Phosphorus atoms are to be diffused into a silicon wafer using both predeposition and drive-in heat treatments; the background concentration of P in this silicon material is known to be 5 × 1019 atoms/m3. The predeposition treatment is to be conducted at 950°C for 45 minutes; the surface concentration of P is to be maintained at a constant level of 1.5 × 1026 atoms/m3. Drive-in diffusion will be carried out at 1200°C for a period of 2.5 h. For the diffusion of P in Si, values of Qd and D0 are 3.40 eV and 1.1 × 10-4 m2/s, respectively.
(a) Calculate the value of Q0.
(b) Determine the value of xj for the drive-in diffusion treatment.
(c) Also for the drive-in treatment, compute the position x at which the concentration of P atoms is 1024