公开(公告)号：US20210108333A1

公开(公告)日：2021-04-15

申请号：US16464327

申请日：2017-11-30

Applicant: ELEMENT SIX TECHNOLOGIES LIMITED

Inventor： MATTHEW LEE MARKHAM ,  ANDREW MARK EDMONDS ,  HARPREET KAUR DHILLON ,  DAVID WILLIAM HARDEMAN

IPC: C30B29/04 ,  C30B29/68 ,  C30B25/20 ,  C30B33/12

Abstract: A single crystal CVD diamond material is disclosed, the material comprising a total nitrogen concentration of at least 3 ppm as measured by secondary ion mass spectrometry (SIMS); and a low optical birefringence such that in a sample of the single crystal CVD diamond material having an area of at least 1.3 mm×1.3 mm, and measured using a pixel size of area in a range 1×1 μm2 to 20×20 μm2, a maximum value of Δn[average] does not exceed 1.5×10−4, where Δn[average] is an average value of a difference between refractive index for light polarised parallel to slow and fast axes averaged over the sample thickness. A method of making the material is also disclosed.