Dopant diffusion during amorphous silicon crystallization

A. Portavoce (1) , R Simola (1) , D. Mangelinck (1) , J. Bernardini (1) , P. Fornara (2)

1 L2MP - Laboratoire matériaux et microélectronique de Provence
2 ST Microlectronics

We have investigated the redistribution of B during the crystallization of an amorphous Si layer homogeneously doped with P. The redistribution of B only occurs for concentrations lower than 2 × 10 20 at cm −3. Crystallization leads to a non "Fickian" redistribution, allowing an abrupt interface between the regions doped and undoped with B. Once the crystallization is ended, B diffuses through the layer in the type B regime with a coefficient which is in agreement with the literature data for diffusion in polycrystalline Si. Although the P distribution is homogeneous in the entire layer, for a temperature as high as 755 °C, P diffuses towards the region the most concentrated in B. The B and P interactions are interpreted as chemical interactions.

Mots clés: Silicon crystallization; boron; phosphorus; diffusion; polycrystalline silicon; dopant interactions

Domaines: Science des matériaux [cond-mat.mtrl-sci]

A. Portavoce, R Simola, D. Mangelinck, J. Bernardini, P. Fornara. Dopant diffusion during amorphous silicon crystallization. Defect and Diffusion Forum, 2007, 264, pp.33-38. ⟨hal-02406682⟩