A High Frequency C-V Measurement Platform For MOS Capacitors And Threshold Voltage Model For SiGe PMOSFET

The high frequency C-V measurement for MOS capacitor is widely used in the global semiconductor industry and institute, providing an effective way for characterizing the interface properties of MOS devices; SiGe is an ideal semiconductor material which has advantages in the application of high frequency, low temperature and low power dissipation electronic devices, because of its higher mobility, narrower band-gap and its better compatibility with traditional CMOS fabricating process flow.A high frequency C-V measurement platform for MOS capacitor is mainly studied and designed. Due to the exact need of the Central Laboratory for the undergraduates of our department, a hardware circuit for the high frequency C-V measurement platform for MOS capacitor, together with its 5 main modules, including high frequency waveform generation module, capacitors-test module, signal filter module, demodulation module and power supply module, are designed on our consideration of modularization method, simple construction and materials'easy purchasing. Finally, the measurement platform is constructed successfully by the 5 main modules and the multifunctional data acquisition card USB7333B. The measurement platform function well within certain test precision, according to the final testing results.A threshold voltage model of strained SiGe channel PMOSFET is also developed. 1-D threshold voltage model is proposed first. Then a quasi-2-D threshold voltage model appropriated for short channel is established after considering the lateral channel electric field. The simulation results match well with experimental datas and 2-D numerical simulation. On the basis of this model, influences of various parameters on threshold voltage of this device are simulated. Threshold voltage of devices without Si cap layer is also simply discussed.