Diffusion length, λ , is a popular term in characterizing the production of semiconductors by the controlled diffusion of impurities into a high-purity material. the value of λ is taken as 2dt−−−√ , 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 700 ∘c.