Patent ID: 8470654
Filing Date: 2013-06-25
Classification: H01L

Abstract:
1. A method of forming a buried access line and an electrical contact thereto, the method comprising: providing a longitudinally elongated trench within semiconductive material, the trench having a longitudinal end portion that is laterally wider than another longitudinal portion, the trench comprising a gate dielectric lining; depositing a first conductive material into the trench to fill the another longitudinal portion but to not fill the longitudinal end portion, the first conductive material being laterally outward of the trench elevationally over the semiconductive material; after depositing the first conductive material, depositing a second conductive material over and in electrical connection with the first conductive material to overfill remaining volume of the longitudinal end portion of the trench, the first and second conductive materials being of different composition relative one another, the second conductive material not being within the another longitudinal portion of the trench, the second conductive material being laterally outward of the trench elevationally over the first conductive material and the semiconductive material; removing outermost portions of the first and second conductive materials back to remove the first and second conductive materials from being laterally outward of the trench; selectively etching the first conductive material relative to the second conductive material to elevationally recess the first conductive material within the trench in the longitudinal end portion and within the trench in the another longitudinal portion, the selective etching leaving the second conductive material projecting elevationally outward relative to the first conductive material within the longitudinal end portion of the trench, the buried access line being formed comprising the first and second conductive materials; after the selective etching, forming insulative material over the longitudinal end portion of the trench; etching a contact opening through the insulative material to the second conductive material projecting elevationally outward relative to the first conductive material within the longitudinal end portion of the trench; and forming conductor material in the contact opening in electrical connection with the second conductive material.