公开(公告)号：US11744155B2

公开(公告)日：2023-08-29

申请号：US17672283

申请日：2022-02-15

Applicant: ROHM CO., LTD.

Inventor： Koji Nomura ,  Nobufumi Matsuo ,  Tomohiro Date

IPC: H10N35/00 ,  H10N30/00 ,  H10N30/079 ,  H10N30/87 ,  H10N30/853 ,  H10N30/067 ,  H10N30/078

CPC classification number: H10N30/10516 ,  H10N30/079 ,  H10N30/8554 ,  H10N30/871 ,  H10N30/877 ,  H10N30/067 ,  H10N30/078

Abstract: A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT (100) peak intensity with respect to a Pt (111) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT (100) peak intensity with respect to the Pt (111) peak intensity is within a range in the curve Q1 until the PLT (100) peak intensity decreases by 5% from a peak point P, at which the PLT (100) peak intensity is the maximum, and a (100) orientation rate of PLT constituting the seed layer is not less than 85%.

公开(公告)号：US11289642B2

公开(公告)日：2022-03-29

申请号：US16122392

申请日：2018-09-05

Applicant: ROHM CO., LTD.

Inventor： Koji Nomura ,  Nobufumi Matsuo ,  Tomohiro Date

IPC: H01L41/08 ,  H01L41/047 ,  H01L41/187 ,  H01L41/319 ,  H01L41/297 ,  H01L41/318

Abstract: A piezoelectric element 10 includes a lower electrode, constituted of a Pt/Ti laminated film, a PLT seed layer, formed on the lower electrode, a PZT piezoelectric film, formed on the PLT seed layer, and an upper electrode, formed on the PZT piezoelectric film. A curve Q1 is a curve drawn such as to pass through a plurality of plotted points, each expressing a PLT (100) peak intensity with respect to a Pt (111) peak intensity according to a substrate setting temperature during forming of the Pt/Ti laminated film. A relationship of the PLT (100) peak intensity with respect to the Pt (111) peak intensity is within a range in the curve Q1 until the PLT (100) peak intensity decreases by 5% from a peak point P, at which the PLT (100) peak intensity is the maximum, and a (100) orientation rate of PLT constituting the seed layer is not less than 85%.