US 12,408,372 B2
Process method for fabricating a three-dimensional source contact structure
Bing-Yue Tsui, Hsinchu (TW); Jui-Cheng Wang, Hsinchu (TW); Li-Tien Hsueh, Taipei (TW); and Jui-Tse Hsiao, Taichung (TW)
Assigned to NATIONAL YANG MING CHIAO TUNG UNIVERSITY, Hsinchu (TW)
Filed by National Yang Ming Chiao Tung University, Hsinchu (TW)
Filed on Jan. 19, 2023, as Appl. No. 18/098,930.
Claims priority of application No. 111134909 (TW), filed on Sep. 15, 2022.
Prior Publication US 2024/0097018 A1, Mar. 21, 2024
Int. Cl. H10D 30/66 (2025.01); H01L 21/306 (2006.01); H01L 21/3065 (2006.01); H10D 30/01 (2025.01); H10D 64/01 (2025.01)
CPC H10D 30/66 (2025.01) [H01L 21/30604 (2013.01); H01L 21/3065 (2013.01); H10D 30/0291 (2025.01); H10D 64/021 (2025.01)] 22 Claims
OG exemplary drawing
 
1. A process method for fabricating a three-dimensional source contact structure applicable to a power device, comprising:
providing a semiconductor substrate and sequentially forming an epitaxial layer and a body region on the semiconductor substrate;
providing a well region buried in the body region and sequentially forming a source heavily doped area and an inter-layer dielectric on the well region;
forming a metal contact window in the power device, such that the inter-layer dielectric is divided by the metal contact window into a first dielectric layer and a second dielectric layer and the source heavily doped area is divided by the metal contact window into a first heavily doped region and a second heavily doped region, wherein the first dielectric layer is disposed on the first heavily doped region, the second dielectric layer is disposed on the second heavily doped region, and wherein a contact length of the first dielectric layer and the first heavily doped region is less than a length of the first heavily doped region such that a first metal-source surface contact region is exposed, and wherein a contact length of the second dielectric layer and the second heavily doped region is less than a length of the second heavily doped region such that a second metal-source surface contact region is exposed; and
depositing a source contact metal which is configured between the first dielectric layer and the second dielectric layer, between the first heavily doped region and the second heavily doped region, and on the well region, wherein the source contact metal covers at least the first metal-source surface contact region, the second metal-source surface contact region, a longitudinal surface along the first heavily doped region and the second heavily doped region, and an interval surface between the first heavily doped region and the second heavily doped region, such that the source contact metal has a step-like three-dimensional structure.