A B Given Ā= √2 x B = 2√2x Find the scalar product A - B

What is the minimum fraction of the lasing molecules in a three-level laser that must be in the excited state in order for the laser to operate? Answer the same question for a four-level laser.

In the fabrication of a p-type semiconductor, elemental boron is diffused a small distance into a solid crystalline silicon wafer. The boron concentration within the solid silicon determines semiconducting properties of the material. A physical vapor deposition process keeps the concentration of elemental boron at the surface of the wafer equal to 5.0 x 1020 atoms boron/cm3 silicon. In the manufacture of a transistor, it is desired to produce a thin film of silicon doped to a boron concentration of at least 1.7 x 1019 atoms boron/cm3 silicon at a depth of 0.20 microns (µm) from the surface of the silicon wafer. It is desired to achieve this target within a 30-min processing time. The density of solid silicon can be stated as 5.0 x 1022 atoms Si/ cm3 solid. (a) At what temperature must the boron-doping process be operated? It is known that the temperature dependence of the diffusion coefficient of boron (A) in silicon (B) is given by Where Do=0.019 cm2/s and Qo=2.74 x 105…

An electron is moving in a piece of very lightly doped silicon under an applied fieldsuch that its drift velocity is one-tenth of its thermal velocity. Calculate the averagenumber of collisions it will experience in traversing by drift a region 1 μm long. Whatis the voltage across this region? Temperature= 300°K