Microelectronic devices—having at least one conductive contact structure adjacent a silicide region—are formed using methods that avoid unintentional contact expansion and contact reduction. A first metal nitride liner is formed in a contact opening, and an exposed surface of a polysilicon structure is thereafter treated (e.g., cleaned and dried) in preparation for formation of a silicide region. During the pretreatments (e.g., cleaning and drying), neighboring dielectric material is protected by the presence of the metal nitride liner, inhibiting expansion of the contact opening. After forming the silicide region, a second metal nitride liner is formed on the silicide region before a conductive material is formed to fill the contact opening and form a conductive contact structure (e.g., a memory cell contact structure, a peripheral contact structure).