A memory module set includes a main integrated circuit for transmitting and receiving an electrical signal, a first group of memory modules including at least one memory module having a first pin unit connected to the main IC, and a second group of memory modules including at least one memory module having a second pin unit connected to the main IC. An information provision method for a mobile terminal includes configuring a plurality of identity informations associated with communications of a specific contact item; detecting an input for selecting an integrated contact management menu; and displaying the identity informations or communication informations associated with individual identity informations in an integrated manner. A self-structured mask is formed on the interior surface of the trench.