In etherscan each creation transaction has the contractAddress as 'to' value.
e.g.: https://etherscan.io/tx/0xe0ddfde8610cceae5b360c58a7c016b6654f838b8d820f290403d0c8d2cacfdc here: [Contract 0x85303e8e244b68a100308a59e1a008ff03a384b2 Created]
But actually RPC requests show that the Blockchain saves only "null" in this value in the transaction in the mined Block.
So How do etherscan know, which address the new contract has?