Research


Research areas of  Professor Chee Wee Liu (Distinguished/Chair Professor of NTU)

1. SiGe/Ge/GeSn epi technologies for the more Moore and more than Moore applications, including 3D stacked high mobility channel transistors, related gate stack, and Si photonics (Lidar/IR detector/ CMOS image sensor).

2. Mobility/transport calculations, band structure calculation, First principle calculation.

3. Memory technologies :  MRAM and DRAM.

4. High mobility IGZO TFT and Si solar cells

 

Novel Electronics

 

 

 

Si/Ge/GeSn MOSFET

In this project, we focus on developing the low cost, high performance Ge MOSFETs, which is capable to replace Si as the future industry mainstream.

 

 

CMOS strain engineering

Under 90nm technology node, the strain engineering is the key technique to boost the channel mobility and enhance the performance of CMOS transistors.

 

 

IGZO Thin-Film-Transistors (TFTs)

The a-IGZO TFTs have higher on/off current ratio (~108) and higher carrier mobility (~28 cm2/ V-s) as compared to amorphous Si (a-Si) TFTs, and is suitable for the high performance applications.

 

 

Advanced material process

New SOI, GOI, SSDOI material using smart cut, wafer bonding, and nano-mechanics are developed for future device applications.

 

 

Carbon-based electronics: Graphene and GNRs

Graphene, a carbon-based 2D single atomic layer, is considered to be the potential material for the next generation electronic devices.

 

 

Device Modeling and Simulation

BSIM and Mextram models are being developed to take the strain and optical effects into account for RF and high speed digital applications. Finite element analyses of ISE-TACD and ANSYS are used to simulate Ge FET and MOS LED/GOI detector theoretically.

 Photonics

 

              

Ge/GeSn photonics devices

The bandgap tuning and direct bandgap emission of GeSn can enhance the performance of group IV photonic devices on Si platform.

 

     

NIR cmos image sensor

BSI cmos image sensor with NIR detection can be used in the camera and automobile applications.

 

 

Lidar

Optical steering can achieve by optical phase array.This technique can be used for the Lidar applications

 

  

 

 

Photovoltaic

 

     

Quantum efficiency (QE), solar cell efficiency, dark and photo I-V measurement, carrier lifetime measurement by QSSPC, and FTPS for defect level.