• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Temperature dependence of single-event transients in SiGe heterojunction bipolar transistors for cryogenic applications

    2023-10-11 07:56:32XiaoyuPan潘霄宇HongxiaGuo郭紅霞YahuiFeng馮亞輝YinongLiu劉以農(nóng)JinxinZhang張晉新JunFu付軍andGuofangYu喻國芳
    Chinese Physics B 2023年9期
    關(guān)鍵詞:紅霞

    Xiaoyu Pan(潘霄宇), Hongxia Guo(郭紅霞), Yahui Feng(馮亞輝), Yinong Liu(劉以農(nóng)),Jinxin Zhang(張晉新), Jun Fu(付軍), and Guofang Yu(喻國芳)

    1The Key Laboratory of Particle and Radiation Imaging,Ministry of Education,Department of Engineering Physics,Tsinghua University,Beijing 100084,China

    2State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi’an 710024,China

    3School of Material Science and Engineering,Xiangtan University,Xiangtan 411105,China

    4School of Aerospace Science and Technology,Xidian University,Xi’an 710126,China

    5School of Integrated Circuits,Tsinghua University,Beijing 100084,China

    Keywords: SiGe heterojunction bipolar transistors,pulsed laser,TCAD simulation,single-event transient

    1.Introduction

    Along with the continuous drive to explore deep space,how to save fuel consumption and enhance payload has been an important concern for scientists.Fortunately, silicongermanium heterojunction bipolar transistors (SiGe HBTs)with a wide operating temperature range and radiation resistance (even above the multi-Mrad total ionizing dose tolerance) make it possible to free electronic systems from the‘warm box’and reduce weight and energy consumption.Early SiGe prototypes are already flying in the International Space Station(ISS).[1]

    However, SiGe devices are sensitive to single-event effects (SEEs), and effectively assessing their susceptibility to SEEs under extreme temperature conditions is still a critical issue that needs to be addressed.[2]According to existing research, there have been some valuable studies on the impacts of temperature on SEEs for different devices and ion types;for example, proton-induced SEU in SiGe digital logic,[3]the heavy ion- and pulsed laser-induced SET in a PIN Si epilayer,[4,5]and CMOS bulk technology over temperature.[6]This research has found that the dominant contributor to the temperature response is the variation of carrier mobility,with other factors neglected.The carrier mobility increases with decreasing temperature, which leads to higher transient amplitudes at cryogenic temperatures.However,the effect of incomplete ionization(hereafter abbreviated as i.i.)of impurities was not studied.

    In the literature,[7]the inflection point (induced by the impurity’s incomplete ionization below 130 K) of the collector/substrate(C/S)junction’s transient peaks was found for the first time by TCAD simulation.However, there is no experimental evidence that the inflection point of transient peaks due to i.i.exists.What is more, the simulation LET is too small(only 0.01 pC/μm)to trigger the ions-hunt effect of the emitter/base/collector(E/B/C)stack,which is a common effect induced by space-heavy ions.[8]

    In this work, we investigate the temperature dependence of the SET (especially the ion shunt effect when the initial electron-hole pairs’ (EHPs’) concentration exceeds the doping concentration of the intrinsic base)response in SiGe HBTs by two-dimensional(2D)raster scanning with a well-designed cryogenic test system suitable for pulsed-laser simulation.

    There are two main innovations of this paper.Firstly,the increase in carrier mobility at low temperatures (which is well known already) and the i.i.of impurities (this work provides new experimental evidence)conjointly determine the change in resistivity on the charge-collection pathway, ultimately leading to variations of the drift transient peak.Secondly, when the device under test (DUT) switches from the cut-off state to the turn-on state (or the forward-active bias),there is a novel electron-injection process from the emitter to the base,which will increase the total charge collection.[2]An optimized built-in voltage equation of the high current compact model (HICUM)[9]has been provided with consideration of the i.i.The present experimental results illustrate that this novel injection process will be suppressed with decreasing temperature.According to existing research,this temperature dependence hasn’t been reported otherwise.More importantly, this work provides new evidence for the possibility of using SiGe HBTs at cryogenic temperatures outside the shielding‘warm box’.

    2.Experimental and simulation details

    2.1.Cryogenic system

    As is well known,cryogenic temperature experiments are very difficult to conduct due to the long cooling times to reach a stable temperature and the need for a high vacuum environment to avoid frosting;[10]therefore, temperature-related experiments tend to be performed at temperatures near or above room temperature.When it comes to pulsed-laser experiments,things get even harder because of the very short working distance between the optical lens and the surface of the DUT (<1 cm).It is also important to note that even a very small amount of water vapor residue can have a significant impact on the accuracy of optical experiments.For these reasons, very few pulsed-laser studies have been performed for cryogenic temperatures.

    Fig.1.The cryogenic system suitable for the pulsed-laser test contains(1)the laser system and the liquid nitrogen container; (2)a vacuum chamber with a hot and cold stage; (3) a vacuum pump; and (4) the precision temperature controller,liquid nitrogen cooling system,and the chillers.

    Figure 1 shows the main components of our cryogenic system powered by INSTEC, which can provide a wide temperature range from-196°C to +200°C (with temperature stability better than±0.1°C).Before the experiment,the DUT was fixed directly on the silver stage with temperature sensors monitoring the real-time values.The vacuum pump usually requires 2–3 days(even longer)of continuous operation to remove most of the water vapor in the chamber,which is the key point for a laser test.

    2.2.Radiation source

    Nowadays, pulsed-laser systems are widely used as an important complement to high-energy ion accelerators for investigating SEEs.[11]This work was carried out at Northwest Institute of Nuclear Technology(NINT)by using the Nd:YAG laser system (powered by SPELS and EKSPLA), which can emit Gaussian laser beams with infra-red 1064 nm and visible 532 nm wavelengths.The single-photon energies of the 1064 nm laser and the 532 nm laser areEγ=1.17 eV andEγ=2.33 eV, respectively; both are above silicon’s bandgap(Eg= 1.12 eV) at room temperature to induce inter-band single-photon absorption (SPA).[12]The pulse repetition rate is 1 kHz.

    Since the absorption coefficient(α)of the 1064 nm laser in silicon decreases sharply as the temperature decreases,[13]it is unsuitable to use 1064 nm laser light to simulate heavy ions at low temperatures.[14]Fortunately, the 532 nm laser’sαvaries little with temperature,so the EHPs’generation rate changes a little with temperature just like the heavy ion’s case.[15]In addition,the 1/e penetration length of the 532 nm laser beam is relatively short(about 1.25 μm),which makes it possible to focus on studying the ions-hunt effect of the HBT’s E/B/C stack without considering the drift transient component from the C/S junction.

    2.3.DUT description

    The DUT is a low noise NPN SiGe HBT designed by the School of Integrated Circuits, Tsinghua University.The lithographic node (or the emitter size) of the device is 0.4 μm×20 μm, which is configured by an interdigital chip layout with a 4E5B2C structure,as shown in Fig.2.Detailed information on the device is shown in Table 1.

    Table 1.Technology parameters of the DUT.

    During the whole experiment, we kept the laser incident at the front side of the DUT for two main reasons: (1)decapping the backside package of the DUT can seriously affect its reliability;and(2)the 532 nm laser cannot penetrate the thick substrate layer to the sensitive volume.Since the sensitive area of the DUT is almost covered by a metal layer, only slits between the metal electrodes allow passage of the laser light into the semiconductor material.We selected a 50 μm×60 μm region,which covers all the sensitive volumes,and a 1 μm step size for the 2D raster measurements(in total,3111 data points)to reduce errors caused by fluctuations in laser incidence position and the metal layer’s blocking.The laser energy was fixed at 5 nJ to obtain more obvious transient signals that far exceed the testing noise floor.

    Fig.2.The chip layout of the DUT(left)shows the 2D raster scanning area and the SEM figure(right)shows a cross-section by the cutline.

    2.4.The 2D TCAD process model

    To qualitatively analyze the underlying physical mechanism, we built a well-calibrated 2D TCAD process model,as shown in Fig.3.One may notice that this is a simplified 1E2B2C structure,which gets better convergence at cryogenic temperatures,especially when the incomplete ionization model is activated(note that the convergence problem of threedimensional(3D)simulation at cryogenic temperatures has always been a stumbling block to be solved).The whole 3D process model is also shown in our previous study.[16]

    When the ion-shunt effect of the HBT’s vertical E/B/C stack is triggered, a fast electron drift-collection process occurs from the emitter to the collector.Therefore, the resistance on this charge-collection pathway(shown in Fig.3)can be approximated as a series connection of the vertical E/B/C stack’s resistance(which includesRE,RB-V,andRC)and the lateral sub-collector’s resistance,RSC.In particular,theRB-Vmeans vertical intrinsic base resistance rather than the lateral resistance used in common compact models.Figure 4 plots the doping concentration at theY=0 μm cutline.

    Fig.3.The 2D process model of the DUT,with a zoomed-in view of the inside that shows the parasitic resistance of the E/B/C stack.The different laser normal strike positions,marked with S-in,denote the substrate incidence,and C-in denotes close to the emitter center incidence.

    Fig.4.The doping concentration was extracted from the 2D process model at the Y =0 μm cutline.

    2.5.Process simulation setup

    To simulate the laser-induced SET, we introduced the SPA-induced EHPs’ distribution to the TCAD process simulation by using the analytical calculation methods shown in our previous study.[16]

    There are some related papers on how to calculate the profiles of EHPs generated by a pulsed laser,[17–20]such as Eq.(1), which shows the EHPs’ generation rate at different positions:

    whereαis the linear absorption coefficient,Teffis the effective transmission coefficient,ELis the pulsed-laser energy,Eγis the single-photon energy,randzare the radial and axial propagation distance, respectively,ωandω(z) are the 1/e2spot radius and contour after the wave has propagated a distance ofz,respectively,andτis the pulse duration.

    Table 2.Laser simulation parameters.

    Note in particular that the 532 nm laser’s spot radius in Table 2 is 5.6 μm, which is far beyond the nominal value of 0.6 μm(given in Ref.[16]),and the reason is the presence of the 2 mm thick optical quartz window.As is shown in Fig.5,the quartz window could bring two unfavorable effects: (1)it slows down the convergence of the laser beam due to the law of light refraction;and(2)it makes the CCD camera view unclear.To maintain the consistency of the pulsed-laser experiments, we first adjusted theX–Y–Zpositioning platform in theZ-direction,so that the CCD camera could capture a relatively clear picture of the DUT’s layout.We were then able to compare theZ-coordinates with and without the quartz window to estimate the actual focus position and spot radius(ω)by optical calculations.[11]

    Fortunately,the larger beam spot size does not affect the validity of this work because the sensitive area with the metal layer’s blocking is large enough (about 20 μm×20 μm, as shown in Fig.2) and contains repetitive 4E5B2C structures.Anyway, in the future, we will further optimize this issue by using thinner quartz windows(about 1 mm)and adding a focusing lens.

    Fig.5.Laser path diagram with (right) and without (left) temperature control(note that the impact of the quartz window on the focus location is shown in Δz).

    Fig.6.The 2D profiles for the 532 nm laser-induced EHPs at 27 °C(300 K)and-196 °C(77 K)with 5 nJ laser energy.The yellow arrows indicate the direction of laser incidence and the white dashed lines indicate the 1/e and 1/e2 contours of the carrier density.The absorption coefficients at different temperatures used here are extracted from Ref.[27].

    Finally, according to Eq.(1), and taking into account the laser parameters mentioned above, we can plot the initial EHPs’profiles,shown in a colormap in Fig.6(Teff=1)).As we can see, variation of the absorption coefficientαwith temperature will slightly affect the initial carrier’s distribution(CD)while keeping the total amount constant.For simplicity,we adopted theαat 300 K to generate the initial CD profiles at all simulation temperature points.

    We can then simulate the SPA-induced SET by modifying the heavy ion GCs’model parameters in TCAD.Our previous study[16]shows this process in detail.In addition, to simulate the carrier freeze-out,[21]we activated the Philips unified mobility model (PHUMOB),[22,23]Canali velocity saturation model,[24]Slotboom bandgap narrowing model,[25]and the incomplete ionization model.[26]

    3.Temperature dependence of the transient peak

    3.1.The 2D raster scan measurement

    There are two main reasons for conducting 2D raster scan testing:(1)to obtain the SET sensitivity distribution of the entire chip; and (2) when averaging the waveforms in the same region,the influence of fluctuations in the metal layer’s blocking,and the laser incident position,the incident energy on the experimental results is reduced.

    We set six temperature points at equal intervals (40°C)from+20°C to-180°C by using the cryogenic system mentioned in Subsection 2.1.We also changed the bias conditions of the DUT at each temperature point, including the on-state(withVCE=2 V,VBE=0.7 V)and off-state(withVCE=2 V,VBE=0 V).

    After 2D raster measurements,we statistically calculated the transient peaks and collected charges (CCs) at 3111 laser incident points for each temperature, as shown in the colormaps of Figs.7 and 8.As can be seen, the presence of only one metal layer could also have a significant impact on SPA-induced transient peaks and CCs.The maximum values of both transient peaks and CCs are located in the area without a metal layer(the outside substrate region).

    However, based on our previous studies,[16,28]the most sensitive volume for a SiGe HBT’s SET should be the central interdigital structure (especially the emitter center normal incidence) if there is no metal layer.Therefore, we divided the scanning area into the center-incidence(C-in)region(red boxes in Fig.7)and the substrate-incidence(S-in)region(white arrows in Fig.8).The definitions here are the same as in Fig.3.

    In particular, the red boxes (10 μm×10 μm) in Fig.7 are the central parts of the 4B5E2C interdigital region(20 μm×20 μm) considering the large 5.6 μm laser-spot radius.We then calculated the mean values of the SET waveforms in the C-in and S-in regions.As an example, the offstate’s results are plotted in Fig.9.One can see that the transient peaks firstly increase with decreasing temperature(a maximum increment of about 25%),and then decrease slightly from-140°C to-180°C for the C-in case.In this region,the fast drift current dominates the SET waveform.

    Fig.7.The 2D raster measurements for the collector transient peaks at different temperatures.The red box illustrates the center-incidence(close to the emitter center)of the 4E5B2C structure with the metal layer’s blocking.

    Fig.8.The 2D raster measurements for the collector collected charges at different temperatures.The white arrows illustrate the substrateincidence(outside the 4E5B2C structure)positions without the metal layer’s blocking.

    As a comparison,the transient peaks continue to slightly increase (a maximum increment of about 35%) for the S-in case because the dominant current is the diffusion current.For both cases, the full width at half maximum(FWHM)decreases with decreasing temperature and the total CCs show little change(as shown in Fig.10).What is more,we can obtain an estimate of the effective laser energy(0.15 nJ)and the surface LET value(28.37 pC/μm)of the C-in case.

    Fig.9.Mean waveforms for the collector’s SETs at different temperatures under (a) the C-in case and (b) the S-in case.The different time scales are shown right below.

    Fig.10.Relative percentage change (relative to 20 °C) on the collector’s SET peak,CCs,and FWHM under the C-in case and the S-in case(with VCE=2 V,VBE=0 V).

    3.2.The 2D process simulation and analysis

    In this paper,we have modified the TCAD parameter file of the heavy-ion model according to the analytical calculation results in Subsection 2.5 and have modified the simulation script file to simulate the pulsed laser penetrating a device structure based on the approach in our previous study.[16]

    First, let us focus on the C-in case.Taking the transmission coefficient of the 2 mm thickness quartz window,the reflection of the DUT surface, and the blocking of the metal layer into account,we give a relatively rough estimated value of the effective transmission coefficient (in Subsection 2.5)based on the simulation results, hereTeff=0.1.[29]What is more, we have set the laser incidence position exactly to the emitter center normal incidence(the most sensitive volume).

    It should be noted that it is difficult to find the real laser incidence position precisely.And considering that the high concentration of carrier profiles generated by the 5 nJ laser energy is sufficient to trigger the ion-shunt effect,these assumptions for the laser incidence position and effective transmission coefficientTeffare relatively reasonable,and do not affect the qualitative analysis and interpretation of the experimental phenomena in this paper.Figure 11 shows the SET simulation results in the off-state.The maximum value of the SET peak is around-160°C,which is 23.7%higher than 20°C and is similar to the testing results shown in Fig.9(a).The difference in FWHMs and durations between the simulation and experimental results come from the 2D simplified 1E2B2C simulation structure and the parasitic parameters from our testing system.

    Fig.11.The C-in (emitter center normal incidence) SET waveforms from the TCAD simulation at different temperatures.

    As mentioned before, many previous studies have attributed the temperature dependence of SET to carrier mobility.Carrier freeze-out at low temperatures doesn’t get enough attention.However, the TCAD simulation results in Ref.[7]have compared the SET’s temperature response with and without considering the i.i.at low temperatures.The peak inflection was only observed at the C/S junction’s transient component because the simulation LET is too small to trigger the ion-shunt effect.

    The law of exponential variation of carrier mobility with temperature has been generally accepted for a long time.In the following, we focus on the i.i.of impurities at low temperatures.Taking the moderately doped intrinsic base as an example,we will introduce the ionization rate(IR)calculation process in detail.According to Altermatt’s i.i.model[30,31]and the optimized compact model by Luoet al.,[32]the impurity states could be divided into the always completely ionized free-states(with the share of 1-b)and partially ionized bound-states(with the share ofb),then the ionized acceptor’s concentration is shown below:

    whereNAis the doping concentration,andf(EA)is the probability of the acceptor energy levelEAbeing occupied by electrons

    withgA= 2 being a degeneracy factor for boron doping.Therefore,the IR with temperature could be found by

    whereEV,EF, andEdopare, respectively, the valence band level,Fermi level,and the acceptor’s activation energy.

    Fig.12.The ionization rate(unit: one)versus doping concentration at different temperatures for phosphorus,arsenic,and boron doping.

    Detailed parameter settings and descriptions can be found in Refs.[30–32] and will not be presented here one by one.Finally, we calculated the three dopants’ ionization rates for the DUT, which are shown in Fig.12.We can see that i.i.could occur even at room temperature when the doping concentration is close to the Mott(metal–insulator)transition.[33]What is more, the ionization rate will decrease significantly when the temperature changes from-140°C to-180°C for both less than and close to the Mott transition.The peak doping concentrations in the base and the selectively implanted collector(SIC)are about 1×1019cm-3and less than 1×1018cm-3,respectively(from Fig.4),so these two moderate doping resistances(RB-VandRCin Fig.3)are dominated by both mobility and impurity IRs.For heavily doped regions(above 5×1019cm-3) like the emitter and sub-collector (or n+buried), the impurities are always completely ionized and the resistances (REandRSCin Fig.3) are controlled directly by the carrier mobility.

    In addition,the SPA-induced high-density EHPs will also impact the local resistance on the charge-collection pathway because they can significantly change the free carriers’ concentration.Therefore, we need to calculate the resistivity by considering both the electrons’and holes’mobilities and concentrations by using

    wherenandpare the electron and hole concentrations generated by both the intrinsic impurity’s ionization and the radiation-induced ionization, andμn,pare the electron and hole mobility, respectively.As shown in Fig.13, to qualitatively illustrate the relationship between the drift peak and resistivity, we extracted the resistivity values on the transient current pathway at the SET peak moments(around 20 ps)from the 2D process model.From-140°C to-180°C,RB-VandRCobviously increase andREandRSCslightly decrease.

    Fig.13.Variation of resistivity(at 20 ps)with temperature at different positions: (a)cutline at Y =0;(b)cutline at X =0.5.

    Finally,we should also consider the structural dimensions of different regions on the E/B/C stack to obtain series resistance (details in Fig.3) other than resistivity.There are two competing mechanisms for the variation of the total series resistance with temperature:(1)the moderate doping base(RB-V) and lighter doping SIC (RC) with relatively high resistivities(which increase as temperature decreases)and very small vertical size; and (2) the heavy doping sub-collector(RSC) with lower resistivity (which drops along with temperature) and a much larger lateral size.In addition, the contribution of the emitter(RE)to the total series resistance can be considered negligible because of its low resistivity and small vertical size.

    Taking into account these two competing mechanisms,it is not surprising to see a shift in the total resistance on the charge-collection pathway,which finally leads to an inflection point in the transient peak.In future work, the coupling between the 3D structure size and charge distribution needs to be fully considered in the calculation of series resistance.

    Next, we discuss the S-in case (in Figs.3 and 8), which means that the pulsed laser strikes the outside substrate region without the metal layer.From the experimental results in Fig.9(b), we can see that the transient peak continues to slightly increase as the temperature decreases.The reason for this is that the SET current for substrate-incidence is mainly the diffusion current,which is dominated by the ambipolar diffusion coefficient(Da).For high-level injection(when EHPs’concentration is far beyond the background doping level,just like in this work),we could estimateDafrom the equation in Ref.[34].From the exponential increase of mobility with decreasing temperature, the carrier mobility’s variation will always dominate the bipolar-diffusion process.

    4.Temperature dependence of the novel electron-injection process

    4.1.Experimental and simulation results

    During the 2D raster scan measurements,we also considered the impact of different bias conditions.We then found an important conclusion: that the novel electron injection from the emitter to the base will be suppressed at cryogenic temperatures.And this time,we will focus on the C-in case(emitter center strike)again.

    By keeping all the experimental and simulation setups the same as in Section 3, we could obtain the collector transient currents with different bias conditions and temperatures,which are shown in Fig.14.The transient peaks for both the experimental and simulation results show a similar pattern of variation.When it comes to the total CCs, the simulation results have amplified the changes in the experiments.This deviation comes from the difference between the 2D simulation and the actual 3D device structure as well as the accuracy of the TCAD physical model.

    Nevertheless, we can conclude that the transient peaks and CCs at low temperatures remain stable under different bias conditions.There will also be more electron injection from the emitter to the base when the temperature increases.

    Fig.14.Variation of collector transient currents with temperature under different bias conditions: (a)experimental waveforms(note that,to show the differences between waveforms more clearly, the waveforms are artificially shifted in the time axis.); (b) TCAD simulation waveforms.Note that all DC components have been filtered out here.

    4.2.Theoretical analysis

    There are few studies on the bias condition dependence of a SiGe HBT’s SET.In the literature,[2]the conception of a‘novel collector-emitter diffusive component’was proposed after SET testing on a 9HP SiGe HBT.In this work, we call it the ‘novel electron-injection process from emitter to base’.It should be noted that the‘electron’here indicates the laserinduced free electrons at the emitter.The conduction band electrons generated by intrinsic impurity ionizing mainly produce the DC component,which has been filtered out here.

    As is shown in Fig.15,this novel carrier injection is based on the principle that the positive bias voltage applied at the base lowers the potential barrier between the emitter and the base, thus allowing more electrons to cross (a diffusion-like process) the barrier layer to the base and eventually be collected by the collector terminal.Therefore, the temperature dependence of the E/B junction’s potential barrier will dominate this electron-diffusion process.

    The built-in voltage(Vbi)of the E/B junction is dominated by the material’s lattice temperature and doping-dependent bandgap narrowing (BGN).[35]For silicon, the bandgap voltage (Vg) decreases as temperature increases, which could be described by Eq.(6)(from the HICUM model[9])

    whereTis the nominal temperature 300 K(27°C),andk1=-0.025 V andk2=-0.053 V are constant parameters.

    Fig.15.Novel carrier injection schematic.Note: the variation of the conduction band energy near the emitter-base junction with temperature and bias is extracted from the 2D TCAD simulation results.

    Considering the i.i.(detailed in Subsection 3.2),we have then optimized the built-in voltage as

    whereNDis the donor concentration(complete ionization due to the high doping level)of the emitter,NAis the ionized acceptor concentration of the base,VTis the thermal voltage(kT/q), andnieis the effective intrinsic carrier concentration by considering the BGN’s influence

    Next, taking the i.i.into account, we could obtain the optimized built-in voltage in Eq.(9), and the last term shows the role of i.i.Eq.(10) illustrates the proportional relationship between the IR and ionized impurity concentration from Subsection 3.2.

    It should be noted that the reference bandgap voltageVg(T0)=1.01 V is the average bandgap voltage of the emitter and the base,[9]by considering the impact of the Ge mole fraction.

    Using the equations above, we could calculate the builtin voltages of the E/B junction at different temperatures, as shown in Fig.16.The built-in voltage of the E/B junction will increase as temperature decreases.And the simulation’s builtin barrier’s height is consistent with the analytical calculation results,which validate the effectiveness of our optimized builtin voltage calculation model.

    Fig.16.The built-in voltages of the E/B junction at different temperatures by using the optimized model calculation(blue line and font)and TCAD simulation(red symbols and font).

    When the E/B bias is zero(VBE=0 V),one can see there is little electron injection from the emitter to the base because the potential barriers at the E/B junction remain at a high level at almost all temperature points.WhenVBE=0.7 V,this forward base bias could pull down the E/B barriers by about 0.7 V; at this point, the difference between the E/B barriers with different temperatures comes to the fore.Finally, more electrons are accepted(green arrows in Fig.15),injected from the emitter to the base at relatively higher temperatures due to the relatively lower barrier height.

    In a word,our optimized built-in voltage model could extend the temperature range of the original HICUM model to extremely low temperatures.

    5.Summary and conclusion

    In this paper,the temperature dependence of single-event transients in SiGe HBTs was investigated.Comparing the experimental data and TCAD simulation results, we found that the variation of carrier mobility with temperature always plays a key role in SET peaks,and the impurity’s i.i.will also dominate and make an inflection point when it comes to cryogenic temperatures.These two factors together lead to a significant change in the resistivity of the intrinsic base region and the light-doped collector(both close to the Mott transition).What is more, the novel electron injection from the emitter to the base(when the transistor is in the on-state)will be significantly suppressed at cryogenic temperatures.This phenomenon is mainly due to the high emitter/base junction’s barrier heights at low temperatures.An optimized built-in voltage model is proposed to extend the original HICUM model to extremely low temperatures.The present work has provided new evidence for the adaptability and reliability of the SiGe HBT in cryogenic environments.

    More work is necessary to improve the convergence of the 3D process simulation at cryogenic temperatures.The cryogenic experimental system needs to be further optimized, especially by thinning the thickness of the quartz window and adding focusing lenses as needed.What is more, we need to study a more accurate simulation method to extract the parasitic series resistance based on the 3D model.

    Acknowledgements

    The authors want to thank the contributions of the Institute of Microelectronics, Tsinghua University, for providing the DUT in this work.Sun Yabin and Fu Jun have also provided many valuable suggestions on the process simulation.Furthermore,the authors are very grateful to the engineers of SPELS and EKSPLA for their technical support in the daily use of the laser system.

    Project supported by the National Natural Science Foundation of China(Grant Nos.61704127 and 11775167).

    猜你喜歡
    紅霞
    如何推薦一部動畫片
    點(diǎn)詞成金
    請你幫個(gè)忙
    《烏鴉喝水》中的“想”
    Therapeutic efficacy of moxibustion plus medicine in the treatment of infertility due to polycystic ovary syndrome and its effect on serum immune inflammatory factors
    A Study of Combination of English Language Teaching and Context
    大東方(2018年1期)2018-05-30 01:27:23
    高紅霞教授
    讓動作“活”起來
    “光的直線傳播”“光的反射”練習(xí)
    夕陽依舊映紅霞
    中國火炬(2014年7期)2014-07-24 14:21:26
    性色avwww在线观看| 国产精品嫩草影院av在线观看| 一区二区日韩欧美中文字幕| 一边亲一边摸免费视频| 两性夫妻黄色片| 中文欧美无线码| 一级爰片在线观看| 亚洲国产精品一区二区三区在线| 在线天堂中文资源库| 国产成人午夜福利电影在线观看| 成年女人在线观看亚洲视频| 久热这里只有精品99| 国产不卡av网站在线观看| 蜜桃国产av成人99| 亚洲伊人色综图| 一区二区日韩欧美中文字幕| 国产伦理片在线播放av一区| 久久99一区二区三区| 69精品国产乱码久久久| 国产精品女同一区二区软件| 成人二区视频| 捣出白浆h1v1| 日韩中字成人| 国产精品秋霞免费鲁丝片| 久久精品国产自在天天线| 久久久久久伊人网av| 男女国产视频网站| 少妇猛男粗大的猛烈进出视频| 婷婷成人精品国产| 老汉色av国产亚洲站长工具| 永久网站在线| 亚洲美女黄色视频免费看| 日韩av不卡免费在线播放| 久久精品人人爽人人爽视色| 国产 一区精品| 国产精品 国内视频| 制服诱惑二区| 青草久久国产| 亚洲国产av影院在线观看| 最新中文字幕久久久久| 寂寞人妻少妇视频99o| 亚洲色图 男人天堂 中文字幕| 免费看不卡的av| 欧美国产精品一级二级三级| 好男人视频免费观看在线| 免费看av在线观看网站| 日韩一区二区视频免费看| 岛国毛片在线播放| 一级毛片黄色毛片免费观看视频| 观看av在线不卡| 97在线视频观看| 国产人伦9x9x在线观看 | 国产97色在线日韩免费| 国产精品免费大片| 日日爽夜夜爽网站| a 毛片基地| 国产在线一区二区三区精| 人妻一区二区av| 午夜日本视频在线| 中国三级夫妇交换| 在线观看免费高清a一片| 国产精品国产三级国产专区5o| 极品少妇高潮喷水抽搐| 亚洲中文av在线| 国产熟女午夜一区二区三区| 成人漫画全彩无遮挡| 久久久久久人妻| 久热这里只有精品99| 制服丝袜香蕉在线| 精品久久久久久电影网| 欧美日韩视频高清一区二区三区二| 亚洲欧美中文字幕日韩二区| 涩涩av久久男人的天堂| 欧美在线黄色| 精品国产露脸久久av麻豆| 国产极品粉嫩免费观看在线| 亚洲av电影在线观看一区二区三区| 亚洲国产精品成人久久小说| 午夜福利视频在线观看免费| 亚洲成色77777| 波多野结衣一区麻豆| 日本猛色少妇xxxxx猛交久久| 国产精品免费大片| 嫩草影院入口| 一区二区三区激情视频| 国产一区有黄有色的免费视频| 国产成人一区二区在线| 国产高清不卡午夜福利| 精品国产乱码久久久久久小说| 丰满乱子伦码专区| 夜夜骑夜夜射夜夜干| 三上悠亚av全集在线观看| 一区二区日韩欧美中文字幕| 亚洲第一区二区三区不卡| 亚洲伊人久久精品综合| 亚洲欧洲日产国产| 日韩免费高清中文字幕av| 青春草国产在线视频| 亚洲三级黄色毛片| 国产一区二区三区综合在线观看| 中文字幕另类日韩欧美亚洲嫩草| 久久精品国产自在天天线| 成人国语在线视频| 天美传媒精品一区二区| 热99国产精品久久久久久7| 飞空精品影院首页| 青春草视频在线免费观看| 老鸭窝网址在线观看| 精品一区在线观看国产| 黄网站色视频无遮挡免费观看| 久久精品国产亚洲av涩爱| 中文欧美无线码| 日日摸夜夜添夜夜爱| 国产精品蜜桃在线观看| 满18在线观看网站| 丰满乱子伦码专区| 久久久久久久国产电影| 满18在线观看网站| 在线观看美女被高潮喷水网站| 亚洲国产成人一精品久久久| 寂寞人妻少妇视频99o| www.熟女人妻精品国产| 国产成人欧美| 成人亚洲欧美一区二区av| 日日撸夜夜添| 国产黄色视频一区二区在线观看| 久久久久国产网址| 18禁裸乳无遮挡动漫免费视频| 午夜激情av网站| 久久av网站| 免费在线观看黄色视频的| av国产久精品久网站免费入址| 亚洲欧美色中文字幕在线| 欧美精品人与动牲交sv欧美| 啦啦啦在线免费观看视频4| 女人高潮潮喷娇喘18禁视频| 欧美精品人与动牲交sv欧美| 在线观看美女被高潮喷水网站| 伊人久久大香线蕉亚洲五| 精品国产乱码久久久久久男人| av网站在线播放免费| 丰满饥渴人妻一区二区三| 亚洲中文av在线| 日韩三级伦理在线观看| 国产成人欧美| 成人毛片60女人毛片免费| 国产日韩一区二区三区精品不卡| videos熟女内射| 成人毛片a级毛片在线播放| 搡老乐熟女国产| 午夜精品国产一区二区电影| 男的添女的下面高潮视频| 久久久久久久久免费视频了| 亚洲国产精品国产精品| 精品福利永久在线观看| 免费观看性生交大片5| av线在线观看网站| 麻豆av在线久日| 色视频在线一区二区三区| 精品亚洲乱码少妇综合久久| 久久久久久久久久久久大奶| 大片免费播放器 马上看| 巨乳人妻的诱惑在线观看| 免费高清在线观看视频在线观看| 天天躁日日躁夜夜躁夜夜| 久久精品aⅴ一区二区三区四区 | 亚洲国产最新在线播放| 亚洲精品一二三| 免费播放大片免费观看视频在线观看| 国产精品免费视频内射| 久久精品人人爽人人爽视色| 国产高清国产精品国产三级| 日本91视频免费播放| 日韩一本色道免费dvd| 久久精品久久精品一区二区三区| 欧美97在线视频| 91国产中文字幕| 午夜老司机福利剧场| 午夜免费观看性视频| av免费观看日本| 亚洲精品国产av成人精品| 午夜免费男女啪啪视频观看| 国产成人免费观看mmmm| 亚洲成人一二三区av| 丝袜美腿诱惑在线| 日韩成人av中文字幕在线观看| 高清在线视频一区二区三区| 国产精品偷伦视频观看了| 99九九在线精品视频| 国产午夜精品一二区理论片| 日日撸夜夜添| 女人被躁到高潮嗷嗷叫费观| 一级片免费观看大全| 啦啦啦中文免费视频观看日本| 丝袜喷水一区| 制服诱惑二区| 少妇 在线观看| 国产精品.久久久| 啦啦啦在线观看免费高清www| 精品少妇一区二区三区视频日本电影 | 少妇熟女欧美另类| 国产成人精品福利久久| 国产亚洲最大av| 韩国精品一区二区三区| 青草久久国产| 国产成人91sexporn| 少妇熟女欧美另类| 国产熟女欧美一区二区| 9色porny在线观看| 午夜福利视频在线观看免费| 免费在线观看黄色视频的| 777久久人妻少妇嫩草av网站| 国产欧美亚洲国产| av天堂久久9| 男女午夜视频在线观看| 日韩中字成人| 一级黄片播放器| 性高湖久久久久久久久免费观看| 成人18禁高潮啪啪吃奶动态图| videos熟女内射| 亚洲美女黄色视频免费看| 99久国产av精品国产电影| 91精品三级在线观看| 777米奇影视久久| 纯流量卡能插随身wifi吗| 美女大奶头黄色视频| 少妇猛男粗大的猛烈进出视频| 久久精品aⅴ一区二区三区四区 | 国产成人欧美| 最新的欧美精品一区二区| 咕卡用的链子| 欧美激情极品国产一区二区三区| 久久久精品94久久精品| 精品一区二区三卡| 国产成人免费观看mmmm| 亚洲av综合色区一区| 在线看a的网站| 国产成人av激情在线播放| 亚洲国产毛片av蜜桃av| 欧美日韩精品成人综合77777| a 毛片基地| 色94色欧美一区二区| 熟女少妇亚洲综合色aaa.| 在线亚洲精品国产二区图片欧美| 欧美精品一区二区免费开放| 一二三四在线观看免费中文在| 国产精品一区二区在线观看99| 亚洲精品国产色婷婷电影| 十八禁高潮呻吟视频| 国产精品偷伦视频观看了| www日本在线高清视频| 国产白丝娇喘喷水9色精品| av天堂久久9| 日本欧美视频一区| 欧美bdsm另类| 蜜桃国产av成人99| 久久99精品国语久久久| 亚洲欧美精品综合一区二区三区 | 亚洲精品久久午夜乱码| 18+在线观看网站| 一级毛片 在线播放| 国产一级毛片在线| 91国产中文字幕| 亚洲欧美中文字幕日韩二区| 久久精品国产亚洲av高清一级| 高清不卡的av网站| 精品人妻熟女毛片av久久网站| 欧美另类一区| 日韩电影二区| 色吧在线观看| 一边摸一边做爽爽视频免费| 一本一本久久a久久精品综合妖精 国产伦在线观看视频一区 | 中文精品一卡2卡3卡4更新| 99久国产av精品国产电影| av视频免费观看在线观看| 黄片无遮挡物在线观看| 男男h啪啪无遮挡| 美女午夜性视频免费| 亚洲一区二区三区欧美精品| av国产精品久久久久影院| 久久精品国产鲁丝片午夜精品| 亚洲国产精品一区二区三区在线| 成人18禁高潮啪啪吃奶动态图| 一级爰片在线观看| 桃花免费在线播放| 999久久久国产精品视频| 久久精品亚洲av国产电影网| 亚洲欧美日韩另类电影网站| 狠狠婷婷综合久久久久久88av| 91精品伊人久久大香线蕉| 国产精品二区激情视频| 搡老乐熟女国产| 精品一品国产午夜福利视频| 国产亚洲欧美精品永久| 国产日韩欧美亚洲二区| 极品人妻少妇av视频| 女人被躁到高潮嗷嗷叫费观| 久久精品亚洲av国产电影网| 一区二区三区激情视频| 久久99精品国语久久久| 国产亚洲一区二区精品| 超色免费av| av女优亚洲男人天堂| 人人妻人人爽人人添夜夜欢视频| 哪个播放器可以免费观看大片| 日韩欧美精品免费久久| 成人亚洲精品一区在线观看| 啦啦啦在线免费观看视频4| 亚洲男人天堂网一区| 夫妻午夜视频| 亚洲人成网站在线观看播放| 精品一区在线观看国产| 亚洲精华国产精华液的使用体验| 午夜久久久在线观看| 久久久久久久亚洲中文字幕| 桃花免费在线播放| 免费黄频网站在线观看国产| 一本色道久久久久久精品综合| 自线自在国产av| 成人黄色视频免费在线看| 亚洲欧美日韩另类电影网站| 日韩av在线免费看完整版不卡| 日本欧美国产在线视频| 亚洲av日韩在线播放| 午夜老司机福利剧场| 亚洲经典国产精华液单| 丝袜美足系列| 国产又色又爽无遮挡免| 午夜av观看不卡| 五月天丁香电影| 免费女性裸体啪啪无遮挡网站| 午夜日韩欧美国产| 99国产综合亚洲精品| av卡一久久| 国产一区二区激情短视频 | 日本免费在线观看一区| 99久久精品国产国产毛片| 大陆偷拍与自拍| 少妇猛男粗大的猛烈进出视频| 日韩,欧美,国产一区二区三区| 两个人看的免费小视频| 人人妻人人爽人人添夜夜欢视频| 日韩成人av中文字幕在线观看| 熟女av电影| av天堂久久9| 亚洲人成网站在线观看播放| 制服人妻中文乱码| 久久久a久久爽久久v久久| 免费观看a级毛片全部| 亚洲三区欧美一区| 青草久久国产| 老汉色∧v一级毛片| 香蕉国产在线看| 国产无遮挡羞羞视频在线观看| 亚洲人成电影观看| 国产亚洲一区二区精品| 亚洲天堂av无毛| 国产成人欧美| 日韩不卡一区二区三区视频在线| 午夜精品国产一区二区电影| 菩萨蛮人人尽说江南好唐韦庄| 久久人人97超碰香蕉20202| 26uuu在线亚洲综合色| 激情视频va一区二区三区| 亚洲精品自拍成人| 我要看黄色一级片免费的| 成年动漫av网址| 另类亚洲欧美激情| 2022亚洲国产成人精品| 精品卡一卡二卡四卡免费| 丝袜在线中文字幕| 老鸭窝网址在线观看| 一级毛片我不卡| 老汉色av国产亚洲站长工具| 免费女性裸体啪啪无遮挡网站| 丰满迷人的少妇在线观看| 91成人精品电影| 午夜av观看不卡| 侵犯人妻中文字幕一二三四区| 亚洲欧美精品自产自拍| 久久韩国三级中文字幕| 欧美成人午夜精品| 久久精品国产亚洲av天美| 超色免费av| 亚洲综合色网址| 国产亚洲一区二区精品| 男女下面插进去视频免费观看| 卡戴珊不雅视频在线播放| 捣出白浆h1v1| 久久人人爽av亚洲精品天堂| 伦精品一区二区三区| 免费女性裸体啪啪无遮挡网站| 大片电影免费在线观看免费| 中文字幕亚洲精品专区| 汤姆久久久久久久影院中文字幕| 久久久久网色| 丝袜美腿诱惑在线| 卡戴珊不雅视频在线播放| 国产欧美亚洲国产| 99香蕉大伊视频| 精品少妇一区二区三区视频日本电影 | 王馨瑶露胸无遮挡在线观看| 欧美人与善性xxx| 国产精品人妻久久久影院| 自线自在国产av| 久久精品国产自在天天线| 最近2019中文字幕mv第一页| 女性生殖器流出的白浆| 亚洲欧洲精品一区二区精品久久久 | 亚洲精品国产色婷婷电影| 国产精品麻豆人妻色哟哟久久| 日韩不卡一区二区三区视频在线| 一二三四在线观看免费中文在| 永久免费av网站大全| 男男h啪啪无遮挡| 精品亚洲成a人片在线观看| 女性生殖器流出的白浆| 色视频在线一区二区三区| 人妻 亚洲 视频| 国产一区亚洲一区在线观看| 新久久久久国产一级毛片| 一区二区av电影网| 国产亚洲一区二区精品| 伊人亚洲综合成人网| 在现免费观看毛片| 亚洲国产精品一区二区三区在线| 9191精品国产免费久久| 国产一区二区激情短视频 | 91精品国产国语对白视频| 国产亚洲精品第一综合不卡| 欧美精品一区二区免费开放| 美女xxoo啪啪120秒动态图| 亚洲精品中文字幕在线视频| 国产成人精品久久二区二区91 | 一本—道久久a久久精品蜜桃钙片| 久久人人爽人人片av| 国产有黄有色有爽视频| 青春草亚洲视频在线观看| 国产精品香港三级国产av潘金莲 | 最近2019中文字幕mv第一页| 母亲3免费完整高清在线观看 | 精品国产超薄肉色丝袜足j| 欧美精品人与动牲交sv欧美| 亚洲精品久久午夜乱码| 日本欧美视频一区| 精品一区二区三区四区五区乱码 | 免费观看性生交大片5| 亚洲国产精品999| av又黄又爽大尺度在线免费看| 侵犯人妻中文字幕一二三四区| 久久97久久精品| 男女午夜视频在线观看| 日产精品乱码卡一卡2卡三| 亚洲国产精品成人久久小说| 欧美日韩一区二区视频在线观看视频在线| 国产1区2区3区精品| 久久av网站| 制服人妻中文乱码| 国产精品国产av在线观看| 最近最新中文字幕免费大全7| 一二三四在线观看免费中文在| 一级片免费观看大全| 9热在线视频观看99| 国产免费福利视频在线观看| 免费在线观看视频国产中文字幕亚洲 | 国产日韩欧美亚洲二区| 日韩中字成人| 国产精品久久久久久精品古装| 欧美日韩成人在线一区二区| 欧美成人午夜精品| 亚洲精品久久久久久婷婷小说| 人妻系列 视频| 久久久久精品人妻al黑| 成人漫画全彩无遮挡| 午夜福利,免费看| 久久热在线av| 亚洲男人天堂网一区| 青青草视频在线视频观看| 十八禁网站网址无遮挡| 看免费av毛片| 亚洲久久久国产精品| 国产成人91sexporn| 99久久中文字幕三级久久日本| 免费观看性生交大片5| 成年女人在线观看亚洲视频| 国产成人精品婷婷| 在线观看免费视频网站a站| 欧美国产精品一级二级三级| 久久毛片免费看一区二区三区| 亚洲av国产av综合av卡| 国产黄色视频一区二区在线观看| 天天躁夜夜躁狠狠久久av| 在线 av 中文字幕| 99精国产麻豆久久婷婷| 欧美人与性动交α欧美软件| 久久99一区二区三区| 久久精品夜色国产| 国产黄频视频在线观看| 欧美亚洲日本最大视频资源| 欧美人与性动交α欧美精品济南到 | 99久久精品国产国产毛片| 亚洲国产精品一区二区三区在线| 老司机亚洲免费影院| 一级,二级,三级黄色视频| 精品国产超薄肉色丝袜足j| 国产 一区精品| 999久久久国产精品视频| 又大又黄又爽视频免费| 999久久久国产精品视频| 国产97色在线日韩免费| 午夜福利视频在线观看免费| 最近最新中文字幕免费大全7| 亚洲少妇的诱惑av| 各种免费的搞黄视频| 一区福利在线观看| 搡老乐熟女国产| 中文字幕人妻丝袜一区二区 | 亚洲一区中文字幕在线| 亚洲激情五月婷婷啪啪| 亚洲一区二区三区欧美精品| 亚洲情色 制服丝袜| 午夜福利,免费看| 国产av国产精品国产| 性高湖久久久久久久久免费观看| 亚洲婷婷狠狠爱综合网| 十八禁网站网址无遮挡| 热re99久久国产66热| 久久久久久久久久人人人人人人| 高清欧美精品videossex| 国产免费福利视频在线观看| 侵犯人妻中文字幕一二三四区| 波多野结衣一区麻豆| 亚洲精品一区蜜桃| 熟女少妇亚洲综合色aaa.| 热99久久久久精品小说推荐| 人人妻人人添人人爽欧美一区卜| 成人免费观看视频高清| 一级毛片我不卡| 亚洲国产精品一区二区三区在线| 热99国产精品久久久久久7| 国产福利在线免费观看视频| 一级黄片播放器| 丝袜人妻中文字幕| 女的被弄到高潮叫床怎么办| 亚洲欧美成人综合另类久久久| 亚洲av在线观看美女高潮| 最近最新中文字幕免费大全7| 免费黄频网站在线观看国产| 亚洲av男天堂| 日本欧美视频一区| 欧美国产精品一级二级三级| 18禁国产床啪视频网站| 天堂8中文在线网| 91精品三级在线观看| 精品少妇内射三级| 精品国产露脸久久av麻豆| 在线 av 中文字幕| 汤姆久久久久久久影院中文字幕| 女的被弄到高潮叫床怎么办| 国产精品亚洲av一区麻豆 | 在现免费观看毛片| 免费在线观看黄色视频的| 精品人妻在线不人妻| 毛片一级片免费看久久久久| 汤姆久久久久久久影院中文字幕| 一个人免费看片子| 久久精品久久精品一区二区三区| 人成视频在线观看免费观看| av线在线观看网站| 多毛熟女@视频| 欧美日韩综合久久久久久| 亚洲精品在线美女| 中文精品一卡2卡3卡4更新| 看免费成人av毛片| 777久久人妻少妇嫩草av网站| 亚洲国产av新网站| 欧美激情 高清一区二区三区| 亚洲av免费高清在线观看| av福利片在线| 18+在线观看网站| 国产精品久久久久成人av| 亚洲天堂av无毛| 精品人妻在线不人妻| 丰满少妇做爰视频| 亚洲美女黄色视频免费看| 久久狼人影院| 好男人视频免费观看在线| av在线观看视频网站免费| 亚洲第一av免费看| 国精品久久久久久国模美| 亚洲精品美女久久av网站| 男人爽女人下面视频在线观看| 99热国产这里只有精品6| 1024香蕉在线观看| 国产精品嫩草影院av在线观看| 看非洲黑人一级黄片| 午夜免费男女啪啪视频观看| 免费在线观看视频国产中文字幕亚洲 | 亚洲精品乱久久久久久| 精品人妻在线不人妻| av国产精品久久久久影院| 中文字幕另类日韩欧美亚洲嫩草| 曰老女人黄片| 菩萨蛮人人尽说江南好唐韦庄| 中文字幕人妻丝袜一区二区 | 国产不卡av网站在线观看| 欧美 亚洲 国产 日韩一| 婷婷色综合大香蕉| 久久毛片免费看一区二区三区| 国产精品久久久久成人av| 亚洲欧美成人综合另类久久久| 免费在线观看完整版高清| 欧美日韩av久久| 一本—道久久a久久精品蜜桃钙片| 大香蕉久久网|