DIFFUSION FROM POLYMER SPIN-ON FILMS - MEASUREMENTS AND SIMULATIONS

The possibilities of diffusion from polymer spin-on films have been in vestigated for the purpose of obtaining shallow junctions in Si, GaAs, InP, and InGaAs. Compared to the conventional diffusion techniques, d iffusion from polymer spin-on films is simpler and more controllable. The peculiarities of the method are associated with a uniform distribu tion of the dopant atoms in the three-dimensional network of the polym er chains. The possibilities have been demonstrated for control of the atomic concentration of B in silicon and of Zn in III-V compounds (fr om 10(21) to 10(17) cm(-3)) and for obtaining shallow p-n junctions; f or example, a junction depth of 40 nm has been obtained in silicon. Di ffusion conditions have been analyzed which provide 3 near-entire acti vation of the impurity. Moreover, gettering the defects and the backgr ound impurities by the spin-on film in the near-surface region of the semiconductor has been investigated. (C) 1998 American Vacuum Society.