A planarizing process is disclosed for planarizing an integrated circuit structure using a low melting inorganic planarizing material which comprises flowing while depositing a low melting inorganic planarizing layer such as a boron oxide glass over a layer of insulating material such as an oxide of silicon and then dry etching the low melting inorganic planarizing layer to planarize the structure. The method eliminates the need for separate coating, drying, and curing steps associated with the application of organic-based planarizing layers usually carried out outside of a vacuum apparatus. In a preferred embodiment, the deposition steps and the etching step are carried out without removing the integrated circuit structure from the vacuum apparatus. An additional etching step may be carried out after depositing the insulating layer and prior to deposition of the planarizing layer to remove any voids formed in the insulating layer.