Semiconductor Device & Analysis Center Berlin University of Technology Christian Boit TUB Berlin University of Technology Sect. Semiconductor Devices Christian.Boit@TU-Berlin.DE 1
Semiconductor Device & Analysis Center Berlin Scope: Research: FA Techniques for Faster Turnaround - Edit techniques on devices - Physical interactions of devices for localization - Standard solutions (cook book etc.) - Device Design & Characterization Education: Full Device Development Process - Semiconductor Devices in Basic Curriculum - Full Microelectronic Business Process (FET) - Failure Analysis, Power & Special Devices Service: Commerical-like Application Lab - Lab unique for service of design verification and failure analysis processes from chip backside 2
Semiconductor Device & Analysis Center Berlin Resources: 1 Lead Engineer (permanent) 3 PhD Students based on educational track 4 Technical Staff (permanent contracts) More PhD Students per cooperation contracts State of the Art tools Hamamatsu Phemos 1000, NPTest OPTIFIB, Agilent 83000 Tester Device Simulation & Know How (FET, Power, PV) Sample Preparation Mech, Chem Wet &Dry 1000 sqft Small Clean Room Technology More than 5000 sqft lab and office space 3
Semiconductor Device & Analysis Center Berlin Who we are Device Dynamics Make the Difference in Functional Analysis Challenges of Backside Approach Device Localization with Laser Stimulation Device Repair (Circuit Edit) with FIB Where we want to go 4
Photon Emission Basics: Electroluminescence The Two Basic Mechanisms of Photon Emission in IC P/N Junction: Reverse Bias 1) Deceleration: Radiant loss of energy gained in electrical field Leakage Current I Detection Limit V Forward Bias 2) Injection: Radiant Interband Recombination 5
Photon Emission Microscopy Direct defect identification: Gate oxide defect X5 X25 X0.8 Emission images at magnification: X 100 6
Substrate [µa] I sub Correlation of MOSFET Light Emission to Electrical Operation Mode current I D Gate voltage [V] Drain [ma] Light emission and substrate current vs. gate voltage Substrate Current Gate voltage [V] Light Intensity 7
Dynamic Photon Emission in CMOS Photon Emission in Switching Phase of FET Required Time Resolution: 30-40 ps Measurement Challenge: ~ 1 photon / 10 5 events Stroboscopic Imaging: IC Signal Tracing All figures from J.C. Tsng, Picosecond imaging circuit analysis 8
Design Verification: Signal Propagation in IC visualized with Dynamic Photon Emission t=3.876ns: t=4.080ns: t=6.800ns: Emission from a ring oscillator at various times. Example: ring oscillator: Three optical waveforms of switching induced light emission from neighbouring inverters of the ring oscillator; Vdd -> 0V: high intensity 0V -> Vdd: low intensity All figures from J.C. Tsng, Picosecond imaging circuit analysis 9
Design Verification & Failure Analysis: Identification and Localization of Erratic Device fail reference Time integrated image of light from a register file while running a test pattern producing a fail fail optical waveform from normal and faulty latch pair All figures from J.C. Tsng, Picosecond imaging circuit analysis 10
Why FA through Backside of the Die? New Packages Multi-Level Metallization LOC ( Lead On Chip) Flip-Chip Die Flip-chip substrate Data taken from Fujitsu 11
Observability of ofsignals with Beam Techniques Drastically Reduced by bymulti Layer Wiring DatatakenfromN.Kujietal.,NTT,ESREF97 Image taken from IBM Research Labs Cu 6 Cu 5 Cu 4 Cu 3 Cu 2 Cu 1 tungsten 1 12
Challenge of Analysis Techniques Through Chip Backside: IR Optics Resolution vs. Feature Size 13
Resolution of different immersion media gas, air (a), liquid, oil(b), solid, Si (c) 14
Semiconductor Device & Analysis Center Berlin!"#"$%&'()*%+,(%-(./-0,%1-"2(3-"245%5(1+((( )6'%01-$/0,1#(768%065./-0,%1-"2(3-"245%5(,*#1/&*(9*%:(;"0<5%$6(! "#$%&'(&)#*+,$#-&.+,/#0$/+&*+12%$34+0&&&&&&! 5+&$%/+%*&(4--&#%#-60$0&.,'1+00&! 760*+)#*$1&4%8+,0*#%8$%9&'(&+((+1*0&-#1:$%9&;& *+12%$34+0&%'*&6+*&+).-'6+8&*'&*2+$,&.'*+%*$#- 15
Semiconductor Device & Analysis Center Berlin Who we are Device Dynamics Make the Difference in Functional Analysis Challenges of Backside Approach Device Localization with Laser Stimulation Device Repair (Circuit Edit) with FIB Where we want to go 16
Beam Induced Device Stimulation Set Up: 5678%-,) 8!9 51%#, */,)&%:!"#$%&'.,/"+, 0*1234,) ()*+,--"$#.,;&,+4"*$ -"#$%& 17
Principle of Laser Induced Thermal Stimulation Electrical Signal responding to laser stimulation <"#=7>67"; 67="#=?7-,$-"4"/,74*7="#=767"$4,)+*$$,+4-8*+%& 4=,)1*/*&4%#, %47="#=7+3)),$4-?7-,$-"4"/,74*7&*@ 67-,+4"*$- ()*A&,1?7!"#$%&7(%4= ;)*1,B+"4%4"*$ 4*74,)1"$%& $*4 @,&&7C,;"$,C DEF Source: Nikawa 18
Transmission (%) Thermal Stimulation of Silicon Device by IR Laser Intraband Free Carrier Absorption : 100 10 1 0.1 0.01 Si indirect bandgap 1.0 1.5 2.0 2.5 IR Absorption in Highly Doped Layers: 0.1 to 0.05% of 1.3µm Laser power (c) (a) (b) (d) Si thickness 625µm Dopant Conc. x10 16 cm -3 (a) 1.5 (b) 33 (c) 120 (d) 730 Wavelength (µm) Local Heating of Active Device 19
Thermal Laser Stimulation in Metal Wire & in Semiconductor Device M2 M1 S/D, typ. 10 19 /cm 3 Cap Silicide Poly-Si M1 well, typ. 10 17 /cm 3 typ. 10 19-10 20 /cm 3 S/D Si-Substrate, typ. 10 15-10 16 /cm 3 Interactions: Wiring: Device: 20
Thermal Laser Stimulation in Metal Wire & in Semiconductor Device Heat λ=1.3 m laser illumination Interactions: Wiring: Voltage Alteration Resistive Change Device: 21
Heat reflected beam Heat Thermal Laser Stimulation in Metal Wire & in Semiconductor Device laser illumination, λ=1.3 m Interactions: Wiring: Voltage Alteration Resistive Change Device: Performance Reduction - Mobility -Vτ - Speed 22
Heat Heat Heat t=1ms Thermal Laser Stimulation in Metal Wire & in Semiconductor Device Heat Interactions: Wiring: Voltage Alteration Resistive Change Device: Performance Reduction - Mobility -Vτ - Speed 23
Soft Defect Localization - FET Source: Ed Cole 24 Section Semiconductor Devices / C. Boit
Soft Defect Localization Soft Defect: Test Fail occurring only in special Environment TUB Research Result: Quantitative Investigation of FET Device Parametrics with Thermal Laser Stimulation to be submitted 10/03 Source: Ed Cole 25
Semiconductor Device & Analysis Center Berlin =>)(=*6#'"2(>"56#(),%'/2",%1-(1+()1+,(76+60,5?( @%22(A6(%':1#,"-,(B--18",%1-(%-(>10"2%C",%1-(1+( B9(768%06(./-0,%1-"2%,4("-$(."%2/#65(! <,'=+&;&.#,#)+*,$1&)'8$($1#*$'%&'(&8+/$1+! 7$9%#-&.#*2&(',&8+*+1*$'%&8+($%+8&=6&*+0*+,&! >#%&8+*+,)$%+&9,#84#-&8+/$1+&.+,(',)#%1+!?%8+,0*#%8$%9&'(&+((+1*0&01#**+,+8&&& ;@&,+0+#,12&%+1+00#,6&(',&.,'.+,&40+&$%&$%840*,6 26
Semiconductor Device & Analysis Center Berlin D6E,(F6-6#",%1-(>10"2%C",%1-(=60*-%G/65( H I64?(+/#,*6#(%':#186'6-,(1+(,/#-"#1/-$ A 76,60,%1-(1+(+/#,*6#(5%&-"25(6'%,,6$(A4($68%06J( %K6K('"&-6,%0(+%62$(L)MNB7O(( A B-,6#"0,%1-(1+(0%#0/%,#4(,%'6($62"4("-$( :#1:"&",%1-(1+(%-$/06$(5%&-"2( H )%&-"2(,#"0%-&(P%,*("22("8"%2"A26($4-"'%0(,60*-%G/65(L>"56#(%-$/06$J(:*1,1-6'%55%1-J(1,*6#QO(( 27
Outline: Who we are Device Dynamics Make the Difference in Functional Analysis Challenges of Backside Approach Device Localization with Laser Stimulation Device Repair (Circuit Edit) with FIB Where we want to go 28
Previous Process Device Repair (Circuit Edit) with FIB: Short Redesign Loop and Access to Cells Circuit CircuitDesign Simulation Simulation Layout LayoutDesign Mask MaskProduction Engineering EngineeringSample Evaluation Evaluation Production Production Quality QualityControl FIB Deposition of Probing Pads for SRAM Cell on Via1level (Prep: surface parallel polishing) FIB 29
The OptiFIB Column Photon Beam Ion Beam Coaxial Photon-Ion Microscope Simultaneous Imaging & Editing Photon Image Ion Editing 100nm FIB Placement Accuracy 30
M5 M4 M3 M2 M1 FIB Editing of ICs through Si Backside 2-5µm Silicon Substrate 48 µm FIB Trench Very thin remaining bulk Si - Risks: Flatness, Endpoint, Navigation ILD1 ILD0 Transistor Level 31
Voltage Contrast by Silicon Active Volume TUB Research Result: FIB Image Contrast of n- Wells for - Endpoint Control and - Navigation to be presented at ESREF & ISTFA 03 32
M1 Endpoint Detection for Active Si Volume M1 n+ n+ - p+ p+ + + p-well - n-well + + + + + + + + + - - - - - Si-p-Substrate - - - - Scanned Ion Beam 700nm 4 µm Ion Beam removes material 33
M1 Endpoint Detection for Active Si Volume M1 n+ n+ - p+ p+ + + p-well - n-well + + + + + + + + + - - - - - Si-p-Substrate - - - - + + + + + + + + + 700nm 4 µm Ion Beam removes material and implants Ga ions into the back surface. 34
M1 Endpoint Detection for Active Si Volume M1 n+ n+ - p+ p+ + + p-well - n-well + + + + + + + + + - - - - - Si-p-Substrate - - - - + + + + + + + + + e- e- 700nm 4 µm Ion Beam removes material and implants Ga ions into the back surface. Influence of SCR causes contrast of secondary particle emission rate 35
Semiconductor Device & Analysis Center Berlin: Wherewewanttogo Establish TUB as Solution Center for Advanced Analysis Problems in Electronic Devices Microelectronics: Dynamics of Device and Analysis Pervasive Techniques (i.e. SQUID) Focused Ion Beam Processes for Edit in Si Power Devices & Compound Semiconductors: Adaption of Localization Techniques to Discrete Devices, Band Gap and Mechanisms of Direct SC Adaption of FIB processes to Material Components 36