radiation effects in semiconductor materials and devices for space

RADIATION EFFECTS INSEMICONDUCTOR MATERIALSAND DEVICES FOR SPACEAPPLICATIONSCor Claeys and Eddy Simoen© IMEC 2010

OUTLINEIntroductionTotal Dose Effects in thin gate oxidesRILC, RSB, SEGR, Latent DamageMicrodose EffectsDevice Scaling▸ Bulk & SOI FinFETs▸ Ge devicesConclusions© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 2

INTRODUCTIONCOTS important for Space ApplicationsAdvanced CMOS TechnologiesReduced Gate DielectricsAlternative Substrates: SOI, sSOI, Ge, sGe, GOI...Advanced Process Modules:High-κ Dielectrics, Strain Engineering, …Alternative Device ConceptsDouble gate, FinFETs, GAA, Nanowires, …Impact on Radiation Hardening ?© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 3

IONIZING AND DISPLACEMENTDAMAGE = F(PARTICLE, ENERGY)The energy loss rate throughionization and excitation ofthe Si lattice (LET) and throughatomic displacements (NIEL)versus proton energy. Only afraction of 1% of the energyloss goes into displacementprocesses© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 5

IONIZING DAMAGE IN MOSGate: carries away the chargeOxidegate++n-Si--+p-type siliconSilicon: electron-hole pairs canrecombine in the neutral bulkIn case of a p-n junction, theelectric field separates electronsand holes. This leads to atransient charging phenomenonSingle Event Upsets (SEU)Permanent ionizing damage onlyin the dielectric layers: gate oxide,isolation or field oxide and buriedoxide (SOI)© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 6

STANDARD TOTAL DOSE RADIATIONEFFECTSN ot & N it© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 7

GATE OXIDE SCALINGGate current before (full lines) and after (dashed lines) a 67 MeV 2.9x10 12 p/cm 2proton irradiation for a 0.09 µm n- and 0.08 µm p-MOSFET with 2.0 nm oxide.10 -9 -1.5 -1 -0.5 0 0.5 1 1.5Gate Current (A)10 -1010 -1110 -12L=0.09 µm n-MOS; L=0.08 µm p-MOSV DS=-0.025 Vn-MOSp-MOSfloatingV DS=0.025 Vn-MOSp-MOS10 -13t ox=2 nmGate Voltage (V)© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 8

DEVICE SCALING∆V t ~ t ox2Good TID resistance of the Gate oxideRadiation effects will be caused by parasitic conductionrelated toShallow Trench Isolation oxide: BulkBuried oxide for SOI devicesOccurrence of other radiation related phenomena© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 9

IONIZING DAMAGE: THIN GATE OXIDESUniform gate current flowBreakdown pathTrap-assisted RILCRILC by radiation-inducedNeutral electron traps© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 10

IMPACT OF HIGH-ENERGY IONS ON GATEOXIDERadiation-Induced Leakage Current(RILC)Radiation-Induced Soft Breakdown(RSB)Increase of off-state power consumptionbut no real concern© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 11

ION-INDUCED DEGRADATION OF GATEDIELECTRICSA. Cester, L. Bandiera, M. Ceschia, G. Ghidini and A. Paccagnella, IEEE Trans. Nucl. Sci.,48, pp. 2093-2100 (2001)© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 12

SINGLE EVENT GATE RUPTUREL.W. Massengill, B.K. Choi, D.M. Fleetwood, R.D. Schrimpf, M.R. Shaneyfelt, T.L. Meisenheimer,P.E. Dodd, J.R. Schwank, Y.M. Lee, R.S. Johnson and G. Lucovsky, IEEE Trans. Nucl. Sci., 48,pp. 1904-1912 (2001)SEGR* Operating voltagelower than criticalvalue* Critical LET threshold© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 13

LATENT RADIATION DAMAGE IN THIN GATEOXIDES1J.S. Suehle, E.M. Vogel, P. Roitman, J.F. Conley Jr., J.B. Bernstein and C.E. Weintraub,Appl. Phys. Lett., 80, pp. 1282-1284 (2002)129 Xe Irradiation, t ox= 3.0 nm, V stress= - 4.9 V* No parameter shiftafter irradiation only* Reduced oxide lifetimeafter accelerated testingln(ln(1/(1-F)))0-1-2-31 10 100 1000 10000Pre-irradiation1 x 10 5 ions/cm 21 x 10 6 ions/cm 21 x 10 7 ions/cm 2LET > 30 MeV/cm 2Time-to-Breakdown (s)Weibull lifetime distribution of MOS capacitors subjected to constant voltage stressat V stress =-4.9 V before and after heavy ion irradiation© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys14

LATENT RADIATION DAMAGE IN THIN GATEOXIDESJ.S. Suehle, E.M. Vogel, P. Roitman, J.F. Conley Jr., J.B. Bernstein and C.E. Weintraub,Appl. Phys. Lett., 80, pp. 1282-1284 (2002)Weibull lifetime distribution of MOS capacitors subjected to constant voltage stressat V stress =-5.0 V before and after 60 Co irradiation.© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 15

LATENT RADIATION DAMAGE - ION FLUENCEEFFECTA. Cester, S. Cimino, E. Miranda, A. Candelori, G. Ghidini and A. Paccagnella, IEEE Trans. Nucl. Sci., 50,pp. 2167 2175 (2003)Gate current during CVS at V CVS = 4.2 V on threesamples with gate area 10 -2 cm 2 irradiated with256-MeV I ions at different fluencesExcess gate current Density (J e )normalized to the ion fluence (φ)measured during CVS at V CVS =4.2 V© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 16

LATENT RADIATION DAMAGE – STRESSINGVOLTAGEA. Cester, S. Cimino, E. Miranda, A. Candelori, G. Ghidini and A. Paccagnella, IEEE Trans. Nucl. Sci., 50,pp. 2167-2175 (2003)=∆I N [1-exp(-λt s )]Gate current derivative dI g /dt of the gate current, equivalent to the density of spots, withrespect to the stressing time during CVS. The derivative has been evaluated as the slope of theinitial part of the gate current evolution (t stress < 1000 s), i.e., where the gate currentincreases almost linearly© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 17

100 NM PD SOI TECHNOLOGY10-20% CHANGE F(ION FLUENCE)STAIRCASE VOLTAGE STRESSA. Cester, S. Gerardin, A. Paccagnella, E. Simoen and C. Claeys, IEEE Trans. Nucl. Sci., 52, pp. 2252-2258 (2005)Gate current measured at V g = V g,stress during FN injection of devices processed in an 0.1 µm PDSOI technology. V g,stress starts from 2.5 V and increases up to 4 V with 50-mV step every 100 s.The stress was performed on fresh and irradiated devices with two different ion fluences(2.5 and 0.5 I ions/µm 2 ).© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 18

65 NM FD SOI TECHNOLOGYNO CHANGE.A. Griffoni, S. Gerardin, A. Cester, A. Paccagnella, E. Simoen and C. Claeys, IEEE Trans. Nucl. Sci., 54,pp. 2257-2263 (2007)Gate current time to breakdown for irradiated (2.5 I ions/µm 2 ) and unirradiated FD SOI MOSFETs(W=L = 10 µm/10 µm) fabricated in a 65 nm technology with different strain levels.The devices were stressed with a staircase voltage from 2 V to 4 V with 50-mV steps, each lasting100 s.© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 19

HEAVY ION STRIKES: MICRODOSE EFFECTSS. Gerardin, M. Bagatin, A. Cester, A. Paccagnella and B. Kaczer, IEEE Trans. Nucl. Sci., 53, pp. 3675-3680 (2006)charge build-up in the STIcharge build-up in the LDD regionStatistical in natureDefect generation in the oxide© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 20

TRANSISTOR SCALINGNew process modulesNew materialsNew device conceptsmetal gateFinFETgraphenenanowiresGe/IIIV16 and beyondsilicide>=130USJstrain90-65-45NiSi NiSiFUSIStrain, USJ25 nmHfO 2high -ktime45-32High-k, Metal Gate32-22-16Non-planardevicesFront End© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 21

HIGH MOBILITY SUBSTRATESGe DEVICESR. Arora, E. Simoen, E.X. Zhang, D.M. Fleetwood, R.D. Schrimpf,K.F. Galloway, B.K. Choi,J. Mitard, M. Meuris, C. Claeys, A. Madan,J. D. Cressler, RADECS 2009 (IEEE T-NS)8 ML SI 5 ML SI© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 23

CONCLUSIONS‣ Deep submicron CMOS technologies are radiation hard for total dose effects‣STI or BOX must be optimized‣ RILC, RSB, SEGR and Latent Damage‣For thin gate oxides heavy ion strikes are important‣ Microdose effects have to be taken into account requiring a statistical analysis of atechnology‣New process modules, new materials and alternative device concepts have to beinvestigated© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 24

ACKNOWLEDGMENTThe authors want to acknowledgeA. Griffoni, D. Fleetwood, K. Galloway,S. Gerardin, G. Meneghesso, A. Paccagnella and S. Putfor the use of co-authored results.Part of the work was done under ESA contract22485/09/NL/PA.The imec Process Technology Unit is acknowledged for thedevice fabrication© IMEC 2010 IEEE EDS Colloquia, June 7 / C. Claeys 25

© IMEC 2010