METAL-NONMETAL TRANSITION AND RESISTIVITY OF SILICON IMPLANTED WITH BISMUTH

Bismuth was implanted at room temperature in (100)-Si wafers with cont rolled energy and doses to result in a plateau-like implantation profi le. The van der Pauw Si:Bi samples were characterized by the Hall effe ct and resistivity measurements from room temperature down to 13 K. Th e electron concentration of the prepared samples at 290 K varied from 3.0 x 10(17) to 1.4 x 10(20) cm(-3). The resistivity of the Si:Bi samp les presents a larger enhancement, compared to other dopants, when dec reasing the Bi concentration. The metal-nonmetal transition was determ ined to be around 2 x 10(19) cm(-3). The calculated values obtained fr om the Generalized Drude Approach and an equation derived from Kubo fo rmalism agree very well with the experimental data. The results confir m also the behavior rho(c)(Bi) < rho(c)(As) < rho(c)(P) < rho(c)(Sb) a t 290 K.