查看完整版本: 请教一个基础问题

请教一个基础问题

我们的一个练习题，希望高手过来讨论一下S:|5MBvR
In his talk ，Richard P.Feynmann described storing bits 3-dimensionally using cubes of 5x5x5= 125 atoms.
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k%g#r9@*?,[] Assume that we built such a structure by MBE or MOCVD, followed by e-beam
]9P{&ato8xY lithography (or x-ray lithography). For convenience, assume that the 125 atom dots are'Mp:J&L3j mF_
Ge, and that the substrate and the matrix surrounding the dots are Si. Assume that

M&ge*[wP8w [ along the x direction, 5 atoms of Si (lattice constant a= 0.5431 nm) separate the 5
}M9?3iw atoms of Ge (a= 0.5658 nm). Along one cubic axis, the resulting structure will then be:

qP1O$u({;A (SiSiSiSiSi)(GeGeGeGeGe)(SiSiSiSiSi)(Ge… etc.. ) Neglect any lattice strain effects
q)g1c6htj and assume that in each region the atoms take on their bulk lattice constant with noMe)`5~#S&rE6o r
dislocations. a) What is the bit density on the surface (per cm-2) i.e. of one layer? b)
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Ua(p;kBS9k What is the volume density of bits for multiple layers? c) What area is needed to store t$EW/Z t m{\g-@
one Terabit on one surface layer? d) For a 1 cm2 area, how many bits are stored in 10
#h3Q,aMkM2qK layers?

看来同行少啊，没有人参与啊