Diffusion Profiles of Cd in InP

We report the diffusion characteristics of Cd in InP in which the diffusion profiles have been investigated as a function of diffusion time and P pressure. For diffusion times shorter than 25 h, the diffusion profiles have two diffusion fronts, namely a steep diffusion front which leads to an abrupt p-n junction and a deep diffusion front giving a graded junction. However, for diffusion times longer than 36 h, the profiles become the error function complement. It has also been found that both the surface acceptor concentration and the diffusion coefficient decrease when excess P is added to the diffusion source. These diffusion characteristics are discussed in comparison with the results of photoluminescence and Hall-effect measurements.