In this paper, a mechanism of 64mb dram circuit degradation was described. The lbtbt is the dominant mechanism for gateinduced drain leakage gidl in the gaa nwfets and the conventional transverse btbtinduced gidl in the gatedrain overlap region occurs only when v. The depletion region causes significant band bending which inturn allows conductive bandtoband tunneling creating excess current. Detection of thermal transport using gidl gate induced drain leakage current. Cristoloveanua a imeplahc, inpgrenoble, minatec, 3 parvis louis neel, bp 257, 38016 grenoble, france bcealeti, minatec, 17 avenue des martyrs, 38054 grenoble cedex 9, france cschool of engineering, brown university, providence, ri 02912, usa. It is known that gidl current is attributed to tunneling taking place in the deepdepleted drain region underneath the gate oxide. The gidl can be reduced by reducing shallow junction depth of drain extension.
The drain current when the transistor is biased in its off state. Gl is a trappedcharge phenomenon found in plastic encapsulated bipolari. Based on a microscopic, nonlocal model of bandtoband tunneling, transfer characteristics are. In this paper, novel nanoscale mosfet with sourcedraintogate nonoverlapped and highk spacer structure has been demonstrated to reduce the gate leakage current for the first time. A large component of offstate leakage current is gate induced drain leakage gidl current, caused by bandto band tunneling in the drain region underneath the gate when there is a large gatetodrain bias, there can be sufficient energyband. Pdf 3dnand gidlassisted body biasing for erase enabling. This study describes the dependence of the surface electric field to the junction depth of sourcedrainextension, and the suppression of gate induced drain leakage gidl in fully depleted shallow junction gateoverlapped sourcedrainextension sde. The reasons are i the subthreshold conduction increases exponentially due to the threshold voltage reduction. As a result, the gateinduced drain leakage gidl current is. As the conventional mosfet is scaled down, gateinduced drain leakage gidl current is becoming a critical issue. Gateinduced drain leakage gidl current is investigated in singlegate sg ultrathin body field effect transistor fet, symmetrical doublegate dg finfet. Impact of gate induced drain leakage on overall leakage of. Join date nov 2007 posts 263 helped 21 21 points 2,981 level 12.
Induced parasitic gate leakage etipgl or gl is an environment and materials induced failure mechanism that adversely affects the performance and reliability of an integrated circuit. It is shown by tcad simulations how the gateinduced drain leakage which dominates the. Suppression of gateinduced drain leakage by optimization of. Dec 10, 2016 praveen meduri ee478 presentation on gate induced drain leakage current. In a classic planar fieldeffect transistor with a long channel, the bottleneck in channel formation occurs far enough from the drain contact that it is electrostatically shielded from the drain by the combination of the. The impact of gateinduced drain leakage current on mosfet. The gate induce drain leakage gidlassisted body biasing for erase, which is a technique essential to enabling 3dnand flash cmos under array architectures, has been extensively studied and. It is obtained by subtracting the sourcebody junction current from the total sourceterminal leakage current isource. Behaviors of gate induced drain leakage stress in lightly doped drain nchannel metaloxidesemiconductor. Detection of thermal transport using gidl gate induced drain. Gateinduced drain current or leakage can also be induced in the high. We can run a relatively small number of samples and fit them into a known distribution. In this work, we provide insight and design guidelines of doublegate mpi 1t dram device. Gateinduced drain leakage gidl is an unwanted shortchannel effect that occurs at higher drain biases in an overdriven off state of a transistor.
Pdf a physical model for gate induced drain leakage current in. This is a measure of gate leakage of a logic gate during its steady state. The hole driftmobility of germanium is 4x that of silicon, leading researchers to evaluate germanium as a possible channel material replacement for pmos expected at the 32 nm. It is shown by tcad simulations how the gate induced drain leakage which dominates the offcurrent in 22nm double gate soi nfets with highk gate stacks, can be minimized by proper variations of the junction profiles. The gate induced drain leakage gidl current is recognized as a major drain leakage phenomenon in offstate mosfets. Drain induced barrier lowering dibl is a shortchannel effect in mosfets referring originally to a reduction of threshold voltage of the transistor at higher drain voltages. Generic interface definition language, an extension to corba idl. Outline silicon and doping pn junction cmos transistor threshold voltage on current ion channel length modulation velocity saturation subthreshold leakage drain induced barrier leakage gate induced drain leakage reverse short channel e. Pdf gateinduced drain leakage gidl improvement for. What is the abbreviation for gateinduced drain leakage. Suppression of gateinduced drain leakage by optimization. Fringing gate electric field through the dielectric spacer induces. The leakage in the drain region is a crucial issue for scaling of the mosfet towards the deep submicron regime. Recent radiation test results for trench power mosfets.
Accurate stacking effect macromodeling of leakage power in. In an nmos transistor, when the gate is biased to form accumulat ion layer in the silicon surface under the gate, the silicon surface has almost the same potential as. Cristoloveanua a imeplahc, inpgrenoble, minatec, 3 parvis louis neel, bp 257, 38016 grenoble, france bcealeti, minatec, 17 avenue des martyrs, 38054 grenoble cedex 9, france. In this work, we provide insight and design guidelines of double gate mpi 1t dram device. The mfla split had only charge, vg is the gate voltage, vds is the source voltage, vdd is 2 to 3 nm of dopant diffusion, which was far less diffusion the drain voltage, and vt is the threshold voltage. The competing tfet device, which is of interest due to its potentially lower subthreshold slope and partial immunity to shortchannel effects 15, also faces the problem of relatively high leakage current. This paper compares the gateinduced drain leakage gidl in fullydepleted fd silicononinsulator. I guess that just driving the gate at the off condition with a negative voltage a few beyond 0v would probably close a bit more the chanel, increasing its resistve characteristic, therefore decreasing the leakage current.
In contrast, the body leakage at low gate bias is lower in the drainonbottom con. The principal difference between asymmetric and symmetric sourcedrain mosfets is the drainside structure. A large component of offstate leakage current is gate induced drain leakage gidl current, caused by bandto band tunneling in the drain region underneath the gate when there is a large gate to drain bias, there can be sufficient energyband. Hao3,a 1school of technical physics, xidian university, xian 710071, peoples republic of china 2school of mechanoelectric engineering, xidian university, xian 710071, peoples republic of china. Pdf in this work, a physical model for mosfet gate induced drain leakage current gidl field has proposed witch takes into account of the. Those three major leakage current mechanisms are illustrated in fig. Investigation and optimization of doublegate mpi 1t dram. Us7359271b2 gate induced drain leakage current reduction by. It is shown by tcad simulations how the gateinduced drain leakage which dominates the offcurrent in 22nm doublegate soi nfets with highk gate stacks, can be minimized by proper variations of the junction profiles.
The problem was an abnormally high leakage current at the field oxide edges of locos isolation. Mechanism analysis of gateinduced drain leakage in offstate. Program by gate induced drain leakage gidl can reduce the destructive carrier injections and consequently suppress oxide degradation and power loss in the 1t dram operation. Effect of fin shape on gidl and subthreshold leakage currents. Note i dleak may have contributions from channel offstate current, gate induced drain leakage, and drain to gate tunneling currents. For a transistor with 0 at the gate and vdd at the drain, gate leakage is dominated by i gd. Since the channel must be depleted of charge before inversion takes place, any help on depletion process will reduce vt. Measured reductions in gidl current for sg and dg thinbody devices are reported for the first time.
Gidl suppression by optimization of junction profiles in. Gate induced drain leakage gidl is an unwanted shortchannel effect that occurs at higher drain biases in an overdriven off state of a transistor. As shown in 5 and in figure 2, gate leakage is far less sensitive to applied body bias than btbt or subthreshold current. The asymmetric sourcedrain mosfet has a lightlydoped drain for a low electric field. Junction depth dependence of the gate induced drain. The gate leakage behavior of novel mosfet structure has been investigated with help of compact analytical model and sentaurus simulation. Gate induced drain leakage, a leakage mechanism in mosfets due to large field effect in the drain junction. Impact of junction depth and abruptness on the activation. Accurate stacking effect macromodeling of leakage power. Note i dleak may have contributions from channel offstate current, gateinduced drain leakage, and draintogate tunneling currents. The gateinduced drain leakage gidl current is recognized as a major drain leakage phenomenon in offstate mosfets. It is shown by tcad simulations how the gate induced drain leakage which dominates the offcurrent in 22 nm double gate and 32 nm single gate soi nfets with highk gate stacks, can be minimized by proper variations of the junction profiles. The gidl is the result of a deep depletion region that forms in the drain at high draintogate biases. Effectiveness of reverse body bias for leakage control in.
Gate induced drain leakage gidl b s p vgs leakage between the gate and the substrate. There are still other leakage components, like gate induced drain leakage gidl and punchthrough current, however those ones. G exceeding manufacturer specification during beam run or pigs. The gidl is the result of a deep depletion region that forms in the drain at high drain to gate biases. Analysis of gateinduced drain leakage mechanisms in silicongermanium channel pfet article pdf available in ieee transactions on electron devices 615. This is greatest when the device is off, at which time the. Standby supply voltage minimization for reliable nanoscale.
In this paper, novel nanoscale mosfet with source drain to gate nonoverlapped and highk spacer structure has been demonstrated to reduce the gate leakage current for the first time. Other components of leakage current described in roy et al. The larger the area of gatedrain overlap, the higher the current. Circuit techniques for leakage reduction mixedsignal. High field induced stress suppression of gidl effects in. Pdf a systematic study of gateinduced drain leakage gidl in singlediffusion drain sd, lightly doped drain ldd, and fully. Pdf investigation of gateinduced drain leakage gidl current. Junction depth dependence of the gate induced drain leakage. Study on improvement of the leakage like defect problems in. Draininduced barrier lowering dibl is a shortchannel effect in mosfets referring originally to a reduction of threshold voltage of the transistor at higher drain voltages. For example, one circuit component that is the building block of digital logic functions, including data storage memory circuits is the socalled field effect transistor. Based on a microscopic, nonlocal model of bandtoband tunneling, transfer characteristics are computed after systematic changes in sourcedrain doping. Contribution of gate induced drain leakage to overall.
The lbtbt is the dominant mechanism for gate induced drain leakage gidl in the gaa nwfets and the conventional transverse btbt induced gidl in the gate drain overlap region occurs only when v. Abstractin this paper, we propose a double gate onetransistor dynamic randomaccess memory 1t dram with middle partial insulation mpi structure for low power application. Gidl suppression by optimization of junction profiles in 22nm. There has been considerable interest in the study of the mechanisms responsible for gidl current 1, 2, 3, 4. Pdf design for suppression of gateinduced drain leakage in. L and complimentary metaloxide semiconductor cmos microcircuit technologies. Pdfdetection of thermal transport using gidl gate induced drain leakage current. What is the abbreviation for gate induced drain leakage. Mechanism analysis of gateinduced drain leakage in off. Study on improvement of the leakage like defect problems. Introduction l eakage power continues to increase in both active and standby modes as technologies scale 1. Program by gateinduced drain leakage gidl can reduce the destructive carrier injections and consequently suppress oxide degradation and power loss in the 1t dram operation.
Praveen meduri ee478 presentation on gate induced drain leakage current. Gatetochannel parasitic capacitance minimization and source. Abstract this thesis is a study of dynamic power estimation at registertransfer level using. One leakage current mechanism that has been mostly neglected until recently is called the gate induced drain leakage gidl. The sourcesubstrate and drain substrate reverse biased pn junction btbt leakage. The sourcesubstrate and drainsubstrate reverse biased pn junction btbt leakage. State independent average gate leakage current of a logic gate 4 1.
Low power operation with the gate induced drain leakage gidl programming method can be obtained while maintaining the original advantages of mpi 1tdram. Standby supply voltage minimization for reliable nanoscale srams 127 goodness of the sampling distribution and the tail filter respectively. Optimal body bias selection for leakage improvement and. Large vds large depletion layer around drain part of channel surface already depleted lowered barrier vt reduced increased leakage current. Significant gateinduced drain leakage current can be detected in thin gate oxide mosfets at drain voltages much lower than the junction breakdown.
Cdsub and cssub are junction capacitances from drain to substrate and source to substrate. The model parameters of the bsim4 model can be divided into several groups. Iint is simply the transistor subthreshold leakage. Gateinduced drain leakage current of mosfet with junction doping. Gate induced drain leakage cmos latchup poly depletion effect. Insight into gateinduced drain leakage in silicon nanowire. Asymmetric gateinduced drain leakage and body leakage in. For nanometer devices, leakage current is dominated by subthreshold leakage, gate oxide tunneling leakage and reversebias pnjunction leakage. A mosfet is supposed to have a very high input impedance and any leakage would lower it.
The gidl at high negative gate bias is a factor of approximately 10 higher in the drainonbottom con. Lin et al gidl improvement for millisecond flash anneal mfla in dram application 1611 fig. Gateinduced drain leakage in fdsoi devices brown university. For nanometer devices, leakage current is dominated by subthreshold leakage, gateoxide tunneling leakage and reversebias pnjunction leakage. Gateinduced drain leakage gidl current is investigated in singlegate sg ultrathin body field effect transistor fet, symmetrical doublegate dg finfet, and asymmetrical dg metal oxide semiconductor field effect transistor mosfet devices. Extrapolation is an alternative way to avoid a full mc simulation. Sounds like what it says, which in mosfets is an unwanted leakage between the gate and drain terminals which is undesired for a couple of reasons that come to mind.
In a classic planar fieldeffect transistor with a long channel, the bottleneck in channel formation occurs far enough from the drain contact that it is. Gidl abbreviation stands for gateinduced drain leakage. Spectral density of induced gate noise at drain side. Gateinduced drain leakage, a leakage mechanism in mosfets due to large field effect in the drain junction.
Postirradiation gate stress pigs test performed and bv. Investigation of gateinduced drain leakage gidl current. Pdf analysis of gateinduced drain leakage mechanisms in. Leakage current and defect characterization of short channel. Measurement and analysis of gateinduced drain leakage in short. Gate leakage, gateinduced drain leakage gidl, and reversebiased diode leakage all contribute to the higher leakage power 2, but subthreshold leakage dominates for 0. Gidl is defined as gateinduced drain leakage somewhat frequently.
Hao3,a 1school of technical physics, xidian university, xian 710071, peoples republic of china. The gidl can be reduced by reducing shallow junction depth of drainextension. Behaviors of gate induced drain leakage stress in lightly. Gatetochannel parasitic capacitance minimization and. This study describes the dependence of the surface electric field to the junction depth of source drain extension, and the suppression of gate induced drain leakage gidl in fully depleted shallow junction gate overlapped source drain extension sde. Gateinduceddrainleakage current in 45nm cmos technology. The gidl current characteristics was analyzed and discussed in mosfets for the channel and junction doping dependences.
Gidl is defined as gate induced drain leakage somewhat frequently. The main model parameters are used to model the key physical effects in the dc and cv behavior of submicron mos devices at room temperature. Gate leakage behavior of sourcedraintogate nonoverlapped. Contribution of gate induced drain leakage to overall leakage. Gateinduced drain leakage gidl is another significant leakage mechanism, resulting due to the depletion at the drain surface below the gatedrain overlap region. 0 mosfet model, users manual, 2004, available for download at. Gidl abbreviation stands for gate induced drain leakage. However, gateinduced drain leakage gidl is a major concern at low power technology nodes because of bandtoband and trapassisted tunneling tat due. Gateinduced drain leakage gidl gidl is due to high field effect in the drain junction of an mos transistor. Gate induced drain leakage gidl gateinduced drain leakage gidl is caused by high field effect in the drain junction of mos transistors. Yfs is the transadmittance between drain current and gatesource voltage. This work studies the behavior of both gatetochannel capacitance cgc and sourcechanneldrainwell leakage in metalgatehigh. Gate induced drain leakage gidl current is investigated in single gate sg ultrathin body field effect transistor fet, symmetrical double gate dg finfet, and asymmetrical dg metal oxide semiconductor field effect transistor mosfet devices. Another gidl mechanism observed in the analyzed chip was mentioned in 3.
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