| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor device manufacturing method which can reduce characteristic variations of a semiconductor device by reducing height variations of a conductive film left in a trench. <P>SOLUTION: The semiconductor device manufacturing method comprises steps of etching a semiconductor substrate 13 to form a first trench part 51 of a width W<SB POS="POST">1</SB>, subsequently etching the semiconductor substrate 13 positioned below the first trench part 51 to form a second trench part 52 of a width W<SB POS="POST">2</SB>narrower than the width W<SB POS="POST">1</SB>, thereby forming a bit line formation trench 15 having the first trench part 51, the second trench part 52 and a pair of stepped parts 54 facing one another each formed of a bottom face of the first trench part 51 and a side face of the second trench part 52, subsequently filling the second trench part 52 via an insulator film 16 covering an inner surface of the bit line formation trench 15, depositing a first conductive film 56 having a thickness which does not fill the first trench part 51, subsequently etchbacking the first conductive film 56 to leave the first conductive film 56 in a part of the second trench part 52. <P>COPYRIGHT: (C)2012,JPO&INPIT |
