Pdf analysis of gateinduced drain leakage mechanisms in. 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. Gidl abbreviation stands for gate induced drain leakage. What is the abbreviation for gateinduced drain leakage. Contribution of gate induced drain leakage to overall. Measured reductions in gidl current for sg and dg thinbody devices are reported for the first time. One of the definitions of gidl is gate induced drain leakage. 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. The meaning of gidl abbreviation is gate induced drain leakage. Lin et al gidl improvement for millisecond flash anneal mfla in dram application 1611 fig. Large vds large depletion layer around drain part of channel surface already depleted lowered barrier vt reduced increased leakage current.
There are still other leakage components, like gate induced drain leakage gidl and punchthrough current, however those ones. The gidl can be reduced by reducing shallow junction depth of drain extension. Gidl gateinduced drain leakage in technology, it etc. Gate induced drain leakage gidl gidl is due to high field effect in the drain junction of an mos transistor. In contrast, the body leakage at low gate bias is lower in the drainonbottom con. 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. Another gidl mechanism observed in the analyzed chip was mentioned in 3. 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. Aug 24, 2010 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.
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. Gidl is defined as gate induced drain leakage somewhat frequently. The drain current when the transistor is biased in its off state. 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. State independent average gate leakage current of a logic gate 4 1. However, gateinduced drain leakage gidl is a major concern at low power technology nodes because of bandtoband and trapassisted tunneling tat due to reduced bandgap. One leakage current mechanism that has been mostly neglected until recently is called the gate induced drain leakage gidl.
Gate induced drain leakage an overview sciencedirect. Stronger gidl temperature dependence in fd mosfets compared to tfets, confirms the. As shown in figure 1a maximum gate oxide leakage current flows when the transistor is turned on and maximum potential difference between gate tosource and gate to drain terminals. Gidl abbreviation stands for gateinduced drain leakage. L and complimentary metaloxide semiconductor cmos microcircuit technologies. It is known that gidl current is attributed to tunneling taking place in the deepdepleted drain region underneath the gate oxide. Drain induced barrier lowering dibl is the effect the drain voltage on the output conductance and measured threshold voltage. Gate leakage increases with temperature at about 2x100oc.
Asymmetric gateinduced drain leakage and body leakage in. Impact of gate induced drain leakage on overall leakage of. Vg gate induced drain leakage gidl in gate drain overlap region, in accumulation bias condition draws great attention 1 2 345, in addition to subthreshold. Us7359271b2 gate induced drain leakage current reduction. Gidl in tfets can be accurately modeled by considering the gated tunneling junction only, whereas gidl in mosfets requires the addition of a field effect diode fed component. 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. This effect occurs in devices where only the gate length is reduced without properly scaling the other dimensions. 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. Gate induced drain leakage gidl b s p vgs gate induced drain leakage gidl has been investigated to optimize fin fieldeffect transistors finfets for ultralowpower ulp applications.
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. Gateinduceddrainleakage current in 45nm cmos technology. High field induced stress suppression of gidl effects in tfts. For nanometer devices, leakage current is dominated by subthreshold leakage, gate oxide tunneling leakage and reversebias pnjunction leakage. Note i dleak may have contributions from channel offstate current, gate induced drain leakage, and drain to gate tunneling currents. However, gateinduced drain leakage components and mechanisms are dominant compared to all the other leakage mechanisms in high threshold voltage devices. When the channel length shrinks, the gate control over the channel reduces due to various sces, such as dibl, charge sharing, and subsurface punch through 3. Drain leakage and hot carrier reliability characteristics of. The use of silicongermanium as a channel material in highk metal gate first pfet technologies of 32nm and beyond has been widely accepted for high performance and low power applications. An optimum substrate doping concentration in the range of 1 5. Those three major leakage current mechanisms are illustrated in fig. Stronger gidl temperature dependence in fd mosfets compared to. Gate induced drain leakage can be abbreviated as gidl. In this paper, a mechanism of 64mb dram circuit degradation was described.
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. This happens when the applied voltage vgs is less than the threshold voltage vth of the transistor, i. The tunnelingbased leakage currents caused where the gate overlaps the drain is referred to as the gateinduced drain leakage gidl. Subthreshold leakage isub the subthreshold leakage current is the drain tosource leakage current when the transistor is in the off mode. Highlights gate induced drain leakage gidl current in tfets is higher than that in fd mosfets, especially under low drain bias. The influence of the extension doping conditions on gateinduced drain leakage gidl has been investigated to optimize fin fieldeffect transistors finfets for ultralowpower ulp applications.
Impact of junction depth and abruptness on the activation and. The leakage in the drain region is a crucial issue for scaling of the mosfet towards the deep submicron regime. There has been considerable interest in the study of the mechanisms responsible for gidl current 1, 2, 3, 4. What is the abbreviation for gate induced drain leakage. Gate induced drain leakage, a leakage mechanism in mosfets due to large field effect in the drain junction. The gidl at high negative gate bias is a factor of approximately 10 higher in the drainonbottom con. The problem was an abnormally high leakage current at the field oxide edges of locos isolation. Gate induced drain leakage gidl is an unwanted shortchannel effect that occurs at higher drain biases in an overdriven off state of a transistor. 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. Effect of new electric field on the old pn depletion region holes tunnel to substrate from drain. Gateinduced drain leakage gidl gidl is due to high field effect in the drain junction of an mos transistor. Highlights gateinduced drain leakage gidl current in tfets is higher than that in fd mosfets, especially under low drain bias. The reasons are i the subthreshold conduction increases exponentially due to the threshold voltage reduction.
Praveen meduri ee478 presentation on gate induced drain leakage current. During a standby mode, a voltage supplied to a plurality of circuits is reduced so as to reduce gate induced leakage gidl current associated with said. A mosfet is supposed to have a very high input impedance and any leakage would lower it. Analysis of gate leakage current in ip3 sram bitcell under. Gateinduced drain leakage how is gateinduced drain. The asymmetric source drain mosfet has a lightlydoped drain for a low electric field. It is observed as a variation of the measured threshold voltage with reduced gate length. Effect of fin shape on gidl and subthreshold leakage currents. An increased gidl for a smaller fin thickness and a dependence on the implanted ion species, i. Gate induced drain leakage gidl is another significant leakage mechanism, resulting due to the depletion at the drain surface below the gate drain overlap region. Since the channel must be depleted of charge before inversion takes place, any help on depletion process will reduce vt. As a result, the gate induced drain leakage gidl current is reduced, and the hot carrier reliability is improved. Gateinduced drain leakage, a leakage mechanism in mosfets due to large field effect in the drain junction.
For low power applications, gate induced drain leakage gidl in gate drain overlap region, in accumulation bias condition draws great attention 1 2 345, in addition to subthreshold. Analysis of total doseinduced dark current in cmos image sensors from interface state and trapped charge density measurements. Generic interface definition language, an extension to corba idl. Insight into gateinduced drain leakage in silicon nanowire. Mechanism analysis of gateinduced drain leakage in offstate. Here, we have studied the gidl dependence on temperature as well as drain and substrate bias. Us7359271b2 gate induced drain leakage current reduction by.
This is a measure of gate leakage of a logic gate during its steady state. Investigation of gateinduced drain leakage gidl current in. Because of the relatively large thickness of the sti oxide, gate leakage current can be neglected. 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. 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. Junction depth dependence of the gate induced drain leakage. 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. The gate induced drain leakage gidl current is recognized as a major drain leakage phenomenon in offstate mosfets. Impact of extension implantation conditions of fin field. Join date nov 2007 posts 263 helped 21 21 points 2,981 level 12. Mechanism analysis of gateinduced drain leakage in off.
Figure 1a maximum gate oxide leakage current flows when the transistor is turned on and maxi mum potential difference between gate tosource and gate to drain terminals. A new dualthreshold technique for leakage reduction in 65nm. The gateinduced drain leakage gidl current is recognized as a major drain leakage phenomenon in offstate mosfets. Sep 11, 20 the principal difference between asymmetric and symmetric source drain mosfets is the drain side structure. 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. 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. A new technique for leakage reduction in 65 nm footerless. Leakage current mechanisms and leakage reduction techniques.
Sces include drain induced barrier lowering dibl, threshold voltage roll off problem, increase in gate leakage current, mobility degradation, etc. Pdf gateinduced drain leakage gidl improvement for. Dec 10, 2016 praveen meduri ee478 presentation on gate induced drain leakage current. A semiconductor integrated circuit device and method for reducing gate induced leakage current associated with circuits of the semiconductor electrical device, such as a semiconductor integrated circuit memory device. 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. For nanometer devices, leakage current is dominated by subthreshold leakage, gateoxide tunneling leakage and reversebias pnjunction leakage. Gl is a trappedcharge phenomenon found in plastic encapsulated bipolari. Asymmetric gateinduced drain leakage and body leakage. Investigation of gateinduced drain leakage gidl current. Under the application of strong vertical and longitudinal fields, the drain region in the overlap region may go into deep depletion as the vertical field tends to invert the region and the longitudinal field sweeps the inverted carriers holes for n channel devices. 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. 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.
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