Sample stage/holder for improved thermal and gas flow control at elevated growth temperatures
Apparatuses and methods are provided for manufacturing diamond electronic devices. The apparatus includes a base comprising a water-block and a cover that at least partially covers the water-block. The apparatus includes a sample stage disposed on the base. The apparatus further includes a sample holder disposed on the sample stage and configured to accept a diamond substrate. The apparatus includes controlled thermal interfaces between water-block, sample stage, sample holder and diamond substrate.
1. An apparatus, comprising:
a base comprising a water-block and a cover that at least partially covers the water-block;
a sample stage disposed on the base; and
a sample holder disposed on the sample stage and comprising a pocket, the sample holder having at least one sidewall comprising an inner edge and an outer edge, with the inner edge of the at least one sidewall laterally bounding an upper portion of the pocket and a lower portion of the pocket, wherein the lower portion of the pocket is arranged below the upper portion of the pocket and is configured to accept a diamond substrate;
wherein the inner edge of the at least one sidewall defines at least one inlet opening in the upper portion of the pocket, and the outer edge of the at least one sidewall defines at least one outlet opening;
wherein the sample holder comprises at least one flow channel extending through the at least one sidewall, and the at least one flow channel extends from the at least one inlet opening to the at least one outlet opening.
2. The apparatus of claim 1 , wherein the cover comprises at least one of the following: molybdenum, tantalum, tungsten, molybdenum carbides, tantalum carbides, and tungsten carbides with an optional diamond coating.
3. The apparatus of claim 1 , further comprising a plurality of thermal interfaces that are adjusted to achieve a preset temperature for diamond growth.
4. The apparatus of claim 1 , wherein the sample holder is configured to fully recess the diamond substrate in the pocket.
5. The apparatus of claim 1 , wherein the at least one flow channel extends radially outward from the pocket and is configured to establish a controlled flow of gaseous species across an upper surface of the diamond substrate.
6. The apparatus of claim 5 , wherein for each flow channel of the at least one flow channel, the inlet opening is arranged at an elevation higher than the outlet opening, with the flow channel being angled away from horizontal at an angle within a range of between 0.1° and 45°.
7. The apparatus of claim 1 , further comprising:
an inlet pipe that provides cold water to the water-block; and
an outlet pipe that removes warm water from the water-block.
8. The apparatus of claim 7 , further comprising one or more pumps configured to adjust flow rates of cold water and warm water in the inlet pipe and the outlet pipe.
9. The apparatus of claim 1 , wherein the sample stage comprises a circular stage that is separated from the base by one or more spacers.
10. An apparatus, comprising:
a base comprising a fluid container and a cover that at least partially covers the fluid container;
a sample stage holder disposed on the base, the sample stage holder comprising a sample holder having a pocket, the sample holder defining at least one sidewall comprising an inner edge and an outer edge, with the inner edge of the at least one sidewall laterally bounding an upper portion of the pocket and a lower portion of the pocket, wherein the lower portion of the pocket is arranged below the upper portion of the pocket and is configured to accept a diamond substrate; and
a thermal interface between the base and the sample stage holder;
wherein the inner edge of the at least one sidewall defines at least one inlet opening in the upper portion of the pocket, and the outer edge of the at least one sidewall defines at least one outlet opening; and
wherein the sample holder comprises at least one flow channel extending through the at least one sidewall, and the at least one flow channel extends from the at least one inlet opening to the at least one outlet opening.
11. The apparatus of claim 10 , wherein the cover, sample stage holder, and sample holder comprise: molybdenum, tantalum, tungsten, their carbides or a combination of these with an optional diamond coating.
12. The apparatus of claim 10 , further comprising a second thermal interface disposed at least partially between the fluid container and the cover.
13. The apparatus of claim 10 , wherein the sample holder is configured to fully recess the diamond substrate in the pocket.
14. The apparatus of claim 10 , wherein the at least one flow channel extends radially outward from the pocket and is configured to establish a controlled flow of gaseous species across an upper surface of the diamond substrate.
15. The apparatus of claim 14 , wherein for each flow channel of the at least one flow channel, the inlet opening is arranged at an elevation higher than the outlet opening, with the flow channel being angled away from horizontal at an angle within a range of between 0.1° and 45°.
16. The apparatus of claim 10 , further comprising:
an inlet pipe that provides cold water to the fluid container; and
an outlet pipe that removes warm water from the fluid container.
17. The apparatus of claim 10 , wherein the sample stage holder comprises a circular stage that is separated from the base by one or more spacers.
18. A plasma enhanced chemical vapor deposition (PECVD) reactor, comprising:
a chamber surrounded at least partially by a reactor wall;
a base disposed in the chamber, the base comprising a fluid container and a cover that at least partially covers the fluid container;
a sample stage holder disposed on the base, the sample stage holder comprising a sample holder having a pocket, the sample holder having at least one sidewall comprising an inner edge and an outer edge, with the inner edge of the at least one sidewall laterally bounding an upper portion of the pocket and a lower portion of the pocket, wherein the lower portion of the pocket is arranged below the upper portion of the pocket and is configured to accept a diamond substrate; and
a thermal interface between the base and the sample stage holder;
wherein the inner edge of the at least one sidewall defines at least one inlet opening in the upper portion of the pocket, and the outer edge of the at least one sidewall defines at least one outlet opening; and
wherein the sample holder comprises at least one flow channel extending through the at least one sidewall, and the at least one flow channel extends from the at least one inlet opening to the at least one outlet opening.
19. The PECVD reactor of claim 18 , further comprising:
an inlet pipe that provides cold water to the fluid container; and
an outlet pipe that removes warm water from the fluid container.
20. The PECVD reactor of claim 18 , wherein for each flow channel of the at least one flow channel, the inlet opening is arranged at an elevation higher than the outlet opening, with the flow channel being angled away from horizontal at an angle within a range of between 0.1° and 45°.