Browsing by Author "Hsiao, Chih-Hua"

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Characterization of Annular-Structure RF LDMOS Transistors Using Polyharmonic Distortion Model
(2009)
Chiu, Chia-Sung
;
Chen, Kun-Ming
;
Huang, Guo-Wei
;
Hsiao, Chih-Hua
;
Liao, Kuo-Hsiang
An annular-structure lateral-diffused metal-oxide semiconductor (LDMOS) RF transistor with polyharmonic distortion (PHD) model characterized by nonlinear vector network analyzer is described in this paper. The devices were fabricated using a 0.5 mu m LDMOS process. The DC, small-signal, and large-signal characteristics of RF LDMOS transistors with annular-structures were also studied in this work. Using the PHD model, the accuracy of intermodulation and time waveform is verified. Furthermore, the model via X-parameter shows good agreement without optimization.
LDMOS Transistor High-Frequency Performance Enhancements by Strain
(2012-04-01)
Chen, Kun-Ming
;
Huang, Guo-Wei
;
Chen, Bo-Yuan
;
Chiu, Chia-Sung
;
Hsiao, Chih-Hua
The effects of mechanical stress on the dc and high-frequency performances of laterally diffused MOS (LDMOS) transistors with different layout structures were investigated by using the wafer bending method. A 3.1% peak cutoff frequency (f(T)) enhancement is achieved for the multifinger device under 0.051% biaxial tensile strain. For LDMOS with annular layout, the f(T) enhancement is increased to 3.7% due to the various channel directions. Our results suggest the strain technology can be adopted in LDMOS for RF applications. The transconductance and gate capacitance were also extracted to clearly demonstrate the f(T) variations.