1. Microwave and Millimeter-wave Technology(MMT) Lab
微波毫米波集成电路与系统实验室
Microwave and Millimeter-wave Technology(MMT) Lab
Quasi-Physical Zone Division (QPZD) Model for Wide-bandgap Semiconductor Technology
Yuehang Xu

2. Outline
Background
Theory of QPZD model
QPZD Diamond FET model
Summary

3. Trends of RF transistors
Ⅰ. Background
Trends of RF transistors
Performance
(Power、noise)
Si, Ge, etc.
GaAs,InP, etc.
GaN, Diamond,
etc.
Integration
（node）
~um
~nm
< 1nm

4. Ⅰ. Background
Material
process
model
design
system

5. Ⅰ. Background Compact model coalition(CMC) UESTC model since 2005
1.SiC MESFET
2.GaAs HEMT
3.GaN HEMT
4.InP HBT
5.Graphene FET
6.CMOS
7.Diamond FET
Empirical model (Angelov)
Physical compact model

6. Physical compact models
Ⅰ. Background
Physical compact models
Pao-Sah I-V Current equation
IEEE Trans. Electron Devices, 52(8), , 2005.
Surface potential model (i.e. ASM-HEMT)
Charge based model ( i.e. MVSG)
Advantages
More intuitive in physics;
Less fitting parameters;
Naturally scalable;
Problems
Increasing fitting parameters when considering self-heating, ambient temperature, and trapping effects;
Easily not convergence in microwave high power amplifiers (HPAs) ;
Is there any model with less fitting parameters, high convergence for microwave application?

7. Outline
Background
Theory of QPZD model
QPZD Diamond FET model
Summary

8. Theory of QPZD model Zone Division Triode operation
Saturation operation
Intrinsic FET Zone(IFZ)
Space-charge Limited Zone(SLZ)
Charge Deficit Zone(CDZ)

9. Theory of QPZD model Drain current model
D. Hou, G. L. Bilbro, and R. J. Trew, IEEE TED , 2013.
Zhang wen, Yuehang Xu* , et al.，IEEE T-MTT, 2017,65(12):

10. Theory of QPZD model Capacitance models
Gate channel capacitance Cgc in ON state
Inner fringing capacitance Cif in OFF state
Bias-dependent
The depletion regions
Yonghao Jia , Yuehang Xu*, etc. IEEE T-ED, 2019,66(1):

11. Analytical capacitance equations
Theory of QPZD model
Analytical capacitance equations
Ward–Dutton charge partition
(IEEE JSSCC,1980)

12. Includes self-heating, ambient temperature, trapping effects
Theory of QPZD model
Includes self-heating, ambient temperature, trapping effects

13. Does it work for GaN HEMTs and MMICs?
Theory of QPZD model
Does it work for GaN HEMTs and MMICs?
（a）2×125μm
（b）6×100μm
（c）8×125μm
0.25um GaN HEMT, 4*125um, Vgs=-3V, Vds=25V

14. Does it work for GaN HEMTs and MMICs?
Theory of QPZD model
Does it work for GaN HEMTs and MMICs?
X-band MMIC

15. Is it physical enough for statistical model ?
Theory of QPZD model
Is it physical enough for statistical model ?
DC-IV Measurement for batches of devices
Statistical property of physical parameters:
d, vmax, nsmax, µsat
Statistical Model
Automatic
Parameter
Extraction d
vmax
nsmax, α1, α2,
α3, βn
a0, a1,
b0, b1, b2 ns
Parameter Data Set
Factor Analysis
Statistical Model
Zhang Wen , Shuman Mao, Yuehang Xu*, etc. IEEE IMS, 2019

16. Theory of QPZD model Factor Analysis (FA)
Standardization
Correlation
Coefficient
Common Factor
Load
Matrix
Factor
Calculation

17. Theory of QPZD model
vmax d
µsat
nsmax

18. Statistical Property of the Physical Parameters
Theory of QPZD model
Statistical Property of the Physical Parameters
Simulation
Measured

19. Power Sweep Characteristics
Theory of QPZD model
Power Sweep Characteristics

20. Sensitive Analysis in Power Sweep
Theory of QPZD model
Sensitive Analysis in Power Sweep
vmax ns

21. Sensitive Analysis in Impedance Chart
Theory of QPZD model
Sensitive Analysis in Impedance Chart

22. Outline
Background
Theory of QPZD model
QPZD Diamond FET model
Summary

23. Diamond FET model
Michale W. Geis, Phys. Status Solidi A. 2018

24. Lower Energy Consumption
Diamond FET model
Power Electronics Application
RF Electronics Application
High-Temperature
High-Power
High-Frequency Application
Lower Energy Consumption
Higher Output Power

25. Diamond FET model World-scale Diamond Device Research Distribution
Univ of Bristol : Martin Kuball
Univ of Glasgow: David Moran
Univ of Ulm: E.Kohn
Institute Neel:Pham
Univ of Rome Tor Vergata:
Pasciuto
Waseda University
Hiroshi Kawarada
Saga University
Makoto Kasu
World-scale Diamond Device
Research Distribution

26. Diamond FET model
Developments of TCAD Simulation Models for C-H Diamond FETs
2001
0.2 nm p-type doping in diamond surface
H atoms of the C-H bonds act as surface acceptors
2017
Negative fixed charge sheet induces a 2DHG channel
transfer doping mechanism due to C-H dipoles and surface adsorbates is not clear
2017
Negative charge sheet (source to drain) induces a 2DHG channel, and positive charge sheet (under gate) calibrates the model
Not explain the physical meaning of the positive charge sheet and the role of surface adsorbate layer in the transfer doping

27. Diamond FET model C-H Diamond FET Operation Mechanism and TCAD Model
C-H dipole effect induced transfer doping mechanism
I-V characteristics
Transfer characteristics
Drift-Diffusion transport equation
Wachutka’s thermodynamically rigorous model
Shockley-Read-Hall (SRH) Recombination Model
Yu Fu, Ruimin Xu, …, Yuehang Xu* IEEE EDL, 2018

28. Diamond FET model
Zone division for diamond FET
TCAD simulation

29. Linear-mode I-V Model Parameter Extraction and Modeling
Diamond FET model
Linear-mode I-V Model Parameter Extraction and Modeling
Basic assumption

30. Diamond FET model
COMSOL VS
38.73 C/W
33.81 C/W
C-H Diamond FET

31. I-V Model Verification
Diamond FET model
I-V Model Verification
Saturated-mode I-V model
LG = 0.5 m, WG = 2* 500 m
Modeling Flowchart

32. Small signal S-Parameter Extraction and Verification
Diamond FET model
Small signal S-Parameter Extraction and Verification

33. Diamond FET model Large-signal Modeling and Verification
1 GHz Power Sweep
Electrothermal large signal model topology
Yu Fu, Ruimin Xu, …, Yuehang Xu*, IEEE Access, 2019
2 GHz Power Sweep

34. Outline
Background
Theory of QPZD model
QPZD Diamond FET model
Summary

35. Summary
QPZD model is validated by GaN HEMT transistors and further validated by a X-band GaN High power amplifier
QPZD statistical model is used for MMIC yield analysis
QPZD model is used for microwave diamond FETs

36. Acknowledgement