US 12,136,647 B2
Super junction power device and method of making the same
Min-Hwa Chi, Qingdao (CN); Conghui Liu, Qingdao (CN); Huan Wang, Qingdao (CN); Longkang Yang, Qingdao (CN); and Richard Ru-Gin Chang, Qingdao (CN)
Assigned to SiEn (QingDao) Integrated Circuits Co., Ltd., Qingdao (CN)
Filed by SiEn (QingDao) Integrated Circuits Co., Ltd., Shandong (CN)
Filed on Jun. 11, 2021, as Appl. No. 17/346,038.
Claims priority of application No. 202010536040.3 (CN), filed on Jun. 12, 2020.
Prior Publication US 2021/0391419 A1, Dec. 16, 2021
Int. Cl. H01L 29/06 (2006.01); H01L 29/66 (2006.01); H01L 29/78 (2006.01)
CPC H01L 29/0634 (2013.01) [H01L 29/66734 (2013.01); H01L 29/7811 (2013.01); H01L 29/7813 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of making a super junction power device, characterized by, comprising:
forming an epitaxial layer of a first conductivity type, comprising a cell region and a termination region surrounding the cell region;
forming a trench gate structure of the cell region in the epitaxial layer of the first conductivity type, the trench gate structure comprising a gate oxide layer and a gate conductive layer;
through a well mask, in the epitaxial layer of the first conductivity type, forming a plurality of wells of a second conductivity type comprising a well of the second conductivity type of the cell region and a well of the second conductivity type of the termination region, and before or after forming the wells of the second conductivity type, directly through the well mask, implanting dopant of the second conductivity type into the epitaxial layer of the first conductivity type to form a plurality of floating islands of the second conductivity type and a plurality of pillars of the second conductivity type successively, wherein:
the plurality of floating islands of the second conductivity type, positioning in the epitaxial layer of the first conductivity type, are formed, thereby top surfaces and bottom surfaces of the floating islands of the second conductivity type are in mutual contact with the epitaxial layer of the first conductivity type, and the floating islands of the second conductivity type comprise a floating island of the second conductivity type of the cell region and a floating island of the second conductivity type of the termination region, and
the plurality of pillars of the second conductivity type, positioning in the epitaxial layer of the first conductivity type and right above the floating islands of the second conductivity type, are formed, thereby the pillars of the second conductivity type are in mutual contact with the well of the second conductivity type, and the pillars of the second conductivity type comprise a pillar of the second conductivity type of the cell region and a pillar of the second conductivity type of the termination region; and
the floating islands of the second conductivity type and the pillars of the second conductivity type have the same width as that of the wells of the second conductivity type;
through a source mask, in the well of the second conductivity type of the cell region, forming a source of the first conductivity type of the cell region; and
through a contact mask, forming a plurality of contact structures comprising a contact structure in the cell region and a contact structure in the termination region, the contact structure in the cell region passing through the source of the first conductivity type of the cell region and in mutual contact with the well of the second conductivity type of the cell region, and the contact structure in the termination region being in mutual contact with the well of the second conductivity type of the termination region.