Browsing by Author "Cheng, Kuan-Hao"

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Hole Effective Masses as a Booster of Self-Consistent Six-Band k . p Simulation in Inversion Layers of pMOSFETs
(2011-04-01)
Chen, Ming-Jer
;
Lee, Chien-Chih
;
Cheng, Kuan-Hao
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Self-consistently solving the Schrodinger and Poisson's equations in the six-band k . p context can yield the valence-band structure in the inversion layers of pMOSFETs. In this numerically demanding process, the central processing unit (CPU) time is extraordinarily long. To overcome the hurdle, we construct a novel computational accelerator to intrinsically boost a self-consistent six-band k . p simulation. This accelerator comprises a triangular-potential-based six-band k . p simulator, a hole effective mass approximation (EMA) technique, and an electron analogy version of the self-consistent Schrodinger and Poisson's equations solver. The outcome of the accelerator furnishes the initial solution of the confining electrostatic potential and is likely close to the realistic one, which is valid for different temperatures, substrate doping concentrations, inversion hole densities, and surface orientations. The results on (001) and (110) substrates are supported by those published in the literature. The overall CPU time is reduced down to around 8% of that without the accelerator. This is the first successful demonstration of the EMA in the self-consistent hole subband structure calculation. The application of the proposed accelerator to more general situations is projected as well.
Temperature-Dependent Remote-Coulomb-Limited Electron Mobility in n(+)-Polysilicon Ultrathin Gate Oxide nMOSFETs
(2011-04-01)
Chen, Ming-Jer
;
Chang, Sou-Chi
;
Kuang, Shin-Jiun
;
Lee, Chien-Chih
;
Lee, Wei-Han
Additional electron mobility due to remote scatterers in n(+)-polysilicon 1.65-nm gate oxide (SiO(2)) n-channel metal-oxide-semiconductor field-effect transistors is experimentally extracted at three different temperatures (i.e., 233, 263, and 298 K). The core of the extraction process consists of simulated temperature-dependent universal mobility curves and Matthiessen's rule in a mobility universality region. Resulting additional mobility for the first time experimentally exhibits a negative temperature coefficient, confirming interface plasmons in a polysilicon depletion region to be dominant remote Coulomb scatterers. We also present corroborative evidence as quoted in the literature, including: 1) calculated temperature-dependent remote Coulomb mobility due to ionized impurity atoms in a polysilicon depletion region; 2) experimentally assessed additional mobility at room temperature; and 3) simulated remote Coulomb mobility due to interface plasmons in a polysilicon depletion region as well as its temperature coefficient. Validity of Matthiessen's rule used in this paper is verified.