单粒子效应.PPT

1、单粒子效应（单粒子效应（Single Event Effect）SemiconductorDevicesCosmic rays Nuclear explosionsNuclear power plantAtmospheric radiationClassification 非破坏性单粒子效应非破坏性单粒子效应 (Soft Error)- 单粒子翻转（单粒子翻转（SEU: Single Event Upsets ）- 单粒子瞬变效应（单粒子瞬变效应（SET: Single Event Transient） 灾难性单粒子效应灾难性单粒子效应 (Hard Failure)- 单粒子锁定（单粒子锁定（

2、SEL: Single Event Latchup）- 单粒子烧毁（单粒子烧毁（SEB: Single Event Burnout）- 单粒子门断裂（单粒子门断裂（SEGR: Single Event Gate Rupture）Space applications: High-energy heavy ions Long range in Si, large LET, direct interaction High-energy protons (trapped, solar, cosmic) Direct / Indirect interaction through nuclear reac

3、tionsTerrestrial and avionic applications: High energy neutrons (cosmic ray byproducts) Indirect interaction through nuclear reactions Low energy neutrons (thermal) Indirect interaction via 10B nuclear reaction Alpha particles from radioactive decay of contaminants (from U, Th decay chains) in the c

4、hip/package/solder Short range in Si, small LET, direct interaction 1975 年美国发现通信卫星的数字电路年美国发现通信卫星的数字电路JK 触发器由于单个重触发器由于单个重核粒子的作用被触发。核粒子的作用被触发。 陆续发现陶瓷管壳所含的微量放射性同位素铀和钍放出的陆续发现陶瓷管壳所含的微量放射性同位素铀和钍放出的粒子以及宇宙射线中的高能中子、质子、电子等粒子以及宇宙射线中的高能中子、质子、电子等, 都能使集都能使集成电路产生单粒子效应。成电路产生单粒子效应。 进一步的模拟试验和在轨卫星的测试证实进一步的模拟试验和在轨卫星的测试

5、证实: 几乎所有的集成几乎所有的集成电路都能产生这种效应。电路都能产生这种效应。（19711986） Moores law is (self-)validated by reducing the device dimension over the years, by scaling down the minimum feature size of the CMOS technology node Single Event Effect (SEE): perturbation of the behavior of electronic (optoelectronic) devices, circ

6、uits and/or systems produced by a single ionizing particle. Charge generation Direct ionizing (Heavy ion) Indirect ionizing (Proton) Charge collection Prompt componentDrift/funneling (high field regions) Delayed componentDiffusion (low field regions) An ionizing particle generates a (dense) track of

7、 electron-hole pairs in semiconductors (Silicon) and dielectrics (SiO2); The number of generated carriers is proportional to the particle Linear Energy Transfer (LET) coefficient (MeVcm2/mg), i.e., the ionizing energy loss/unit path length (Energy / e-h pair: 3.6 eV in Si, 17 eV in SiO2) Under an ex

8、ternal electric field the two columns of carriers recombine and drift: many electrons and holes survive in Si, fewer in SiO2; Eventually, a net negative/positive charge can be collected at sensitive nodes: if this charge exceeds a threshold value (critical charge) an event may be observed affecting

9、the circuit.SEE tests are performed to evaluate the expected error/failure rate of the device/system in the specific operating environment (Space, HEP, Avionic, Sea level,) by using: Ion beams from accelerators Neutron beams Alpha sources Lasers A large number of devices operating under low intensit

10、y radiation (unaccelerated tests: the Rosetta experiment)The SEE sensitivity of each SEE type (SEU, SEL, SEB, ) in any particular device is evaluated by measuring the corresponding cross section vs LET: Cross section : (LET) = # Events / particle fluence (cm2)The error rates in operating condition i

11、s derived from cross sections and the features (nature of particles, corresponding fluxes, mission duration) of the actual environment Error rate = # errors / device dayaccelerated tests LETth is the minimum (threshold) LET to cause the specific SEE. The saturation cross section sat is approached at

12、 high LET values. The (LET) curve is obtained by measuring the cross section at a few LET values and fitting data with a Weibull curve.“School book” Example反应堆反应堆Single Event Effects in devices/circuits can be mitigated by using different strategies at different levels. For instance: Circuit level, by using specific technologies or processes for fabrication (such as epi-CMOS, SOI, additional capacitors in SRAM, or rad-hardened electronic components) Design level, by using ad hoc logic structures aiming to SEE immunity (such as S