Element Six Technologies Limited

Element Six Gmbh

Rizwan Uddin Ahmad Khan

Daniel James Twitchen

Philip Maurice Martineau

Harpreet Kaur Dhillon

Andrew Michael Bennett

Neil Perkins

Sarah Louise Geoghegan

Nicholas Matthew Davies

Dianel James Twitchen

There is described a single crystal CVD diamond material comprising three orthogonal dimensions of at least 2 mm; one or more regions of low optical birefringence, indicative of low strain, such that in a sample of the single crystal CVD diamond material having a thickness in a range 0.5 mm to 1.0 mm and an area of greater than 1.3 mm&#xd7;1.3 mm and measured using a pixel size of area in a range 1&#xd7;1 &#x3bc;mto 20&#xd7;20 &#x3bc;m, a maximum value of &#x394;ndoes not exceed 1.5&#xd7;10for the one or more regions of low optical birefringence, where &#x394;nis an average value of a difference between refractive index for light polarised parallel to slow and fast axes averaged over the sample thickness; one or more regions of high optical birefringence, indicative of high strain, such that in said sample of the single crystal CVD diamond material and measured using said pixel size, &#x394;nis greater than 1.5&#xd7;10and less than 3&#xd7;10; and is wherein every 1.3 mm&#xd7;1.3 mm area of the sample of the single crystal CVD diamond material comprises at least one of said regions of high optical birefringence. There is also described a method of making the CVD diamond material.

Single crystal synthetic diamond material via chemical vapour deposition

The present disclosure relates to methods for synthesizing synthetic CVD diamond material and high quality synthetic CVD diamond materials.

Synthetic CVD diamond

A single crystal CVD synthetic diamond layer comprising a non-parallel dislocation array, wherein the non-parallel dislocation array comprises a plurality of dislocations forming an array of inter-crossing dislocations, as viewed in an X-ray topographic cross-sectional view or under luminescent conditions.

Dislocation engineering in single crystal synthetic diamond material

A single crystal CVD synthetic diamond material comprising: a total as-grown nitrogen concentration equal to or greater than 5 ppm, and a uniform distribution of defects, wherein said uniform distribution of defects is defined by one or more of the following characteristics: (i) the total nitrogen concentration, when mapped by secondary ion mass spectrometry (SIMS) over an area equal to or greater than 50&#xd7;50 &#x3bc;m using an analysis area of 10 &#x3bc;m or less, possesses a point-to-point variation of less than 30% of an average total nitrogen concentration value, or when mapped by SIMS over an area equal to or greater than 200&#xd7;200 &#x3bc;m using an analysis area of 60 &#x3bc;m or less, possesses a point-to-point variation of less than 30% of an average total nitrogen concentration value; (ii) an as-grown nitrogen-vacancy defect (NV) concentration equal to or greater than 50 ppb as measured using 77K UV-visible absorption measurements, wherein the nitrogen-vacancy defects are uniformly distributed through the synthetic single crystal CVD diamond material such that, when excited using a 514 nm laser excitation source of spot size equal to or less than 10 &#x3bc;m at room temperature using a 50 mW continuous wave laser, and mapped over an area equal to or greater than 50&#xd7;50 &#x3bc;m with a data interval less than 10 &#x3bc;m there is a low point-to-point variation wherein the intensity area ratio of nitrogen vacancy photoluminescence peaks between regions of high photoluminescent intensity and regions of low photolominescent intensity is &#x3c;2&#xd7; for either the 575 &#x3bc;m photoluminescent peak (NV) or the 637 nm photoluminescent peak (NV); (iii) a variation in Raman intensity such that, when excited using a 514 nm laser excitation source (resulting in a Raman peak at 552.4 nm) of spot size equal to or less than 10 &#x3bc;m at room temperature using a 50 mW continuous wave laser, and mapped over an area equal to or greater than 50&#xd7;50 &#x3bc;m with a data interval less than 10 &#x3bc;m, there is a low point-to-point variation wherein the ratio of Raman peak areas between regions of low Raman intensity and high Raman intensity is &#x3c;1.25&#xd7;; (iv) an as-grown nitrogen-vacancy defect (NV) concentration equal to or greater than 50 ppb as measured using 77K UV-visible absorption measurements, wherein, when excited using a 514 nm excitation source of spot size equal to or less than 10 &#x3bc;m at 77K using a 50 mW continuous wave laser, gives an intensity at 575 nm corresponding to NVgreater than 120 times a Raman intensity at 552.4 nm, and/or an intensity at 637 nm corresponding to NVgreater than 200 times the Raman intensity at 552.4 nm; (v) a single substitutional nitrogen defect (N) concentration equal to or greater than 5 ppm, wherein the single substitutional nitrogen defects are uniformly distributed through the synthetic single crystal CVD diamond material such that by using a 1344 cminfrared absorption feature and sampling an area greater than an area of 0.5 mm, the variation is lower than 80%, as deduced by dividing the standard deviation by the mean value; (vi) a variation in red luminescence intensity, as defined by a standard deviation divided by a mean value, is less than 15%; (vii) a mean standard deviation in neutral single substitutional nitrogen concentration of less than 80%; and (viii) a color intensity as measured using a histogram from a microscopy image with a mean gray value of greater than 50, wherein the color intensity is uniform through the single crystal CVD synthetic diamond material such that the variation in gray color, as characterized by the gray value standard deviation divided by the gray value mean, is less than 40%.

Single crystal CVD synthetic diamond material

A method of introducing NV centers in single crystal CVD diamond material is described. One step of the method comprises irradiating diamond material that contains single substitutional nitrogen to introduce isolated vacancies into the diamond material in a concentration of at least 0.05 ppm and at most 1 ppm. Another step of the method comprises annealing the irradiated diamond to form NV centers from at least some of the single substitutional nitrogen defects and the introduced isolated vacancies.

Growing community of inventors

Berkshire, United Kingdom

Rizwan Uddin Ahmad Khan