US 6,982,198 B2
Semiconductor device and its manufacturing method
Takeo Furuhata, Mie (Japan); Ichiro Mizushima, Kanagawa (Japan); Akiko Sekihara, Kanagawa (Japan); Motoya Kishida, Kanagawa (Japan); Tsubasa Harada, Kanagawa (Japan); and Takashi Nakao, Danbury, Conn. (US)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Mar. 02, 2005, as Appl. No. 11/68,853.
Application 11/068853 is a division of application No. 10/410442, filed on Apr. 10, 2003.
Claims priority of application No. 2002-344959 (JP), filed on Nov. 28, 2002.
Prior Publication US 2005/0167720 A1, Aug. 04, 2005
Int. Cl. H01L 21/8242 (2006.01)
U.S. Cl. 438—243 8 Claims
OG exemplary drawing
 
1. A method of manufacturing a semiconductor device comprising:
forming a trench in a semiconductor substrate or in a layer deposited on the semiconductor substrate;
depositing a first conductive layer in the trench;
etching a part of the first conductive layer in a relatively upper location in the trench;
depositing an electrically conductive and burying-use material having a melting point lower than that of the first conductive layer on a recess that is produced in the top surface of the first conductive layer in the step of etching the first conductive layer;
heating the burying-use material to a temperature higher than the melting point thereof and lower than the melting point of the first conductive layer;
etching the burying-use material to remove the part thereof from the sidewall of the trench and maintain the part thereof near the recess; and
depositing a second conductive layer on the burying-use material in the recess.