A method of fabricating memory cells with buried bit lines. In this method, a pad oxide layer is formed on a first conductivity-type silicon substrate. A photoresist layer is formed on the pad oxide layer while exposing predetermined areas of channels. A thick oxide layer is deposited by liquid phase deposition (LPD). The photoresist layer is removed. Second conductivity-type impurities are implanted to form source-drain electrodes using the thick oxide layer as a mask. The thick oxide layer and the pad oxide layer are removed to form bit lines and then word lines are formed crossing the bit lines, whereby the structure with buried bit lines and an array of memory cells is completed.