The electron-phonon scattering effect in Modulation- Doped Field-Effect Transistors

• Main Authors: Jiunn-Way Miaw, 繆俊偉
• Other Authors: Mau-Phon Houng, Yeong-Her Wang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/08062726299511609204

碩士 === 國立成功大學 === 電機工程研究所 === 84 === The electric and thermal characteristics of modulation -doped field-effect transistor (MODFET) is investigated in this thesis, and we combine these results with the electron -PO phonon (phonon-optical phonon) mechanism to study the thermal effect in MODFET.In the channel of MODFET, 2-D electron exists due to quantum size effect. So, in this paper, we get the potential and charge distribution by solving the time independent Schr鐰inger equation with one electron effective mass approach and Poisson's equation simultaneously. It is so- called self-consistent method. From results of this calculation we could understand the electron behaviors and some quantum effects in the growth direction.Then, we use a analytical current-voltage model and the charge control model which is 2-D electron concen- tration in the InGaAs channel as the function of gate voltage to solve the current-voltage characteristics, voltage and electric field in the channel of MODFET. Be- cause the heat generation in device results from the applied bias when device is in operation, we apply the results obtained from the study of electric characher- istics to investigate the thermal effect of MODFET. At first, we get the effect of applied electric field on the distribution relationship of 2-D electron gas concen- tration, electron velocity and electron temperature, and then we discuss the principles of electron- polar-optical phonon scattering and the energy relaxation time of 2DEG. At last, we use these data to calculate the heat flux distribution and temperature distri-bution in devices. So far, the electric and thermal characteristics of MODFET are obtained. Futhermore, we will discuss the effect of structure on device characteristics, all this results would provide guideline in device design.