High-concentration in-diffusion of P in both Czochralski-grown and solar grade multicrystalline Si from a spray-on liquid source was studied by using secondary ion mass spectrometry and electrochemical capacitance-voltage profiling (figures 16 and 17). By extracting the concentration-dependent effective diffusivity via the Boltzmann-Matano analysis, an integrated diffusion model based upon previous work was adapted in order to gain some insight into the mechanisms governing such in-diffusion. It was found that, in the tail region of the profiles, diffusion was mediated by interaction with Si self-interstitials, whereas a vacancy mechanism via doubly negative vacancies predominated in the higher concentration region towards the surface, in correspondence with a previous analysis. It was found that both the vacancy and interstitial High-concentration in-diffusion of P in both Czochralski-grown and solar grade multicrystalline Si from a spray-on liquid source was studied by using secondary ion mass spectrometry and electrochemical capacitance-voltage profiling (figures 16 and 17). By extracting the concentration-dependent effective diffusivity via the Boltzmann-Matano analysis, an integrated diffusion model based upon previous work was adapted in order to gain some insight into the mechanisms governing such in-diffusion. It was found that, in the tail region of the profiles, diffusion was mediated by interaction with Si self-interstitials, whereas a vacancy mechanism via doubly negative vacancies predominated in the higher concentration region towards the surface, in correspondence with a previous analysis. It was found that both the vacancy and interstitial

Figure 17

Diffusivity of P in Si

(Open squares: interstitial mechanism D = 2.3 x 10-1exp[-2.6(eV)/kT], open circles: vacancy mechanism D = 7.6 x 104exp[-5.2(eV)/kT], filled circles: interstitial mechanism D = 4.9 x 10-6exp[-2.1(eV)/kT])