A connector is capable of being miniaturised, whilst inadvertent pushing in of a retainer is prevented. The method includes serially exposing a substrate to a flow of a nitrogen-containing gas, such as ammonia NH3, and a tantalum containing gas. After receiving a document for an e-commerce agreement that represents a legal agreement for a commercial transaction between the first business entity and the second business entity, the first business entity retrieves dependency information about the commercial transaction from the e-commerce agreement.