Ga is to be diffused into a bulk (semi-infinite) piece of pure Si (i.e. there is no Ga in the Si initially). The concentration of Ga at the surface of the Si piece is held constant at a value of...

Ga is to be diffused into a bulk (semi-infinite) piece of pure Si (i.e. there is no Ga in the Si initially). The concentration of Ga at the surface of the Si piece is held constant at a value of 2.5000 x 1018 atoms/cm3. After treatment at 1200 C, the Ga concentration at 0.6 micrometers below the Si surface is found to be 8.9500 x 1017 atoms/cm3.

1. a) If this concentration value was produced after a period of 35 hours, find the diffusion coefficient for Ga in Si at 1200 C?


2. b) If the activation energy for Ga diffusion in Si is 3.8 eV/atom, what process temperature will be required to obtain the same concentration (i.e. 8.9500 x 1017 atoms/cm3) at a depth of 0.6 microns inhalfthe diffusion time?