Investigation of Deembedding. up to 110GHz J.BAZZI *1, C. RAYA, A.CURUTCHET *, F.POURCHON #, N.DERRIER #, D.CELI #, T.ZIMMER *

Transcription

1 Investigation of Deembedding procedures up to 110GHz J.BAZZI *1, C. RAYA, A.CURUTCHET *, F.POURCHON #, N.DERRIER #, D.CELI #, T.ZIMMER * 1 jad.bazzi@ims-bordeaux.fr * IMS Laboratory # STMicroelectronics

2 Outline Introduction Calibration De-embedding steps OPEN-SHORT 3 steps 4 steps 5 steps 6 steps Two-step de-embedding Conclusion 2

3 Introduction Deembedding importance: - For process engineers (technology performance f T, f max ) - Highly important for compact device modeling - S parameter perfectly corrected Main issues - What is an accurate deembedding technique? 3

4 Outline Introduction Calibration De-embedding steps OPEN-SHORT 3 steps 4 steps 5 steps 6 steps Two-step de-embedding Conclusion 4

5 Calibration Takes into account parasitic between VNA and Probe tips After calibration the reference planes are at the probe tips Emitter Base collector Emitter Source: IBM IEEE Spectrum DUT 5

6 De-embedding Retrieve intrinsic device performance de-embedding How?!! Reference plane after calibration Reference plane after de-embedding Source: IBM IEEE Spectrum 6

7 Outline Introduction De-embedding De-embedding steps OPEN-SHORT 3 steps 4 steps 5 steps 6 steps Two-step de-embedding Conclusion 7

8 De-embedding steps Open-Short Open Short *Koolen, Bipolar Circuits and Technology Meeting, Sep Steps Open Short *H. Cho and al., IEEE Trans. Electron Devices, June Steps Open Short Short * T.E.Kolding, IEEE Trans. Electron Devices, April

9 De-embedding steps 5 Steps Probes-Short Pad-Open Pad-Short Complete-Short * F. Pourchon et al, BCTM 08, Invited talk 6 Steps Probes-Short Pad-Open Pad-Short Complete-Short C PBE /C PBC /C PCE C PBC C PBE CPCE * C. Raya et al, HICUM Workshop 08 9

10 De-embedding Steps 5 de-embedding steps Y 3PO C Open1 C PBC Z 1PBS Z 1PS Z PB /N B DUT Z PC /N C Z 2PS Z 2PBS Y 1PO C PBE C PCE Y 2PO Z PE /N E Source: IBM IEEE Spectrum Z 3PBS 10

11 De-embedded equivalent circuit (1): Probe Short Y 3PO Probe Short C Open1 1 C PBC 1 Z 1PBS Z 1PS Z PB /N B DUT Z PC /N C Z 2PS Z 2PBS Y 1PO C PBE C PCE Y 2PO Z PE /N E 1 Z 3PBS 11

12 Resistance (Ohms) Results Probe short: short circuit for the probes Correct the probe contact resistance 1,0 0,8 Z 1 Z 2 0,6 0,4 0,2 0,0-0,2 Z 3-0,4-0,6-0,8-1,0-1,2 R1 R2 R3 1G 10G 100G Attention: probe contact problem at Port 1 Manual probing!!! Frequency (Hz) 12

13 De-embedded equivalent circuit (2): Pad Open 2 Pad Open Y 3PO Y 1PO Z 1PS C Open1 C PBC Z PB /N B Z PC /N C DUT Z 2PS C PBE C PCE 2 2 Z PE /N E Y 2PO 13

14 Capacitance (F) De-embedded equivalent circuit (2): Pad Open Pad capacitance Equivalent circuit (2) 25f 20f 15f 10f 5f C1 C2 C 1PO C 2PO 0 1G 10G 100G Frequency (Hz) 14

15 De-embedded equivalent circuit (3): Pad Short Pad Short C Open1 3 C PBC 3 Z 1PS Z PB /N B C PB DUT Z PC /N C C PCE Z 2PS E Z PE /N E 15

16 S11 S22 Inductance (H) De-embedded equivalent circuit (3): Pad Short Pad short: short circuit at the edge of the signal pad. L1 2*L3 L *L3 24p p 20p 18p L1 L2 L3 16p p 12p 10p 8p 6p 4p 2p G 40G 60G 80G 100G Frequency (Hz) Frequency 16

17 De-embedded equivalent circuit (4): scalable C PBC 4 4 Z PB /N B DUT C Open1 Z PC /N C C PBE C PCE Z PE /N E 17

18 S12 S12 S21 deemb S12 deemb De-embedded equivalent circuit (4): scalable First: measure and de-embed a long Plot line: deemb/nbhsba/thru/sxx_m de-embedding Frequency 18

19 Phase (degree) Re-dimensioning the line L L /N L /N N=4 L /N L /N T a d K a d K 2 4bc si 0 ou i si 0 n L /L 1 ( K)(T ) n ( K)(T ) n (T ) n (T ) n n b a b n 1 n c d (T ) n (T ) n ( K)(T ) n ( K)(T ) n c n n ,0-0,5-1,0-1,5-2,0-2,5 S12 S21 S12_Shortline S21_Shortline 0 20G 40G 60G 80G 100G Frequency (Hz) 19

20 De-embedded equivalent circuit (5): Complete short 5 Z PB /N B C PBC DUT 5 Z PC /N C C PBE C PCE 5 Z PE /N E 20

21 De-embedded equivalent circuit (5): Complete short Z B Z C 2.Z E 2.Z E Z B /N B Z C / N C ZB: Base impedance ZC: Collector impedance ZE: Emitter impedance Z E / N E 21

22 Resistance (Ohm) The three shorts: 1,0 0,8 Probes-Short 0,6 0,4 0,2 0,0 Pad-Short -0,2-0,4 complet_short probe_short pad_short -0,6 1G 10G 100G Frequency (Hz) Complete Short 22

23 De-embedded equivalent circuit (6): Capacitances 6 de-embedding steps C PBC DUT C PBE C PCE C PBC C PBE C PBE C PBC C PBC C PBE C PBE C PBC Open2 Specific open could be used only between port 1 & 2 (C PBC capacitance) 23

24 De-embedded equivalent circuit (6): Capacitances Symmetrical test structures C BE (2.B) C BE (1.B) C B E B C C B E 2 base contacts 1 base contact C backend (1.B) C BE (2.B) C BE (1.B) 24

25 Comparison (Open Vs 6 steps): f T [GHz] BiCMOS9MW CBEBC W E =0.3mm, L E =14.92mm et L E =3.7mm V Open correction BC =-0.5V f T [GHz] Full correction (6 steps) 300 L E =14.92mm L 250 E =3.7mm V BE [V] V BE [V] f T extracted from 25

26 Discussion Good correction for 6 steps Different type of dummies processing is more complex More de-embedding dummies for one DUT Large set of devices end by doubling or tripling the number of dummies Si area 6 steps very complex Specified approach, Two steps Probes-Short Pad-Open Pad-Short Complete-Short C PBE /C PBC /C PCE C PBC C PBE CPCE R, L circuit 26

27 Capacitance (F) Y1 Y2 Two-Step de-embedding Pad Open i1 i2 V1 V2 25f 20f i1 Y11 Y12 v1 i Y Y v C C 1 2* * f Im * * f Im 2 22 Y Y 15f 10f 5f 0 C1 C2 1G 10G 100G Frequency (Hz) 27

28 Resistance (Ohms) Two-Step de-embedding Complete-Short Base DUT Collector i1 R1 L1 L2 R2 i2 Metal 1 Emitter V1 R3 L3 V2 v1 Z11 Z12 i1 v Z Z i Re Re R Re Z Z R Re Z Z R Re Z Re Z ,7 1,6 1,5 1,4 1,3 1,2 1,1 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 R1 R2 R3 1G 10G 100G Frequency (Hz) 28

29 Re Y 21 [S] Imag Y 21 [S] Comparison: Validation of the Two-steps method CBEBC LE=5µm, VBE=0.9V, VCB=0V 0,10-0,01 0,09 0,08 Two_Step Five_Step -0,02-0,03 Two_Step Five_Step 0,07-0,04 0,06 0,05 0,04 0,03 0,02 20G 40G 60G 80G 100G Frequency [Hz] -0,05-0,06-0,07-0,08-0,09 20G 40G 60G 80G 100G Frequency [Hz] 29

30 Re Y 22 [S] Imag Y 22 [S] Comparison: Validation of the Two-steps method CBEBC LE=5µm, VBE=0.9V, VCB=0V 0,012 0,010 0,008 Two_Step Five_Step 0,0105 0,0090 0,0075 0,006 0,004 0,0060 0,0045 Two_Step Five_Step 0,002 0,0030 0,000 0,0015-0,002 20G 40G 60G 80G 100G Frequency [Hz] 0, G 40G 60G 80G 100G Frequency [Hz] 30

31 Conclusion Different de-embedding methods were presented A scalable solution for deembedding is the key De-embedding structures use a lot of Si surface Pad open and complete short may be sufficient 31

32 Acknowledgements This work is part of the: Dotfive project supported by the European Commission through the Seventh Framework Programme for Research and Technological Development Acknowledgements also to the Medea+ Siam project We want to thank F. Pourchon, D. Celi and N. Derrier from ST and C. Raya from XMOD Technologies for helpful discussions. A grand merci to Magali for efficient support and the very accurate measurements. 32

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