Ultratough CVD single crystal diamond and three dimensional growth thereof

A method for growing an ultratough, single-crystal diamond comprising:

• i) placing a seed diamond in a heat sink holder made of a material that has a high melting point and high thermal conductivity to minimize temperature gradients across the growth surface of the diamond;
• ii) controlling the temperature of a growth surface of the diamond such that the temperature of the growing diamond crystals is in the range of about 1050-1200° C.;
• and
• iii) growing single-crystal diamond by microwave plasma chemical vapor deposition on the growth surface of a diamond in a deposition chamber, wherein the atmosphere comprises a nitrogen to methane ratio of about 4% N2/CH4,
• iv) annealing the single-crystal diamond such that the annealed single-crystal diamond has a toughness of at least about 30 MPa m1/2.

A process for producing a single-crystal CVD diamond in three dimensions on a single crystal diamond substrate, comprising:

• i) growing single crystal diamond in a first <100> face of the single crystal diamond substrate;
• ii) repositioning the single crystal diamond substrate with the grown single crystal diamond thereon;
• and
• iii) growing single crystal diamond in a second <100> face of the single crystal diamond substrate.