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Unformatted text preview: 22 Show that the relationship between vacancy concentration and fractional dimension
changes for the case shown in Figure 5.4 is approximately [Note that for small x] Volume of a cube:
Increase of vo lume from concentration of vacancies: Volume and vacant sites: Lattice expansion: 2 Justin Wang
Engineering 45
Gronsky 5.24 Diffusion length, λ, is a popular term in characterizing the production of semiconductors
by the controlled diffusion of impurities into a highpurity material. The value of λ is
taken as , where λ represents the extent of diffusion for an impurity with a diffusion coefficient, D, over a period of time, t. Calculate the diffusion length for B in Ge for a
total diffusion time of 30 minutes at a temperature of (a) 800°C and (b) 900°C. (a) At 800°C (1073K) (b) At 900°C (1173K) 3...
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This note was uploaded on 10/31/2013 for the course ENGINEERIN 45 taught by Professor Devine during the Fall '09 term at Berkeley.
 Fall '09
 Devine

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