1 / 28

Semiconductor Device Modeling and Characterization EE5342, Lecture 20 -Sp 2002

Semiconductor Device Modeling and Characterization EE5342, Lecture 20 -Sp 2002. Professor Ronald L. Carter ronc@uta.edu http://www.uta.edu/ronc/. Equivalent circuit above OSI. Depl depth given by the maximum depl = x d,max = [2 e Si |2 f p |/(qN a )] 1/2

cyma
Télécharger la présentation

Semiconductor Device Modeling and Characterization EE5342, Lecture 20 -Sp 2002

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Semiconductor Device Modeling and CharacterizationEE5342, Lecture 20 -Sp 2002 Professor Ronald L. Carter ronc@uta.edu http://www.uta.edu/ronc/

  2. Equivalent circuitabove OSI • Depl depth given by the maximum depl = xd,max = [2eSi|2fp|/(qNa)]1/2 • Depl cap, C’d,min = eSi/xd,max • Oxide cap, C’Ox = eOx/xOx • Net C is the series comb C’Ox C’d,min

  3. MOS surface states**p- substr = n-channel

  4. n-substr accumulation (p-channel) Fig 10.7a*

  5. n-substrate depletion(p-channel) Fig 10.7b*

  6. n-substrate inversion(p-channel) Fig 10.7*

  7. Ideal 2-terminalMOS capacitor/diode conducting gate, area = LW Vgate=VG -xox SiO2 0 y 0 L silicon substrate tsub Vsub=VB x

  8. Band models (approx. scale) metal silicon dioxide p-type s/c Eo Eo qcox ~ 0.95 eV Eo qcSi= 4.0eV qfm= 4.28 eV for Al Ec qfs,p Eg,ox ~ 8 eV Ec EFm EFi EFp Ev Ev

  9. Flat band with oxidecharge (approx. scale) Al SiO2 p-Si +<--Vox-->- q(Vox) Ec,Ox q(ffp-cox) Ex q(fm-cox) Eg,ox~8eV Ec EFm EFi EFp q(VFB) Ev VFB= VG-VB, when Si bands are flat Ev

  10. Values for gate workfunction, fm

  11. Values for fmswith metal gate

  12. Values for fmswith silicon gate

  13. Experimental valuesfor fms Fig 10.15*

  14. Calculation of thethreshold cond, VT

  15. Equations forVT calculation

  16. Fully biased n-MOScapacitor VG Channel if VG > VT VS VD EOx,x> 0 e- e- e- e- e- e- n+ n+ p-substrate Vsub=VB Depl Reg Acceptors y 0 L

  17. Effect of contacts,VS and VD

  18. Computing theD.R. width at O.S.I. Ex Emax x

  19. Computing thethreshold voltage

  20. Fully biased MOScapacitor in inversion VG>VT Channel VS=VC VD=VC EOx,x> 0 e- e- e- e- e- e- n+ n+ p-substrate Vsub=VB Depl Reg Acceptors y 0 L

  21. Flat band with oxidecharge (approx. scale) Al SiO2 p-Si +<--Vox-->- q(Vox) Ec,Ox q(ffp-cox) Ex q(fm-cox) Eg,ox~8eV Ec EFm EFi EFp q(VFB) Ev VFB= VG-VB, when Si bands are flat Ev

  22. Flat-band parametersfor n-channel (p-subst)

  23. MOS energy bands atSi surface for n-channel Fig 8.10**

  24. Fully biased n-channel VT calc

  25. References * Semiconductor Physics & Devices, by Donald A. Neamen, Irwin, Chicago, 1997. **Device Electronics for Integrated Circuits, 2nd ed., by Richard S. Muller and Theodore I. Kamins, John Wiley and Sons, New York, 1986

More Related