Impurity distribution and electrical characteristics of boron-doped Si1−x Ge x /Si p +/N heterojunction diodes produced using pulsed UV-laser-induced epitaxy and Gas-immersion laser doping

A two-step pulsed UV-laser process which independently controls the metallurgical and electrical junction depth of a Si_1–x Ge _x /Si heterojunction diode has been implemented. Pulsed Laser-Induced Epitaxy (PLIE) combined with Gas-immersion Laser Doping (GILD) are used to fabricate boron-doped heteroepitaxial p ⁺/N Si_1–x Ge _x /Si layers and diodes. Borontrifluoride is used as the gaseous dopant source in the GILD process step. Boron incorporation and activation are investigated as a function of laser energy fluence and the number of laser pulses using SIMS and Halleffect measurements. The dose of incorporated dopant is on the order of 10¹³ cm^–2 per pulse. The B profiles obtained are flat except for a peak at the interface resulting from segregation effects. The B and Ge distributions are compared with shifts in the turn-on voltage of p ⁺/N Si_1–x /Si heterojunction diodes produced by the process. The GILD/PLIE process is spatially selective with the resulting diodes fabricated being quasiplanar. Hole mobilities in the heavily doped Si_1–x Ge _x films are found to be slightly lower than in comparable Si films.Presently at the Oregon Graduate Institute, Beaverton, OR 97006, USA     

Heat transfer in a MHD flow between eccentric disks rotating at different speeds

Heat transfer in a MHD flow between two infinite eccentric disks rotating with different speeds is considered when the plates are maintained at different temperatures. The results for the corresponding nonmagnetic case presented wrongly by Banerjee and Borkakati [7] are corrected. It is observed that the eccentric rotation reduces the heat transfer on the disks.     

Frequency dependence of conductivity in highly compensated n-type ZnSe crystals

Ac conductivity measurements, made in the frequency range 0.1 to 100 kHz on a highly compensated ZnSe sample, excessively doped with indium, suggest a contribution of impurity band conduction. The results are discussed in the light of various existing theories.     

A new relation between molar sound velocity and molar volume in carboxy acid solutions

A new relationship between molar sound velocity ‘R ’ and molar volume (M/ρ) in carboxy acid solutions has been established. Using the composite ultrasonic interferometer, both monocarboxylic and dicarboxylic acid solutions in common solvents like methyl alcohol, carbontetrachloride have been studied and it has been established that a linear relationshipR =a ₀ +a ₁ · M/ρ holds good in all solutions of homologous series of acids in a common solvent at a particular temperature. The constantsa ₀ anda ₁ for a number of carboxy acid solutions have been evaluated.     

A facile greener synthesis,antimicrobial evaluation and molecular modelling of new 4-aryl-2-(3-(2-(trifluoromethyl)phenyl)-1,8-naphthyridin-2-yl)phthalazin-1(2H)-one derivatives

Research on Chemical Intermediates - The synthesis of 4-aryl-2-(3-(2-(trifluoromethyl)phenyl)-1,8-naphthyridin-2-yl)phthalazin-1(2H)-ones was performed by cyclization of...