductor structure including a semiconductor body and a semiconductor substrate formed on the semiconductor substrate. A high dielectric constant dielectric layer having a majority of charge carrier traps formed therein. The method 100 further includes a step 108 of at least partially penetrating incident light having incident energy through the high-k dielectric layer and at least partially being absorbed by the semiconductor substrate. In an embodiment of the invention, the incident energy is sufficient to cause a portion of the electrons to be transferred from the semiconductor substrate into the electron trap and temporarily trapped by the electron trap. In addition, the incident energy is sufficient to cause a frequency multiplication effect of the electron traps temporarily filled by electrons. The method 100 further includes a step 112 of measuring a second harmonic spectrum generated by the frequency doubling effect, the second harmonic spectrum comprising a first region and a second region, wherein the first region has a rate of change of intensity The second area is fast. The method 100 further includes a step 116 of determining a first time constant of a first region, or a second time constant of a second region, or a combination thereof from the second harmonic spectrum; and step 120, from the first time constant or A second time constant or a combination thereof determines the density of the electron traps in the high-k dielectric layer.

2A illustrates a system 200a for characterizing structural defects in a high-k dielectric. Referring to FIG. 2A, the system 200a includes a semiconductor structure 202 including a semiconductor body 204 and a high-k dielectric layer 212 formed on a surface of the semiconductor substrate 202, wherein the high-k dielectric is dielectric. Layer 212 has an electroactive structural defect, or electron trap 248, formed therein that is characterized.

According to the embodiment provided by the present invention, the semiconductor body 204 includes, but is not limited to, an N-type or a P-type semiconductor substrate, wherein the semiconductor substrate can be a fourth group element (such as carbon, germanium, antimony or tin) or Alloys formed by five elements (such as bismuth alloy, bismuth carbon alloy, tantalum carbide, antimony telluride, antimony tin carbon alloy, antimony tin alloy, etc.); III, V compound semiconductor materials (such as gallium arsenide, nitrogen) Alloys formed by gallium, indium arsenide, etc. or Group III and V elements; Group II and IV semiconductor materials (such as cadmium selenide, cadmium sulfide, zinc selenide, etc.) or alloys of Group II and IV are materials. .

According to some embodiments of the invention, the semiconductor body 204 can be a A semiconductor or an insulator such as a germanium insulator substrate (SOI). The ruthenium insulator substrate basically comprises a structure in which an insulator is sandwiched between the ruthenium. Many of the above structures are isolated from the support substrate by an insulating layer such as a layer of germanium dioxide. Therein, according to embodiments provided by the present invention, a plurality of structures may form a film layer at least on a surface or in a region close to the surface.

As with some embodiments of the present invention, the semiconductor structure 202 can further serve as an intermediate device having a plurality of regions, such as a portion of the tandem characterization step of the method 100 (see FIG. 1), or even processed into a functional metal oxide semiconductor device. Crystal. As with the above embodiments, the semiconductor structure 202 can include doped regions, such as heavily doped regions that are produced during further processing, as sources and/or germanium in a functional metal oxide semiconductor transistor or other device. Polar zone. The semiconductor structure 202 may further comprise isolation regions, such as shallow trench isolation regions. In other embodiments, since the semiconductor structure 202 has a high-k dielectric layer 212 formed thereon, in addition to characterizing its structural defects, it can be used as a monitoring structure, such as monitoring the condition of a manufacturing tool or production line.

Referring to FIG. 2A, although the semiconductor structure 202 is a planar structure, the embodiment is not limited thereto. For example, the semiconductor structure 202 can include a semiconductor body 204 having an isolation region and a fin-shaped semiconductor structure protruding perpendicularly from the isolation regions for further processing into fin-shaped field effect transistors (FinFETs). In these embodiments, the high-k dielectric layer 212 may surround the fin-shaped semiconductor structure.

The high-k dielectric layer disclosed in the present invention refers to a dielectric material having a higher dielectric constant than cerium oxide. According to an embodiment, the dielectric constant k of the high-k dielectric layer 212 may be greater than 4, greater than 8, or greater than 15. According to various embodiments of the present invention, the material of the high-k dielectric layer 212 may be tantalum nitride, hafnium oxide, barium titanate, zirconium oxide, hafnium oxide, aluminum oxide, hafnium oxide, tantalum oxide or hafnium oxide. With yttrium aluminum oxide (including non-stoichiometric forms and various mixtures of the above substances), as well as combinations thereof, stacks or nano-layers, and the like.

Referring to FIG. 2A, there is an interfacial layer 208 between the semiconductor body 204 and the high-k dielectric layer 212. When the high-k dielectric layer 212 is made of hafnium oxide and the semiconductor substrate 204 is a tantalum substrate, the interfacial layer 208 may be made of tantalum oxide or tantalum oxide or the like. The interface layer 208 can diffuse to the interface of the high-k dielectric substrate and the substrate and/or excess oxygen atoms when the high-k dielectric layer 212 is formed by the oxygen precursor to generate the high-k dielectric layer 212 or After the formation, the high-k dielectric layer 212 is inadvertently generated in a bulk diffusion manner. In some embodiments, the interfacial layer 208 can be a deliberately formed ceria layer to inhibit the spontaneous growth of interfacial oxides and/or provide better performance control of the interfacial layer and provide more stable cerium oxide. Nucleation. Embodiments of the invention include, but are not limited to, this. In some embodiments, interface layer 208 can be omitted.

In accordance with an embodiment of the present invention, the high-k dielectric layer 212 is provided with a plurality of structural defects, or electron traps 248, that are formed therein and that can be characterized using the methods and systems of the present invention. These structural defects may be point defects such as missing or additional electrons in the high-k dielectric layer 212. For example, when the high-k dielectric layer 212 is made of oxide or oxynitride, the electron traps 248 may contain oxygen vacancies to correspond to missing oxygen atoms; or interstitial oxygen atoms, corresponding to additional oxygen. atom. If the electronic traps 248 contain oxygen vacancies, the electronic traps may be charged or electrically neutral. For example, oxygen vacancies in cerium oxide have five charge states, which are +2, +1, 0, -1, and -2, respectively.

Referring to FIG. 2A, the system 200a includes a light source 216 that can be a first light source including a laser, a light bulb, and/or a light emitting diode configured to direct an incident light 220 having an incident energy hν ₁ to The semiconductor structure 202 further penetrates the interface layer 208 while aiming. The light source 216 is further configured to enable the incident light 220 to be at least partially absorbed by the semiconductor body 204 and to transfer energy to the semiconductor body 204 to initiate an elastic or inelastic process therein. Further, the light source 216 emits a monochromatic incident light 220, and the partially penetrated incident light 220 has sufficient incident energy to cause charge carriers (such as electrons) to be at least partially transferred from the semiconductor substrate 204 to the electronic traps. 248 is temporarily trapped by the electronic traps 248 to obtain a capture cross-sectional area σ.

In some embodiments, the light source 216 can provide a suitable wavelength range such that the electronic traps 248 are easily temporarily filled by the electrons and generate a light; wherein the energy of the light is different from the incident energy of the incident light 220. Hν ₁ , the generation of this light is based on a nonlinear optical effect. In some embodiments, the source 216 may provide a source of light having a wavelength in the range of 700-2000 nm and a peak power of approximately 10 kW to 1 GW.

In some embodiments, the light source 216 can provide a suitable intensity or power density range such that the electronic traps 248 are easily temporarily filled by the electrons and generate a light; wherein the energy of the light is different from the incident light 220. The incident energy hν ₁ is based on a nonlinear optical effect. In some embodiments, the light source 216 may provide an average supply rate of between about 10 milliwatts and about 10 watts, or between about 100 milliwatts and about one watt, such as 300 milliwatts.

Referring to FIG. 2A, in some embodiments, the incident light 220 having incident energy is sufficient to cause the electron traps to be filled with charge carriers and to produce a frequency multiplication effect. As mentioned above, the frequency doubling effect can be observed in non-centrosymmetric solids. Without explaining any scientific principle, even if the semiconductor body 204 is centrally symmetric, such as a 具有 having a diamond-shaped cubic structure, according to the equation [3]: I ^{2 ω} ( t ) = | χ ₂ + χ ₃ E ( t )| ² ( I ^ω ) ² , [3] When the dielectric layer formed on the surface of the semiconductor substrate 204 is provided with an electron trap 248, the net polarization can be generated through the interface of the semiconductor/dielectric. In equation [3], I ^ω and I ^2ω are the signal strengths of the fundamental and frequency doubling effects, respectively, χ ₂ and χ ₃ are the second and third order susceptibility, respectively, and E(t) is the electric field passing through the interface. The frequency doubling effect is generated because at least some of the structural defects or traps are filled by charge carriers such as electrons. The frequency of the second harmonic light 228 is twice that of the incident light 220.

Referring to FIG. 2A, in some embodiments, system 200a further includes a sensor 232 for measuring a second harmonic generated by the second harmonic light 228 having twice the energy of the incident light 220. The spectrum is further measured or filtered to reflect light 224 having the same energy as incident light 220. The sensor 232 can be an opto-amplifier tube, an electro-coupling camera, a crash sensor, a photodiode sensor, a stripe camera, and a sputum sensor, or other type of sensor.

In the embodiment of the present invention, although the light source 216 is a single light source and acts as both an actuator and a detector to generate and measure the second harmonic light 228, it is not limited thereto. In other embodiments, a separate second source (not shown) may be provided at the same time, and the second source may be a laser or a bulb. In these embodiments, the light source 216 can act as an actuator or detector, and the second source can act as a detector or actuator relative to the source 216. In some embodiments, the second source can provide light having a wavelength in the range of from about 80 to about 800 nanometers and an average supply rate of between about 10 milliwatts and 10 watts.

Although not shown in the drawings, system 200a can include other optical components. For example, the system 200a can include: a photon counter; a reflection or refraction filter that selectively filters the second harmonic signal; and a dipole that separates the weaker two from the stronger multi-order reflected main beam. Subharmonic signal; a diffraction grating or a thin film splitter; a beam for focusing and collimating; a color filter wheel, a zoom lens and/or a polarizer.

As described above with respect to the description of other optical components in FIG. 2A and variations thereof, in US 14/690,179 "Pump and Probe Type Second Harmonic Generation Metrology" (2015.04.17), US 14/690,256 "Charge Decay Measurement Systems and Methods" (2015.04) .17), US 14/690, 251 "Field-Based Second Harmonic Generation Metrology" (2015.04.17), US 14/690,279 "Wafer Metrology Technologies" (215.04.17) and US 14/939,750 "Systems for Parsing Material Properties From Within It is described in SHG Signals” (2015.11.12). The above documents are all referenced The manner is incorporated in the present invention.

The system 200a further includes an electronic device or a time constant measuring unit 246 for determining a first time constant τ1 of a first region, or a second time constant τ2 of a second region, or a combination thereof, from the second harmonic spectrum. The first time constant τ1 is related to at least a rate at which the electron traps 248 are trapped, and the second time constant τ2 is at least related to a rate at which the electron traps 248 are discharged.

The system 200a further includes an electronic device or an electronic trap density determining unit 250 for determining a charge trap in the high-k dielectric layer 212 from the first time constant τ1 or the second time constant τ2 or a combination thereof. Density.

The time constant measuring unit 246 and the electronic trap density measuring unit 250 may be part of an electronic device 260, which may be a computing device, such as a programmable logic circuit (FPGA), which is particularly suitable for implementing the present invention. The method of disclosure is as follows. The electronic device 260 can be a computing device, a computer, a tablet computer, a microprocessor or a programmable logic circuit. The electronic device 260 includes a processor or a processing electronics and can execute one or more software modules. In addition to executing an operating system, the processor can be used to execute one or more software applications, such as a web browser, a phone application, an email program, or any other software application. The electronic device 260 can be implemented by executing instructions in a machine-readable non-transitory memory (such as random access memory RAM, read-only memory ROM, electronic erasable rewritable read-only memory EEPROM, etc.) The method disclosed by the present invention. The electronic device 260 can include a display device and/or a user graphical interface to interact with the user. The electronic device 260 can communicate with one or more devices through a network interface. The network interface can include a transmitter, a receiver, and/or a transceiver to communicate via a wired or wireless connection.

2B illustrates an energy band diagram 200b of semiconductor structure 202 in system 200a (see FIG. 2A). More precisely, the energy band diagram 200b corresponds to the initial phase of the second harmonic spectrum, such as the first region of the second harmonic spectrum.

In the energy band diagram 200b, the high-k dielectric layer 212 is provided with a structural defect or electron trap 248 (shown as a distribution curve) as may be a point defect as described above. The energy distribution of the electron traps 248 may surround a peak or have a central energy level E _τ . In some embodiments, the electron traps 248 may be distributed throughout the thickness of the high-k dielectric layer 212; in other embodiments, the defects may be locally concentrated, such as when no interfacial layer 208 is present. The distribution will be concentrated at the interface of the high-k dielectric layer 212 and the semiconductor body 204; for example, when the interface layer 208 is present, it will concentrate at the junction of the high-k dielectric layer 212 and the interface layer 208. In some embodiments, the electron traps 248 are used to trap electrons that are diverted from the semiconductor body 204.

As described above, when the incident light 220 having the incident energy hν ₁ penetrates the high-k dielectric layer 212 and the interface layer 208, the incident energy will partially have a conduction band edge (CB _SUB ) and a valence band. The conductor base 204 of the edge (VB _SUB ) is absorbed.

In some embodiments, when the semiconductor body 204 is undoped, relatively lightly doped (eg, below 1*10 ¹⁴ /cm ³ ), or p-doped, the concentration of electrons in the conduction band may be relatively low. In these embodiments, the incident energy hν ₁ of the incident light 220 can be selected such that hν ₁ is at least 0.1 eV or at least 0.3 eV higher than the energy band gap of the semiconductor body 204, such that electrons 240 and/or electrons can be generated in the semiconductor body 204. The hole 244 is transferred to the high dielectric constant boundary layer 212 and trapped by the electron trap 248. For example, when the semiconductor body 204 is made of tantalum, the incident energy hν _{1 of} the incident light 220 is higher than the energy band gap of 1.12 eV (1110 nm) so that sufficient electrons 240 are filled in the conduction band. For example, the energy of the incident light may be 1.2 eV or even higher.

On the other hand, in some embodiments, if the semiconductor body 204 is relatively highly doped n-doped (eg, higher than 1*10 ¹⁴ /cm ³ ), the incident energy hν ₁ cannot be higher than the semiconductor substrate 204. Can carry a gap. In contrast, since the conduction band of the semiconductor body 204 has been filled by the electrons 240, the incident energy hν _{1 of} the incident light 220 needs to transfer additional energy to the electrons filled in the conduction band, so that the electron energy can be transferred to the high dielectric. The coefficient boundary layer 212 is trapped by the electron trap 248.

Once the conduction band of the semiconductor body 204 is filled with electrons, the electrons 240 will penetrate the interface layer 208 and/or at least partially penetrate the thickness of the high-k dielectric layer 212, being trapped by the electron trap 248, such as Arrow 238a is shown.

The electrons 240 can be transferred from the conduction band of the semiconductor body 204 to the energy level of the electron trap 248 via tunneling (eg, direct tunneling or trap assist tunneling). The direct tunneling of electrons is a phenomenon of quantum mechanics, which may be affected by the thickness of physical barriers, the height of electrons to be tunneled, and other factors. When the potential barrier thickness and/or height is low, the probability of tunneling will be relative. improve. In general, the probability of tunneling in the initial state (in the semiconductor body 204) will be higher than in the final state (in the high-k dielectric layer 212). When the energy level of the electrons 240 located in the semiconductor body 204 is relatively high and does not fall within the energy levels of the electron traps 248, thermal relaxation may occur prior to tunneling, as indicated by arrow 242. However, electron transfer has other mechanisms besides tunneling, such as the Pur-Frenkel transfer effect, Fowler-Norheim tunneling, thermionic radiation, and other mechanisms.

In some embodiments, the thickness of the high-k dielectric layer 212, or high dielectric, is tunneled into the structural defects of the high-k dielectric layer 212 or the electron trap 248 in order to allow electrons to pass from a large amount inside the semiconductor body 204. The thickness of the combination of the coefficient dielectric layer 212 and the interface layer 208 is no more than 5 nanometers, no more than 4 nanometers, or no more than 3 nanometers, so that the electrons 240 can pass through the high-k dielectric layer 212 and the interface layer. A portion of 208 (if any interface layer 208 is present) reaches a structural defect or electron trap 248 located in the high-k dielectric layer 212. Furthermore, tunneling is essentially produced between measuring the second harmonic spectrum, for example, in less than 30 seconds, less than 1 second, or less than 1 millisecond. In addition, when a high-k dielectric layer 212 or a high-k dielectric layer 212 is combined with the interface layer 208 as part of the metal oxide semiconductor transistor fabrication process, the effective oxide thickness (EOT) is about 0.5-3 nm, 0.5-2 Nano or between 0.5-1 nm.

Further, in order to provide electrons with the opportunity to reach structural defects or electron traps 248 in the high-k dielectric layer 212 and be trapped to practice the methods disclosed herein, the defect energy distribution of the electron trap 248 needs to be along with the conduction band edge. Fully overlapping. In an embodiment of the invention, the different peaks or energy centers E _τ of the defect energy of the electron trap 248 are less than about 2 eV, less than about 1 eV, or less than about 0.5 eV. In some other embodiments, E _τ is between the conduction band of the high-k dielectric layer 212 and the conduction band of the semiconductor body 204.

Referring to FIG. 2B, before the structural defects or electron traps 248 are filled by the electrons 240, a relatively weak frequency doubling effect is produced, with most of the photons having reflected light 224 of the same energy hν ₁ as the incident light 220.

2C is an energy band diagram 200c of semiconductor structure 202 in system 200a (see FIG. 2A). More precisely, the energy band diagram 200c corresponds to measuring the later stages of the second harmonic spectrum, such as the second region of the second harmonic spectrum.

2C illustrates an energy band diagram 200c of system 200a of FIG. 2A. More precisely, the band diagram 200c is compared to the band diagram 200b (see FIG. 2B) for the later stages in which the electrons 240 begin to be released from the structural defects or electron traps 248. In some embodiments, when a large number of electrons 240 are trapped by the electron trap 248, an electric field that facilitates reverse tunneling of the electrons 240 is established, and significant electron release is also produced, as indicated by the arrows.

When the electron trap 248 is largely occupied by the electrons 240, a significant frequency doubling effect is produced, emitting second harmonic light 228 having twice the energy of the incident light 220, while producing the same reflected light 224 of energy as the incident light 220.

Since the signal of the second harmonic is weaker than the reflected beam, how to improve the signal-to-noise ratio of the second harmonic is very important. One way to reduce noise is to actively cool the sensor. Cooling reduces false positive photon sensing due to thermal noise. This method can be cooled by a cryogenic fluid such as liquid nitrogen/helium or solids, as in the form of a Peltier device. to make.

Determination of time constant and density of electron trap from second harmonic spectrum

Referring to FIG. 1, method 100 includes a step 116 after measuring a second harmonic spectrum at step 112, from the second harmonic spectrum, a first time constant associated with a rate at which electrons 240 are trapped by electron trap 248, A second time constant (refer to Figures 2A-2C) associated with the rate at which electrons 240 are released from electronic trap 248, or a combination thereof.

3 is a second harmonic spectrum diagram 400 used to determine time constants and electron trap densities in some embodiments. The second harmonic spectrum 404 includes a first region 404a that is relatively time-varying but relatively short-lived, and a second region 404b that is relatively slow at one time but has a longer duration of illumination.

The first region 404a can correspond to a portion of the second harmonic spectrum 404. As described above, the secondary spectral signal of the portion is dominated by the density of the electron trap 248 which is increased by being filled by the electron 240 (Fig. 2A, 2B), so the signal intensity of the second harmonic is relatively fast. Enhancement (characterized by the first time constant τ ₁ ). In this state, the effect of the electron trap density reduction (as shown in FIG. 2C) due to the release of the electrons 240 by the electron traps 248 is relatively low.

Conversely, the portion of the second harmonic spectrum 404 corresponding to the second region 404b is no longer dominated by the density of the electron trap 248 that is increased by the filling of the electrons 240 (Figs. 2A, 2B). In this state, the effect of the electron trap density reduction due to the release of the electrons 240 by the electron trap 248 is relatively large (as shown in FIGS. 2A and 2C), so that the growth of the second harmonic spectrum is relatively slow (with the second time constant τ). ₂ characterization).

In some embodiments, the second harmonic signal of the first region 404a and the second region 404b in the second harmonic spectrum 404 is proportional to the density of structural defects filled by the electrons 240, and has logarithmic time dependence. . The logarithmic time dependence may be the distance between an electron trap 248 and the high-k dielectric layer/semiconductor substrate interface, or the distance from the high-k dielectric layer/interface layer interface (when an interfacial layer is present) The function. As previously described in Figures 2B and 2C, as the tunneling distance increases, the probability of electron transfer decreases, and the rate at which electrons are trapped and released increases. Since the signal strength of the second harmonic is directly proportional to the density of the electron trap filled by the electron, the second harmonic signal generated by the electron trap 240 in the first region 404a and the second region 404b is effective. Time dependence can be expressed as: versus

In equations [4] and [5], I ₁ (t) and I ₂ (t) are the intensities of the first region 404a and the second region 404b in the second harmonic spectrum 404, respectively, and τ ₁ and τ ₂ are respectively The first and second time constants of the corresponding regions. The overall second harmonic spectrum 404 can be expressed as a sum:

τ ₁ and τ ₂ can be obtained by approximating the nearly independent second harmonic signals 408 and 412 in the two regions 404a, 404b, respectively, as shown in FIG.

The τ ₁ dominated by the filling of the electronic trap can be expressed as:

In equation [7a], σ _t captures the cross-sectional area, the thermal velocity of the ν _th- based electrons, and the density of n _c (x, t) electrons from the ruthenium matrix (eg, tunneling) to the high-k dielectric. The values of σ _t and ν _th can be measured by independent theory or experiment. As noted above, n _c (x, t) is related to the probability of electrons tunneling from the semiconductor substrate (eg, direct tunneling) to electron traps distributed in the high-k dielectric layer. Since tunneling is a phenomenon of quantum mechanics, which may be affected by the thickness of physical barriers, the height of electrons to be tunneled, and other factors, n _c (x, t) is affected by many factors, including the energy and intensity of incident light. . The nearly saturated second harmonic spectrum is measured when the energy and intensity of the incident light is sufficient to capture electrons in almost all of the electron traps in the high-k dielectric layer. For example, when the energy of the incident light is sufficient to transfer most of the electrons from the semiconductor substrate to the higher energy electron trap, and when the intensity of the incident light is sufficient to cause the electron trap to be quickly filled, all structural defects can basically start with electrons. Capture electrons before being released. In this case, a saturated second harmonic spectrum can be obtained. The second harmonic spectrum 400, which is not shown in FIG. 3, has a first region 404a having a short duration and relatively fast time dependence, and a second region 404b having a longer duration but a relatively slow time dependency, The saturated second harmonic spectrum has a second region with a short duration, relatively fast time dependence, and a first region with a constant time dependence. That is, a saturated second harmonic spectrum will have a pattern similar to the deconvolved second harmonic optical signal 408 of FIG. In this case, equation [7a] can be expressed as:

In equation [7b], the N _t is the total concentration of filled electron traps in the dielectric layer and unfilled electron traps. In some embodiments, based on the quantitation N _t secondary harmonic intensity correlation completely filled, τ ₁ N _t may be obtained separately.

Different structural defects lead to different τ ₁ and τ ₂ . Many embodiments can measure or extract a range of time constants. For example, the time constant can range from 0.1 femtosecond to 1 femtosecond, between 1 femtosecond to 10 femtoseconds, between 10 femtoseconds to 100 femtoseconds, between 100 femtoseconds to 1 picosecond, and 1 picosecond. Between 10 picoseconds, 10 picoseconds to 100 picoseconds, between 100 picoseconds and 1 nanosecond, between 1 nanosecond and 10 nanoseconds, between 10 nanoseconds and 100 nanoseconds, 100 nanoseconds Between 1 microsecond, 1 nanosecond to 100 microsecond, 100 microsecond to 1 millisecond, 1 microsecond to 100 millisecond, 100 microsecond to 1 second, 1 second to 10 second Between 10 seconds and 100 seconds, or longer, or shorter. Similarly, the delay time Δ between the detector and the actuator or between the actuator and the detector can be between 0.1 femtoseconds to 1 femtosecond, between 1 femtosecond and 10 femtoseconds, 10 femtoseconds Between 100 femtoseconds, 100 femtoseconds to 1 picosecond, 1 picosecond to 10 picoseconds, 10 picoseconds to 100 picoseconds, 100 picoseconds to 1 nanosecond, 1 nanosecond Between 10 nanoseconds, 10 nanoseconds and 100 nanoseconds, between 100 nanoseconds and 1 microsecond, between 1 nanosecond and 100 microseconds, between 100 microseconds and 1 millisecond, and 1 microsecond to Between 100 milliseconds, between 100 microseconds and 1 second, between 1 second and 10 seconds, or between 10 seconds and 100 seconds. The time constant may also fall outside the above range.

Although the total concentration N _{t of the} electron trap can be obtained from some second harmonic spectrum (such as a saturated spectrum) and based on the equation [7a], the method of obtaining N _t is not limited thereto. Referring to FIG. 1, after determining τ ₁ and τ ₂ (as described above), the method 100 further includes the step 120 of determining the density of the electron trap in the high-k dielectric layer from the first time constant or the second time constant or a combination thereof. . In some embodiments, the density of the electron trap can be determined by a partial differential equation:

In equation [8], n _t (x, t) is the curve of the electron trap concentration filled in the high-k dielectric layer, and the total concentration of the N _t-type electron trap. Referring to FIG. 3, based on the values of τ ₁ and τ ₂ measured from the second harmonic spectrum, n _t (x, t) and N _t can be determined by numerical solution as in the finite difference method, and other n _t (x, t) and N _t are used as input values. As an example, taking n _t (x, t) as an input value and solving the differential equation [8] numerically by the finite difference method, the total concentration of the electron trap N _t can be measured, for example, passing through a high dielectric constant dielectric. The n _t (x, t) curve with different layer thicknesses is used as an input value, such as a constant curve, a normal distribution curve or a Δ function curve (such as the interface between the high-k dielectric layer and the ceria), only List a few examples.

Experimental data

Referring to Figures 5 to 7, the second harmonic spectrum of the embodiment will be exemplified below. These second harmonic spectra were measured from physical samples made by atomic layer deposition. In each sample, a cerium oxide film formed by atomic layer deposition on the surface of the (100) slab has about 1-5 ohms ^. The resistivity of centimeters. Each of the second harmonic spectra in Figures 5 to 7 is induced by an incident light of a photon energy of 1.5895 eV and an average laser power of 300 mW, so that the photon energy of the corresponding second harmonic is 3.179 eV. The incident photons are incident on the surface of the ruthenium dioxide film at an incident angle of about 45 degrees. Each incident light and the measured output light are P-polarized. The split table for the sample analyzed is as follows:

4 is a graph 500 of a second harmonic spectrum 504 and a mode fit 508 of an embodiment obtained by the above method (including numerical solution of equation [8]). The second harmonic spectrum 504 of this example was measured from sample 7 in Table 1. As described above with respect to FIG. 3, the second harmonic spectrum 504 of the embodiment and the mode fit 508 each have a first region of short duration (approximately 5 seconds maximum) and relatively fast time dependence (ie, The region of τ ₁ is measured, with a second region that lasts longer (more than 5 seconds) but has a relatively slow time dependence (ie, the region where τ ₂ is measured). The measured τ ₁ and τ ₂ were 2.6 seconds and 17 seconds, respectively. The second harmonic spectrum 504 of this embodiment has a relatively high consistency with the mode fit 508.

Figure 5 shows a graph 600 of the second harmonic spectra 608, 604 of Samples 7 and 9, as in Table 1 above, in which Samples 7 and 9 were pulsed with water vapor of different lengths of time. As explained above with respect to Figure 3, the second harmonic spectra 608 and 604 of these embodiments have a shorter duration (up to about 5 seconds) and time. The first regions 608a, 604a are relatively fast in dependence, and the second regions 608b, 604b are relatively long (more than 5 seconds) but relatively slow in time dependence. By comparing the second harmonic spectra of the two samples, it can be inferred that the strontium precursor is treated with a longer time steam pulse, which will result in higher filling efficiency of the electron trap.

Figure 6 shows a graph 700 of the second harmonic spectra 712, 608, and 704 of Sample 6, Sample 7, and Sample 8, as in Table 1, above, with Sample 6, Sample 7, and Sample 8, respectively, having different film thicknesses. As described above with respect to FIG. 3, the second harmonic spectra 712, 608, and 704 have first regions 712a, 608a, 704a that are relatively short in duration (up to about 5 seconds long) and relatively time dependent, and last. Second regions 712b, 608b, and 704b that are relatively long (more than 5 seconds) but have relatively slow time dependencies. By comparing the intensity and time constant of the second harmonic spectrum of the three samples, it can be inferred that as the thickness increases, the time constant τ ₁ increases, and the intensity of the first regions 712a, 608a, and 704a, which are fast in time dependence, decreases. .

Figure 7 is a graph 800 showing the relationship between τ ₁ of sample 6-9 and its thickness as measured by the foregoing method. Data points 816, 808, 812, 804 are data for Sample 6, Sample 7, Sample 8, and Sample 9, respectively. From graph 800, when the thickness of the high-k dielectric layer is thickened, the average time for electrons to transfer from the germanium matrix to the high-k dielectric layer increases, and τ ₁ also increases. Comparing the results of FIG. 7 and FIG. 6 with reference to each other, it can be inferred that the structural defects do not necessarily accumulate at the interface of cerium oxide/cerium oxide or cerium oxide/cerium, but are distributed throughout the thickness of the cerium oxide film. The probability of filling electrons from the ruthenium matrix to structural defects in the ruthenium dioxide film is reduced.

Change

The details of the feature selection have been described above in connection with the exemplary aspects of the invention. Other details of the invention can be understood in conjunction with the above-referenced patents and disclosures, or may be understood or understood by those skilled in the art to which the invention pertains. For the method according to the invention to use the usual or logical extra actions, the same It is suitable for use in aspects of the method of the invention. The method provided in accordance with the present invention includes methods of manufacture and use, including but not limited to being performed in the order of enumerating steps, and the methods may further comprise any logically feasible sequence of steps. Further, where a range of values is provided, it is understood that the value between the upper and lower limits of the range, and any other stated value or intermediate value in the stated range, Within the invention. Furthermore, any optional features described herein can be set forth or claimed in isolation or in combination with any one or more of the features described herein.

In addition, although the present invention has been described with reference to a number of embodiments, the various features are described as being described, and the invention is not limited to the description or representation of each variant. Various changes may be made to the described invention without departing from the true spirit and scope of the invention, and the equivalents (herein described or not included herein) To replace.

The various steps described in the present invention may use a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic array (FPGA) or other programmable logic device, and a separate Logic gate or transistor logic, individual hardware components, or any combination designed to perform the functions disclosed herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller or state machine. The processor can further be a part of a computer system including a user interface, which can communicate with the user through the user interface, receive commands input by the user, and have at least one memory (eg, a hardware or Any equivalent storage device, and random access memory), the memory can store electronic information including a processing program controlled by the processor, communication through a user interface, and video output, the video output Generated by any type of video output format, such as a variable-amplifier, digital video interface, resolution multimedia interface, display port or any other type formula.

A processor can be further a combination of computing devices, such as a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, at least one microprocessor and a digital signal processing core, or any similar configuration. These devices are more useful for selecting values for devices as described herein.

The method or the calculation step described in connection with the embodiment of the present invention may be implemented directly by hardware, by a software module executed by a processor, or by a combination of the two. A software module may reside in random access memory (RAM), flash memory, read only memory (ROM), stylized read-only memory (EPROM), electronic erasable rewritable read-only memory Body (EEPROM), scratchpad, hard drive, removable disk, CD-ROM, or any form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read a message from the storage medium and write the message to the storage medium. Alternatively, the storage medium can be part of the processor. The processor and the storage medium may reside in a special application integrated circuit (ASIC). The special application integrated circuit can exist at the user end. Alternatively, the processor and the storage medium can be individual components in the user terminal.

In at least one exemplary embodiment, the functions described herein can be performed by hardware, software, firmware, or any combination thereof. If executed by software, these functions may store, transfer or generate analytical/computed data for output on one or more instructions, code or other computer readable medium. The computer readable medium includes a computer storage medium and a communication medium, and the communication medium includes any medium that facilitates transferring the computer program from one end to the other. The storage medium can be any medium that can be accessed by a computer. The computer readable medium can be, but is not limited to, random access memory (RAM), read only memory (ROM), electronic erasable rewritable read only memory (EEPROM), CD-ROM (CD) -ROM) or other disc storage, disk storage, magnetic memory, or any program code that can be carried or stored in the form of an instruction or data structure. And the medium read by the computer. The memory can be a rotating magnetic hard disk drive, a compact disk drive, a flash memory based memory drive or any solid state, magnetic or optical storage device.

The operations of the present invention can be operated through a website. The website can be operated on a server computer or a local computer, such as a client computer, or operated by a server farm. The website can be accessed by any client such as a mobile phone or a personal digital processor. The website may use any form of Hypertext Markup Language (HTML) code, such as Extensible Hypertext Markup Language (XHTML) or Extensible Markup Language (XML), and by any form, such as Cascading Style Sheets (CSS) or other form.

Furthermore, the inventors of the present invention mean that the method of the present invention is explained only in accordance with 35 USC 112, (f). More particularly, the scope of the invention is not limited to the embodiments and/or the description, but is defined by the scope of the claims language associated with the disclosure. The computer used in the present invention can be any form of computer, including a general purpose computer or some special functional computer such as a computer workstation. The program of the present invention can be written in C language, Java language (Java), Wireless Binary Execution Environment (BREW) or any programming language. The programs can reside in a storage medium, such as a magnetic or optical storage medium such as a computer hard drive, a removable disk, a memory card, a secure digital medium (SD), or any removable medium. The program can be executed by the network, for example, by transmitting a signal to a local computer through a server or other device, so that the local computer can perform the operations described in the present invention.

It should be noted that all of the features, elements, components, functions, acts or steps disclosed in the embodiments of the present invention can be combined and replaced with other embodiments. It is to be understood that the features, elements, components, functions, or steps disclosed in the present invention are intended to be applicable to any other embodiment provided by the present invention, even if only disclosed in a particular embodiment. Therefore, this paragraph is The first basis for applying for a patent. At the time, features, elements, components, functions, acts or steps selected from the various embodiments of the invention may be substituted or used in accordance with the features, elements, components, functions, acts or steps of other embodiments, even in the following description. It is not explicitly stated that such combinations or substitutions are still within the scope of the invention. It should be recognized that it is to be understood that each possible combination and substitution will be too cumbersome, and that each combination and substitution of the present invention can be readily recognized and carried out by those of ordinary skill in the art.

In some cases, the entities disclosed herein may be described as being coupled to other entities. It will be understood that the terms "interacting", "coupled", "connected" or any of the terms used in the present invention are interchangeable in the present invention and can be used interchangeably for the direct coupling of two entities ( There are no intermediate entities that cannot be ignored, such as parasitic entities, or indirect couplings (with at least one non-negligible intermediate entity). In the present invention, when a plurality of entities are described as being directly coupled or in the context of their coupling, no intermediate entities are mentioned, unless otherwise specifically stated, it should be understood that the entities may also be indirectly coupled.

The reference to a single item of the invention encompasses the possibility of having multiple identical items. Rather, the singular forms "a", "the", "the" In other words, the use of the articles allows the item of the invention to be "at least one"

Further, it should be noted that the scope of the present invention can be written to exclude any optional elements, such as those specified as "typical" in the specification, which may be used or may be used. Therefore, this statement is used as antecedent basis for the use of such exclusive terms such as "individual", "only", or "negative" in the relevant statements of the claimed elements. In the absence of such exclusive terms, the term "comprising", used in the scope of the claims of the invention, should be construed to include any additional elements, whether or not a given number of elements are recited in the scope of the claims. The addition of additional features or features may be considered to change the nature of the elements in the scope of the claimed patent. However, any term such as "comprising" in the scope of the claims can be modified to the exclusive language such as "composition." In addition to the particular definitions of the invention, all technical and scientific terms used in the present invention are intended to be broadly understood by those skilled in the <RTIgt;

While the invention may be susceptible to various modifications and alternatives, the specific embodiments of the present invention are described in the specification and drawings. All modifications, equivalents, or substitutions are intended to be included within the scope of the invention. In addition, any features, functions, acts, steps or elements disclosed in the embodiments are intended to limit the scope of the invention, and the features, functions, acts, steps, or components are not limited, and may be cited or added to the scope of the patent application. Therefore, the scope of the invention is not limited by the scope of the embodiments and/or the description of the invention, but only by the language of the following claims.

Claims (20)

A method of characterizing a semiconductor structure, the method comprising the steps of: providing a semiconductor structure comprising a semiconductor and a high-k dielectric layer formed on the surface of the semiconductor, wherein the high-k dielectric layer Providing a plurality of electron traps formed therein; causing incident light having incident energy to at least partially penetrate the high-k dielectric layer, and at least partially incident light is absorbed by the semiconductor; the incident light causes a portion of the semiconductor The electrons are temporarily transferred into the electron traps and temporarily filled with the electron traps, wherein the incident energy is sufficient to transfer part of the electrons from the semiconductor to the electron traps and temporarily trapped by the electron traps; the electrons generate a a light having energy, wherein the energy of the light is different from the incident energy of the incident light, wherein the light is generated based on a nonlinear optical effect; measuring a nonlinear spectrum of the light, wherein the spectrum has a first region and a a second region, wherein the first region has a different rate of change in intensity from the second region; from the nonlinear spectrum A second predetermined time constant of the first time constant or the second area of the first area, or combinations thereof; and a time constant based on the first or the second time constant or a combination of determining the density of the plurality of electron traps. The method of claim 1, further comprising providing one on the substrate (Hf) is a high dielectric constant dielectric layer of the substrate. The method of claim 2, wherein the electronic traps comprise oxygen vacancies. The method of claim 3, further comprising inserting a ruthenium dioxide layer between the ruthenium substrate and the high-k dielectric layer based on ruthenium (Hf). The method of claim 4, wherein the cerium oxide layer is combined with the high dielectric constant dielectric layer based on hafnium (Hf) to have a physical thickness of not more than 4 nm, so that the electrons can be The time during which the nonlinear spectrum is measured is transferred from the ruthenium matrix to the oxygen vacancies by tunneling. The method of claim 1, wherein the trapping potential of the electron traps is between the conduction band of the high-k dielectric layer and the conduction band of the semiconductor body. The method of claim 1, wherein the first time constant is related to at least an electron capture rate of an electron trap, and wherein the second time constant is related to at least an electron release rate of an electron trap. The method of claim 1, further comprising determining a first time constant of the first region from the nonlinear spectrum and a second time constant of the second region, and determining from the first time constant and the second time constant The density of the electron traps in the high dielectric constant dielectric layer. The method of claim 8, wherein determining the density of the electron traps further comprises numerically solving a partial differential equation, the partial differential equation and a reciprocal of the first time constant and the second time constant, the electronic traps It is related to the rate of change of the electronic filling. The method of claim 9, wherein the partial differential equation is expressed as: Where n _t (x, _t ) is the electron fill concentration of the high-k dielectric layer, N _t is the total density of the electron traps, τ ₁ is the first time constant, and τ ₂ is the second time constant . The method of any one of claims 1 to 10, wherein the incident energy is sufficient to temporarily fill the electron traps in the electron traps and generate a frequency doubling effect, and wherein measuring the nonlinear spectroscopy comprises measuring one a second harmonic spectrum of the first region and the second region. The method of any one of claims 1 to 10, wherein the first region has a rate of change in intensity that is faster than the second region. A system for characterizing a semiconductor structure, the system comprising: a light source that emits incident light having incident energy, wherein the incident light at least partially penetrates a high-k dielectric formed on a semiconductor surface a layer, and at least partially absorbed by the semiconductor, wherein the high-k dielectric layer is provided with a plurality of electron traps, wherein the incident energy is sufficient to cause a portion of electrons to be transferred from the semiconductor to the electron traps and temporarily trapped by the electron traps Trapped, the electrons can generate a light having energy different from the incident energy of the incident light, wherein the light is generated based on a nonlinear optical effect; a sensor for detecting the light a nonlinear spectrum, wherein the nonlinear spectrum has a first region and a second region, wherein the first region has a rate of change of intensity that is faster than the second region; An electronic device for determining a first time constant of a first region or a second time constant of a second region or a combination thereof from the second harmonic spectrum, and further for using the first time constant or the first The two time constants or a combination thereof determines the density of the electron traps in the high-k dielectric layer. The system of claim 13, wherein the high-k dielectric layer is a high-k dielectric layer based on hafnium (Hf), and the semiconductor is made of tantalum. The system of claim 14, wherein the electronic traps comprise oxygen vacancies. The system of claim 15 wherein the incident light emitted by the light source at least partially penetrates a layer of germanium dioxide between the high-k dielectric layer and the semiconductor. The system of claim 16, wherein the cerium oxide layer is combined with the high dielectric constant dielectric layer based on hafnium (Hf) to have a physical thickness of not more than 4 nm, so that the electrons can be The time during which the nonlinear spectrum is measured is transferred from the semiconductor to the oxygen vacancies by tunneling. The system of claim 17, wherein the trapping potential of the electron traps is between the conduction band of the high-k dielectric layer and the conduction band of the semiconductor. The system of any one of claims 13 to 18, wherein the incident energy is sufficient to temporarily fill the electron traps in the electron traps and produce a frequency multiplication effect, and wherein measuring the nonlinear spectrum comprises measuring one a second harmonic spectrum of the first region and the second region. The system of any one of claims 13 to 18, wherein the first region has a rate of change in intensity that is faster than the second region.