US Patent 8012876 Delivery of vapor precursor from solid source

A method is disclosed that uses solid precursors for semiconductor processing. A solid precursor is provided in a storage container. The solid precursor is transformed into a liquid state in the storage container. The liquid state precursor is transported from the storage container to a liquid holding container. The liquid state precursor is transported from the liquid holding container to a reaction chamber. The molten precursor allows the precursor to be metered in the liquid state. The storage container can be heated only when necessary to replenish the liquid holding container, thereby reducing the possibility of thermal decomposition of the precursor.