Co-deposited layers formed on inner divertor tiles during 1998-2004 and 2001-2004 campaigns have been investigated using Secondary Ion Mass Spectrometry (SIMS), Rutherford Backscattering (RBS) and optical microscopy. The thickness of the deposit decreases from the top of Tile 1 to the bottom and then increases on Tile 3 reaching ~ 60mm. There are even thicker deposits on the small sloping section of the floor Tile 4 that can be accessed by the plasma at the inner divertor legs. Co-deposited films on divertor inner wall tiles are enriched in Be indicating chemical erosion of C and a multi-step transport of C to the shadowed area on floor Tile 4. The films have generally a layered and globular structure in the areas with plasma contact.