roof deck help

We have a 15 x 35 foot 2nd floor deck off our bdr that is the roof for the underlying kitchen and den. It is covered by a rolled asphalt roof that we would like to cover with something better than the out door carpet we used to have. It became moldy and contributed to leaks. We were thinking of a traditional wood deck built up on short risers to allow air to circulate under it so roof can dry out. We heard debris can also accumulate in this space and dam up the water. We also heard of wood tiles that interconnect and lay directly on top of the asphalt that would not accumulate debris but would seem to cause same mold issue as old carpet did.
Any ideas what to do? Thanks