US 12,328,884 B2
Semiconductor device, power module and manufacturing method for the semiconductor device
Toshiharu Marui, Kanagawa (JP); Tetsuya Hayashi, Kanagawa (JP); Keiichiro Numakura, Kanagawa (JP); Wei Ni, Kanagawa (JP); and Ryota Tanaka, Kanagawa (JP)
Assigned to NISSAN MOTOR CO., LTD., Yokohama (JP); and RENAULT S.A.S., Boulogne-Billancourt (FR)
Filed by NISSAN MOTOR CO., LTD., Yokohama (JP); and RENAULT S.A.S., Boulogne-Billancourt (FR)
Filed on Apr. 17, 2023, as Appl. No. 18/301,793.
Application 18/301,793 is a division of application No. 17/263,617, granted, now 11,664,466, previously published as PCT/IB2018/001120, filed on Aug. 1, 2018.
Prior Publication US 2023/0253512 A1, Aug. 10, 2023
Int. Cl. H10D 1/66 (2025.01); H10D 1/00 (2025.01); H10D 1/68 (2025.01); H01L 25/07 (2006.01)
CPC H10D 1/665 (2025.01) [H10D 1/042 (2025.01); H10D 1/047 (2025.01); H10D 1/716 (2025.01); H01L 25/074 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method for manufacturing a semiconductor device, the method comprising:
forming a trench on a first main surface of a conductive semiconductor substrate;
laminating a plurality of conductive layers, each of which is either a first conductive layer or a second conductive layer, on one another along a side surface of the trench in a direction that is normal to the side surface of the trench;
forming dielectric layers (i) between a conductive layer closest to the side surface of the trench among the plurality of conductive layers and the side surface of the trench, and (ii) between the plurality of corresponding conductive layers;
removing the first conductive layer formed on a bottom portion of the trench and one of the dielectric layers that is (i) adjacent to the first conductive layer and (ii) formed on the bottom portion of the trench, such that the second conductive layer is electrically connected to the conductive semiconductor substrate at the bottom portion of the trench;
forming a first electrode, physically connected to the first conductive layer, outside the trench, wherein the first conductive layer includes
(i) one first conductive layer, and
(ii) another first conductive layer, the first electrode extending only through the one first conductive layer, of the first conductive layer, in a contact hole outside the trench in plan view; and
forming a second electrode, electrically connected to the second conductive layer via the conductive semiconductor substrate, on a second main surface of the conductive semiconductor substrate,
wherein the first conductive layer is electrically insulated from the conductive semiconductor substrate, and
wherein a portion of the first main surface outside the trench is covered with an insulating protective film, prior to removal of the first conductive layer formed on the bottom portion of the trench and the one of the dielectric layers that is (i) adjacent to the first conductive layer and (ii) formed on the bottom portion of the trench.