Variable-temperature vapor deposition process

A method of growing a single crystal diamond material synthesized using a homoepitaxial chemical vapor deposition process, the method comprising:

• placing a free-standing diamond starting seed substrate on a substrate holder within a reaction chamber for chemical vapor deposition;
• feeding a process gas into the reaction chamber, the process gas including hydrogen gas;
• igniting a plasma within the reaction chamber to activate the process gas by adjusting the substrate temperature to increase to be within a first substrate temperature range;
• adding a carbon-containing gas to the process gas once the substrate temperature is within the first substrate temperature range to initiate diamond growth;
• and
• adjusting the substrate temperature to a second substrate temperature range that is outside the first substrate temperature range during the diamond growth;
• wherein the diamond growth at or near the first target substrate temperature range defines a first stage of the diamond growth and the diamond growth at or near the second target substrate temperature range defines a second stage of the diamond growth, and wherein the first stage of diamond growth includes bi-dimensional nucleation growth morphologies, and the second stage of diamond growth includes step-flow growth morphologies.

A method of growing a single crystal diamond material synthesized using a homoepitaxial chemical vapor deposition process, the method comprising:

• placing a diamond substrate on a substrate holder within a chemical vapor deposition reaction chamber;
• feeding a process gas into the reaction chamber, the process gas including hydrogen gas;
• igniting a plasma within the reaction chamber to activate the process gas by adjusting a substrate temperature to be within a first substrate temperature range defining a bi-dimensional nucleation growth regime;
• feeding a carbon-containing gas to the process gas to grow diamond on the diamond substrate within a bi-dimensional nucleation growth regime;
• and
• adjusting the substrate temperature to a second substrate temperature range that is outside the first substrate temperature range during the diamond growth, wherein the second substrate temperature range defines a step-flow growth regime.