Index. Cambridge University Press Fundamentals of Modern VLSI Devices: Second Edition Yuan Taur and Tak H. Ning.

Transcription

1 abrupt junction, 38 acceptor, 17 acceptor level, 18 9 access transistor, 477 8, 496 accumulation, 76 7 accumulation layer, 250 charge density, 250 resistance, sheet resistivity, 251 ac equivalent circuit, 356 ac model, 355 active power, 220 1, 264 5, activity factor of circuits, 265, 301 admittance matrix, 598 bipolar, 617 extrinsic, 601, 618 intrinsic, 309, 601 MOSFET, 309 alignment tolerance, 271 analog bipolar devices, 463 analytic potential drain-current model: DG MOSFET, 529, 532 surrounding-gate MOSFET, 536 anode, 130 antifuse, 500 apparent bandgap narrowing, 325 applied voltage, 32, 35, 40 arsenic, 18 Auger recombination, 34 avalanche breakdown, 122 avalanche hot electron injection, 503 avalanche hot hole injection, 503 avalanche multiplication, 123 ballistic MOSFET, 192 current model, 588 saturation current, 592 saturation voltage, 592 ballistic transport, 192 4, band bending: in MOS device, 77, 79 in polysilicon gate, 92 band diagram: bipolar transistor, 319 buried-channel MOSFET, 222 MOS capacitor, 73 5, 77, 79, 95 7 MOSFET, 179, 193, 589, 595 n-type silicon, 18 p n junction, 35 p-type silicon, 18 SiGe-base bipolar transistor, 391 Si SiGe n p diode, 614 Si-SiO 2,73 bandgap, 12 temperature coefficient, 12 band-to-band tunneling, 108, 125 barrier height, 109 barrier lowering, 114, 569 base: bipolar transistor, 318, 377 extrinsic, 350, 377 intrinsic, 350, 377 p n diode, 55 base charge, 341 base collector depletion layer delay time (see base collector transit time) base-collector diode, 322, 341, 385 base collector junction avalanche, 343, 367 base-collector transit time, 361, 452 base-conductivity modulation, 344 base current, 320, 330 base delay time, 361 base design, 377 base-emitter depletion layer delay time (see base emitter transit time) base-emitter transit time, 361, 451 base Gummel number, 330, 379 base junction depth, 320, 375 base resistance: extrinsic, 338, 605 intrinsic, 338, 605, 610 base series resistance (see base resistance) base sheet resistivity, 379 base transit time, 65, 384, 452 base transport factor, 368 base widening: at collector end, 345 at emitter end, 419 base width, 320, 375 base width modulation: by V BE, 419 by V BC, 340 basic equations for device operation, BESOI, 517

2 645 bias point trajectory in switching, 292 BiCMOS, 523 bipolar digital circuit: current-switch emitter-follower circuit, 442 delay components, 442 device structure, 429, 445 differential-current-switch circuit (differential ECL), 442 emitter-coupled logic (ECL), 441 layout, 445 bipolar inverter, 489 bipolar latch, 488 bipolar SRAM cell, 487 bipolar transistor: as an amplifier, 362, 463 as an on-off switch, 489 breakdown voltages, 366 device model, 352 device optimization, 447, 463 figures of merit, 437 forward-mode I V, 336 in saturation, 336, 491 multi-emitter, 488 n p n, 318, 429 optimization for digital circuits, 447 optimization for RF and analog applications, 463 p n p, 318 reverse-mode I V, 423 saturation currents, 369 scaling, 457, 463 scaling limits, 460, 468, 471 SiGe base, 389, 431 bird s beak, 279 bistable latch, 478, 486 bitline, 476 complementary, 478, 497 folded, 499 body effect, 157 8, 166 7, 307 coefficient, 157 8, 581 Boltzmann s constant, 14 Boltzmann s relations, 30 Boltzmann transport equation, 192 bonding (of silicon wafer), 517 boosted wordline, 497 boron, 18, 222 BOX (buried oxide of SOI), 520 boxlike doping profile, 380 breakdown voltage: bipolar transistor, 366 MOSFET, 200 p n junction, 122 BSIM compact model, 290 buffer stage, 297, 316 built-in electric field, 324 built-in potential, 37 bulk mobility, 23 4 buried-channel MOSFET, 222 burn in, 214 butterfly plot, 478 capacitance: depletion-layer, 41, 87 diffusion, 70, 359, 562 interconnect (wire), interface-trap, 104 intrinsic MOSFET, inversion layer, 87, 89, 173, 175, 593 junction, 41, 278 Miller, MOS, overlap, 279 capacitance-voltage characteristics: high-frequency, 88 9 low-frequency (quasi-static), 88 MOS, p n junction, 42 capture and emission at a trap center, 553 capture cross section, 102 field dependence, 102 for electrons, 101 for holes, 102 temperature dependence, 102 capture rate: electron, 553 hole, 554 carrier concentration: extrinsic, 20 1 intrinsic, 16 carrier confinement, 82, 234, 594 carrier transport, 23 7, carrier velocity at source, at drain, 192 cathode, 130 channel doping: counter-doping, 222, 231 extreme retrograde, 230 graphical interpretation, 232 halo (pocket), 233 high-low, 225 laterally nonuniform, 233 low-high, 229 nonuniform, nonuniform, band diagram, 233 profile design, 224 pulse-shaped (delta), 230 retrograde, 229 superhalo, 234 channel length, 149 definition, 242 effective, 243 extraction, extraction by C V, 252

3 646 channel length (cont.) metallurgical, 243 minimum, 183, 219 channel length bias, 244 channel length modulation, 159, 195 channel profile design, channel resistance, 196, 244 channel sheet resistivity, 196 short-channel device, 248 channel width, 150 charge-control analysis, 67, 361 charge erasure (in NVRAM): by Fowler-Nordheim tunneling, 507 by high-energy photons, 507 charge injection (in NVRAM): by avalanche hot electrons, 503 by channel hot electrons, 502 by tunneling, 505 source side, 512 charge in silicon dioxide: fixed charge, 99 interface trapped charge, 99 mobile ionic charge, 99 oxide trapped charge, 99 charge neutrality, 20, 79 charge-sheet model, 153 charge storage (in NVRAM): in floating gate, 505 in nanocrystals, 515 in silicon nitride, 505 charge to breakdown, 139 chemical-mechanical polish (CMP), 517, 538 circuit: bipolar, 352, 441 digital, 441 static CMOS, clock frequency, 220, 265 CMOS: advanced, circuit, 256 inverter, low power, 221, 300 NAND, , 304 NOR, 266 performance-power tradeoff, 221, process flow, scaling, scaling limit, 219 technology generations, 208, 220 technology trends, 220, 223 two-way NAND, 266, μm parameters for circuit model, 291 CMOS delay sensitivity: to body effect, 307 to channel length, 298 to device width, to gate oxide thickness, 298 to junction capacitance, to load capacitance, 297 to mobility, to n- and p-device width ratio, 296 to overlap capacitance, 302 to power supply voltage, to saturation velocity, to source-drain series resistance, 301, to temperature, 314 to threshold voltage, CMOS inverter, 256 bias point trajectory, 292 cascade, 290 cross coupled, 478 delay equation, 294 folded layout, 272 input capacitance, 294, 304 intrinsic delay, 294 layout, 272 maximum voltage gain, 260 noise margin, 259 noise margin, graphical interpretation, 262 noise margin, regenerative, 260 output capacitance, 294, 304 power-delay tradeoff, 300 pull down delay, 264, 293 pull up delay, 264, 293 switching resistance, transfer curve, waveform, 291 CMOS NAND, 266 bottom switching, 268, 305 delay sensitivity to body effect, 307 layout, 273 noise margin, 270 propagation delay, 306 switching resistance, 307 top switching, 268, 305 two-input, 268, 304 waveform, 305 collector, 318, 385 collector current, 320, 329, 352 collector current falloff, 343 collector design, 385 collector resistance, 338 common-base current gain, 334, 367 common-emitter current gain, 334 compensated semiconductor, 35 complementary metal-oxide-semiconductor (see CMOS) complementary MOSFET (see CMOS) concentration gradient, 27, 544 conduction band, 11 constant-field scaling, constant-source diffusion, 281 constant-voltage scaling, 209, 457 contact hole, 270

4 647 contact resistance, 276 contact resistivity: between silicide and metal, 277 between silicon and silicide, 121, 276 continuity equation, 33 control gate, 506 Coulomb scattering, 23, 170 screening, 171 covalent bond, 11, 17 critical field for velocity saturation, 187 cross-coupled latch, 478 cross-over current, 265, 292, 300 current at MOSFET threshold, 213 current crowding, 276 current density equation, 31 for electrons in p-type base, 328 for holes in n-type emitter, 329 current gain, 322, 334 common-base, 334 common-emitter, 334 fall off at high currents, 338, 343 fall off at low currents, 338, 347 MOSFET, 310 current injection from surface into bulk, 250, 275 current-voltage characteristics (see I V characteristics) cutoff frequency ( f T ), 437, 601, 617 dc equivalent circuit, 352 dc model, 352 Debye length, 30 deep emitter, 333 deep impurity level, 34 deep-trench isolation, 429 defect generation, 129 degeneracy, 13, 237, 594 degenerately doped silicon, 22 delay components: bipolar circuits, 442 CMOS circuits, 263, 293 delay equation: bipolar, 442 CMOS, 293 delay sensitivity (see CMOS delay sensitivity) delay time: emitter, 361, 451 base collector depletion-layer, 361, 452 base emitter depletion-layer, 361, 452 base, 361, 452 density of states, 12 4 effective, 16 2-D, 594 depletion: in MOS, 78 in p n junction, 38 depletion approximation, 38, 81 depletion charge, 82, 84 depletion layer, 38 depletion-layer capacitance: MOS device, 87 p n junction, 41 depletion-layer width: drain junction, 205, 576 gate-controlled, 82 maximum, 82 p n junction, 40 source junction, 576 depletion of polysilicon gate, 92 4 design points (for bipolar transistor), 447 device design: bipolar, 374 CMOS, 204, 217 device reliability, 137, 198 device scaling: bipolar, 457, 463 CMOS, DIBL, 177 dielectric boundary condition, 28 dielectric breakdown: 137 breakdown event, 137 breakdown field, 138 catastrophic breakdown, 137 charge to breakdown, 139 degradation rate, 140 progressive breakdown, 140 soft breakdown, 138 successive breakdown, 140 time to breakdown, 139 dielectric constant, 13 dielectric relaxation time, 34 diffused emitter, 320, 375 diffusion capacitance, 70, 359, 562 diffusion coefficient, 27 diffusion current, 27 diffusion equation, 281 diffusion length, 34, 53 digital circuit: bipolar, 441 CMOS, 256, 266 diode (see p n junction) diode equation, 46 diode leakage current, 57 direct tunneling, 128 discharge time: for narrow-base diode, 69 for wide-base diode, 68 discrete dopant effects (see dopant number fluctuations) donor, 17 donor level, 18 9 dopant, 17 8 dopant number fluctuations, in SRAM cell, 485 double-gate (DG) MOSFET, 529 planar, 535

5 648 double-gate (DG) MOSFET (cont.) vertical, 535 FinFET, 536 drain-current model, drain-current overshoot in SOI, 519 drain-current saturation, , drain-induced barrier lowering (see DIBL) DRAM, 3, DRAM cell, 496 planar capacitor, 497 read, 497 retention time, 500 scaling, 499 stacked capacitor, 497 trench capacitor, 497 write, 497 drift current, 23 drift-diffusion model, 192 drift transistor, 382 drift velocity, 23 dual n + /p + polysilicon gates, 223, 538 Early voltage, 340 Ebers-Moll model, 352 ECL, 440 ECL scaling, 457 EEPROM, 501, 507 effective channel length: definition, extraction, physical interpretation, effective density of states, 16 effective electric field, 169, 325 effective generation and recombination centers, 556 effective intrinsic-carrier concentration, 325 effective mass of electrons, 13 density of state, 237, 596 longitudinal, 13 transverse, 13 effective mobility, effective vertical field, 169 eigenfunction, orthogonality, 586 Einstein relations, 27, 543 electric field, 23, 28 at silicon surface, 76, 236 in intrinsic base, 381 in quasi-neutral region, 323, 381 normal, 29, 584 tangential, 29, 584 electromagnetic wave, 288 electromigration, 286 electron affinity, 73 electron diffusion coefficient, 27 electron-hole pair generation, 34, 122 electron mobility, 23, 170 electron trap, 101 electrostatic potential, 28, 177 emission rate: electron, 554 hole, 554 emitter, 55, 318, 331, 374 emitter-base diode, 320, 350 emitter-coupled logic (see ECL) emitter current, 334, 352 emitter current crowding, 328, 612 emitter delay time, 361, 451 emitter depth variation, 410 emitter design, 374 emitter diffusion capacitance, 359 emitter Gummel number, 332 emitter injection efficiency, 368 emitter junction depth, 320, 375 emitter series resistance, 338, 375, 605 emitter stripe width, 459, 607, 610 energy band (see band diagram) energy gap (see bandgap) energy-momentum relationship, 13, 594 epitaxially grown base, 380, 467 EPROM, 501 equipartition of energy, 545 equivalent circuit: bipolar, 352 MOS capacitor, 87 MOSFET, 167, 245, 309 equivalent oxide charge per unit area, 104 erase, 507 excess minority carriers: in the base, 64, 359 in the emitter, 359 extrinsic base, 339, 377 extrinsic-base resistance, 338, 605 extrinsic Debye length, 30 1 extrinsic silicon, 17 f max : bipolar, 620 MOSFET, 310, 603 f T : bipolar, 619 MOSFET, 310, 602 fall time, 263, 291 FAMOS, 511 fan in, 266, 307 fan out, 293 feedforward, 303 Fermi-Dirac distribution function, 14 Fermi integral, 590 Fermi level, 14 16, 20 2, 32 local, 32 Fermi potential, 29, 31 field crowding, 136 field-dependent mobility, 169 field-effect transistor, 148

6 649 field emission, 119 field oxide, 149, FinFET, 536 fixed oxide charge, 101 Flash, 4, 507 Flash memory arrays, 507 bitline, 508 erase, 508 NAND, 509 NOR, 509 over erasure, 509 read, 508 wordline, 508 write, 508 flat-band condition, 74, 92 flat-band voltage, 74, 91 floating-body effect, floating gate NVRAM cell, 511 coupling factor, 506 select gate, 512 sidewall floating gate, 512 split gate, 513 stacked gate, 513 folded bitline, 499 folded layout, 272 forward-active mode, 336, 355, 442 forward bias, 40 forward current gain, 352 forward transit time, 360, 450 Fowler-Nordheim tunneling, 127, 505 free electron level, 72 4 freeze-out, 21 fully-depleted SOI, 518, 520 fully velocity saturated current, 188 fuse, 500 GaAs HBT, 469 gamma function, 16, 597 gate-all-around MOSFET, 536 gate bias (voltage) equation, 76, 84 gate capacitance: to channel, 173 to source-drain, to substrate, 172 gate-controlled depletion charge, 180 gated diode, 94, 135 gate depletion width, 82 maximum, 82, 183, 218 gate-induced drain leakage (see GIDL) gate length, gate overdrive, 189 gate oxide, 73 breakdown, 137 limit, 219 gate resistance, gate-to-source/drain overlap region, gate tunneling current, gate workfunction, 74, 91 effect on threshold voltage, 221 effect on channel profile design, Gaussian doping profile, 227, 380 Gauss s law, 28, 80 Ge in base: constant distribution, 406 linearly graded distribution, 390 optimal distribution, 414 trapezoidal distribution, 401 Ge in emitter, 396 generalized scale length, 184, 582 generalized scaling, generation and recombination centers, 107, 553 generation rate (see emission rate) generation-recombination, 34, 553 GIDL, 136 graded base bandgap, 390 graded doping profile, 382 gradual channel approximation, 150, 160, 189, 531 graphical representation of nonuniform channel doping, 232 ground-plane MOSFET, 230, 232 Gummel number: base, 330 emitter, 332 Gummel plot, 61, 337 halo doping, HBT, 390, 426, 469 heat dissipation, 209 heavily-doped silicon, 22 3 heavy doping effects, 325 heterojunction bipolar transistor (see HBT) high-field effect: in diode, 122 in gated diode, 135 in oxide, 127 high-field region, 192, 197 high field transport, 186, 192 high-frequency capacitance, 88 9 high-κ (permittivity) dielectric, 184 high-level injection, 47, 51, 325, 347 high-low doping profile, 225 history effect in SOI MOSFET, 519 hole diffusion coefficient, 27 hole mobility, 24, 171 hole trap, 102 hot-carrier effect: channel hot electron, 198 channel hot hole, 199 substrate hot electron, 199 hot carriers, 133, 192, 197 hot-electron emission probability, 134 hot-electron injection, 133, 502 hot-electron reliability, 192, 217 hot hole injection, 199 hybrid-π model, 357

7 650 ideal current-voltage characteristics, 327 ideal diode, 61 ideality factor: collector current, 337, 422 diode current, 61 i-layer, 43 image-force-induced barrier lowering, 133, 569 impact ionization, 122 impact ionization rate, 123 implanted emitter, 318, 374 implanted polysilicon gate, 91 impurity ionization energy, 19 impurity energy level, 18 impurity scattering, 23, 170 input capacitance, 294 input resistance, 357 input voltage, 257, 308, 441 input waveform, 263, 291 integrated base dose, 379 interconnect capacitance: fringing field, parallel-plate, wire-to-wire, interconnect RC delay: global wires, local wires, interconnect resistance, 286 interconnect scaling, interdigitated layout, 282 interface-state generation, 129 interface states, 99 interface-trap capacitance, 104 interface trapped charge, 99 interface traps, 99 inter-poly oxide, 506 interstitial, 18 intrinsic base, 350, 378 intrinsic-base dopant distribution, 380 intrinsic-base resistance, 338, 605, 610 intrinsic capacitance of MOSFET, intrinsic carrier concentration, 16 intrinsic Fermi level, 16 intrinsic potential, 28 intrinsic inverter delay, 294 intrinsic silicon, 16 inversion, 78 strong, 78 weak, 78 inversion layer: capacitance, 89, 173 charge, 83 quantum effect, thickness, 83, 239 inverter: propagation delay, switching waveform, 291 transfer curve, ion implantation: dose, 227 Gaussian profile, straggle, 227 ionization energy, isolation, 148 9, 429, 538 ITRS, 4 I V characteristics: ballistic MOSFET, 591 MOSFET, 159, 162, 186 nmosfet, 258, 292 n p n, 327, 336, 337 pmosfet, 258, 292 p n junction, 51 Schottky barrier diode, 115 junction breakdown, 122, 366 junction capacitance, 42, 278, junction depth, 149, junction isolation, 429 kinetic energy of electrons, 13, 545, 594 kink effect in SOI, 518 Kirk effect, 345 Laplace equation, 575 large-signal analysis, 352 latch up, 538 lateral field, 189 lateral source-drain doping gradient, lateral transistor, 318 layout: bipolar transistor, 445 CMOS inverter, 272 folded, 272 groundrules, 271 MOSFET, 271 two-way NAND, 273 leakage current, 57 lifetime, 52, 557 lightly-doped drain (LDD), 199, 201 linearly-extrapolated threshold voltage, 175, 291 linearly graded bandgap, 390 linear region, lithography, 3 load capacitance, 290, 294, 297, 441 load resistor, 441 logic gate, 266, 290, 441 logic swing, 441 long-channel MOSFET (see MOSFET) low-frequency capacitance, 88 low-high doping profile, low-high-low profile, 231 low-level injection, 47 low-power CMOS, 221 low-temperature CMOS, lucky electrons, 134

8 651 majority carrier, 21, 34, 37 majority-carrier response time (see dielectric relaxation time) manufacturing tolerance (see process tolerances) Matthiessen s rule, 23 maximum available gain, 598 maximum electric field, 40 maximum gate depletion width, 82, 183, 218 maximum oscillation frequency ( f max ), 440, 603, 617 maximum oxide field, Maxwell-Boltzmann statistics, Maxwell equations, 27 mean free path, 134, 543 metallurgical channel length, metal-oxide-semiconductor (see MOS) metal-silicon contact, 108 metal work function, 74 microprocessor, 3 midgap work-function gate, 223 Miller effect, minimum channel length, 183, 219 bulk MOSFET, 183 DG MOSFET, 534 FD-SOI MOSFET, 521 with high-κ gate dielectric, 185 minimum feature size, 2 3, 271 minimum overlap, 280 minimum threshold voltage, 214, 220 minority carriers, 21, 34, 37 minority-carrier current, 54 minority-carrier diffusion length, 34, 62 minority-carrier lifetime, 34, 62 electrons, 52, 558 holes, 557 minority-carrier mobility, 62 MNOS: reversed source-drain mode, 514 two-bits per cell, 515 mobile ions, 101 mobility: bulk, 24 effective, 169 electron, 24 hole, 24 minority carrier, 62 MOSFET channel, temperature dependence, 23, 172 universal, vertical field dependence, MOS: band diagram, 73 5, 77, 84, 92 capacitor, 72 C V characteristics, equivalent circuit, 87 under nonequilibrium, 94 8 MOSFET: admittance matrix, extrinsic, 602 admittance matrix, intrinsic, 309 body effect, 166 breakdown, 200 buried channel, 222 channel mobility, 169 common-source RF circuit, 308 current gain, extrinsic, 603 current gain, intrinsic, 310 drain current model, 149 effective channel length, 242 equipotential contours, 178 intrinsic capacitance, 172 I V characteristics, 155 linear region characteristics, 156 output conductance, 255, 308 p-channel, 162 saturation region characteristics, 158 scale length, 183 4, 582 scaling, 204 short-channel, 175 small-signal equivalent circuit, 309, 602 subthreshold characteristics, 163 threshold voltage, 156, 212 transconductance, extrinsic, 602 transconductance, intrinsic, 192, 308 unity-current-gain frequency, extrinsic, 603 unity-current-gain frequency, intrinsic, 310 unity-power-gain frequency, 604 voltage gain, 310 multiple-gate (MG) MOSFET: omega-gate, 536 pi-gate, 536 quadruple-gate, 536 surrounding-gate, 536 triple-gate, 536 multiplication factor, 123, 367, 573 NAND EEPROM, 510 NAND gates, 266 two-way, 268, 304 nanowire MOSFET, 536 narrow-base diode, 57 n-channel MOSFET (see MOSFET) negative bias temperature instability (NBTI), 199 net recombination rate, 556 noise margin, 259, 269, 482 CMOS inverter, 259 CMOS NAND, 269 SRAM cell, 482 nonequilibrium transport, 192 non-ideal base current, 347 non-scaling factors: primary, 210 secondary, 211 non-transparent emitter (see deep emitter) non-transparent polysilicon emitter, 400 nonuniform channel doping,

9 652 nonvolatile memory: cell, 511, 514 charge injection, 502 charge storage, 505 data retention time, 501, 510 endurance, 510 erasure, 507 programming, 508 read, 508 write, 508 nonvolatile random access memory (NVRAM), 500 NOR: EEPROM, 509 logic gate, 266 n p n transistor (see bipolar transistor) n-type silicon, 17 n-well, 257, 538 off current, 169, 210, 213 requirement, 214 ohmic contact, 120, 276 Ohm s law, 24 on current, 214, 263, 295 one-sided junction, 42 optical phonon, 26 output capacitance, 294 output conductance, 195, 255, 308 output resistance, 357 output voltage, 257, 260, 310, 441 over erasure, 509 overlap capacitance, 279, 302 oxide (see silicon dioxide) oxide charge, 98, 103 oxide field, 76, 128 maximum, 219 oxide trapped charge, 101 packing density, 1 Pao-Sah s double integral, 153 parabolic band, 13 parabolic region, 157 parallel-plate capacitance, 283 parasitic capacitance, 277, 356 parasitic resistance, 196, 245, 274, 301, 338, 356 partially-depleted SOI, 518 p-channel MOSFET, 162 pedestal collector, 431 performance factor of bipolar circuits: analog, 463 digital, 441 performance factor of CMOS circuits, 256 advanced, 307 low temperature, 312 SiGe, 311 SOI, 519 permittivity: Si, 28 SiO 2,75 vacuum, 28 phonon scattering, 23, 169 phosphorus, 18 physical properties of Si and SiO 2,13 pinch-off, 159 current, 158 voltage, 158 p i n diode, 43 Planck s constant, 12 p n diode: breakdown, 122 capacitance, 41 depletion approximation, 38 forward-biased, 40 I V characteristics, 51 leakage, 57 reverse-biased, 40 saturation current, 57 p n junction, 35 pn product, 17 p n p transistor (see bipolar transistor) pocket doping, 233 Poisson s equation, 27 polysige emitter, 400 polysilicon base contact, 430 polysilicon emitter, 321, 333, 430 transparent, 333 non-transparent, 400 polysilicon gate, 91 depletion, 91 4 depletion capacitance, 93 dual n + /p +, 5, 538 potential barrier, power-delay product, 206, 209, 300 power density, 206, 209, 462 power dissipation: active, 220, 265, 299 cross-over current, 265 standby, 213 power gain, 598 power supply voltage, 208, , 300 power vs. delay trade-off: bipolar circuits, 453 CMOS circuits, 299 principle of detailed balance, 554 process flow: bipolar, 542 CMOS, 538 process tolerances, 212 PROM, 500 propagation delay, 289 CMOS inverter chain, ECL, 440 two-way NAND, p-type silicon, 18 pull-down delay, 264, 293

10 653 pull-up delay, 264, 293 punch-through in short-channel MOSFET, 179 quantum confinement, 234, 594 quantum effect on threshold voltage, 234, 237 quasi-fermi level, 32 quasi-fermi potential, 33 quasineutrality, 47 quasineutral region, 37, 320 quasistatic assumption, 265 quasistatic C V curve, 86 radiative process, 34 random access memory (RAM), 476 RC delay: interconnect, 287 MOSFET gate, 282 reach-through, 318, 385 read, 480, 497, 508 reciprocity, 353 recombination, 34, 553 rectifier, 41 refresh, 496 resistivity of aluminum, 287 resistivity of bulk silicon, 25 retention time, 89 DRAM data, 500 NVRAM, 501 retrograde doping profile, 229, 388 extreme, 230 reverse bias, 40 reverse current, 352 reverse current gain, 352 reverse Early effect, 419 RF (radio-frequency) circuits, 308 Richardson s constant, 118 ring oscillator, 290, 440 rise time, 289 Sah Noyce Shockley diode equation, 60, 561 saturated base current density, 332 saturated collector current density, 330 saturation current of MOSFET, 158, 188, 191 2, 592 saturation currents in bipolar, 369 saturation point, 160 1, 189 saturation region, 336 saturation velocity, 26, 186 saturation voltage of MOSFET, 158, 188, 191, 592 scale length: bulk MOSFET, double-gate MOSFET, 533 surrounding-gate MOSFET, 537 scale length model: generalized, 582 high-κ gate dielectric, 184 one region, 183 two region, 582 three region, 584 scaling: bipolar, 457 constant-field, 204 constant-voltage, 209 generalized, 207 ideal, 204 interconnect, 284 MOSFET, scaling limit: bipolar, 460 bulk MOSFET, 219 DG MOSFET, 534 FD-SOI MOSFET, 522 with high-κ gate dielectric, 219 scaling rules: bipolar, 458 interconnect, 286 MOSFET constant field, 206 MOSFET generalized, 209 scattering: interface, 169 ionized impurity, 23 phonon, 23 surface roughness, 170 scattering theory of MOSFET, 192 Schottky barrier: barrier height, 109 effect of electric field, 114 for electrons, 109 for holes, 114 measured barrier heights, 113 Schottky barrier diode (Schottky diode), 108 Schottky barrier emission: field emission, 119 thermionic emission, 116 thermionic-field emission, 119 Schrödinger equation, 235 self-aligned base contact, 430 self-aligned silicide, 276 sense amplifier, 477, 498 series resistance, 196, 245, 301 shallow emitter, 331 shallow impurities, 18 shallow trench isolation, 5, 538 sheet resistance, 25 sheet resistivity, 25 aluminum, 274 base, 379 channel, 196 gate, 280 silicide, 276 source drain, 276 thin film, 25 shift and ratio (S&R) method, 247 Shockley diode current equation, 54

11 654 Shockley diode equation, 50 Shockley-Read recombination, 34, 553 short-channel effect, 176, 575 DIBL, 177 extreme retrograde doped MOSFET, 581 ground-plane MOSFET, 581 substrate sensitivity, 581 subthreshold current slope, 580 threshold voltage (V t ) rolloff, 176, 182 short-channel MOSFET, 175 short-circuit current, 265 SiGe base, 389, 431 SiGe-base bipolar transistor: comparison with GaAs HBT, 469 heterojunction nature, 426 SiGe MOSFET, 311 silicide, 276, 538 silicon (Si): bandgap, 12 covalent bonds, 11 degenerate, 22 dielectric constant, 13 energy bands, 12, 18 extrinsic, 17 intrinsic, 16 lattice constant, 13 n-type, 17 permittivity, 28 physical properties, 13 polycrystalline, 91 p-type, 17 resistivity, 25 solid solubility, 20 thermal conductivity, 13 silicon dioxide: band diagram, 73 breakdown event, 137 breakdown field, 138 charge, 98 charge to breakdown, 139 damage, 105 defect generation, 129 defects, 129 dielectric constant, 13 permittivity, 75 physical properties, 13 successive breakdown, 137 time to breakdown, 139 trapped charge, 99, 101 tunneling, 127 silicon-germanium base (see SiGe base) silicon-on-insulator (SOI), 517 silicon-rich oxide, 512 SIMOX, 517 Si SiGe n p diode, 614 Si-SiO 2 interface, 99 Si-SiO 2 system, 73, 98 slow states, 105 small-signal analysis, 308, 356, 438 Smart-Cut, 517 sodium ion contamination, 101 soft error, 518 SOI bipolar, 523 SOI CMOS, 517 solid solubility, 20 source and drain junction depth, 183, 274 source-drain series resistance, 196, 245, 274 source-drain sheet resistivity, 276 source starvation, 593 source (thermal) injection velocity, 194 source-to-body potential, 268, 305 source-to-drain current, 149 source-to-drain current at threshold, 213 space-charge region (space-charge layer), 38 space-charge region current, 553 specific contact resistivity, 121, 276 SPICE, 290 spin, 13 split C V measurement, spreading resistance, 275 SRAM (static random access memory), 477 SRAM cell: bipolar, 487 depletion load, 487 device sizing, 482 full CMOS, 478 read, 480 resistor load, 487 scaling, 485 static noise margin, 482 TFT load, 487 write, 481 standardized signal, 290 standby power, 213, 221, 301 static CMOS circuit, 256 static power dissipation, 213 step input, 263 step profile, 225, 229 storage capacitor, 496 stored minority-carrier charge (see excess minority carriers) straggle, 227 strained-silicon MOSFET, 311 strong inversion, 78, 80 sub-band, 235 energy level, subcollector, 318, 339, 385 substitutional, 18 substrate bias, 166 forward, 207, 231 reverse, 168, 207 substrate current, substrate sensitivity, 166 subthreshold characteristics, subthreshold current, 165, 210

12 655 subthreshold non-scaling, 210 subthreshold slope, 165, 580 surface-channel MOSFET, 223 surface electric field, 76 at threshold, 232 surface generation-recombination center, 107 surface potential, 76 effect of oxide charge, 103 surface potential based compact model, 155 surface recombination velocity, 331 surface scattering, 169 surface state density, 100 surface states, 99 surrounding-gate MOSFET, 536 switch current, 441 switching delay, 264, 293, 442 switching energy, 300 switching power, 299 switching resistance, 294 inverter, 294 two-way NAND, 307 switching trajectory, 292 switching waveform: abrupt input transition, 263 linear chain of inverters, 291 two-way NAND, 305 symbols: bipolar transistor, 319 nmosfet, 257 pmosfet, 257 temperature dependence: CMOS performance, 314 Fermi level, 22 mobility, 23 off-current, 213 threshold voltage, 168 thermal energy, 14 thermal velocity, 543 thermal voltage, 210 thermionic emission, 116 thermionic-field emission, 119 threshold voltage: design, 213, 219 discrete dopant effect, 239 linearly-extrapolated, 175 long-channel MOSFET, 156 minimum, 214 multiple, 221 nonuniformly-doped MOSFET, 224 performance sensitivity, 215 quantum correction, 238 requirement, 213 roll-off, 176 short-channel MOSFET, 182 substrate-bias dependence, 166 temperature dependence, 167 tolerances, 218 work-function effect, 221 2ψ B defined, 156 time-dependent analysis, 361 time to breakdown, 139 t-inversion (t inv ), 175, 239 transconductance: bipolar, 357 large signal, 295, 299 linear, 175 MOSFET, 308 saturation, 192 transfer characteristics: inverter, 259 two-way NAND, 269 transfer device, 496, 500 transfer length, 276 transfer ratio (DRAM read), 498 transistor equation, 365 transit time: base, 65, 384, 452 base-collector, 361, 452 base-emitter, 361, 451 emitter, 361, 451 forward, 360, 450 MOSFET, 265 transmission coefficient (in tunneling), 121 transmission line delay, 288 transmission line model, 276 transparent emitter (see shallow emitter) trap-assisted tunneling: bulk-trap-assisted, 130 interface-trap-assisted, 131 into an electron trap, 129 traps: Coulomb-attractive, 102 Coulomb-repulsive, 102 electron, 102 hole, 102 neutral, 102 trench isolation, 429 triangular potential well, 236, 595 triode region (see linear region) tunneling: band-to-band, 108, 125 direct, 128 Fowler-Nordheim, 127 into silicon dioxide, 127 through silicon dioxide, 127, 219 tunneling current, 126, 128 tunnel oxide, 506 silicon rich, 512 two-dimensional effect, 177 two-dimensional electron gas (2DEG), 235 two-port network, 598

13 656 two-way NAND: propagation delay, 306 switching waveform, 305 top and bottom switching, 268, 304 transfer curves, 269 uniformly-doped channel, 223 unilateral power gain, 599 unity current gain frequency (f T ): bipolar, 619 MOSFET, 309, 602 unity power-gain frequency: bipolar, 620 MOSFET, 603 universal mobility behavior, 169 vacuum level (see free electron level) valence band, 11 V BE reference, 422 velocity-field relationship, 26, 187, 190 velocity of light, velocity overshoot, 192 velocity saturation, 26, 186 current limit, 188 velocity saturation model: n = 1, 187 n =, 190 piecewise, 191 vertical transistor, 318 very-large-scale-integration (VLSI), 1 3 voltage gain, 310, 464 volume inversion, 530, 533 weak inversion, 78 Webster effect, 325 wide-base diode, 57 wide-gap emitter, 426, 470 wide-gap-emitter HBT, 426, 469 wire capacitance, 283 wire resistance, 286 wordline, 477 boosted, 497 work function, 74 metal, 74 midgap, 223 n + polysilicon, 91 n-type silicon, 78 p + polysilicon, 91 p-type silicon, 74 write, 481, 497, 508 write disturb, 504